Efficacy of PHILOS combined with n-HA/PA66 augmentation for treating three- or four-part proximal humeral fractures in elderly patients

Efficacy of PHILOS combined with n-HA/PA66 augmentation for treating three- or four-part proximal humeral fractures in elderly patients | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Efficacy of PHILOS combined with n-HA/PA66 augmentation for treating three- or four-part proximal humeral fractures in elderly patients Linwei Li, Lujie Zong, Chunye Tan, Xinyu Hu, Zhihui Huang, Wenming Ma This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7136478/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 27 Oct, 2025 Read the published version in Journal of Orthopaedic Surgery and Research → Version 1 posted 9 You are reading this latest preprint version Abstract Background Achieving stable fixation in highly unstable proximal humeral fractures (PHFs) remains a significant challenge in orthopedic surgery. Research increasingly highlights the importance of medial calcar support in these complex injuries. This study aimed to compare and analyze the clinical outcomes of two surgical approaches for treating Neer three- and four-part PHF in elderly patients: fixation with the proximal humeral internal locking system (PHILOS) alone, and fixation with PHILOS augmented by a bionic nanohydroxyapatite/polyamide 66 (n-HA/PA66) composite material. Methods From October 2022 to March 2024, a retrospective review identified 62 elderly patients with Neer three- or four-part PHF admitted to our institution. These patients were divided into two groups: the n-HA/PA66 group (n = 27), which was treated with PHILOS plate fixation combined with n-HA/PA66, and the PHILOS group (n = 35), which was treated with PHILOS alone. All patients were followed for 12 months. Functional outcomes were assessed via the Disability of the Arm-Shoulder-Hand (DASH) score, the Constant-Murley score (CMS), the American Shoulder and Elbow Surgeons (ASES) score, and the visual analog scale (VAS) for pain. Radiological outcomes were evaluated by measuring the neck-shaft angle (NSA) and humeral head height (HHH). Postoperative complications were also recorded for each group. Results At baseline, no significant differences in demographic characteristics, injury profiles, fracture classifications, or medical histories were observed between the two groups. The mean operative time in the n-HA/PA66 group (103.5 minutes) was significantly shorter than that in the PHILOS group (128.6 minutes) (P = 0.018). Postoperative follow-up assessments were conducted at 1 day, 1 month, 3 months, 6 months, and 12 months. Both groups demonstrated a reduction in disability over the 12-month follow-up period. At the final follow-up, the n-HA/PA66 group presented a mean DASH score of 25.5 ± 5.1 points, compared with 28.1 ± 4.7 points in the PHILOS group (p = 0.04; 95% CI, -5.1 to 0.1), and a mean ASES score of 78.9 ± 8.9 points, compared with 73.0 ± 10.3 points in the PHILOS group (p = 0.04; 95% CI, -3.9 to 5.7). However, no significant differences were found between the groups at other time points for these measures. Furthermore, there were no statistically significant differences between the two groups in CMS, range-of-motion scores, or VAS pain scores at any of the assessed time points. The mean difference in NSA and HHH was significantly lower in the n-HA/PA66 group than in the PHILOS group (P < 0.001). Regarding complications, 5 patients (18.5%) in the n-HA/PA66 group reported a total of 5 complications, whereas 8 patients (22.9%) in the PHILOS group reported 8 complications over the 12-month period; this between-group difference was not statistically significant (χ² = 0.256, p = 0.92). Conclusion While the PHILOS plate alone demonstrates efficacy in treating PHF, augmenting this fixation with n-HA/PA66 may further mitigate postoperative loss of the neck-shaft angle and humeral head height in elderly patients with three- or four-part fractures. Moreover, this combined approach shows promise in improving specific functional outcomes. Proximal humeral fracture PHILOS Medial calcar ORIF n-HA/PA66 Figures Figure 1 Figure 2 Figure 3 Introduction Proximal humeral fractures are the third most common osteoporotic fracture in elderly individuals after hip fracture and distal radius fracture, accounting for 4–5% of all fractures [ 1 ]. The prevalence of proximal humeral fractures in older individuals has been increasing as the population ages, and it has become a serious social and public health issue for middle-aged and older adults [ 2 ]. According to the Neer classification, elderly patients with proximal humeral fractures involving three- or four- parts generally require surgical intervention [ 3 ], and the associated compression defects, weak bony support, poor stability of endoprosthetic fixation, and combined rotator cuff dysfunction have always been the focus and difficulty of surgical treatment [ 4 ]. The treatment options for proximal humeral fractures are still disputed. Despite the existence of various complications, proximal humeral internal locking systems (PHILOS) are becoming more common because of their superior biomechanics; their divergent and convergent fixed-angle screws improve fixation strength and resistance to pullout in osteoporotic bone [ 5 , 6 ]. However, fracture fixation failure rates range from 9.5 to 40% despite advancements [ 7 , 8 ]. Varus collapse is a primary factor in internal fixation failure, which often results in poor shoulder mobility [ 9 , 10 ]. Strategies for minimizing fixation failure and subsequent varus collapse, with different degrees of effectiveness, have been devised. When treating these fractures, there is a growing emphasis on medial calcar support with additional screws [ 11 , 12 ]. Two novel techniques are using a fibular allograft (FA) as a medial endosteal strut and, less typically, utilizing a supplemental orthogonal plate to reinforce lateral locking plates [ 13 , 14 ], both of which indicate the significance of supporting the medial calcar. The n-HA/PA66 composite, which leverages the structural characteristics of nanohydroxyapatite (n-HA) crystals and the collagen matrix found in natural bone, represents a bioactive material composed of n-HA and polyamide (PA). Mechanical testing has demonstrated that this composite has mechanical properties comparable to those of cortical bone, particularly in compressive strength, bending strength, and elastic modulus [ 15 ]. Furthermore, in vivo studies have confirmed the excellent biocompatibility and osteogenic potential of the n-HA/PA66 composite [ 16 ]. Consequently, n-HA/PA66 composite struts have been successfully implemented in spine reconstruction and fusion [ 17 ]. To date, no studies have investigated the application of this material in proximal humeral fractures. This study was conducted to evaluate the functional and radiographic outcomes of PHILOS fixation augmented with medial calcar support via a bionic n-HA/PA66 composite material in elderly patients with Neer three- or four-part proximal humeral fractures, compared with PHILOS fixation alone. We hypothesized that patients receiving n-HA/PA66 augmentation would demonstrate superior clinical outcomes and lower complication rates than those treated with PHILOS fixation alone. Materials and methods This research was a retrospective study and was approved by the Ethics Committee of the First People's Hospital of Changzhou affiliated with Soochow University. Written informed consent was obtained from all enrolled patients. Patients Between October 20, 2022, and March 10, 2024, a total of 62 elderly patients with Neer three- or four-part proximal humeral fractures were admitted to the First People's Hospital of Changzhou. The inclusion criteria were as follows: age > 60 years; unilateral acute shift of Neer classification [ 3 ] of three- or four-part proximal humeral fractures (< 14 days after fracture occurrence); patient’s fragments were either displaced more than 1.0 cm or angulated more than 45° and were preoperatively confirmed by radiograph or computed tomography (CT) with three dimensional (3D) reconstructions. The exclusion criteria were old fracture; systemic bone disease (e.g., hyperparathyroidism) or local disease (e.g., tumor, Paget’s disease, or rheumatoid arthritis); treatment other than VLP or EF; complications of serious nervous or vascular injury; hypertensive or diabetic patients with poor control; and loss to follow-up or incomplete data. All patients were randomly divided into two groups, 35 patients in the PHILOS group were treated with open reduction and internal fixation (ORIF) via PHILOS (Double Medical, Xiamen, China) alone. The n-HA/PA66 group was treated with PHILOS combined with the biomimetic composite n-HA/PA66 (Guona Technology Co., LTD, Sichuan, China) for medical support. The demographic characteristics of the patients in the two groups are shown in Table 1 . Interventions Team of four surgeons, two with > 20 years of experience performing shoulder surgery, participated in operations involving all the procedures in the study. After placing the patient in the beach chair position and administering general anesthesia, a deltopectoral approach with an approximately 13 cm skin incision was performed for all patients. First, the synovium and hematoma around the fracture must be removed so that the fracture and the individual bone fragments can be clearly visualized. Nonabsorbable sutures were subsequently placed into the tendons of the supraspinatus and subscapularis muscles to reduce the greater and lesser tuberosity. The surgical procedure requires the use of sutures, which affix the tendons to the plate after the operation. This was undertaken to prevent secondary dislocation through the exertion of muscular force. To achieve a satisfactory overview of the morphology of the intraarticular fracture, it was necessary to sometimes open the rotator interval. A 2.5 mm Kirschner-wire (K-wire) was inserted into the humeral head to control rotation, and a periosteal elevator was used as a joystick at the fracture site to achieve reduction. In some cases, a distractor can be a good choice to reduce fracture. After reduction of the humeral head, several 1.5 mm K-wires were used for temporary fixation. The n-HA/PA66 (Fig. 1 A) was inserted into the distal medullary canal and was medialized maximally toward the medial calcar to indirectly reduce the medial column and support the humeral head fragment. The incorporation of n-HA/PA66 to support the humeral head, followed by K-wire insertion through the n-HA/PA66 construct, can potentially improve the overall stability of temporary fixation (Fig. 1 B). The reduction is verified through fluoroscopy. The next procedure involved placing a PHILOS on the humerus laterally to the bicipital groove and fixing it temporarily until the greater or lesser tuberosity was reduced (Fig. 1 C). If anatomical reduction was achieved, locking screws were placed through the fibula into the humeral head and shaft to secure its position (Fig. 1 D). The wound was closed after rotator cuff sutures were inserted through the proximal humeral locking plate and secured with screws via the plate's eyelets. Postoperative Rehabilitation All patients were encouraged to carry out shoulder exercises from the first day onward without limitations such as passive and active-assisted motion exercises and pendulum exercises, but with complete load restriction for six weeks. However, the shoulders were immobilized in a functional brace when at rest for 4 weeks if shoulder dislocation occurred preoperatively. Outcome parameters and follow-up We collected data at baseline (preoperatively) as well as at postoperative follow-ups at 1 day, 1 month, and 3, 6, and 12 months. Patients visited outpatient clinics to meet an orthopedic surgeon for medical consultations and radiograph prescriptions and the function assessor for shoulder function assessments and questionnaires. The primary outcome parameter was the Disabilities of the Shoulder, Arm, and Hand (DASH) score after 12 months [ 18 ]. The secondary outcome parameters were: the Constant-Murley score (CMS) [ 19 ]; the visual analog scale (VAS) pain score [ 20 ]; the range-of-motion score [ 19 ]; and the American Shoulder and Elbow Surgeons (ASES) score [ 21 ] after 1 month, and 3, 6, and 12 months. Radiological evaluation was performed immediately after the operation and after 12 months by measuring the neck-shaft angle (NSA) and humeral head height (HHH) [ 22 ] obtained from the postoperative true anteroposterior (AP) radiographs of the shoulder (Fig. 2 ). Two orthopedic surgeons viewed radiographs after completing all follow-ups and measured the NSA and HHH independently. The final result was the mean of the 2 measurements. In addition, complications, such as avascular necrosis (AVN), screw cutout, nonunion, nerve injury and infection, were recorded from the day they were observed. Statistical analysis Statistical analyses were performed via SPSS version 21.