A study of the modified sacroiliac screw technique in Day type II crescent fracture dislocation of the pelvis

A study of the modified sacroiliac screw technique in Day type II crescent fracture dislocation of the pelvis | 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 A study of the modified sacroiliac screw technique in Day type II crescent fracture dislocation of the pelvis Renjie Li, Leyu Liu, Jianzhong Guan, Xiaopan Wang, Peishuai Zhao, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4817453/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background When the traditional sacroiliac screw is used in the treatment of Day type II crescent fracture dislocation of the pelvis, the screw entry point may be located near the fracture line and lead to the failure of screw pressurization, and at the same time, the short channel of the iliac segment of the screw has defects such as insufficient holding power. This study proposes a modified sacroiliac screw technique and investigates the value of the modified sacroiliac screw in the treatment of Day type II crescentic fracture dislocations of the pelvis. METHODS We retrospectively analyzed 44 patients with pelvic Day type II crescent fracture dislocations who underwent surgical treatment from January 2019 to June 2023 in our hospital. They were divided into two groups according to the sacroiliac screws for comparative study. We compared the gender, age, cause of injury, fracture classification, time from injury to surgery, intraoperative bleeding, anterior ring fixation method, iliac fixation method, total length of sacroiliac screw, length of iliac and sacral segments of sacroiliac screw, shortest distance from the sacroiliac screw entry point to iliac fracture line, quality of reduction, postoperative complications, and clinical prognosis of the patients in the two groups. RESULTS Follow-up was obtained in all patients, and the differences between the two groups in terms of gender, age, cause of injury, fracture classification, time from injury to surgery, intraoperative bleeding, and fixation method of the anterior ring and ilium were not statistically significant (P > 0.05). The average length of the iliac segment of sacroiliac screws in group A was 3.71 ± 0.85 cm, which was significantly longer than that in the control group (2.12 ± 0.47 cm, P < 0.01).The shortest distance between the entry point of sacroiliac screws and the iliac fracture line in group A was 3.31 ± 0.88 cm, which was significantly longer than that in the control group (1.22 ± 0.64 cm, P < 0.01). The quality of fracture reduction was assessed according to the Matta score based on the pelvic X-ray results in the first week after surgery: group A: 12 cases with excellent results, 7 cases with good results, 2 cases with acceptable results, and no poor results; group B: 6 cases with excellent results, 12 cases with good results, 5 cases with acceptable results, and no poor results; the quality of reduction in group A was better than that in group B (P < 0.05). The VAS score of sacroiliac joint pain at the last follow-up was 0 in 10 patients, < 3 in 7 patients, and 4–6 in 4 patients in Group A. In Group B, there were 5 patients with a score of 0, 8 patients with a score of < 3, and 10 patients with a score of 4–6. The relief of sacroiliac joint pain in Group A was better than that in Group B. (p < 0.05) Conclusion When the modified sacroiliac screw is used to treat Day type II crescent fracture of the pelvis, the screw entry point can avoid the iliac fracture line, and at the same time, the screw channel is long and the holding force is stronger than that of the traditional sacroiliac screw, which is worthy of popularization and application in the clinic. Pelvic fracture Sacroiliac joint Fracture fixation Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Introduction Crescent fracture dislocation of the pelvis (CFDP), also known as a fracture dislocation passing through the sacroiliac joint, is a subtype of lateral compression-type pelvic injuries and accounts for approximately 12% of lateral compression-type pelvic injuries [1] . It results mainly from lateral compression, with the fracture line passing through the sacroiliac joint and extending outward and upward to the iliac wing, forming a characteristic crescent-shaped iliac fragment that firmly attached to the sacrum, accompanied by sacroiliac joint dislocation [2, 3] . Day [1] classified CFDP into three types based on the sacroiliac joint involvement and the size of the iliac fracture fragment: Type I involves less than one-third of the sacroiliac joint, resulting in a large posterior crescent-shaped iliac fracture fragment; and Type II involves the middle one-third of the sacroiliac joint, resulting in a moderately sized posterior crescent-shaped iliac fracture fragment; Type III involves more than two-thirds of the sacroiliac joint, resulting in a small posterior crescent-shaped iliac fracture fragment. Day type II CFDP accounts for about half of the incidence of CFDP, and surgery is now mostly advocated to restore the stability of the pelvic ring and to promote early rehabilitation exercises for patients [4–6] . The previous surgical method was mainly to perform incision and internal fixation from a posterior approach, which increased the trauma to the patient and the incidence of postoperative complications. Starr [7] proposed the adoption of hollow LC-II screws for the minimally invasive treatment of Day type II CFDP, which preserves the blood supply to the bone, reduces soft-tissue damage, and decreases intraoperative bleeding. With the popularity of the minimally invasive concept and the use of navigation devices such as TiRobot, the percutaneous cross-screw internal fixation technique has been promoted [8, 9] , and the treatment of Day type II CFDP by percutaneous sacroiliac screws in combination with posterior iliac screws has been widely used in clinical practice [10] . (Fig. 1 ) Kebaish [11] and Sponseller [12] have proposed the sacral wing-iliac screw via S2 (Second Sacral-alar-iliac screw, S2AIS). The screw entry point is between the dorsal sacral 1 and sacral 2 foramina of the sacral wing, which passes through the sacroiliac joint and is fixed to the iliac wing, and has been used primarily for minimally invasive thoracolumbar deformity surgery. Shabtai [13] suggested that S2AIS can pass through 3–4 layers of bone cortex and the screw has a long channel, so it is strong against vertical shear, and it reduces the risk of neurological injury in the treatment of certain specific posterior pelvic ring instability injuries such as sacroiliac fracture dislocations and it can achieve a higher biomechanical stability than the traditional sacroiliac screws. Facing the problems associated with the traditional sacroiliac screw technique in the clinical setting applications and inspired by the advantages of the S2AIS technique. We propose a modified sacroiliac screw placement technique, which is a change from the traditional posterior-anterior or horizontal direction to the anterolateral to posterior-inferior sacral wing direction of the external plate of the ilium. We call it the modified sacroiliac screw technique. (Fig. 2 ) The purpose of this study was to investigate the clinical efficacy of modified sacroiliac screws in the treatment of Day type II CFDP by comparative analysis with traditional sacroiliac screws and to assess their clinical application value. Patients and methods The study follows the guidelines of the Declaration of Helsinki. The surgical approach was approved by the hospital ethics committee. Informed consent was obtained from the patients and their families before the surgical treatment using the surgical approach in this study. From January 2019 to June 2023, a total of 312 patients with pelvic fractures underwent surgery at our hospital. The following were the inclusion criteria: 1.Day type II crescent fracture-dislocation of the pelvis; 2. Age ≥ 18 years; Exclusion criteria include:1.Pelvic ring structural abnormalities due to congenital or acquired bone lesions; 2. Concomitant acetabular fractures with significant displacement; 3. Follow-up duration < 6 months; 4.Pathological fracture of the pelvis. A total of 44 patients who met the inclusion and exclusion criteria were included in this study. According to the differences of sacroiliac screw, we divided these patients into two groups: Modified sacroiliac screw group (Group A, 21 cases), Traditional sacroiliac screw group (Group B, 23 cases). The patient is admitted to the hospital for evaluation of the indicators of vital signs and is treated accordingly. The patient underwent multi-angle radiographs of the pelvic front view, inlet view, and outlet view and a thin-layer CT scan of the pelvis (layer thickness 0.625 mm). The surgery was performed by the same trauma surgeon experienced in the treatment of pelvic fractures, and the intraoperative navigational aid was the TiRobot system (TINAVI Medical 45 Technologies, Beijing, China). Surgical treatment Modified sacroiliac screw group (Group A): After successful anesthesia, the patient is placed in the supine or prone position, depending on the patient's combined other injuries. The surgery was performed on a fluoroscopic carbon fibre operating table. We start with reduction and fixation of the affected iliac bone, and use a 5 mm Schanz nail drilled into the iliac crest to assist in rotational reduction of the ilium or take an apex cone to push the external plate of the ilium to assist with reduction. The LC-II screws can be inserted for fixation after satisfactory reduction. When it is difficult to reset, a small incision can be made in the iliac crest to reset the crescent-shaped iliac bone block under direct vision, and then screws or plates can be inserted for fixation. Next, the modified sacroiliac screw was placed with robotic assistance was performed. Patient trackers were installed on the anterior superior iliac spine or posterior superior iliac spine. X-ray images of the pelvis in three positions, including the inlet, lateral, and outlet views, were obtained using fluoroscopy and uploaded to the main control computer. Screw trajectories were planned on the inlet and outlet views, and the safety of the screw placemen was validated on the lateral view. During planning, the entry point of the screw on the inlet view was located on the anterior-lateral aspect of the ilium, and the exit point was located on the medial aspect of the S1 vertebral body. On the outlet view, the entry point of the screw was located on the superior border of the acetabulum, pointing toward the S1 vertebra, passing through the S1 anterior sacral foramen and between the sacral alar slope (SAS). In the lateral view, when the screw entered the sacroiliac joint, the upper boundary should not exceed the iliac cortical density line and the SAS, and the lower boundary should not exceed the greater sciatic notch. After completing the planning, the robotic arm