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics for epidemiological data are presented with either standard deviations or 95% confidence intervals, as appropriate. The Shapiro-Wilk test was employed to assess the normality assumption prior to conducting parametric tests. Categorical variables were compared between groups via Pearson's chi-square test. In instances where the expected frequency within any cell was less than 5, Fisher's exact test was used to determine the associated p-value. For numerical variables, group comparisons were conducted via Student's t-test. A significance level of α = 0.05 was adopted for all the statistical tests, with p-values less than 0.05 considered statistically significant. Results Between October 20, 2022, and March 10, 2024, a total of 62 patients with proximal humeral fractures were assessed for eligibility in this study. The cohort comprised 9 men and 53 women, with a mean age of 70.7 ± 6.2 years. Thirty-five patients were enrolled in the PHILOS group and underwent ORIF using a PHILOS plate alone. The remaining 27 patients were assigned to the n-HA/PA66 group and received PHILOS fixation supplemented with a biomimetic composite for medial calcar support. While all patients completed the 12-month follow-up, a statistically significant difference (p = 0.018) was observed in the operative time between the two groups. Specifically, the n-HA/PA66 group demonstrated a mean operative time of 103.5 minutes, which was 25.1 minutes less than the mean operative time of 128.6 minutes for the PHILOS group. Crucially, baseline characteristics, including demographic details, injury profiles, fracture classification and medical histories, were not significantly different between the groups, mitigating potential confounding factors. The detailed patient data are presented in Table 1 . Table 1 Baseline and surgical characteristics of the two groups Characteristic n-HA/PA66 group (n = 27) PHILOS group (n = 35) Sex Male 5 (18.5%) 4 (11.4%) Female 22 (81.5%) 31 (88.6%) Age (yr) 71.3 ± 6.1 70.2 ± 6.5 BMI (kg/m²) 24.9 ± 3.1 25.0 ± 2.7 Injured arm Left 10 (37.0%) 12 (34.3%) Right 17 (63.0%) 23 (65.7%) Dominant arm Left 2 (7.4%) 3 (8.6%) Right 25 (92.6%) 32 (91.4%) Cause of injury Fall 22 (81.5%) 30 (85.7%) Traffic accident 4 (14.8%) 5 (14.3%) Not reported 1 (3.7%) 0 (0%) Diabetes Yes 6 (22.2%) 11 (31.4%) No 21 (77.8%) 24 (68.6%) Smoking Yes 1 (3.7%) 1 (2.9%) No 26 (96.3%) 34 (97.1%) Osteoporosis Yes 14 (51.9%) 20 (57.1%) No 13 (48.1%) 15 (42.9%) ASA class 2.2 ± 0.6 2.2 ± 0.8 Neer classification Three- parts 16 (59.3%) 24 (68.6%) Four- parts 11 (40.7%) 11 (31.4%) OTA/AO classification Type B 16 (59.3%) 22 (62.9%) Type C 11 (40.7%) 13 (37.1%) With shoulder dislocation 4 (14.8%) 4 (11.4%) VAS pain score 6.3 ± 1.8 6.4 ± 1.6 Time from injury to operation (days) 3.7 ± 1.1 2.9 ± 1.3 Operative time (minutes)* 103.5 128.6 ASA = American Society of Anesthesiologists; *: There was a statistically significant difference in operative time between the two groups (Student’s t-test, p = 0.018) Functional outcomes Patients in both groups reported reduced disability over the 12 months after the surgical procedure, regardless of primary or secondary functional outcomes. The primary outcomes, DASH scores at 1, 3, 6, and 12 months, are presented in Table 2 and Fig. 2 A. At the primary time point (12 months) the mean DASH score was 25.5 ± 5.1 points in the n-HA/PA66 group compared with 28.1 ± 4.7 points in the PHILOS group (p = 0.04), and a significant difference was found between the two groups as well as mean difference (-2.6 [95% CI, -5.1 to 0.1]). Furthermore, no significant difference was found at other time points. Table 2 Functional outcomes in the two groups Outcomes n-HA/PA66 group (n = 27) PHILOS group (n = 35) Mean Difference (95% CI) P Value DASH score 1 months 46.3 ± 8.9 47.6 ± 7.8 -1.3 (-5.5 to 2.9) 0.54 3 months 40.6 ± 14.3 42.4 ± 10.2 -1.8 (-8.2 to 4.6) 0.56 6 months 30.5 ± 7.4 33.7 ± 8.6 -3.2 (-7.2to 0.8) 0.13 12 months 25.5 ± 5.1 28.1 ± 4.7 -2.6 (-5.1 to -0.1) 0.04 CMS 1 months 44.2 ± 9.3 44.8 ± 14.1 -0.6 (-6.4 to 5.2) 0.85 3 months 54.8 ± 7.8 53.5 ± 11.6 1.3 (-3.5 to 6.1) 0.62 6 months 65.6 ± 9.7 61.7 ± 9.4 3.9 (-0.9 to 8.7) 0.11 12 months 73.8 ± 8.1 70.5 ± 6.8 3.3 (-0.5 to 7.1) 0.09 Range-of-motion score 1 months 17.1 ± 4.3 17.4 ± 6.4 -0.3 (-3.0 to 2.4) 0.83 3 months 23.9 ± 4.5 22.6 ± 5.8 1.3 (-1.3 to 3.9) 0.34 6 months 28.6 ± 4.8 26.7 ± 5.1 1.9 (-0.6 to 4.4) 0.14 12 months 32.0 ± 4.1 29.5 ± 5.5 2.5 (0.1 to 4.9) 0.05 ASES score 1 months 44.1 ± 12.1 43.9 ± 9.4 0.2 (-5.3 to 5.7) 0.94 3 months 49.0 ± 9.9 47.7 ± 7.7 1.3 (-3.2 to 5.8) 0.56 6 months 69.4 ± 7.1 63.9 ± 13.7 5.5 (0.2 to 10.8) 0.06 12 months 78.9 ± 8.9 73.0 ± 10.3 5.9 (-3.9 to 5.7) 0.02 VAS pain score Preoperative 6.3 ± 1.8 6.4 ± 1.6 -0.1 (-1.0 to 0.8) 0.82 1 day 4.9 ± 1.5 4.6 ± 1.3 0.3 (-0.4 to 1.0) 0.40 1 months 4.1 ± 1.7 4.2 ± 1.6 -0.1 (-0.9 to 0.7) 0.81 3 months 3.9 ± 1.5 3.8 ± 2.1 0.1 (-0.8 to 1.0) 0.83 6 months 3.0 ± 2.0 3.1 ± 1.4 -0.1 (-1.0 to 0.8) 0.82 12 months 2.1 ± 1.4 1.7 ± 1.2 0.4 (-0.3 to 1.1) 0.23 At the 12-month follow-up, the mean DASH score and ASES score in the n-HA/PA66 group were greater than those to the PHILOS group (Student’s t-test, p < 0.05) At the 12-month follow-up, the n-HA/PA66 group presented a mean CMS of 73.8 ± 8.1 points, whereas the PHILOS group presented a score of 70.5 ± 6.8 points (p = 0.09) (Table 2 , Fig. 2 B). Conversely, the mean ASES score was 78.9 ± 8.9 points in the n-HA/PA66 group compared with 73.0 ± 10.3 points in the PHILOS group (p = 0.02) (Table 2 , Fig. 2 D). However, no significant differences were observed at the other time points. Although patients in the n-HA/PA66 group, regardless of medical support, reported improvements in pain levels throughout the 12-month follow-up, there was no statistically significant difference between the two groups in VAS pain scores or range-of-motion scores (Table 2 , Fig. 2 E and 2 C, respectively). Radiological outcomes The radiological outcomes are detailed in Table 3 . In the n-HA/PA66 group, the average NSA immediately postoperatively was 136.3° ± 13.3°, which decreased to 132.7° ± 13.8° at the final follow-up, yielding a mean difference of 3.6° ± 1.6°. Conversely, in the PHILOS group, the average postoperative NSA was 135.3° ± 17.0°, decreasing to 125.9° ± 17.1° at the final follow-up, resulting in a mean difference of 9.5° ± 2.0°. Table 3 Radiological outcomes in the two groups Outcomes n-HA/PA66 group (n = 27) PHILOS group (n = 35) P Value NSA (°) Postoperative 136.3 ± 13.3 135.3 ± 17.0 12 months 132.7 ± 13.8 125.9 ± 17.1 Mean difference 3.6 ± 1.6 9.5 ± 2.0 < 0.001 HHH (mm) Postoperative 11.9 ± 3.0 12.4 ± 2.4 12 months 9.5 ± 3.0 8.3 ± 2.5 Mean difference 2.4 ± 0.7 4.1 ± 0.6 < 0.001 The mean difference in the NSA and HHH was significantly greater in the PHILOS group (Student’s t-test, p < 0.05) Postoperative measurements revealed an average HHH of 11.9 mm ± 3.0 mm in the n-HA/PA66 group, which decreased to 9.5 mm ± 3.0 mm at the final follow-up, resulting in a mean HHH loss of 2.4 mm ± 0.7 mm. In the PHILOS group, the average postoperative HHH was 12.4 mm ± 2.4 mm, which decreased to 8.3 mm ± 2.5 mm at the final follow-up, yielding a mean HHH loss of 4.1 mm ± 0.6 mm. While both groups demonstrated a loss of NSA and HHH, the n-HA/PA66 group presented a significantly smaller reduction in NSA and HHH than did the PHILOS group (p < 0.001). Complications Over the 12-month follow-up period, the n-HA/PA66 group experienced a total of five (18.5%) postoperative complications, specifically one case of AVN, two cases of screw cutout, one case of nonunion, and one case of nerve injury. In comparison, the PHILOS group presented with eight (22.9%) postoperative complications, including one case of AVN, four cases of screw cutout, two cases of nerve injury, and one case of infection (Table 4 ). Despite the observed differences in complication rates, the overall difference between the two groups was not statistically significant (χ² = 0.256, p = 0.92). Table 4 Rate of complications in the two groups over 12 months Complication n-HA/PA66 group (n = 27) PHILOS group (n = 35) AVN 1 (3.7%) 1 (2.9%) Screw cutout 2 (7.4%) 4 (11.4%) Nonunion 1 (3.7%) 0 (0%) Nerve injury 1 (3.7%) 2 (5.7%) Infection 0 (0%) 1 (2.9%) Overall 5 (18.5%) 8 (22.9%) The between-group difference was not significant (χ² = 0.256, p = 0.92) Discussion This study retrospectively analyzed the clinical outcomes of 62 elderly patients with Neer three- or four-part proximal humeral fractures who underwent PHILOS plate fixation, with or without the adjunctive use of a bionic n-HA/PA66 composite for medial support. Elderly patients who present with Neer three- or four-part proximal humerus fractures frequently exhibit significant comminution and severe osteoporosis, which can substantially complicate fracture reduction and fixation during surgical intervention [ 23 ]. A key difficulty in the surgical management of these fractures lies in obtaining precise reduction and strong fixation, with accurate reduction of the humeral head being paramount. Furthermore, the importance of a stable calcar to prevent secondary varus displacement, particularly in distracted varus-type fractures, is well-established [ 9 , 10 , 24 , 25 ]. A study examining the outcomes of angle-stable plating for the treatment of primarily three- and four-part proximal humeral fractures reported a high rate of secondary varus collapse (63.3%) in a cohort followed for an average of 16.4 months [ 26 ]. This finding is consistent with biomechanical evidence demonstrating that medial instability significantly reduces the mean load to failure by 48% [ 27 ]. Double-plate osteosynthesis, typically employing a lateral locking plate in conjunction with a ventrally placed one-third tubular plate, has emerged as a technique to enhance primary stability and facilitate anatomical reconstruction in humeral head fractures characterized by calcar region destruction, aiming to prevent secondary dislocation [ 28 ]. Wanner et al. initially described a double one-third tubular plate technique in 2003, positioning one plate laterally and the other anteriorly on the humeral head [ 29 ]. While biomechanical investigations have demonstrated significantly improved stiffness under axial loading with angle-fixed plating, no statistically significant difference in torsional bending forces has been observed [ 30 ]. While Theopold et al. [ 31 ] reported that supplemental fixation with an inverted one-third tubular plate alongside a lateral locking plate in the bicipital groove, with a mean follow-up of 24 months, may enhance stability in complex proximal humeral fractures with metaphyseal comminution, Mara Warnhoff et al. [ 32 ] suggested that double-plate osteosynthesis can provide multidirectional stability and yield favorable clinical outcomes in 25 patients with proximal humeral fractures lacking medial support. However, the technique is not without potential drawbacks. Despite postoperative complication rates being comparable to those of single-plate fixation, the increased dissection and exposure required for double-plate placement may increase the risk of vascular nerve bundle injury and humeral head necrosis, thereby placing greater demands on surgical expertise. While segmental fibular allograft augmentation, placed endosteally in conjunction with a lateral locking plate, is frequently suggested as a strategy for enhancing medial support in proximal humerus fractures [ 14 ], the evidence regarding its efficacy remains somewhat equivocal. Dasari et al. [ 33 ] synthesized data from ten observational studies encompassing 802 patients, reporting a 95% rate of improved radiographic outcomes, increased ASES clinical outcome scores, and reduced odds of major complications in patients treated with a PHILOS plate augmented with a fibular allograft compared with those treated with a locking compression plate alone. However, these findings are not universally supported. Lee et al. [ 34 ] demonstrated improved forward elevation and a lower incidence of complications in osteoporotic patients with comminuted proximal humeral fractures treated with locking plate fixation and fibular strut allograft, although other clinical factors did not significantly differ. Furthermore, a randomized controlled trial [ 35 ] concluded that fibular allograft augmentation provided no additional benefit in the treatment of medial column comminuted proximal humeral fractures. Moreover, some researchers have explored the use of bone cement to augment the stability of the PHILOS plate in proximal humeral fractures, reporting promising clinical outcomes and reduced complication rates [ 36 ], but the body of research on this technique remains limited. Furthermore, the potential for