was maneuvered to the designated position, and a guide wire was inserted and measured for length before inserting the cannulated screw. (Fig. 3 ) Finally, to deal with the injury to the anterior pelvic ring. we adopt INFIX fixation of the anterior ring in patients with pubic branch fractures without significant displacement bilaterally; For patients with anterior unilateral superior pubic branch fractures without obvious displacement; we adopt closed reduction superior pubic ramus screws for fixation; If the displacement of the anterior ring fracture is obvious and the patient's general condition is good, we adopt incisional reduction plate fixation. Traditional sacroiliac screw group (Group B): We treated iliac fractures in the same way as in group A. Next, the traditional sacroiliac screw was placed with robotic assistance. Fluoroscopy was performed for planning the screw trajectories in the inlet, lateral, and outlet views of the pelvis. During planning, the entry point of the screw on the inlet view was located on the posterior-lateral aspect of the ilium, and the exit point was close to the anterior edge of the S1 vertebral body. On the outlet view, the entry point of the screw was located on the superior border of the acetabulum, pointing toward the S1 vertebra, passing through the S1 anterior sacral foramen and between the SAS. The safety of the screw placement was validated on the lateral image. After completing the planning, the robotic arm was maneuvered to the designated position, and a guide wire was inserted and measured for length before inserting the cannulated screw. (Fig. 4 ) The principle of management of the anterior pelvic ring was the same as that of Group A. INFIX, superior pubic ramus screws or plates were taken to treat the injury of the anterior pelvic ring according to the different characteristics of the patients. Posterior treatment To prevent deep vein thrombosis of the lower extremities, anticoagulants are routinely applied to all patients after surgery. Multi-angle radiographs (including pelvic front view, inlet view, and outlet views) and thin-layer CT (0.625 mm) were performed within one week after surgery. X-rays were routinely taken at 6 weeks, 3, 6, 12, and 24 months postoperatively, and patients were instructed on functional exercises by assessing their recovery. At 8 weeks postoperatively, patients were allowed to go down on crutches, and at 12 weeks postoperatively, patients were allowed to attempt to walk off the crutches, depending on the healing of the fracture. Statistical analysis We recorded the patient's gender, age, cause of injury, fracture classification (according to Tile classification), operative time, intraoperative bleeding, mode of fixation of the anterior pelvic ring, mode of fixation of the ilium, total length of the sacroiliac screw, length of the iliac segment of the sacroiliac screw versus that of the sacral segment, shortest distance between the sacroiliac screw entry point and the iliac fracture line, the quality of the sacroiliac joint's resurfacing, postoperative complications, and clinical prognosis. The length of the iliac segment of the sacroiliac screw was measured by measuring the maximum length of the long axis of the screw within the ilium on CT, and the length of the sacral segment of the screw was measured by measuring the maximum length of the long axis of the screw within the sacrum on CT (Fig. 5 ). The Matta scoring system [14] was used to evaluate the quality of pelvic fracture reduction. The maximum displacement of the fracture on X-rays taken at three positions (pelvic front view, inlet view, and outlet views) within one week after surgery was used to assess the reduction quality: <4 mm was considered excellent, 4–10 mm was considered good, 11–20 mm was considered fair, and over 20 mm was considered poor. Functional outcome was assessed at the final follow-up using the Majeed scale [15] for pain level, ability to sit and stand, ability to work, sexuality, assisted ambulation, gait, and distance travelled, with scores of ≥ 85 being excellent, 70–84 being good, 55–69 being acceptable, and < 55 being poor. And the pain visual analogue scale (VAS) was used to evaluate sacroiliac joint pain at the final follow-up. All statistical analyses were performed using the statistical software SPSS 22.0 (SPSS, Chicago, IL). Measurement data were determined by the Shapiro-Wilk test to determine whether they conformed to normal distribution, and conformity to normal distribution was expressed as the mean ± standard deviation, and comparisons between groups were made using the independent samples t-test; count data were expressed as the frequency (n, %), and comparisons between groups were made using the chi-square test; The Mann-Whitney U test was used for comparison between groups. p-value < 0.05 was considered statistically significant. Results The differences in gender, age, cause of injury, fracture classification, operative time, fixation of the anterior pelvic ring and fixation of the iliac bone were not statistically significant (P > 0.05) (Table 1 ), so the two groups were comparable. Table 1 Demographic data Project Group A(n = 21) Group B(n = 23) p Sex 0.592 Male, n(%) 13(61.9) 16(69.6) Female, n(%) 8(38.1) 7(30.4) Mean age(岁) 42.6 ± 5.3 45.3 ± 6.1 0.126 Mechanism of injury, n(%) 0.987 Traffic accident 12(57.1) 13(56.5) Injury caused by falling from a height 6(28.6) 7(30.4) Crush injury from a heavy object 3(14.3) 3(13.0) Tile classification, n(%) 0.896 B 17(81.0) 20(87.0) C 4(19.0) 3(13.0) Operating time(min) 77.9 ± 13.1 79.0 ± 16.0 0.805 Intraoperative haemorrhage(ml) 63.8 ± 52.5 68.3 ± 49.4 0.771 Fixation of anterior pelvic ring(cases) 0.980 Infix 12 13 Superior pubic ramus screws 5 6 Steel plate 4 4 Fixation of ilium (cases) 1.000 LC-II screw 17 18 Steel plate 4 5 All patients successfully completed the surgery, in which the total length of sacroiliac screws in group A and sacroiliac screws in group B were 9.44 ± 0.76cm and 8.47 ± 0.61cm, respectively, and the difference was not statistically significant (P = 0.26).The mean iliac segment length of sacroiliac screws in group A was 3.83 ± 1.05cm, which was longer than that of the control group, which was 2.15 ± 0.60cm (P < 0.01) The mean sacroiliac segment length of sacroiliac screws in group A and group B was 5.72 ± 0.94cm and 6.48 ± 0.85cm, respectively, with no statistically significant difference (P = 0.066). The mean shortest distance from the iliac fracture line of the sacroiliac screw entry point in group A was longer than that in the control group (3.44 ± 1.07cm vs. 0.91 ± 0.55cm, P < 0.01) (Table 2 ). Table 2 Comparison of sacroiliac screw data between the two groups Group n Total length of screw Length of iliac segment of screw Length of screw sacral segment Minimum distance of the screw entry point from the iliac fracture line Group A 21 9.44 ± 0.76cm 3.71 ± 0.85 cm 5.65 ± 0.79 cm 3.31 ± 0.88 cm Group B 23 8.47 ± 0.61cm 2.12 ± 0.47 cm 6.09 ± 0.70 cm 1.22 ± 0.64 cm p < 0.001 < 0.001 0.057 < 0.001 According to the pelvic X-ray results within one week after surgery, there were 12 cases with excellent quality of reduction, 7 cases with good quality, 2 cases with acceptable quality and no poor results in group A. There were 6 cases with excellent quality of reduction, 12 cases with good quality, 5 cases with acceptable quality and no poor results in group B. The quality of reduction in group A was better than that in group B (P < 0.05) (Table 3 ). There was no statistically significant difference between the Majeed scores of the two groups at the final follow-up (P = 0.568) (Table 4 ), with 13 cases of excellent, 6 cases of good, 2 cases of acceptable, and no poor results in group A, and 11 cases of excellent, 8 cases of good, 1 case of acceptable, and 1 case of poor results in group B. (Fig. 6 , 7 , 8 ). The VAS score of sacroiliac joint pain in group A at the last follow-up was 0 in 10 cases, < 3 in 7 cases, and 4–6 in 4 cases, and 0 in 5 cases, < 3 in 8 cases, and 4–6 in 10 cases in group B. The relief of sacroiliac joint pain in group A was better than that in group B (P < 0.05) (Table 5 ). Table 3 Comparison of the quality of reduction between the two groups Group n Quality of pelvic fracture reduction(%) z p Excellent Good Fair Group A 21 12(57.14) 7(33.33) 2(9.52) -2.055 0.040 Group B 23 6(23.81) 12(57.14) 5(19.05) Table 4 Comparison of prognosis between the two groups Group n Majeed score at final follow-up (%) z p Excellent Good Fair Poor Group A 21 13(61.90) 6(28.57) 2(9.52) 0(0) -0.921 0.357 Group B 23 11(47.82) 9(39.13) 2(8.69) 1(4.35) Table 5 Comparison of VAS scores of sacroiliac joint pain between the two groups Group n Sacroiliac joint pain VAS score (points) z p 0 <3 4–6 Group A 21 10(47.62) 7(33.33) 4(19.05) -2.031 0.042 Group B 23 5(21.74) 8(34.78) 10(43.48) In Group A, 2 patients developed deep vein thrombosis of the lower limbs after surgery, and 1 patient developed incision infection, with a complication rate of 14.29% (3/21), while in Group B, there were 2 cases of combined deep vein thrombosis of the lower limbs after surgery, 1 case of incision infection, and 1 patient's sacroiliac screw entered the sacral foramen without symptoms of nerve injury, with a complication rate of 17.39% (4/23). Meanwhile, in group B, there were 3 patients whose sacroiliac screw entry points were located in the iliac fracture line, and 1 of them was found to have lost resurfacing of the sacroiliac joint at follow-up, which fortunately did not have a significant impact on the patient's life and work, and therefore no further treatment was done, which was not found in group A. Discussion Burgess [16] and Man-son [17] classified pelvic ring injuries into 3 major categories based on the mechanism of injury: anterior-posterior compression (APC), lateral compression (LC), and vertical shear (VS). Day type II CFDP belong to the LC-II type of injury. Previous studies have mostly concluded that the ligaments in the lower part of the sacrum are not damaged and therefore only rotational instability exists and are stable in the vertical direction [3, 18] . However, Burgess [16] suggested that when the pelvis is subjected to vertically orientated violence, it is also capable of producing injuries similar to crescentic fractures, and on pelvic front view, the anterior half of the ilium can show significant vertical displacement. Zong et al. [4] used whether the sacroiliac joints were displaced in the vertical direction by more than 1 cm as a basis for determining whether the pelvis was stable in the vertical direction, and their study of 31 patients with CFDP found that 27 of them had rotational instability of the pelvis, and 4 of them had pelvic instability in the vertical direction. In the two groups of Day type II CFDP patients in this study, a total of 7 patients had significant vertical displacement of the sacroiliac joints, and we found that all 7 patients originated from traffic injuries, we believe this is due to the multidirectional, high-energy nature of the violence of traffic injuries, so the patients with Day II CFDP can also have vertical displacement of the pelvis. We performed preoperative supracondylar femoral traction in all of these patients, which had a certain effect on the resetting of sacroiliac joint subluxation, and intraoperatively, intraoperative attention should also be paid to the need for vertical traction repositioning when correcting rotational displacement [19] . Xiang et al. [20] have been using percutaneous posterior iliac screws in combination with traditional sacroiliac screws to treat Day type II CFDP patients since 2005, and have achieved satisfactory results. In this study, a total of 35 patients' iliac fractures were fixed with LC-II screws, and we found that through appropriate reduction methods, most of the patients' iliac could be fixed with closed-replacement screws, thus reducing the trauma caused to the patients and promoting their early rehabilitation exercises. Sacroiliac screws are widely used for fixation of the posterior pelvic ring with its advantages of minimally invasive and biomechanical stability, but when we took traditional sacroiliac screws to treat Day type II CFDP patients, we found that the entry point of sacroiliac screws was located in the iliac fracture line in three patients, which resulted in our inability to use the screws to pressurize and fix the sacroiliac joints, and even internal fixation failure occurred. Moreover, from an anatomical point of view, the traditional sacroiliac screw has a short iliac segment channel, and the cancellous bone on both sides of the screw, which makes the screw holding force insufficient for elderly osteoporosis patients, and is prone to the "pendulum effect" [8, 21] . To address these shortcomings, we changed the trajectory of the traditional sacroiliac screw and proposed a modified sacroiliac screw channel. The inlet of this channel is located at the posterior superior margin of the acetabulum, and there are no important blood vessels or nerves in the surrounding area, which is a safer position for nail placement. The outlet is located at the medial side of the S1 superior articular process, which is similar to the entry point of the pedicle screw proposed by Roy-Camille, and it has been proved to be a safe position for pedicle screw fixation [5] . Ma et al. [21] conducted anatomical studies on a large number of normal 3D printed pelvises in a 1:1 ratio and proposed the existence of anterior-posterior sacroiliac screw channel. The inner wall of the channel is formed by the pelvic arcuate line, while the outer wall is composed of the posterior-lateral aspect of the sacral wing and the lateral aspect of the ilium. The superior wall is the SAS and the bottom of the greater pelvis, while the inferior wall is the line between the sacral foramen and the greater sciatic notch. In this study, postoperative CT of all patients in group A suggested that the modified sacroiliac screws were located in the bony channel, and none of them entered the acetabulum or sacral canal, which confirmed the safety of the modified sacroiliac screw channel. In this study, although the difference between the total length of the sacroiliac screws and the length of the sacral segment between the two groups was not statistically significant, the length of the iliac segment of the modified sacroiliac screws was longer than that of the traditional sacroiliac screws. Also, from an anatomical point of view, the iliac segments of the modified sacroiliac screws were encapsulated medially and laterally by cortical bone, which better provided stability of the posterior pelvic ring. Therefore, we believe that the biomechanical stability of the modified sacroiliac screw is superior to that of the traditional sacroiliac screw, and it is suitable for the fixation of the posterior pelvic ring in elderly osteoporotic patients. Meanwhile, the shortest distance from the entry point of the modified sacroiliac screw to the iliac fracture line in the ilium is much longer than that of the traditional sacroiliac screw, which effectively avoids the impossibility of pressurized fixation with the screw due to the fact that the entry point is located in the iliac fracture line. From the comparison of the quality of reduction in the two groups, we found that the modified sacroiliac screw had better compression reduction effect on the dislocated sacroiliac joints under the premise of using the same reduction method. We believe that, on the one hand, the limited safe channel of conventional sacroiliac screws, especially in variant sacrum, where the safe channel of the screws is close to the posterior aspect of the sacroiliac joints, makes it difficult to provide good compression reset of anteriorly dislocated sacroiliac joints, on the other hand, the point of action of the modified sacroiliac screw is close to the most obvious position of sacroiliac joint dislocation, and although the screw trajectory is not completely perpendicular to the bone surface, it still has a better compression resetting effect on the dislocated sacroiliac joints(Fig. 9 ). Although the difference in Majeed's functional scores at the final follow-up between the two groups was not statistically significant, the VAS scores of sacroiliac joint pain still showed that the modified sacroiliac screws were more effective than the conventional sacroiliac screws for fixation of sacroiliac joint dislocation. In addition, the use of the intraoperative TiRobot navigation device was of great help, as it improved the accuracy of nail placement, greatly reduced the number of intraoperative fluoroscopies, and shortened the operative time. In clinical application, we also found several problems: 1. The sacral segment of the modified SIS is slightly shorter, and when the vertical pelvic shift is obvious, the S2 penetrating screw can be used to enhance fixation; 2.Fluoroscopy of the iliac wing front view is very important during intraoperative screw placement, as this image can not only prevent the LC-II screw from penetrating the inner or outer iliac plate but also clearly show whether the modified SIS breaks through the medial edge of the iliac bone and enters the pelvic cavity to avoid the "in-out-in" phenomenon with screws; 3.Intraoperative repositioning of the fracture is crucial, and the operator needs to have rich surgical experience in closed and incisional repositioning of pelvic fractures; 4.The sample size of the current study is limited, and there is a need for further expansion of the sample size and regular observation and follow-up in follow-up work to ensure the maturity and reliability of this technique. Conclusions The modified sacroiliac screw technique was used to treat the pelvic Day II crescent fracture dislocation, the screw entry point could effectively avoid the iliac fracture line, and the iliac segment of the modified sacroiliac screw was longer than that of the traditional sacroiliac screw, with the inner and outer sides being wrapped by the cortical bone, which had strong holding power, and it was able to achieve pressurized fixation more effectively and restore the stability of the pelvic ring, which compensated for the deficiencies of the traditional sacroiliac screw, and it is worth to promote the application of this technique in the clinical treatment. Abbreviations CFDP Crescent fracture dislocation of the pelvis SAS sacral alar slope CT Computed tomography LC Lateral compression APC Anterior-posterior compression VS Vertical shear Declarations Ethics approval and consent to participate This study was performed according to the Helsinki declaration and the study was approved by the ethics committee of Bengal Medical College (Number: BYYFY-2018YJS180)). Consent for publication Patients signed informed consent regarding publishing their data and photographs. Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding No funding was received to assist with the preparation of this manuscript. Authors' contributions Min Wu and Renjie Li designed the study. Xiaopan Wang, Peishuai Zhao and Xiaotian Chen collected and analyzed the patient data. Min Wu and Jianzhong Guan performed the operation. Min Wu, Renjie Li and Leyu Liu analyzed the results and prepared the manuscript. All authors read and approved the final manuscript. Acknowledgements Not applicable. Statements All methods were performed in accordance with the relevant guidelines and regulations. References DAY A C, KINMONT C, BIRCHER M D, et al. Crescent fracture-dislocation of the sacroiliac joint: a functional classification [J]. Journal of Bone & Joint Surgery-british Volume, 2007, 89(5): 651-8. BORRELLI J, KOVAL K J, HELFET D L. Operative stabilization of fracture dislocations of the sacroiliac joint [J]. Clin Orthop Relat Res, 1996, 329(329): 141-6. CAI L, ZHANG Y, ZHENG W, et al. A novel percutaneous crossed screws fixation in treatment of Day type II crescent fracture–dislocation: A finite element analysis [J]. Journal of Orthopaedic Translation, 2020, 20. ZONG Z, CHEN S, JIA M, et al. Posterior iliac crescent fracture-dislocation: is it only rotationally unstable? [J]. Orthopedics, 2014, 37(5): e435-40. MENON K V, SURESH S S, KALYANASUNDARAM S, et al. Crescent fractures of the pelvis treated by open reduction and internal fixation: a critique of Day's guidelines [J]. European Journal of Orthopaedic Surgery & Traumatology, 2017. BAI Z, GAO S, LIU J, et al. Anatomical evidence for the anterior plate fixation of sacroiliac joint [J]. J Orthop Sci, 2018, 23(1): 132-6. STARR A J, WALTER J C, HARRIS R W, et al. Percutaneous Screw Fixation of Fractures of the Iliac Wing and Fracture-dislocations of the Sacro-iliac Joint (OTA Types 61-B2.2 and 61-B2.3, or Young-Burgess "Lateral Compression Type II" Pelvic Fractures) [J]. Journal of Orthopaedic Trauma, 2002, 16(2): 116-23. TAKAO M, HAMADA H, SAKAI T, et al. Clinical Application of Navigation in the Surgical Treatment of a Pelvic Ring Injury and Acetabular Fracture [J]. Advances in experimental medicine and biology, 2018. CIOLLI G, CAVIGLIA D, VITIELLO C, et al. Navigated percutaneous screw fixation of the pelvis with O-arm 2: two years' experience [J]. Medicinski glasnik : official publication of the Medical Association of Zenica-Doboj Canton, Bosnia and Herzegovina, 2021, 18(1): 309-15. XIANG G, DONG X, JIANG X, et al. Comparison of percutaneous cross screw fixation versus open reduction and internal fixation for pelvic Day type II crescent fracture-dislocation: case-control study [J]. BioMed Central, 2021, (1). O?BRIEN J R, MATTEINI L, YU W D, et al. Feasibility of minimally invasive sacropelvic fixation: percutaneous S2 alar iliac fixation [J]. Spine, 2010, 35(4): 460-4. CHANG T L. Low profile pelvic fixation: anatomic parameters for sacral alar-iliac fixation versus traditional iliac fixation [J]. Spine, 2009, 8(5). SHABTAI L, ANDRAS L M, PORTMAN M, et al. Sacral Alar Iliac (SAI) Screws Fail 75% Less Frequently Than Iliac