cement-related thermal necrosis warrants continued consideration. The rationale for employing n-HA/PA66 stemmed from its capacity to provide robust support to the humeral head in the context of proximal humeral fractures, thereby augmenting the stability of fixation achieved with the PHILOS plate. This study demonstrated that the combination of PHILOS plate fixation and n-HA/PA66 support can mitigate the postoperative loss of NSA and HHH. While functional outcomes were broadly comparable to those observed with PHILOS plate fixation alone, marginal improvements were noted in DASH and ASES scores. In practice, surgeons often encounter pronounced impingement between the humeral head and shaft, particularly in varus-type fractures [ 24 , 25 ]. Consequently, effectively widening the distance between these structures during surgery is crucial to further reduce the neck-shaft angle, and the supportive properties of n-HA/PA66 are instrumental in addressing this challenge. Importantly, surgeons retain the ability to trim the n-HA/PA66 construct to optimize its contact area with the cancellous bone of the humeral head. While we believe that effective temporary fixation is crucial for surgical success, the traditional use of K-wires presents limitations, particularly instability during repeated reduction adjustments or in the presence of severe osteoporosis. Our experience suggests that incorporating n-HA/PA66 to support the humeral head, followed by K-wire insertion through the n-HA/PA66 construct, can enhance the overall stability of temporary fixation. The n-HA/PA66 effectively acts as a bridging scaffold, mitigating the need for repeated K-wire insertions and maintaining the fracture reduction position. which is the secret of shortening the operation time. This approach has the potential to reduce iatrogenic injury and shorten the surgical procedure time, warranting further investigation. Despite the need to acquire a comprehensive dataset encompassing both imaging and functional outcomes, this study is subject to several limitations. First, the retrospective design, which lacks randomization, inherently introduces the potential for selection bias and confounding variables. Second, while considerable effort was made to ensure appropriate patient selection, the statistical power of this single-center study remains relatively modest, potentially hindering the detection of subtle yet meaningful differences between the groups. Furthermore, the subjective nature of the DASH score may contribute to the discrepancies observed between it and the more objective CMS. Finally, the relatively short one-year follow-up period necessitates caution in drawing definitive conclusions regarding the long-term efficacy of the investigated treatment approach, suggesting the need for studies with extended follow-up durations. Conclusion In conclusion, the findings of this study suggest that the combination of PHILOS and n-HA/PA66 support, compared with PHILOS treatment alone, can mitigate postoperative loss of the neck-shaft angle and humeral head height in elderly patients with three- or four-part proximal humeral fractures. Furthermore, this combined approach has potential benefits for specific functional outcomes. These results underscore the importance of rational and effective calcar support in the management of proximal humeral fractures, especially those associated with osteoporosis. Declarations Declaration of Conflicting Interests : The authors declare that there is no conflict of interest. Ethical Approval : This research was approved by the Ethics Committee of the First People’s Hospital of Changzhou. Funding : None. Availability of data and materials : All the data in this study came from the First People’s Hospital of Changzhou, and all the data were recorded through the contemporaneous preservation of documents. Author Contribution Li Linwei, Zong Lujie, Huang Zhihui, and Ma Wenming participated in all patients' operations. Hu Xinyu, Huang Zhihui, and Ma Wenming designed this study. Zong Lujie and Tan Chunye were responsible for collecting the patient's preoperative basic information and postoperative functional outcomes. Li Linwei collected the imaging data and analyzed the radiological parameters for the study with Tan Chunye. Li Linwei wrote the article, and Hu Xinyu, Huang Zhihui, and Ma Wenming revised it. References Huang Z, Dong H, Ye C, et al. A network meta-analysis of multiple modalities for the treatment of complex proximal humeral fractures in older adults. Injury. 2023;54(10):110958. Court-Brown CM, Caesar B. Epidemiology of adult fractures: a review. Injury. 2006;37(8):691–7. Neer CS. Displaced proximal humeral fractures: part Ⅰ. Classification and evaluation. 1970. Clin Orthop Relat Res, 2006, 442: 77–82. Helen HG, Handoll J, Elliott TM, Thillemann P, Aluko. Stig Brorson. Interventions for treating proximal humeral fractures in adults. Cochrane Database Syst Rev. 2022;2022(6):CD000434. Gönç U, Atabek M, Teker K, Tanrıöver A. Minimally invasive plate osteosynthesis with PHILOS plate for proximal humerus fractures. Acta Orthop Traumatol Turc. 2017;51:17–22. Poole WEC, Wilson DGG, Guthrie HC, et al. Modern’ distal femoral locking plates allow safe, early weight-bearing with a high rate of union and low rate of failure: five-year experience from a United Kingdom major trauma centre. Bone Joint J. 2017;99–B:951–7. Dey Hazra RO, Illner J, Szewczyk K, et al. Age-independent clinical outcome in proximal humeral fractures: 2-year results using the example of a precontoured locking plate. J Clin Med. 2022;11(2):408. Lorenz G, Schönthaler W, Huf W, Komjati M, Fialka C, Boesmueller S. Complication rate after operative treatment of three- and four-part fractures of the proximal humerus: locking plate osteosynthesis versus proximal humeral nail. Eur J Trauma Emerg Surg. 2021;47(6):2055–64. Frima H, Michelitsch C, Beks RB, Houwert RM, Acklin YP, Sommer C. Longterm follow-up after MIPO Philos plating for proximal humerus fractures. Arch Orthop Trauma Surg. 2019;139:203–9. Lorenz G, Schönthaler W, Huf W, Komjati M, Fialka C, Boesmueller S. Complication rate after operative treatment of three- and four-part fractures of the proximal humerus: locking plate osteosynthesis versus proximal humeral nail. Eur J Trauma Emerg Surg. 2021;47(6):2055–64. di Tullio PO, Giordano V, Souto E, et al. Biomechanical behavior of three types of fixation in the two-part proximal humerus fracture without medial cortical support. PLoS ONE. 2019;14(7):e0220523. Jabran A, Peach C, Ren L. Biomechanical analysis of plate systems for proximal humerus fractures: a systematic literature review. Biomed Eng Online. 2018;17(1):47. Warnhoff M, Jensen G, Dey Hazra RO, Theruvath P, Lill H, Ellwein A. Double plating - surgical technique and good clinical results in complex and highly unstable proximal humeral fractures. Injury. 2021;52(8):2285–91. Cheng H, Yu J, Dong Z, et al. Treatment of 2-part proximal humeral fractures in osteoporotic patients with medial calcar instability using a PHILOS plate plus an allogeneic fibula inserted obliquely—a retrospective study. Geriatr Orthop Surg Rehabil. 2021;12:21514593211050156. Wang X, Li Y, Wei J, de Groot K. Development of biomimetic nano-hydroxyapatite/poly (hexamethylene adipamide) composites. Biomaterials. 2002;23:4787–91. Wang H, Li Y, Zuo Y, et al. Biocompatibility and osteogenesis of biomimetic nano-hydroxyapatite/polyamide composite scaffolds for bone tissue engineering. Biomaterials. 2007;28:3338–48. Zhao Z, Jiang D, Ou Y, et al. A hollow cylindrical nano-hydroxyapatite/polyamide composite strut for cervical reconstruction after cervical corpectomy. J Clin Neurosci. 2012;19:536–40. Hudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure: the DASH (disabilities of the arm, shoulder and hand) [corrected]. The Upper Extremity Collaborative Group (UECG). Am J Ind Med. 1996;29:602–8. Constant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res 1987 160–4. Constant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res 1987 160–4. Michener LA, McClure PW, Sennett BJ. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, patient self-report section: reliability, validity, and responsiveness. J Shoulder Elb Surg. 2002;11:587–94. Acklin YP, Stoffel K, Sommer C. A prospective analysis of the functional and radiological outcomes of minimally invasive plating in proximal humerus fractures. Injury. 2013;44:456–60. Matassi F, Angeloni R, Carulli C, et al. Locking plate and fibular allograft augmentation in unstable fractures of proximal humerus. Injury. 2012;43:1939–42. Krappinger D, Bizzotto N, Riedmann S, Kammerlander C, Hengg C, Kralinger FS. Predicting failure after surgical fixation of proximal humerus fractures. Injury.011;42:1283–8. Gardner MJ, Weil Y, Barker JU, Kelly BT, Helfet DL, Lorich DG. The importance of medial support in locked plating of proximal humerus fractures. J Orthop Trauma. 2007;21:185–91. Klitscher D, Blum J, Andreas D, Hessmann M, Kuechle R, du Prel J-B, et al. Osteosynthesis of proximal humeral fractures with the fixed angle PHILOS plate. Eur J Trauma Emerg Surg Off Publ Eur Trauma Soc. 2008;34:29–36. Ponce BA, Thompson KJ, Raghava P, Eberhardt AW, Tate JP, Volgas DA et al. The role of medial comminution and calcar restoration in varus collapse of proximal humeral fractures treated with locking plates. J Bone Jt Surg - Ser A 2013;95: e113 (1–7). Michel PA, Katthagen JC, Heilmann LF, Dyrna F, Schliemann B, Raschke MJ. Biomechanics of upper extremity double plating. Z Orthop Unfall. 2020;158:238–44. Wanner GA, Wanner-Schmid E, Romero J, Hersche O, von Smekal A, Trentz O, et al. Internal fixation of displaced proximal humeral fractures with two one-third tubular plates. J Trauma. 2003;54:536–44. Hessmann MH, Korner J, Hofmann A, Sternstein W, Rommens PM. Angle fixed plate fixation or double-plate osteosynthesis in fractures of the proximal humerus: a biomechanical study. Biomed Tech. 2008;53:130–7. Theopold J, Marquaß B, Fakler J, Steinke H, Josten C, Hepp P. The bicipital groove as a landmark for reconstruction of complex proximal humeral fractures with hybrid double plate osteosynthesis. BMC Surg. 2016;16:4–9. Mara Warnhoff G, Jensen R-OD, Hazra P, Theruvath H, Lill, Alexander Ellwein. Double plating - surgical technique and good clinical results in complex and highly unstable proximal humeral fractures. Injury. 2021;52:2285–91. Dasari SP, Kerzner B, Fortier LM, Rea PM, Bodendorfer BM, Chahla J, Garrigues GE, Verma NN. Improved outcomes for proximal humerus fracture open reduction internal fixation augmented with a fibular allograft in elderly patients: a systematic review and meta-analysis. J Shoulder Elbow Surg. 2022;31(4):884–94. Lee SH, Han SS, Yoo BM, Kim JW. Outcomes of locking plate fixation with fibular allograft augmentation for proximal humeral fractures in osteoporotic patients: comparison with locking plate fixation alone. Bone Joint J. 2019; 101–B (3):260–5. Qiuke Wang N, Sheng J-T, Huang H, Zhu M, Tuerxun Z, Ruan T, Shi Y, Zhu Y, Zhang B, Rui L, Wang. Yunfeng Chen. Effect of Fibular Allograft Augmentation in Medial Column Comminuted Proximal Humeral Fractures: A Randomized Controlled Trial. J Bone Joint Surg Am. 2023;105(4):302–11. Egol KA, Sugi MT, Ong CC, Montero N, Davidovitch R, Zuckerman JD. Fracture site augmentation with calcium phosphate cement reduces screw penetration after open reduction-internal fixation of proximal humeral fractures. J Shoulder Elb Surg. 2012;21:741–8. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 27 Oct, 2025 Read the published version in Journal of Orthopaedic Surgery and Research → Version 1 posted Editorial decision: Revision requested 20 Aug, 2025 Reviews received at journal 14 Aug, 2025 Reviews received at journal 05 Aug, 2025 Reviewers agreed at journal 29 Jul, 2025 Reviewers agreed at journal 29 Jul, 2025 Reviewers invited by journal 29 Jul, 2025 Editor assigned by journal 16 Jul, 2025 Submission checks completed at journal 16 Jul, 2025 First submitted to journal 16 Jul, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7136478","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":493339651,"identity":"7adb2c4f-229c-45a7-828e-15abe5278ed8","order_by":0,"name":"Linwei Li","email":"","orcid":"","institution":"First People’s Hospital of Changzhou Affiliated with Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Linwei","middleName":"","lastName":"Li","suffix":""},{"id":493339652,"identity":"42009714-20a8-45e2-8952-0191881f5b47","order_by":1,"name":"Lujie Zong","email":"","orcid":"","institution":"First People’s Hospital of Changzhou Affiliated with Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Lujie","middleName":"","lastName":"Zong","suffix":""},{"id":493339653,"identity":"08e32b1b-2227-44d8-a3ca-4dacd3804f03","order_by":2,"name":"Chunye Tan","email":"","orcid":"","institution":"First People’s Hospital of Changzhou Affiliated with Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Chunye","middleName":"","lastName":"Tan","suffix":""},{"id":493339654,"identity":"54ed0c64-6765-4a04-9ba3-bdaada87d62b","order_by":3,"name":"Xinyu Hu","email":"","orcid":"","institution":"First People’s Hospital of Changzhou Affiliated with Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Xinyu","middleName":"","lastName":"Hu","suffix":""},{"id":493339655,"identity":"d78156c0-0638-4955-89a1-74156ea21fcf","order_by":4,"name":"Zhihui Huang","email":"","orcid":"","institution":"First People’s Hospital of Changzhou Affiliated with Soochow University","correspondingAuthor":false,"prefix":"","firstName":"Zhihui","middleName":"","lastName":"Huang","suffix":""},{"id":493339656,"identity":"d38c0e8f-3fe6-453e-ac3f-c049ab0b874a","order_by":5,"name":"Wenming Ma","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyUlEQVRIiWNgGAWjYBAC++P9Hx8kGEgw27c3EKvnzAFjgw8FNuwGPAeI1XIjwUxyxoc0fgOJBCJ1MPYcSJDmMTgsbS75eOMNhhqbaIJamNkbDhgDtRhbzk4rtmA4lpbbQEgLG8/BhmSglmSG2zlmEowNhwlr4ZFIZjgM1FLfcPMMkVokJNIYG2cYpDEb3OAhUosBzxlmhg8GNsySPUC/JBDjFwP2HvYfCX8kmPnZD2+88aHGhrAWFO1ERw2SFlJ1jIJRMApGwcgAACxEP08V8ZGAAAAAAElFTkSuQmCC","orcid":"","institution":"The First People’s Hospital of Changzhou Affiliated with Soochow University","correspondingAuthor":true,"prefix":"","firstName":"Wenming","middleName":"","lastName":"Ma","suffix":""}],"badges":[],"createdAt":"2025-07-16 06:38:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7136478/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7136478/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s13018-025-06378-8","type":"published","date":"2025-10-27T15:57:13+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":88098854,"identity":"6a452b18-f3f3-4d96-aae7-682fe0336dff","added_by":"auto","created_at":"2025-08-01 11:11:12","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":2054551,"visible":true,"origin":"","legend":"\u003cp\u003eIllustration of the PHILOS combined with n-HA/PA66 technology. (A) Appearance of n-HA/PA66, which was 60 mm × 10 mm × 10 mm in size. (B) The n-HA/PA66 composite was positioned at the fracture site between the humeral head and humeral shaft. Temporary fixation with K-wires was employed to maintain the achieved reduction. Intraoperative fluoroscopy was utilized to assess the adequacy of the reduction. (C) Rotator cuff sutures were passed through the PHILOS, and then the plate was placed on the humerus lateral to the bicipital groove when the fracture was reduced satisfactorily. (D) Postoperative radiographic evaluation following proximal humeral fracture surgery typically involves X-ray imaging and computed tomography (CT) scans. The region delineated by the green dotted box indicates the location of the n-HA/PA66 composite. Owing to its radiolucent properties, n-HA/PA66 is not discernible via X-ray imaging and presents as a standard low-density shadow in CT scans.\u003c/p\u003e","description":"","filename":"figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7136478/v1/78283fa3f9af687b4a6c323f.jpg"},{"id":88095719,"identity":"4025ebbd-476f-499f-9238-bb8f3ec52a02","added_by":"auto","created_at":"2025-08-01 10:55:12","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":832289,"visible":true,"origin":"","legend":"\u003cp\u003eMeasurements of the neck-shaft angle (NSA) and humeral head height (HHH) were performed. (A) The NSA was defined as the angle formed between a line perpendicular to the articular surface of the humeral head and a line bisecting the humeral shaft. (B) HHH was defined as the distance between the uppermost edge of the proximal humeral plate and the most superior aspect of the humeral head.\u003c/p\u003e","description":"","filename":"figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7136478/v1/89f2309a32e3a4e7f07a92f2.jpg"},{"id":88095722,"identity":"495befcb-0803-440f-8dde-f52850bc1162","added_by":"auto","created_at":"2025-08-01 10:55:12","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1365720,"visible":true,"origin":"","legend":"\u003cp\u003ePostoperative functional outcomes over 12 months in the two groups. The solid line within the box plot indicates the mean value, while the dashed line represents the median. The orange color corresponds to the n-HA/PA66 group, and the green color denotes the PHILOS group. *p \u0026lt; 0.05.\u003c/p\u003e","description":"","filename":"figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7136478/v1/4792265b0ca5d3e4eef82414.jpg"},{"id":95039974,"identity":"4487e807-4f4d-4b90-ac07-48af5be16c28","added_by":"auto","created_at":"2025-11-03 16:06:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5104676,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7136478/v1/e2efc9b7-7e65-4716-a07e-4ea9db3976a3.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Efficacy of PHILOS combined with n-HA/PA66 augmentation for treating three- or four-part proximal humeral fractures in elderly patients","fulltext":[{"header":"Introduction","content":"\u003cp\u003eProximal humeral fractures are the third most common osteoporotic fracture in elderly individuals after hip fracture and distal radius fracture, accounting for 4\u0026ndash;5% of all fractures [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The prevalence of proximal humeral fractures in older individuals has been increasing as the population ages, and it has become a serious social and public health issue for middle-aged and older adults [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. According to the Neer classification, elderly patients with proximal humeral fractures involving three- or four- parts generally require surgical intervention [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], and the associated compression defects, weak bony support, poor stability of endoprosthetic fixation, and combined rotator cuff dysfunction have always been the focus and difficulty of surgical treatment [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe treatment options for proximal humeral fractures are still disputed. Despite the existence of various complications, proximal humeral internal locking systems (PHILOS) are becoming more common because of their superior biomechanics; their divergent and convergent fixed-angle screws improve fixation strength and resistance to pullout in osteoporotic bone [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. However, fracture fixation failure rates range from 9.5 to 40% despite advancements [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Varus collapse is a primary factor in internal fixation failure, which often results in poor shoulder mobility [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Strategies for minimizing fixation failure and subsequent varus collapse, with different degrees of effectiveness, have been devised. When treating these fractures, there is a growing emphasis on medial calcar support with additional screws [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Two novel techniques are using a fibular allograft (FA) as a medial endosteal strut and, less typically, utilizing a supplemental orthogonal plate to reinforce lateral locking plates [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], both of which indicate the significance of supporting the medial calcar.\u003c/p\u003e\u003cp\u003eThe n-HA/PA66 composite, which leverages the structural characteristics of nanohydroxyapatite (n-HA) crystals and the collagen matrix found in natural bone, represents a bioactive material composed of n-HA and polyamide (PA). Mechanical testing has demonstrated that this composite has mechanical properties comparable to those of cortical bone, particularly in compressive strength, bending strength, and elastic modulus [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Furthermore, in vivo studies have confirmed the excellent biocompatibility and osteogenic potential of the n-HA/PA66 composite [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Consequently, n-HA/PA66 composite struts have been successfully implemented in spine reconstruction and fusion [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. To date, no studies have investigated the application of this material in proximal humeral fractures.\u003c/p\u003e\u003cp\u003eThis study was conducted to evaluate the functional and radiographic outcomes of PHILOS fixation augmented with medial calcar support via a bionic n-HA/PA66 composite material in elderly patients with Neer three- or four-part proximal humeral fractures, compared with PHILOS fixation alone. We hypothesized that patients receiving n-HA/PA66 augmentation would demonstrate superior clinical outcomes and lower complication rates than those treated with PHILOS fixation alone.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cp\u003e This research was a retrospective study and was approved by the Ethics Committee of the First People's Hospital of Changzhou affiliated with Soochow University. Written informed consent was obtained from all enrolled patients.\u003c/p\u003e\u003cp\u003e\u003cb\u003ePatients\u003c/b\u003e\u003c/p\u003e\u003cp\u003eBetween October 20, 2022, and March 10, 2024, a total of 62 elderly patients with Neer three- or four-part proximal humeral fractures were admitted to the First People's Hospital of Changzhou. The inclusion criteria were as follows: age\u0026thinsp;\u0026gt;\u0026thinsp;60 years; unilateral acute shift of Neer classification [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] of three- or four-part proximal humeral fractures (\u0026lt;\u0026thinsp;14 days after fracture occurrence); patient\u0026rsquo;s fragments were either displaced more than 1.0 cm or angulated more than 45\u0026deg; and were preoperatively confirmed by radiograph or computed tomography (CT) with three dimensional (3D) reconstructions. The exclusion criteria were old fracture; systemic bone disease (e.g., hyperparathyroidism) or local disease (e.g., tumor, Paget\u0026rsquo;s disease, or rheumatoid arthritis); treatment other than VLP or EF; complications of serious nervous or vascular injury; hypertensive or diabetic patients with poor control; and loss to follow-up or incomplete data.\u003c/p\u003e\u003cp\u003eAll patients were randomly divided into two groups, 35 patients in the PHILOS group were treated with open reduction and internal fixation (ORIF) via PHILOS (Double Medical, Xiamen, China) alone. The n-HA/PA66 group was treated with PHILOS combined with the biomimetic composite n-HA/PA66 (Guona Technology Co., LTD, Sichuan, China) for medical support. The demographic characteristics of the patients in the two groups are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cb\u003eInterventions\u003c/b\u003e\u003c/p\u003e\u003cp\u003eTeam of four surgeons, two with \u0026gt;\u0026thinsp;20 years of experience performing shoulder surgery, participated in operations involving all the procedures in the study.\u003c/p\u003e\u003cp\u003eAfter placing the patient in the beach chair position and administering general anesthesia, a deltopectoral approach with an approximately 13 cm skin incision was performed for all patients. First, the synovium and hematoma around the fracture must be removed so that the fracture and the individual bone fragments can be clearly visualized. Nonabsorbable sutures were subsequently placed into the tendons of the supraspinatus and subscapularis muscles to reduce the greater and lesser tuberosity. The surgical procedure requires the use of sutures, which affix the tendons to the plate after the operation. This was undertaken to prevent secondary dislocation through the exertion of muscular force. To achieve a satisfactory overview of the morphology of the intraarticular fracture, it was necessary to sometimes open the rotator interval. A 2.5 mm Kirschner-wire (K-wire) was inserted into the humeral head to control rotation, and a periosteal elevator was used as a joystick at the fracture site to achieve reduction. In some cases, a distractor can be a good choice to reduce fracture. After reduction of the humeral head, several 1.5 mm K-wires were used for temporary fixation. The n-HA/PA66 (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA) was inserted into the distal medullary canal and was medialized maximally toward the medial calcar to indirectly reduce the medial column and support the humeral head fragment. The incorporation of n-HA/PA66 to support the humeral head, followed by K-wire insertion through the n-HA/PA66 construct, can potentially improve the overall stability of temporary fixation (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). The reduction is verified through fluoroscopy. The next procedure involved placing a PHILOS on the humerus laterally to the bicipital groove and fixing it temporarily until the greater or lesser tuberosity was reduced (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC). If anatomical reduction was achieved, locking screws were placed through the fibula into the humeral head and shaft to secure its position (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eD). The wound was closed after rotator cuff sutures were inserted through the proximal humeral locking plate and secured with screws via the plate's eyelets.