Screws in Neuromuscular Scoliosis [J]. Journal of Pediatric Orthopedics, 2016, 137(Supplement 3). MATTA J M. Fracture of the acetabulum: accuracy of reduction and clinical results in patients managed operatively within three weeks after the injury [J]. Orthopedic Trauma Directions. MAJEED S A. Grading the outcome of pelvic fractures [J]. The Bone & Joint Journal, 1989, 71(2): 304-6. BURGESS A R, EASTRIDGE B J, YOUNG J W, et al. Pelvic ring disruptions: effective classification system and treatment protocols [J]. Journal of Trauma, 1990, 30(7): 848-56. MANSON T, O?TOOLE R V, WHITNEY A, et al. Young-Burgess classification of pelvic ring fractures: does it predict mortality, transfusion requirements, and non-orthopaedic injuries? [J]. Journal of Orthopaedic Trauma, 2010, 24(10): 603-9. BACHHAL V, JINDAL K, RATHOD P M, et al. Bilateral crescent fracture-dislocation of the sacroiliac joint: a case-based discussion and review of literature [J]. International journal of burns and trauma, 2021, 11(3): 260-6. FRANCK A, PILTZ S. The surgical treatment of unstable osteoporotic pelvic ring fractures with bilateral vertebropelvic stabilization using a less invasive technique [J]. Revue de chirurgie orthopediqueet traumatologique, 2022. XIANG G, DONG X, JIANG X, et al. Comparison of percutaneous cross screw fixation versus open reduction and internal fixation for pelvic Day type II crescent fracture-dislocation: case-control study [J]. Journal of Orthopaedic Surgery and Research, 2021, 16(1). MA Y, WANG J, YIN Q, et al. Effect of Iliosacral Screw Implantation Through a New Channel in Three-Dimensional Printing Pelvic Model [J]. Indian Journal of Orthopaedics, 2021: 1-5. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. 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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-4817453","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":341650420,"identity":"b07b8288-2eaa-40d5-9569-936f86a502cf","order_by":0,"name":"Renjie Li","email":"","orcid":"","institution":"The First Affiliated Hospital of Bengbu Medical College","correspondingAuthor":false,"prefix":"","firstName":"Renjie","middleName":"","lastName":"Li","suffix":""},{"id":341650427,"identity":"bbc115ba-d30d-4877-b5b5-d3276baae5b6","order_by":1,"name":"Leyu Liu","email":"","orcid":"","institution":"The First Affiliated Hospital of Bengbu Medical College","correspondingAuthor":false,"prefix":"","firstName":"Leyu","middleName":"","lastName":"Liu","suffix":""},{"id":341650428,"identity":"bbdf3320-4bdf-4471-9e3e-5438ecc7a87f","order_by":2,"name":"Jianzhong Guan","email":"","orcid":"","institution":"The First Affiliated Hospital of Bengbu Medical College","correspondingAuthor":false,"prefix":"","firstName":"Jianzhong","middleName":"","lastName":"Guan","suffix":""},{"id":341650432,"identity":"11d75c02-32e3-43cc-a0cb-c469ec042f68","order_by":3,"name":"Xiaopan Wang","email":"","orcid":"","institution":"The First Affiliated Hospital of Bengbu Medical College","correspondingAuthor":false,"prefix":"","firstName":"Xiaopan","middleName":"","lastName":"Wang","suffix":""},{"id":341650434,"identity":"c4de542e-fd19-4662-8543-7ab9b4facb4a","order_by":4,"name":"Peishuai Zhao","email":"","orcid":"","institution":"The First Affiliated Hospital of Bengbu Medical College","correspondingAuthor":false,"prefix":"","firstName":"Peishuai","middleName":"","lastName":"Zhao","suffix":""},{"id":341650437,"identity":"05aebb00-cb7b-4022-bfc7-a27cbcb857ee","order_by":5,"name":"Xiaotian Chen","email":"","orcid":"","institution":"The First Affiliated Hospital of Bengbu Medical College","correspondingAuthor":false,"prefix":"","firstName":"Xiaotian","middleName":"","lastName":"Chen","suffix":""},{"id":341650438,"identity":"2f304485-f514-4450-8fa0-ee9f2159589a","order_by":6,"name":"Min Wu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyElEQVRIiWNgGAWjYJCCAwwGNvVtzIyNDxIqaojVUpDG2M/OfNjgwZljxNrz4TDjzH62NMmHLcyEFRvcyE48XGBwmNngMI9ZRWIDGwN/e3cCAS25Gw7PMEhnA2m5kbhDhkHizNkNeLWYgbTwGFjzQLScYWMwkMglSguzBEhLQWIbM9FanA0km9nSGIjSYn/mLUhLWgI/M/NhiYQzx3gI+kWyPXfzZ54/Ngls/AcbP/6oqJHjb+/FrwUD8JCmfBSMglEwCkYBVgAAnkZLog6ny+sAAAAASUVORK5CYII=","orcid":"","institution":"The First Affiliated Hospital of Bengbu Medical College","correspondingAuthor":true,"prefix":"","firstName":"Min","middleName":"","lastName":"Wu","suffix":""}],"badges":[],"createdAt":"2024-07-28 15:48:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4817453/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4817453/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":63832849,"identity":"8b09a86f-7e4b-44d0-b249-4933a28d1030","added_by":"auto","created_at":"2024-09-02 19:21:18","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":91996,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Preoperative CT of a 69-year-old male patient with Day type II CFDP. (b) Postoperative CT of this patient treated with traditional sacroiliac screws suggests that the entry point of the sacroiliac screws is located in the iliac fracture line.\u003c/p\u003e","description":"","filename":"Fig.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/dd732b3224ec001e2cad9f08.jpg"},{"id":63831023,"identity":"cbbff2cb-e42a-42b4-a654-40cda27170bd","added_by":"auto","created_at":"2024-09-02 19:05:18","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":65548,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Modified sacroiliac screw front view. (b) Modified sacroiliac screw lateral view. (c) Modified sacroiliac screw outlet view. (d) Modified sacroiliac screw inlet view. (e) Difference between modified and traditional sacroiliac screws in the pelvic inlet view. (f) Difference in the range of the entry point of the modified versus traditional sacroiliac screw in the pelvic lateral view.\u003c/p\u003e","description":"","filename":"Fig2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/c6013df7f2ad0cb65345aeed.jpg"},{"id":63831025,"identity":"1e4189fa-6fd9-4fba-ac49-2f4ef18bc66d","added_by":"auto","created_at":"2024-09-02 19:05:18","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":45455,"visible":true,"origin":"","legend":"\u003cp\u003eIntraoperative planning images of modified sacroiliac screws\u003c/p\u003e","description":"","filename":"Fig3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/37427a7543cbcd978f2464a2.jpg"},{"id":63831866,"identity":"b506254e-475e-4f5f-9ecc-9fbf7d0229de","added_by":"auto","created_at":"2024-09-02 19:13:19","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":50083,"visible":true,"origin":"","legend":"\u003cp\u003eIntraoperative planning images of traditional sacroiliac screws\u003c/p\u003e","description":"","filename":"Fig4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/21bf2320a0b10a103873f109.jpg"},{"id":63831024,"identity":"9edbae4e-b945-47be-8c36-88aeefc0b13a","added_by":"auto","created_at":"2024-09-02 19:05:18","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":7797,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Length of iliac segment for sacroiliac screws. (b) Length of sacral segment for sacroiliac screws\u003c/p\u003e","description":"","filename":"Fig5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/63febeb64d45a91b7869499a.jpg"},{"id":63831027,"identity":"4a61ee72-3fd7-4a8e-a52b-9adf47b22ec9","added_by":"auto","created_at":"2024-09-02 19:05:19","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":183206,"visible":true,"origin":"","legend":"\u003cp\u003ePre-operative CT and X-rays of a 44-year-old female patient with with Day type II CFDP (a, b, c). A 1cm incision was made at the right hip and the fracture was repositioned by inserting an apex cone into the outer plate of the iliac bone, then a guide pin was inserted for fixation, followed by placement of modified SIS, LC-II screws and S2 sacroiliac screws, finally INFIX was used to maintain stability of the anterior pelvic ring (d, e, f). Intraoperative modified sacroiliac screw planning images (g, h, i). The X-ray and CT review 1 year after surgery showed anatomical reduction of the pelvis with good fracture healing and no screw breakage (j, k, l).\u003c/p\u003e","description":"","filename":"Fig6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/e45cc8509edd2b6bf6b7b486.jpg"},{"id":63831030,"identity":"aa151f11-69dc-433e-b49b-c8ee6e0d8a1f","added_by":"auto","created_at":"2024-09-02 19:05:19","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":159421,"visible":true,"origin":"","legend":"\u003cp\u003ePre-operative CT and X-rays of a 58-year-old male patient with Day type II CFDP (a, b, c). In the prone position, a small incision was made in the posterior superior iliac spine and a small incision in the right iliac spine to reposition the iliac fracture, then two LC-II screws were placed in the posterior superior iliac spine for fixation, followed by modified sacroiliac screwplacement, and finally the right pubic bone branch was fixed with an anterior column screw (d, e, f). Post-operative review of the pelvic radiographs showed satisfactory fracture reduction and good screw position (g, h, i).\u003c/p\u003e","description":"","filename":"Fig7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/909fe54c550812aeeb5f2f6f.jpg"},{"id":63831028,"identity":"d92cda69-0e43-4a60-a314-ced38e141ef2","added_by":"auto","created_at":"2024-09-02 19:05:19","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":131857,"visible":true,"origin":"","legend":"\u003cp\u003ePatient in the modified sacroiliac screw group, female, 47 years old, Day II CFDP. (a) Preoperative pelvic orthopantomogram. (b) Preoperative pelvic inlet position image. (c) Preoperative pelvic CT cross-sectional view of the pelvis shows the iliac fracture line accumulating to the sacroiliac joints in 1/3-2/3. (d) Intraoperative pelvic inlet position image. (e) Intraoperative pelvic outlet position image. (f) Intraoperative pelvic lateral view. (g) One-week postoperative orthopantomogram of the pelvis suggests that the pelvis is continuous and intact. (h) Pelvic inlet position suggests bilateral symmetry of the pelvic ring. (i) Orthopantomogram of the pelvic iliac wing suggests a good position of internal fixation.\u003c/p\u003e","description":"","filename":"Fig8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/de507d736083698d0c4d28fe.jpg"},{"id":63831031,"identity":"a93ab283-5054-4158-a1af-7a1272afbda0","added_by":"auto","created_at":"2024-09-02 19:05:19","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":15598,"visible":true,"origin":"","legend":"\u003cp\u003eModified sacroiliac screws and traditional sacroiliac screws have different points of action for resetting the sacroiliac joints because of the difference in screw trajectory.\u003c/p\u003e","description":"","filename":"Fig9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/7c7d34bf90915c17b4ba5a4d.jpg"},{"id":64130766,"identity":"870aa1a9-8405-4dc2-9576-014b5256ea71","added_by":"auto","created_at":"2024-09-08 08:17:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1288999,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4817453/v1/fcecea06-141b-4ec1-a8ab-14df1fc53a21.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A study of the modified sacroiliac screw technique in Day type II crescent fracture dislocation of the pelvis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCrescent fracture dislocation of the pelvis (CFDP), also known as a fracture dislocation passing through the sacroiliac joint, is a subtype of lateral compression-type pelvic injuries and accounts for approximately 12% of lateral compression-type pelvic injuries\u003csup\u003e[1]\u003c/sup\u003e. It results mainly from lateral compression, with the fracture line passing through the sacroiliac joint and extending outward and upward to the iliac wing, forming a characteristic crescent-shaped iliac fragment that firmly attached to the sacrum, accompanied by sacroiliac joint dislocation\u003csup\u003e[2, 3]\u003c/sup\u003e. Day\u003csup\u003e[1]\u003c/sup\u003e classified CFDP into three types based on the sacroiliac joint involvement and the size of the iliac fracture fragment: Type I involves less than one-third of the sacroiliac joint, resulting in a large posterior crescent-shaped iliac fracture fragment; and Type II involves the middle one-third of the sacroiliac joint, resulting in a moderately sized posterior crescent-shaped iliac fracture fragment; Type III involves more than two-thirds of the sacroiliac joint, resulting in a small posterior crescent-shaped iliac fracture fragment.\u003c/p\u003e \u003cp\u003eDay type II CFDP accounts for about half of the incidence of CFDP, and surgery is now mostly advocated to restore the stability of the pelvic ring and to promote early rehabilitation exercises for patients\u003csup\u003e[4\u0026ndash;6]\u003c/sup\u003e. The previous surgical method was mainly to perform incision and internal fixation from a posterior approach, which increased the trauma to the patient and the incidence of postoperative complications. Starr\u003csup\u003e[7]\u003c/sup\u003e proposed the adoption of hollow LC-II screws for the minimally invasive treatment of Day type II CFDP, which preserves the blood supply to the bone, reduces soft-tissue damage, and decreases intraoperative bleeding. With the popularity of the minimally invasive concept and the use of navigation devices such as TiRobot, the percutaneous cross-screw internal fixation technique has been promoted\u003csup\u003e[8, 9]\u003c/sup\u003e, and the treatment of Day type II CFDP by percutaneous sacroiliac screws in combination with posterior iliac screws has been widely used in clinical practice\u003csup\u003e[10]\u003c/sup\u003e. (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eKebaish\u003csup\u003e[11]\u003c/sup\u003e and Sponseller\u003csup\u003e[12]\u003c/sup\u003e have proposed the sacral wing-iliac screw via S2 (Second Sacral-alar-iliac screw, S2AIS). The screw entry point is between the dorsal sacral 1 and sacral 2 foramina of the sacral wing, which passes through the sacroiliac joint and is fixed to the iliac wing, and has been used primarily for minimally invasive thoracolumbar deformity surgery. Shabtai\u003csup\u003e[13]\u003c/sup\u003e suggested that S2AIS can pass through 3\u0026ndash;4 layers of bone cortex and the screw has a long channel, so it is strong against vertical shear, and it reduces the risk of neurological injury in the treatment of certain specific posterior pelvic ring instability injuries such as sacroiliac fracture dislocations and it can achieve a higher biomechanical stability than the traditional sacroiliac screws.\u003c/p\u003e \u003cp\u003eFacing the problems associated with the traditional sacroiliac screw technique in the clinical setting applications and inspired by the advantages of the S2AIS technique. We propose a modified sacroiliac screw placement technique, which is a change from the traditional posterior-anterior or horizontal direction to the anterolateral to posterior-inferior sacral wing direction of the external plate of the ilium. We call it the modified sacroiliac screw technique. (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe purpose of this study was to investigate the clinical efficacy of modified sacroiliac screws in the treatment of Day type II CFDP by comparative analysis with traditional sacroiliac screws and to assess their clinical application value.\u003c/p\u003e"},{"header":"Patients and methods","content":"\u003cp\u003e The study follows the guidelines of the Declaration of Helsinki. The surgical approach was approved by the hospital ethics committee. Informed consent was obtained from the patients and their families before the surgical treatment using the surgical approach in this study.\u003c/p\u003e \u003cp\u003eFrom January 2019 to June 2023, a total of 312 patients with pelvic fractures underwent surgery at our hospital. The following were the inclusion criteria: 1.Day type II crescent fracture-dislocation of the pelvis; 2. Age\u0026thinsp;\u0026ge;\u0026thinsp;18 years; Exclusion criteria include:1.Pelvic ring structural abnormalities due to congenital or acquired bone lesions; 2. Concomitant acetabular fractures with significant displacement; 3. Follow-up duration\u0026thinsp;\u0026lt;\u0026thinsp;6 months; 4.Pathological fracture of the pelvis.\u003c/p\u003e \u003cp\u003eA total of 44 patients who met the inclusion and exclusion criteria were included in this study. According to the differences of sacroiliac screw, we divided these patients into two groups: Modified sacroiliac screw group (Group A, 21 cases), Traditional sacroiliac screw group (Group B, 23 cases).\u003c/p\u003e \u003cp\u003eThe patient is admitted to the hospital for evaluation of the indicators of vital signs and is treated accordingly. The patient underwent multi-angle radiographs of the pelvic front view, inlet view, and outlet view and a thin-layer CT scan of the pelvis (layer thickness 0.625 mm). The surgery was performed by the same trauma surgeon experienced in the treatment of pelvic fractures, and the intraoperative navigational aid was the TiRobot system (TINAVI Medical 45 Technologies, Beijing, China).\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSurgical treatment\u003c/h2\u003e \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e \u003ch2\u003eModified sacroiliac screw group (Group A):\u003c/h2\u003e \u003cp\u003eAfter successful anesthesia, the patient is placed in the supine or prone position, depending on the patient's combined other injuries. The surgery was performed on a fluoroscopic carbon fibre operating table. We start with reduction and fixation of the affected iliac bone, and use a 5 mm Schanz nail drilled into the iliac crest to assist in rotational reduction of the ilium or take an apex cone to push the external plate of the ilium to assist with reduction. The LC-II screws can be inserted for fixation after satisfactory reduction. When it is difficult to reset, a small incision can be made in the iliac crest to reset the crescent-shaped iliac bone block under direct vision, and then screws or plates can be inserted for fixation.\u003c/p\u003e \u003cp\u003eNext, the modified sacroiliac screw was placed with robotic assistance was performed. Patient trackers were installed on the anterior superior iliac spine or posterior superior iliac spine. X-ray images of the pelvis in three positions, including the inlet, lateral, and outlet views, were obtained using fluoroscopy and uploaded to the main control computer. Screw trajectories were planned on the inlet and outlet views, and the safety of the screw placemen was validated on the lateral view. During planning, the entry point of the screw on the inlet view was located on the anterior-lateral aspect of the ilium, and the exit point was located on the medial aspect of the S1 vertebral body. On the outlet view, the entry point of the screw was located on the superior border of the acetabulum, pointing toward the S1 vertebra, passing through the S1 anterior sacral foramen and between the sacral alar slope (SAS). In the lateral view, when the screw entered the sacroiliac joint, the upper boundary should not exceed the iliac cortical density line and the SAS, and the lower boundary should not exceed the greater sciatic notch. After completing the planning, the robotic arm was maneuvered to the designated position, and a guide wire was inserted and measured for length before inserting the cannulated screw. (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFinally, to deal with the injury to the anterior pelvic ring. we adopt INFIX fixation of the anterior ring in patients with pubic branch fractures without significant displacement bilaterally; For patients with anterior unilateral superior pubic branch fractures without obvious displacement; we adopt closed reduction superior pubic ramus screws for fixation; If the displacement of the anterior ring fracture is obvious and the patient's general condition is good, we adopt incisional reduction plate fixation.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eTraditional sacroiliac screw group (Group B):\u003c/h2\u003e \u003cp\u003eWe treated iliac fractures in the same way as in group A.\u003c/p\u003e \u003cp\u003eNext, the traditional sacroiliac screw was placed with robotic assistance. Fluoroscopy was performed for planning the screw trajectories in the inlet, lateral, and outlet views of the pelvis. During planning, the entry point of the screw on the inlet view was located on the posterior-lateral aspect of the ilium, and the exit point was close to the anterior edge of the S1 vertebral body. On the outlet view, the entry point of the screw was located on the superior border of the acetabulum, pointing toward the S1 vertebra, passing through the S1 anterior sacral foramen and between the SAS. The safety of the screw placement was validated on the lateral image. After completing the planning, the robotic arm was maneuvered to the designated position, and a guide wire was inserted and measured for length before inserting the cannulated screw. (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe principle of management of the anterior pelvic ring was the same as that of Group A. INFIX, superior pubic ramus screws or plates were taken to treat the injury of the anterior pelvic ring according to the different characteristics of the patients.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003ePosterior treatment\u003c/h2\u003e \u003cp\u003eTo prevent deep vein thrombosis of the lower extremities, anticoagulants are routinely applied to all patients after surgery. Multi-angle radiographs (including pelvic front view, inlet view, and outlet views) and thin-layer CT (0.625 mm) were performed within one week after surgery. X-rays were routinely taken at 6 weeks, 3, 6, 12, and 24 months postoperatively, and patients were instructed on functional exercises by assessing their recovery. At 8 weeks postoperatively, patients were allowed to go down on crutches, and at 12 weeks postoperatively, patients were allowed to attempt to walk off the crutches, depending on the healing of the fracture.