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003ePostoperative Rehabilitation\u003c/b\u003e\u003c/p\u003e\u003cp\u003eAll patients were encouraged to carry out shoulder exercises from the first day onward without limitations such as passive and active-assisted motion exercises and pendulum exercises, but with complete load restriction for six weeks. However, the shoulders were immobilized in a functional brace when at rest for 4 weeks if shoulder dislocation occurred preoperatively.\u003c/p\u003e\u003cp\u003e\u003cb\u003eOutcome parameters and follow-up\u003c/b\u003e\u003c/p\u003e\u003cp\u003eWe collected data at baseline (preoperatively) as well as at postoperative follow-ups at 1 day, 1 month, and 3, 6, and 12 months. Patients visited outpatient clinics to meet an orthopedic surgeon for medical consultations and radiograph prescriptions and the function assessor for shoulder function assessments and questionnaires.\u003c/p\u003e\u003cp\u003eThe primary outcome parameter was the Disabilities of the Shoulder, Arm, and Hand (DASH) score after 12 months [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. The secondary outcome parameters were: the Constant-Murley score (CMS) [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]; the visual analog scale (VAS) pain score [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]; the range-of-motion score [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]; and the American Shoulder and Elbow Surgeons (ASES) score [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] after 1 month, and 3, 6, and 12 months.\u003c/p\u003e\u003cp\u003eRadiological evaluation was performed immediately after the operation and after 12 months by measuring the neck-shaft angle (NSA) and humeral head height (HHH) [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] obtained from the postoperative true anteroposterior (AP) radiographs of the shoulder (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Two orthopedic surgeons viewed radiographs after completing all follow-ups and measured the NSA and HHH independently. The final result was the mean of the 2 measurements.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eIn addition, complications, such as avascular necrosis (AVN), screw cutout, nonunion, nerve injury and infection, were recorded from the day they were observed.\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eStatistical analyses were performed via SPSS version 21.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics for epidemiological data are presented with either standard deviations or 95% confidence intervals, as appropriate. The Shapiro-Wilk test was employed to assess the normality assumption prior to conducting parametric tests. Categorical variables were compared between groups via Pearson's chi-square test. In instances where the expected frequency within any cell was less than 5, Fisher's exact test was used to determine the associated p-value. For numerical variables, group comparisons were conducted via Student's t-test. A significance level of α\u0026thinsp;=\u0026thinsp;0.05 was adopted for all the statistical tests, with p-values less than 0.05 considered statistically significant.\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eBetween October 20, 2022, and March 10, 2024, a total of 62 patients with proximal humeral fractures were assessed for eligibility in this study. The cohort comprised 9 men and 53 women, with a mean age of 70.7\u0026thinsp;\u0026plusmn;\u0026thinsp;6.2 years. Thirty-five patients were enrolled in the PHILOS group and underwent ORIF using a PHILOS plate alone. The remaining 27 patients were assigned to the n-HA/PA66 group and received PHILOS fixation supplemented with a biomimetic composite for medial calcar support. While all patients completed the 12-month follow-up, a statistically significant difference (p\u0026thinsp;=\u0026thinsp;0.018) was observed in the operative time between the two groups. Specifically, the n-HA/PA66 group demonstrated a mean operative time of 103.5 minutes, which was 25.1 minutes less than the mean operative time of 128.6 minutes for the PHILOS group. Crucially, baseline characteristics, including demographic details, injury profiles, fracture classification and medical histories, were not significantly different between the groups, mitigating potential confounding factors. The detailed patient data are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBaseline and surgical characteristics of the two groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharacteristic\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en-HA/PA66 group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;27)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePHILOS group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;35)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e5 (18.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (11.4%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e22 (81.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e31 (88.6%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAge (yr)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e71.3\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e70.2\u0026thinsp;\u0026plusmn;\u0026thinsp;6.5\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eBMI (kg/m\u0026sup2;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e24.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e25.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.7\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInjured arm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e10 (37.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e12 (34.3%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e17 (63.0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e23 (65.7%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDominant arm\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eLeft\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2 (7.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (8.6%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e25 (92.6%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e32 (91.4%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCause of injury\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFall\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e22 (81.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e30 (85.7%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTraffic accident\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4 (14.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5 (14.3%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNot reported\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1 (3.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDiabetes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6 (22.2%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11 (31.4%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e21 (77.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24 (68.6%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSmoking\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e1 (3.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (2.9%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e26 (96.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e34 (97.1%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOsteoporosis\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eYes\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e14 (51.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e20 (57.1%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNo\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e13 (48.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15 (42.9%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eASA class\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e2.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.2\u0026thinsp;\u0026plusmn;\u0026thinsp;0.8\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNeer classification\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eThree- parts\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e16 (59.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e24 (68.6%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFour- parts\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e11 (40.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e11 (31.4%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOTA/AO classification\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eType B\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e16 (59.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e22 (62.9%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eType C\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e11 (40.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e13 (37.1%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWith shoulder dislocation\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e4 (14.8%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (11.4%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVAS pain score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e6.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTime from injury to operation (days)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e3.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOperative time (minutes)*\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e\u003cp\u003e103.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e128.6\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"3\"\u003eASA\u0026thinsp;=\u0026thinsp;American Society of Anesthesiologists; *: There was a statistically significant difference in operative time between the two groups (Student\u0026rsquo;s t-test, p\u0026thinsp;=\u0026thinsp;0.018)\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eFunctional outcomes\u003c/b\u003e\u003c/p\u003e\u003cp\u003ePatients in both groups reported reduced disability over the 12 months after the surgical procedure, regardless of primary or secondary functional outcomes. The primary outcomes, DASH scores at 1, 3, 6, and 12 months, are presented in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA. At the primary time point (12 months) the mean DASH score was 25.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 points in the n-HA/PA66 group compared with 28.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7 points in the PHILOS group (p\u0026thinsp;=\u0026thinsp;0.04), and a significant difference was found between the two groups as well as mean difference (-2.6 [95% CI, -5.1 to 0.1]). Furthermore, no significant difference was found at other time points.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eFunctional outcomes in the two groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOutcomes\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en-HA/PA66 group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;27)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePHILOS group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;35)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMean Difference\u003c/p\u003e\u003cp\u003e(95% CI)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eP Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDASH score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e46.3\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e47.6\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-1.3 (-5.5 to 2.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.54\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e40.6\u0026thinsp;\u0026plusmn;\u0026thinsp;14.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e42.4\u0026thinsp;\u0026plusmn;\u0026thinsp;10.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-1.8 (-8.2 to 4.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.56\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e30.5\u0026thinsp;\u0026plusmn;\u0026thinsp;7.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e33.7\u0026thinsp;\u0026plusmn;\u0026thinsp;8.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-3.2 (-7.2to 0.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.13\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e25.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e28.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-2.6 (-5.1 to -0.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.04\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCMS\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e44.2\u0026thinsp;\u0026plusmn;\u0026thinsp;9.