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eWe recorded the patient's gender, age, cause of injury, fracture classification (according to Tile classification), operative time, intraoperative bleeding, mode of fixation of the anterior pelvic ring, mode of fixation of the ilium, total length of the sacroiliac screw, length of the iliac segment of the sacroiliac screw versus that of the sacral segment, shortest distance between the sacroiliac screw entry point and the iliac fracture line, the quality of the sacroiliac joint's resurfacing, postoperative complications, and clinical prognosis.\u003c/p\u003e \u003cp\u003eThe length of the iliac segment of the sacroiliac screw was measured by measuring the maximum length of the long axis of the screw within the ilium on CT, and the length of the sacral segment of the screw was measured by measuring the maximum length of the long axis of the screw within the sacrum on CT (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). The Matta scoring system\u003csup\u003e[14]\u003c/sup\u003e was used to evaluate the quality of pelvic fracture reduction. The maximum displacement of the fracture on X-rays taken at three positions (pelvic front view, inlet view, and outlet views) within one week after surgery was used to assess the reduction quality: \u0026lt;4 mm was considered excellent, 4\u0026ndash;10 mm was considered good, 11\u0026ndash;20 mm was considered fair, and over 20 mm was considered poor. Functional outcome was assessed at the final follow-up using the Majeed scale\u003csup\u003e[15]\u003c/sup\u003e for pain level, ability to sit and stand, ability to work, sexuality, assisted ambulation, gait, and distance travelled, with scores of \u0026ge;\u0026thinsp;85 being excellent, 70\u0026ndash;84 being good, 55\u0026ndash;69 being acceptable, and \u0026lt;\u0026thinsp;55 being poor. And the pain visual analogue scale (VAS) was used to evaluate sacroiliac joint pain at the final follow-up.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAll statistical analyses were performed using the statistical software SPSS 22.0 (SPSS, Chicago, IL). Measurement data were determined by the Shapiro-Wilk test to determine whether they conformed to normal distribution, and conformity to normal distribution was expressed as the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation, and comparisons between groups were made using the independent samples t-test; count data were expressed as the frequency (n, %), and comparisons between groups were made using the chi-square test; The Mann-Whitney U test was used for comparison between groups. p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eThe differences in gender, age, cause of injury, fracture classification, operative time, fixation of the anterior pelvic ring and fixation of the iliac bone were not statistically significant (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e), so the two groups were comparable.\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\u003eDemographic data\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=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" 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\u003eProject\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup A(n\u0026thinsp;=\u0026thinsp;21)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup B(n\u0026thinsp;=\u0026thinsp;23)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\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 \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.592\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale, n(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13(61.9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16(69.6)\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\u003eFemale, n(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8(38.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7(30.4)\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\u003eMean age(岁)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42.6\u0026thinsp;\u0026plusmn;\u0026thinsp;5.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45.3\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.126\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMechanism of injury, n(%)\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=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.987\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=\"left\" colname=\"c2\"\u003e \u003cp\u003e12(57.1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13(56.5)\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\u003eInjury caused by falling from a height\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6(28.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7(30.4)\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\u003eCrush injury from a heavy object\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3(14.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3(13.0)\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\u003eTile classification, n(%)\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=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.896\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17(81.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20(87.0)\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\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4(19.0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3(13.0)\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\u003eOperating time(min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e77.9\u0026thinsp;\u0026plusmn;\u0026thinsp;13.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e79.0\u0026thinsp;\u0026plusmn;\u0026thinsp;16.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.805\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIntraoperative haemorrhage(ml)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e63.8\u0026thinsp;\u0026plusmn;\u0026thinsp;52.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e68.3\u0026thinsp;\u0026plusmn;\u0026thinsp;49.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.771\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFixation of anterior pelvic ring(cases)\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=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.980\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInfix\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13\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\u003eSuperior pubic ramus screws\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6\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\u003eSteel plate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4\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\u003eFixation of ilium (cases)\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=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLC-II screw\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18\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\u003eSteel plate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAll patients successfully completed the surgery, in which the total length of sacroiliac screws in group A and sacroiliac screws in group B were 9.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76cm and 8.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61cm, respectively, and the difference was not statistically significant (P\u0026thinsp;=\u0026thinsp;0.26).The mean iliac segment length of sacroiliac screws in group A was 3.83\u0026thinsp;\u0026plusmn;\u0026thinsp;1.05cm, which was longer than that of the control group, which was 2.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.60cm (P\u0026thinsp;\u0026lt;\u0026thinsp;0.01) The mean sacroiliac segment length of sacroiliac screws in group A and group B was 5.72\u0026thinsp;\u0026plusmn;\u0026thinsp;0.94cm and 6.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.85cm, respectively, with no statistically significant difference (P\u0026thinsp;=\u0026thinsp;0.066). The mean shortest distance from the iliac fracture line of the sacroiliac screw entry point in group A was longer than that in the control group (3.44\u0026thinsp;\u0026plusmn;\u0026thinsp;1.07cm vs. 0.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55cm, P\u0026thinsp;\u0026lt;\u0026thinsp;0.01) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\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\u003eComparison of sacroiliac screw data between the two groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTotal length of screw\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eLength of iliac segment of screw\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eLength of screw sacral segment\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eMinimum distance of the screw entry point from the iliac fracture line\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup A\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.85 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88 cm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup B\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.61cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.09\u0026thinsp;\u0026plusmn;\u0026thinsp;0.70 cm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.64 cm\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.001\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.057\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\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\u003e According to the pelvic X-ray results within one week after surgery, there were 12 cases with excellent quality of reduction, 7 cases with good quality, 2 cases with acceptable quality and no poor results in group A. There were 6 cases with excellent quality of reduction, 12 cases with good quality, 5 cases with acceptable quality and no poor results in group B. The quality of reduction in group A was better than that in group B (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). There was no statistically significant difference between the Majeed scores of the two groups at the final follow-up (P\u0026thinsp;=\u0026thinsp;0.568) (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e), with 13 cases of excellent, 6 cases of good, 2 cases of acceptable, and no poor results in group A, and 11 cases of excellent, 8 cases of good, 1 case of acceptable, and 1 case of poor results in group B. (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e,\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e,\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e). The VAS score of sacroiliac joint pain in group A at the last follow-up was 0 in 10 cases, \u0026lt;\u0026thinsp;3 in 7 cases, and 4\u0026ndash;6 in 4 cases, and 0 in 5 cases, \u0026lt;\u0026thinsp;3 in 8 cases, and 4\u0026ndash;6 in 10 cases in group B. The relief of sacroiliac joint pain in group A was better than that in group B (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e).\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\u003eComparison of the quality of reduction between the two groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eQuality of pelvic fracture reduction(%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003ez\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eExcellent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFair\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup A\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12(57.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7(33.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2(9.52)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e-2.055\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.040\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup B\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6(23.81)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e12(57.14)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5(19.05)\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\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\u003eComparison of prognosis between the two groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"4\" nameend=\"c6\" namest=\"c3\"\u003e \u003cp\u003eMajeed score at final follow-up (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003ez\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eExcellent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGood\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFair\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePoor\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup A\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13(61.90)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6(28.57)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2(9.52)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0(0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e-0.921\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.357\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup B\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11(47.82)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9(39.13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2(8.69)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1(4.35)\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\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison of VAS scores of sacroiliac joint pain between the two groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eGroup\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003en\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eSacroiliac joint pain VAS score (points)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003ez\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4\u0026ndash;6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup A\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10(47.62)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7(33.33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4(19.05)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e-2.031\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e0.042\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup B\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5(21.74)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8(34.78)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10(43.48)\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\u003eIn Group A, 2 patients developed deep vein thrombosis of the lower limbs after surgery, and 1 patient developed incision infection, with a complication rate of 14.29% (3/21), while in Group B, there were 2 cases of combined deep vein thrombosis of the lower limbs after surgery, 1 case of incision infection, and 1 patient's sacroiliac screw entered the sacral foramen without symptoms of nerve injury, with a complication rate of 17.39% (4/23). Meanwhile, in group B, there were 3 patients whose sacroiliac screw entry points were located in the iliac fracture line, and 1 of them was found to have lost resurfacing of the sacroiliac joint at follow-up, which fortunately did not have a significant impact on the patient's life and work, and therefore no further treatment was done, which was not found in group A.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eBurgess\u003csup\u003e[16]\u003c/sup\u003e and Man-son\u003csup\u003e[17]\u003c/sup\u003e classified pelvic ring injuries into 3 major categories based on the mechanism of injury: anterior-posterior compression (APC), lateral compression (LC), and vertical shear (VS). Day type II CFDP belong to the LC-II type of injury. Previous studies have mostly concluded that the ligaments in the lower part of the sacrum are not damaged and therefore only rotational instability exists and are stable in the vertical direction\u003csup\u003e[3, 18]\u003c/sup\u003e. However, Burgess\u003csup\u003e[16]\u003c/sup\u003e suggested that when the pelvis is subjected to vertically orientated violence, it is also capable of producing injuries similar to crescentic fractures, and on pelvic front view, the anterior half of the ilium can show significant vertical displacement. Zong et al.\u003csup\u003e[4]\u003c/sup\u003e used whether the sacroiliac joints were displaced in the vertical direction by more than 1 cm as a basis for determining whether the pelvis was stable in the vertical direction, and their study of 31 patients with CFDP found that 27 of them had rotational instability of the pelvis, and 4 of them had pelvic instability in the vertical direction. In the two groups of Day type II CFDP patients in this study, a total of 7 patients had significant vertical displacement of the sacroiliac joints, and we found that all 7 patients originated from traffic injuries, we believe this is due to the multidirectional, high-energy nature of the violence of traffic injuries, so the patients with Day II CFDP can also have vertical displacement of the pelvis. We performed preoperative supracondylar femoral traction in all of these patients, which had a certain effect on the resetting of sacroiliac joint subluxation, and intraoperatively, intraoperative attention should also be paid to the need for vertical traction repositioning when correcting rotational displacement\u003csup\u003e[19]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eXiang et al.\u003csup\u003e[20]\u003c/sup\u003e have been using percutaneous posterior iliac screws in combination with traditional sacroiliac screws to treat Day type II CFDP patients since 2005, and have achieved satisfactory results. In this study, a total of 35 patients' iliac fractures were fixed with LC-II screws, and we found that through appropriate reduction methods, most of the patients' iliac could be fixed with closed-replacement screws, thus reducing the trauma caused to the patients and promoting their early rehabilitation exercises. Sacroiliac screws are widely used for fixation of the posterior pelvic ring with its advantages of minimally invasive and biomechanical stability, but when we took traditional sacroiliac screws to treat Day type II CFDP patients, we found that the entry point of sacroiliac screws was located in the iliac fracture line in three patients, which resulted in our inability to use the screws to pressurize and fix the sacroiliac joints, and even internal fixation failure occurred. Moreover, from an anatomical point of view, the traditional sacroiliac screw has a short iliac segment channel, and the cancellous bone on both sides of the screw, which makes the screw holding force insufficient for elderly osteoporosis patients, and is prone to the \"pendulum effect\"\u003csup\u003e[8, 21]\u003c/sup\u003e. To address these shortcomings, we changed the trajectory of the traditional sacroiliac screw and proposed a modified sacroiliac screw channel. The inlet of this channel is located at the posterior superior margin of the acetabulum, and there are no important blood vessels or nerves in the surrounding area, which is a safer position for nail placement. The outlet is located at the medial side of the S1 superior articular process, which is similar to the entry point of the pedicle screw proposed by Roy-Camille, and it has been proved to be a safe position for pedicle screw fixation\u003csup\u003e[5]\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eMa et al.\u003csup\u003e[21]\u003c/sup\u003e conducted anatomical studies on a large number of normal 3D printed pelvises in a 1:1 ratio and proposed the existence of anterior-posterior sacroiliac screw channel. The inner wall of the channel is formed by the pelvic arcuate line, while the outer wall is composed of the posterior-lateral aspect of the sacral wing and the lateral aspect of the ilium. The superior wall is the SAS and the bottom of the greater pelvis, while the inferior wall is the line between the sacral foramen and the greater sciatic notch. In this study, postoperative CT of all patients in group A suggested that the modified sacroiliac screws were located in the bony channel, and none of them entered the acetabulum or sacral canal, which confirmed the safety of the modified sacroiliac screw channel. In this study, although the difference between the total length of the sacroiliac screws and the length of the sacral segment between the two groups was not statistically significant, the length of the iliac segment of the modified sacroiliac screws was longer than that of the traditional sacroiliac screws. Also, from an anatomical point of view, the iliac segments of the modified sacroiliac screws were encapsulated medially and laterally by cortical bone, which better provided stability of the posterior pelvic ring. Therefore, we believe that the biomechanical stability of the modified sacroiliac screw is superior to that of the traditional sacroiliac screw, and it is suitable for the fixation of the posterior pelvic ring in elderly osteoporotic patients. Meanwhile, the shortest distance from the entry point of the modified sacroiliac screw to the iliac fracture line in the ilium is much longer than that of the traditional sacroiliac screw, which effectively avoids the impossibility of pressurized fixation with the screw due to the fact that the entry point is located in the iliac fracture line.