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e44.8\u0026thinsp;\u0026plusmn;\u0026thinsp;14.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.6 (-6.4 to 5.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.85\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e54.8\u0026thinsp;\u0026plusmn;\u0026thinsp;7.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e53.5\u0026thinsp;\u0026plusmn;\u0026thinsp;11.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.3 (-3.5 to 6.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.62\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e65.6\u0026thinsp;\u0026plusmn;\u0026thinsp;9.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e61.7\u0026thinsp;\u0026plusmn;\u0026thinsp;9.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.9 (-0.9 to 8.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.11\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e73.8\u0026thinsp;\u0026plusmn;\u0026thinsp;8.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e70.5\u0026thinsp;\u0026plusmn;\u0026thinsp;6.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e3.3 (-0.5 to 7.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.09\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eRange-of-motion score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e17.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e17.4\u0026thinsp;\u0026plusmn;\u0026thinsp;6.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.3 (-3.0 to 2.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.83\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e23.9\u0026thinsp;\u0026plusmn;\u0026thinsp;4.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e22.6\u0026thinsp;\u0026plusmn;\u0026thinsp;5.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.3 (-1.3 to 3.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.34\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e28.6\u0026thinsp;\u0026plusmn;\u0026thinsp;4.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e26.7\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.9 (-0.6 to 4.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.14\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e32.0\u0026thinsp;\u0026plusmn;\u0026thinsp;4.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e29.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2.5 (0.1 to 4.9)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.05\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eASES score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e44.1\u0026thinsp;\u0026plusmn;\u0026thinsp;12.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e43.9\u0026thinsp;\u0026plusmn;\u0026thinsp;9.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.2 (-5.3 to 5.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.94\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e49.0\u0026thinsp;\u0026plusmn;\u0026thinsp;9.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e47.7\u0026thinsp;\u0026plusmn;\u0026thinsp;7.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1.3 (-3.2 to 5.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.56\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e69.4\u0026thinsp;\u0026plusmn;\u0026thinsp;7.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e63.9\u0026thinsp;\u0026plusmn;\u0026thinsp;13.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.5 (0.2 to 10.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.06\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e78.9\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e73.0\u0026thinsp;\u0026plusmn;\u0026thinsp;10.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e5.9 (-3.9 to 5.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e0.02\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVAS pain score\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePreoperative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e6.3\u0026thinsp;\u0026plusmn;\u0026thinsp;1.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e6.4\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.1 (-1.0 to 0.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.82\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1 day\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e4.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e4.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.3 (-0.4 to 1.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.40\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e4.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e4.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.1 (-0.9 to 0.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.81\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e3.9\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e3.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.1 (-0.8 to 1.0)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.83\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e3.0\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e3.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-0.1 (-1.0 to 0.8)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.82\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e2.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e1.7\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.4 (-0.3 to 1.1)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e\u003cp\u003e0.23\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eAt the 12-month follow-up, the mean DASH score and ASES score in the n-HA/PA66 group were greater than those to the PHILOS group (Student\u0026rsquo;s t-test, p\u0026thinsp;\u0026lt;\u0026thinsp;0.05)\u003c/p\u003e\u003cp\u003eAt the 12-month follow-up, the n-HA/PA66 group presented a mean CMS of 73.8\u0026thinsp;\u0026plusmn;\u0026thinsp;8.1 points, whereas the PHILOS group presented a score of 70.5\u0026thinsp;\u0026plusmn;\u0026thinsp;6.8 points (p\u0026thinsp;=\u0026thinsp;0.09) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eB). Conversely, the mean ASES score was 78.9\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9 points in the n-HA/PA66 group compared with 73.0\u0026thinsp;\u0026plusmn;\u0026thinsp;10.3 points in the PHILOS group (p\u0026thinsp;=\u0026thinsp;0.02) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eD). However, no significant differences were observed at the other time points. Although patients in the n-HA/PA66 group, regardless of medical support, reported improvements in pain levels throughout the 12-month follow-up, there was no statistically significant difference between the two groups in VAS pain scores or range-of-motion scores (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eE and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eC, respectively).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cb\u003eRadiological outcomes\u003c/b\u003e\u003c/p\u003e\u003cp\u003eThe radiological outcomes are detailed in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. In the n-HA/PA66 group, the average NSA immediately postoperatively was 136.3\u0026deg; \u0026plusmn; 13.3\u0026deg;, which decreased to 132.7\u0026deg; \u0026plusmn; 13.8\u0026deg; at the final follow-up, yielding a mean difference of 3.6\u0026deg; \u0026plusmn; 1.6\u0026deg;. Conversely, in the PHILOS group, the average postoperative NSA was 135.3\u0026deg; \u0026plusmn; 17.0\u0026deg;, decreasing to 125.9\u0026deg; \u0026plusmn; 17.1\u0026deg; at the final follow-up, resulting in a mean difference of 9.5\u0026deg; \u0026plusmn; 2.0\u0026deg;.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eRadiological outcomes in the two groups\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOutcomes\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en-HA/PA66 group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;27)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePHILOS group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;35)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eP Value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNSA (\u0026deg;)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e136.3\u0026thinsp;\u0026plusmn;\u0026thinsp;13.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e135.3\u0026thinsp;\u0026plusmn;\u0026thinsp;17.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e132.7\u0026thinsp;\u0026plusmn;\u0026thinsp;13.8\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e125.9\u0026thinsp;\u0026plusmn;\u0026thinsp;17.1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean difference\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e3.6\u0026thinsp;\u0026plusmn;\u0026thinsp;1.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e9.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHHH (mm)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePostoperative\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e11.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e12.4\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e12 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e9.5\u0026thinsp;\u0026plusmn;\u0026thinsp;3.0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e8.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMean difference\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c2\"\u003e\u003cp\u003e2.4\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c3\"\u003e\u003cp\u003e4.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe mean difference in the NSA and HHH was significantly greater in the PHILOS group (Student\u0026rsquo;s t-test, p\u0026thinsp;\u0026lt;\u0026thinsp;0.05)\u003c/p\u003e\u003cp\u003ePostoperative measurements revealed an average HHH of 11.9 mm\u0026thinsp;\u0026plusmn;\u0026thinsp;3.0 mm in the n-HA/PA66 group, which decreased to 9.5 mm\u0026thinsp;\u0026plusmn;\u0026thinsp;3.0 mm at the final follow-up, resulting in a mean HHH loss of 2.4 mm\u0026thinsp;\u0026plusmn;\u0026thinsp;0.7 mm. In the PHILOS group, the average postoperative HHH was 12.4 mm\u0026thinsp;\u0026plusmn;\u0026thinsp;2.4 mm, which decreased to 8.3 mm\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5 mm at the final follow-up, yielding a mean HHH loss of 4.1 mm\u0026thinsp;\u0026plusmn;\u0026thinsp;0.6 mm. While both groups demonstrated a loss of NSA and HHH, the n-HA/PA66 group presented a significantly smaller reduction in NSA and HHH than did the PHILOS group (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\u003cp\u003e\u003cb\u003eComplications\u003c/b\u003e\u003c/p\u003e\u003cp\u003eOver the 12-month follow-up period, the n-HA/PA66 group experienced a total of five (18.5%) postoperative complications, specifically one case of AVN, two cases of screw cutout, one case of nonunion, and one case of nerve injury. In comparison, the PHILOS group presented with eight (22.9%) postoperative complications, including one case of AVN, four cases of screw cutout, two cases of nerve injury, and one case of infection (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Despite the observed differences in complication rates, the overall difference between the two groups was not statistically significant (χ\u0026sup2; = 0.256, p\u0026thinsp;=\u0026thinsp;0.92).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eRate of complications in the two groups over 12 months\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComplication\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003en-HA/PA66 group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;27)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003ePHILOS group\u003c/p\u003e\u003cp\u003e(n\u0026thinsp;=\u0026thinsp;35)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAVN\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (3.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (2.9%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eScrew cutout\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2 (7.4%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4 (11.4%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNonunion\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (3.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e0 (0%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eNerve injury\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (3.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e2 (5.7%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInfection\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0 (0%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (2.9%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eOverall\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e5 (18.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e8 (22.9%)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"3\"\u003eThe between-group difference was not significant (χ\u0026sup2; = 0.256, p\u0026thinsp;=\u0026thinsp;0.92)\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study retrospectively analyzed the clinical outcomes of 62 elderly patients with Neer three- or four-part proximal humeral fractures who underwent PHILOS plate fixation, with or without the adjunctive use of a bionic n-HA/PA66 composite for medial support.\u003c/p\u003e\u003cp\u003eElderly patients who present with Neer three- or four-part proximal humerus fractures frequently exhibit significant comminution and severe osteoporosis, which can substantially complicate fracture reduction and fixation during surgical intervention [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. A key difficulty in the surgical management of these fractures lies in obtaining precise reduction and strong fixation, with accurate reduction of the humeral head being paramount. Furthermore, the importance of a stable calcar to prevent secondary varus displacement, particularly in distracted varus-type fractures, is well-established [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. A study examining the outcomes of angle-stable plating for the treatment of primarily three- and four-part proximal humeral fractures reported a high rate of secondary varus collapse (63.3%) in a cohort followed for an average of 16.4 months [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. This finding is consistent with biomechanical evidence demonstrating that medial instability significantly reduces the mean load to failure by 48% [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eDouble-plate osteosynthesis, typically employing a lateral locking plate in conjunction with a ventrally placed one-third tubular plate, has emerged as a technique to enhance primary stability and facilitate anatomical reconstruction in humeral head fractures characterized by calcar region destruction, aiming to prevent secondary dislocation [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Wanner et al. initially described a double one-third tubular plate technique in 2003, positioning one plate laterally and the other anteriorly on the humeral head [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. While biomechanical investigations have demonstrated significantly improved stiffness under axial loading with angle-fixed plating, no statistically significant difference in torsional bending forces has been observed [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. While Theopold et al. [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] reported that supplemental fixation with an inverted one-third tubular plate alongside a lateral locking plate in the bicipital groove, with a mean follow-up of 24 months, may enhance stability in complex proximal humeral fractures with metaphyseal comminution, Mara Warnhoff et al. [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] suggested that double-plate osteosynthesis can provide multidirectional stability and yield favorable clinical outcomes in 25 patients with proximal humeral fractures lacking medial support. However, the technique is not without potential drawbacks. Despite postoperative complication rates being comparable to those of single-plate fixation, the increased dissection and exposure required for double-plate placement may increase the risk of vascular nerve bundle injury and humeral head necrosis, thereby placing greater demands on surgical expertise.\u003c/p\u003e\u003cp\u003eWhile segmental fibular allograft augmentation, placed endosteally in conjunction with a lateral locking plate, is frequently suggested as a strategy for enhancing medial support in proximal humerus fractures [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], the evidence regarding its efficacy remains somewhat equivocal. Dasari et al. [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e] synthesized data from ten observational studies encompassing 802 patients, reporting a 95% rate of improved radiographic outcomes, increased ASES clinical outcome scores, and reduced odds of major complications in patients treated with a PHILOS plate augmented with a fibular allograft compared with those treated with a locking compression plate alone. However, these findings are not universally supported. Lee et al. [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e] demonstrated improved forward elevation and a lower incidence of complications in osteoporotic patients with comminuted proximal humeral fractures treated with locking plate fixation and fibular strut allograft, although other clinical factors did not significantly differ. Furthermore, a randomized controlled trial [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e] concluded that fibular allograft augmentation provided no additional benefit in the treatment of medial column comminuted proximal humeral fractures.\u003c/p\u003e\u003cp\u003eMoreover, some researchers have explored the use of bone cement to augment the stability of the PHILOS plate in proximal humeral fractures, reporting promising clinical outcomes and reduced complication rates [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e], but the body of research on this technique remains limited. Furthermore, the potential for cement-related thermal necrosis warrants continued consideration.\u003c/p\u003e\u003cp\u003eThe rationale for employing n-HA/PA66 stemmed from its capacity to provide robust support to the humeral head in the context of proximal humeral fractures, thereby augmenting the stability of fixation achieved with the PHILOS plate. This study demonstrated that the combination of PHILOS plate fixation and n-HA/PA66 support can mitigate the postoperative loss of NSA and HHH. While functional outcomes were broadly comparable to those observed with PHILOS plate fixation alone, marginal improvements were noted in DASH and ASES scores.\u003c/p\u003e\u003cp\u003eIn practice, surgeons often encounter pronounced impingement between the humeral head and shaft, particularly in varus-type fractures [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Consequently, effectively widening the distance between these structures during surgery is crucial to further reduce the neck-shaft angle, and the supportive properties of n-HA/PA66 are instrumental in addressing this challenge. Importantly, surgeons retain the ability to trim the n-HA/PA66 construct to optimize its contact area with the cancellous bone of the humeral head. While we believe that effective temporary fixation is crucial for surgical success, the traditional use of K-wires presents limitations, particularly instability during repeated reduction adjustments or in the presence of severe osteoporosis. Our experience suggests that incorporating n-HA/PA66 to support the humeral head, followed by K-wire insertion through the n-HA/PA66 construct, can enhance the overall stability of temporary fixation. The n-HA/PA66 effectively acts as a bridging scaffold, mitigating the need for repeated K-wire insertions and maintaining the fracture reduction position. which is the secret of shortening the operation time. This approach has the potential to reduce iatrogenic injury and shorten the surgical procedure time, warranting further investigation.\u003c/p\u003e\u003cp\u003eDespite the need to acquire a comprehensive dataset encompassing both imaging and functional outcomes, this study is subject to several limitations. First, the retrospective design, which lacks randomization, inherently introduces the potential for selection bias and confounding variables. Second, while considerable effort was made to ensure appropriate patient selection, the statistical power of this single-center study remains relatively modest, potentially hindering the detection of subtle yet meaningful differences between the groups. Furthermore, the subjective nature of the DASH score may contribute to the discrepancies observed between it and the more objective CMS. Finally, the relatively short one-year follow-up period necessitates caution in drawing definitive conclusions regarding the long-term efficacy of the investigated treatment approach, suggesting the need for studies with extended follow-up durations.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, the findings of this study suggest that the combination of PHILOS and n-HA/PA66 support, compared with PHILOS treatment alone, can mitigate postoperative loss of the neck-shaft angle and humeral head height in elderly patients with three- or four-part proximal humeral fractures. Furthermore, this combined approach has potential benefits for specific functional outcomes. These results underscore the importance of rational and effective calcar support in the management of proximal humeral fractures, especially those associated with osteoporosis.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eDeclaration of Conflicting Interests\u003c/strong\u003e: The authors declare that there is no conflict of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e: This research was approved by the Ethics Committee of\u0026nbsp;the First People\u0026rsquo;s Hospital of Changzhou.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e: None.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e: All the data in this study came from the First People\u0026rsquo;s Hospital of Changzhou, and all the data were recorded through the contemporaneous preservation of documents.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eLi Linwei, Zong Lujie, Huang Zhihui, and Ma Wenming participated in all patients\u0026apos; operations. Hu Xinyu, Huang Zhihui, and Ma Wenming designed this study. Zong Lujie and Tan Chunye were responsible for collecting the patient\u0026apos;s preoperative basic information and postoperative functional outcomes. Li Linwei collected the imaging data and analyzed the radiological parameters for the study with Tan Chunye. Li Linwei wrote the article, and Hu Xinyu, Huang Zhihui, and Ma Wenming revised it.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eHuang Z, Dong H, Ye C, et al. A network meta-analysis of multiple modalities for the treatment of complex proximal humeral fractures in older adults. Injury. 2023;54(10):110958.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCourt-Brown CM, Caesar B. Epidemiology of adult fractures: a review. Injury. 2006;37(8):691\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNeer CS. Displaced proximal humeral fractures: part Ⅰ. Classification and evaluation. 1970. Clin Orthop Relat Res, 2006, 442: 77\u0026ndash;82.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHelen HG, Handoll J, Elliott TM, Thillemann P, Aluko. Stig Brorson. Interventions for treating proximal humeral fractures in adults. Cochrane Database Syst Rev. 2022;2022(6):CD000434.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eG\u0026ouml;n\u0026ccedil; U, Atabek M, Teker K, Tanrı\u0026ouml;ver A. Minimally invasive plate osteosynthesis with PHILOS plate for proximal humerus fractures. Acta Orthop Traumatol Turc. 2017;51:17\u0026ndash;22.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePoole WEC, Wilson DGG, Guthrie HC, et al. Modern\u0026rsquo; distal femoral locking plates allow safe, early weight-bearing with a high rate of union and low rate of failure: five-year experience from a United Kingdom major trauma centre. Bone Joint J. 2017;99\u0026ndash;B:951\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDey Hazra RO, Illner J, Szewczyk K, et al. Age-independent clinical outcome in proximal humeral fractures: 2-year results using the example of a precontoured locking plate. J Clin Med. 2022;11(2):408.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLorenz G, Sch\u0026ouml;nthaler W, Huf W, Komjati M, Fialka C, Boesmueller S. Complication rate after operative treatment of three- and four-part fractures of the proximal humerus: locking plate osteosynthesis versus proximal humeral nail. Eur J Trauma Emerg Surg. 2021;47(6):2055\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFrima H, Michelitsch C, Beks RB, Houwert RM, Acklin YP, Sommer C. Longterm follow-up after MIPO Philos plating for proximal humerus fractures. Arch Orthop Trauma Surg. 2019;139:203\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLorenz G, Sch\u0026ouml;nthaler W, Huf W, Komjati M, Fialka C, Boesmueller S. Complication rate after operative treatment of three- and four-part fractures of the proximal humerus: locking plate osteosynthesis versus proximal humeral nail. Eur J Trauma Emerg Surg. 2021;47(6):2055\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003edi Tullio PO, Giordano V, Souto E, et al. Biomechanical behavior of three types of fixation in the two-part proximal humerus fracture without medial cortical support. PLoS ONE. 2019;14(7):e0220523.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJabran A, Peach C, Ren L. Biomechanical analysis of plate systems for proximal humerus fractures: a systematic literature review. Biomed Eng Online. 2018;17(1):47.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWarnhoff M, Jensen G, Dey Hazra RO, Theruvath P, Lill H, Ellwein A. Double plating - surgical technique and good clinical results in complex and highly unstable proximal humeral fractures. Injury. 2021;52(8):2285\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCheng H, Yu J, Dong Z, et al. Treatment of 2-part proximal humeral fractures in osteoporotic patients with medial calcar instability using a PHILOS plate plus an allogeneic fibula inserted obliquely\u0026mdash;a retrospective study. Geriatr Orthop Surg Rehabil. 2021;12:21514593211050156.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang X, Li Y, Wei J, de Groot K. Development of biomimetic nano-hydroxyapatite/poly (hexamethylene adipamide) composites. Biomaterials. 2002;23:4787\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang H, Li Y, Zuo Y, et al. Biocompatibility and osteogenesis of biomimetic nano-hydroxyapatite/polyamide composite scaffolds for bone tissue engineering. Biomaterials. 2007;28:3338\u0026ndash;48.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhao Z, Jiang D, Ou Y, et al. A hollow cylindrical nano-hydroxyapatite/polyamide composite strut for cervical reconstruction after cervical corpectomy. J Clin Neurosci. 2012;19:536\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHudak PL, Amadio PC, Bombardier C. Development of an upper extremity outcome measure: the DASH (disabilities of the arm, shoulder and hand) [corrected]. The Upper Extremity Collaborative Group (UECG). Am J Ind Med. 1996;29:602\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eConstant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res 1987 160\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eConstant CR, Murley AH. A clinical method of functional assessment of the shoulder. Clin Orthop Relat Res 1987 160\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMichener LA, McClure PW, Sennett BJ. American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form, patient self-report section: reliability, validity, and responsiveness. J Shoulder Elb Surg. 2002;11:587\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAcklin YP, Stoffel K, Sommer C. A prospective analysis of the functional and radiological outcomes of minimally invasive plating in proximal humerus fractures. Injury. 2013;44:456\u0026ndash;60.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMatassi F, Angeloni R, Carulli C, et al. Locking plate and fibular allograft augmentation in unstable fractures of proximal humerus. Injury. 2012;43:1939\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKrappinger D, Bizzotto N, Riedmann S, Kammerlander C, Hengg C, Kralinger FS. Predicting failure after surgical fixation of proximal humerus fractures. Injury.011;42:1283\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGardner MJ, Weil Y, Barker JU, Kelly BT, Helfet DL, Lorich DG. The importance of medial support in locked plating of proximal humerus fractures. J Orthop Trauma. 2007;21:185\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKlitscher D, Blum J, Andreas D, Hessmann M, Kuechle R, du Prel J-B, et al. Osteosynthesis of proximal humeral fractures with the fixed angle PHILOS plate. Eur J Trauma Emerg Surg Off Publ Eur Trauma Soc. 2008;34:29\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePonce BA, Thompson KJ, Raghava P, Eberhardt AW, Tate JP, Volgas DA et al. The role of medial comminution and calcar restoration in varus collapse of proximal humeral fractures treated with locking plates. J Bone Jt Surg - Ser A 2013;95: e113 (1\u0026ndash;7).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMichel PA, Katthagen JC, Heilmann LF, Dyrna F, Schliemann B, Raschke MJ. Biomechanics of upper extremity double plating. Z Orthop Unfall. 2020;158:238\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWanner GA, Wanner-Schmid E, Romero J, Hersche O, von Smekal A, Trentz O, et al. Internal fixation of displaced proximal humeral fractures with two one-third tubular plates. J Trauma. 2003;54:536\u0026ndash;44.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHessmann MH, Korner J, Hofmann A, Sternstein W, Rommens PM. Angle fixed plate fixation or double-plate osteosynthesis in fractures of the proximal humerus: a biomechanical study. Biomed Tech. 2008;53:130\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTheopold J, Marqua\u0026szlig; B, Fakler J, Steinke H, Josten C, Hepp P. The bicipital groove as a landmark for reconstruction of complex proximal humeral fractures with hybrid double plate osteosynthesis. BMC Surg. 2016;16:4\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMara Warnhoff G, Jensen R-OD, Hazra P, Theruvath H, Lill, Alexander Ellwein. Double plating - surgical technique and good clinical results in complex and highly unstable proximal humeral fractures. Injury. 2021;52:2285\u0026ndash;91.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDasari SP, Kerzner B, Fortier LM, Rea PM, Bodendorfer BM, Chahla J, Garrigues GE, Verma NN. Improved outcomes for proximal humerus fracture open reduction internal fixation augmented with a fibular allograft in elderly patients: a systematic review and meta-analysis. J Shoulder Elbow Surg. 2022;31(4):884\u0026ndash;94.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLee SH, Han SS, Yoo BM, Kim JW. Outcomes of locking plate fixation with fibular allograft augmentation for proximal humeral fractures in osteoporotic patients: comparison with locking plate fixation alone. Bone Joint J. 2019; 101\u0026ndash;B (3):260\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQiuke Wang N, Sheng J-T, Huang H, Zhu M, Tuerxun Z, Ruan T, Shi Y, Zhu Y, Zhang B, Rui L, Wang. Yunfeng Chen. Effect of Fibular Allograft Augmentation in Medial Column Comminuted Proximal Humeral Fractures: A Randomized Controlled Trial. J Bone Joint Surg Am. 2023;105(4):302\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEgol KA, Sugi MT, Ong CC, Montero N, Davidovitch R, Zuckerman JD. Fracture site augmentation with calcium phosphate cement reduces screw penetration after open reduction-internal fixation of proximal humeral fractures. J Shoulder Elb Surg. 2012;21:741\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-orthopaedic-surgery-and-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"josr","sideBox":"Learn more about [Journal of Orthopaedic Surgery and Research](http://josr-online.biomedcentral.com)","snPcode":"13018","submissionUrl":"https://submission.nature.com/new-submission/13018/3","title":"Journal of Orthopaedic Surgery and Research","twitterHandle":"@MSKmedBMC","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Proximal humeral fracture, PHILOS, Medial calcar, ORIF, n-HA/PA66","lastPublishedDoi":"10.21203/rs.3.rs-7136478/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7136478/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eAchieving stable fixation in highly unstable proximal humeral fractures (PHFs) remains a significant challenge in orthopedic surgery. Research increasingly highlights the importance of medial calcar support in these complex injuries. This study aimed to compare and analyze the clinical outcomes of two surgical approaches for treating Neer three- and four-part PHF in elderly patients: fixation with the proximal humeral internal locking system (PHILOS) alone, and fixation with PHILOS augmented by a bionic nanohydroxyapatite/polyamide 66 (n-HA/PA66) composite material.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eFrom October 2022 to March 2024, a retrospective review identified 62 elderly patients with Neer three- or four-part PHF admitted to our institution. These patients were divided into two groups: the n-HA/PA66 group (n\u0026thinsp;=\u0026thinsp;27), which was treated with PHILOS plate fixation combined with n-HA/PA66, and the PHILOS group (n\u0026thinsp;=\u0026thinsp;35), which was treated with PHILOS alone. All patients were followed for 12 months. Functional outcomes were assessed via the Disability of the Arm-Shoulder-Hand (DASH) score, the Constant-Murley score (CMS), the American Shoulder and Elbow Surgeons (ASES) score, and the visual analog scale (VAS) for pain. Radiological outcomes were evaluated by measuring the neck-shaft angle (NSA) and humeral head height (HHH). Postoperative complications were also recorded for each group.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eAt baseline, no significant differences in demographic characteristics, injury profiles, fracture classifications, or medical histories were observed between the two groups. The mean operative time in the n-HA/PA66 group (103.5 minutes) was significantly shorter than that in the PHILOS group (128.6 minutes) (P\u0026thinsp;=\u0026thinsp;0.018). Postoperative follow-up assessments were conducted at 1 day, 1 month, 3 months, 6 months, and 12 months. Both groups demonstrated a reduction in disability over the 12-month follow-up period. At the final follow-up, the n-HA/PA66 group presented a mean DASH score of 25.5\u0026thinsp;\u0026plusmn;\u0026thinsp;5.1 points, compared with 28.1\u0026thinsp;\u0026plusmn;\u0026thinsp;4.7 points in the PHILOS group (p\u0026thinsp;=\u0026thinsp;0.04; 95% CI, -5.1 to 0.1), and a mean ASES score of 78.9\u0026thinsp;\u0026plusmn;\u0026thinsp;8.9 points, compared with 73.0\u0026thinsp;\u0026plusmn;\u0026thinsp;10.3 points in the PHILOS group (p\u0026thinsp;=\u0026thinsp;0.04; 95% CI, -3.9 to 5.7). However, no significant differences were found between the groups at other time points for these measures. Furthermore, there were no statistically significant differences between the two groups in CMS, range-of-motion scores, or VAS pain scores at any of the assessed time points. The mean difference in NSA and HHH was significantly lower in the n-HA/PA66 group than in the PHILOS group (P\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Regarding complications, 5 patients (18.5%) in the n-HA/PA66 group reported a total of 5 complications, whereas 8 patients (22.9%) in the PHILOS group reported 8 complications over the 12-month period; this between-group difference was not statistically significant (χ\u0026sup2; = 0.256, p\u0026thinsp;=\u0026thinsp;0.92).\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eWhile the PHILOS plate alone demonstrates efficacy in treating PHF, augmenting this fixation with n-HA/PA66 may further mitigate postoperative loss of the neck-shaft angle and humeral head height in elderly patients with three- or four-part fractures. Moreover, this combined approach shows promise in improving specific functional outcomes.\u003c/p\u003e","manuscriptTitle":"Efficacy of PHILOS combined with n-HA/PA66 augmentation for treating three- or four-part proximal humeral fractures in elderly patients","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-08-01 10:55:07","doi":"10.21203/rs.3.rs-7136478/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-20T08:42:40+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-14T08:40:25+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-06T02:27:05+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"112685343092706728216251285963671889491","date":"2025-07-29T09:53:00+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"219423832410360641518540524701726490830","date":"2025-07-29T09:38:05+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-07-29T09:20:36+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-07-17T01:29:10+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-07-17T00:47:34+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Orthopaedic Surgery and Research","date":"2025-07-16T06:22:11+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-orthopaedic-surgery-and-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"josr","sideBox":"Learn more about [Journal of Orthopaedic Surgery and Research](http://josr-online.biomedcentral.com)","snPcode":"13018","submissionUrl":"https://submission.nature.com/new-submission/13018/3","title":"Journal of Orthopaedic Surgery and Research","twitterHandle":"@MSKmedBMC","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ce2b9165-5b79-47b7-b901-66ee556897dd","owner":[],"postedDate":"August 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-11-03T16:01:56+00:00","versionOfRecord":{"articleIdentity":"rs-7136478","link":"https://doi.org/10.1186/s13018-025-06378-8","journal":{"identity":"journal-of-orthopaedic-surgery-and-research","isVorOnly":false,"title":"Journal of Orthopaedic Surgery and Research"},"publishedOn":"2025-10-27 15:57:13","publishedOnDateReadable":"October 27th, 2025"},"versionCreatedAt":"2025-08-01 10:55:07","video":"","vorDoi":"10.1186/s13018-025-06378-8","vorDoiUrl":"https://doi.org/10.1186/s13018-025-06378-8","workflowStages":[]},"version":"v1","identity":"rs-7136478","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7136478","identity":"rs-7136478","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}