\u003c/p\u003e \u003cp\u003eFrom the comparison of the quality of reduction in the two groups, we found that the modified sacroiliac screw had better compression reduction effect on the dislocated sacroiliac joints under the premise of using the same reduction method. We believe that, on the one hand, the limited safe channel of conventional sacroiliac screws, especially in variant sacrum, where the safe channel of the screws is close to the posterior aspect of the sacroiliac joints, makes it difficult to provide good compression reset of anteriorly dislocated sacroiliac joints, on the other hand, the point of action of the modified sacroiliac screw is close to the most obvious position of sacroiliac joint dislocation, and although the screw trajectory is not completely perpendicular to the bone surface, it still has a better compression resetting effect on the dislocated sacroiliac joints(Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e). Although the difference in Majeed's functional scores at the final follow-up between the two groups was not statistically significant, the VAS scores of sacroiliac joint pain still showed that the modified sacroiliac screws were more effective than the conventional sacroiliac screws for fixation of sacroiliac joint dislocation.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn addition, the use of the intraoperative TiRobot navigation device was of great help, as it improved the accuracy of nail placement, greatly reduced the number of intraoperative fluoroscopies, and shortened the operative time.\u003c/p\u003e \u003cp\u003eIn clinical application, we also found several problems: 1. The sacral segment of the modified SIS is slightly shorter, and when the vertical pelvic shift is obvious, the S2 penetrating screw can be used to enhance fixation; 2.Fluoroscopy of the iliac wing front view is very important during intraoperative screw placement, as this image can not only prevent the LC-II screw from penetrating the inner or outer iliac plate but also clearly show whether the modified SIS breaks through the medial edge of the iliac bone and enters the pelvic cavity to avoid the \"in-out-in\" phenomenon with screws; 3.Intraoperative repositioning of the fracture is crucial, and the operator needs to have rich surgical experience in closed and incisional repositioning of pelvic fractures; 4.The sample size of the current study is limited, and there is a need for further expansion of the sample size and regular observation and follow-up in follow-up work to ensure the maturity and reliability of this technique.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe modified sacroiliac screw technique was used to treat the pelvic Day II crescent fracture dislocation, the screw entry point could effectively avoid the iliac fracture line, and the iliac segment of the modified sacroiliac screw was longer than that of the traditional sacroiliac screw, with the inner and outer sides being wrapped by the cortical bone, which had strong holding power, and it was able to achieve pressurized fixation more effectively and restore the stability of the pelvic ring, which compensated for the deficiencies of the traditional sacroiliac screw, and it is worth to promote the application of this technique in the clinical treatment.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCFDP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCrescent fracture dislocation of the pelvis\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSAS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003esacral alar slope\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eComputed tomography\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLateral compression\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAPC\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAnterior-posterior compression\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eVS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eVertical shear\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003eThis study was performed according to the Helsinki\u003c/p\u003e\n\u003cp\u003edeclaration and the study was approved by the ethics committee of Bengal Medical College (Number: BYYFY-2018YJS180)).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e Patients signed informed consent regarding publishing their data and photographs.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e No funding was received to assist with the preparation of this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e Min Wu and Renjie Li designed the study. Xiaopan Wang, Peishuai Zhao and Xiaotian Chen collected and analyzed the patient data. Min Wu and Jianzhong Guan performed the operation. Min Wu, Renjie Li and Leyu Liu analyzed the results and prepared the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e Not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatements\u0026nbsp;\u003c/strong\u003eAll methods were performed in accordance with the relevant guidelines and regulations.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eDAY A C, KINMONT C, BIRCHER M D, et al. Crescent fracture-dislocation of the sacroiliac joint: a functional classification [J]. Journal of Bone \u0026amp; Joint Surgery-british Volume, 2007, 89(5): 651-8.\u003c/li\u003e\n\u003cli\u003eBORRELLI J, KOVAL K J, HELFET D L. Operative stabilization of fracture dislocations of the sacroiliac joint [J]. Clin Orthop Relat Res, 1996, 329(329): 141-6.\u003c/li\u003e\n\u003cli\u003eCAI L, ZHANG Y, ZHENG W, et al. A novel percutaneous crossed screws fixation in treatment of Day type II crescent fracture\u0026ndash;dislocation: A finite element analysis [J]. Journal of Orthopaedic Translation, 2020, 20.\u003c/li\u003e\n\u003cli\u003eZONG Z, CHEN S, JIA M, et al. Posterior iliac crescent fracture-dislocation: is it only rotationally unstable? [J]. Orthopedics, 2014, 37(5): e435-40.\u003c/li\u003e\n\u003cli\u003eMENON K V, SURESH S S, KALYANASUNDARAM S, et al. Crescent fractures of the pelvis treated by open reduction and internal fixation: a critique of Day's guidelines [J]. European Journal of Orthopaedic Surgery \u0026amp; Traumatology, 2017.\u003c/li\u003e\n\u003cli\u003eBAI Z, GAO S, LIU J, et al. Anatomical evidence for the anterior plate fixation of sacroiliac joint [J]. J Orthop Sci, 2018, 23(1): 132-6.\u003c/li\u003e\n\u003cli\u003eSTARR A J, WALTER J C, HARRIS R W, et al. Percutaneous Screw Fixation of Fractures of the Iliac Wing and Fracture-dislocations of the Sacro-iliac Joint (OTA Types 61-B2.2 and 61-B2.3, or Young-Burgess \"Lateral Compression Type II\" Pelvic Fractures) [J]. Journal of Orthopaedic Trauma, 2002, 16(2): 116-23.\u003c/li\u003e\n\u003cli\u003eTAKAO M, HAMADA H, SAKAI T, et al. Clinical Application of Navigation in the Surgical Treatment of a Pelvic Ring Injury and Acetabular Fracture [J]. Advances in experimental medicine and biology, 2018.\u003c/li\u003e\n\u003cli\u003eCIOLLI G, CAVIGLIA D, VITIELLO C, et al. Navigated percutaneous screw fixation of the pelvis with O-arm 2: two years' experience [J]. Medicinski glasnik : official publication of the Medical Association of Zenica-Doboj Canton, Bosnia and Herzegovina, 2021, 18(1): 309-15.\u003c/li\u003e\n\u003cli\u003eXIANG G, DONG X, JIANG X, et al. Comparison of percutaneous cross screw fixation versus open reduction and internal fixation for pelvic Day type II crescent fracture-dislocation: case-control study [J]. BioMed Central, 2021, (1).\u003c/li\u003e\n\u003cli\u003eO?BRIEN J R, MATTEINI L, YU W D, et al. Feasibility of minimally invasive sacropelvic fixation: percutaneous S2 alar iliac fixation [J]. Spine, 2010, 35(4): 460-4.\u003c/li\u003e\n\u003cli\u003eCHANG T L. Low profile pelvic fixation: anatomic parameters for sacral alar-iliac fixation versus traditional iliac fixation [J]. Spine, 2009, 8(5).\u003c/li\u003e\n\u003cli\u003eSHABTAI L, ANDRAS L M, PORTMAN M, et al. Sacral Alar Iliac (SAI) Screws Fail 75% Less Frequently Than Iliac Screws in Neuromuscular Scoliosis [J]. Journal of Pediatric Orthopedics, 2016, 137(Supplement 3).\u003c/li\u003e\n\u003cli\u003eMATTA J M. Fracture of the acetabulum: accuracy of reduction and clinical results in patients managed operatively within three weeks after the injury [J]. Orthopedic Trauma Directions.\u003c/li\u003e\n\u003cli\u003eMAJEED S A. Grading the outcome of pelvic fractures [J]. The Bone \u0026amp; Joint Journal, 1989, 71(2): 304-6.\u003c/li\u003e\n\u003cli\u003eBURGESS A R, EASTRIDGE B J, YOUNG J W, et al. Pelvic ring disruptions: effective classification system and treatment protocols [J]. Journal of Trauma, 1990, 30(7): 848-56.\u003c/li\u003e\n\u003cli\u003eMANSON T, O?TOOLE R V, WHITNEY A, et al. Young-Burgess classification of pelvic ring fractures: does it predict mortality, transfusion requirements, and non-orthopaedic injuries? [J]. Journal of Orthopaedic Trauma, 2010, 24(10): 603-9.\u003c/li\u003e\n\u003cli\u003eBACHHAL V, JINDAL K, RATHOD P M, et al. Bilateral crescent fracture-dislocation of the sacroiliac joint: a case-based discussion and review of literature [J]. International journal of burns and trauma, 2021, 11(3): 260-6.\u003c/li\u003e\n\u003cli\u003eFRANCK A, PILTZ S. The surgical treatment of unstable osteoporotic pelvic ring fractures with bilateral vertebropelvic stabilization using a less invasive technique [J]. Revue de chirurgie orthopediqueet traumatologique, 2022.\u003c/li\u003e\n\u003cli\u003eXIANG G, DONG X, JIANG X, et al. Comparison of percutaneous cross screw fixation versus open reduction and internal fixation for pelvic Day type II crescent fracture-dislocation: case-control study [J]. Journal of Orthopaedic Surgery and Research, 2021, 16(1).\u003c/li\u003e\n\u003cli\u003eMA Y, WANG J, YIN Q, et al. Effect of Iliosacral Screw Implantation Through a New Channel in Three-Dimensional Printing Pelvic Model [J]. Indian Journal of Orthopaedics, 2021: 1-5.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Pelvic fracture, Sacroiliac joint, Fracture fixation","lastPublishedDoi":"10.21203/rs.3.rs-4817453/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4817453/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eWhen the traditional sacroiliac screw is used in the treatment of Day type II crescent fracture dislocation of the pelvis, the screw entry point may be located near the fracture line and lead to the failure of screw pressurization, and at the same time, the short channel of the iliac segment of the screw has defects such as insufficient holding power. This study proposes a modified sacroiliac screw technique and investigates the value of the modified sacroiliac screw in the treatment of Day type II crescentic fracture dislocations of the pelvis.\u003c/p\u003e\u003ch2\u003eMETHODS\u003c/h2\u003e \u003cp\u003eWe retrospectively analyzed 44 patients with pelvic Day type II crescent fracture dislocations who underwent surgical treatment from January 2019 to June 2023 in our hospital. They were divided into two groups according to the sacroiliac screws for comparative study. We compared the gender, age, cause of injury, fracture classification, time from injury to surgery, intraoperative bleeding, anterior ring fixation method, iliac fixation method, total length of sacroiliac screw, length of iliac and sacral segments of sacroiliac screw, shortest distance from the sacroiliac screw entry point to iliac fracture line, quality of reduction, postoperative complications, and clinical prognosis of the patients in the two groups.\u003c/p\u003e\u003ch2\u003eRESULTS\u003c/h2\u003e \u003cp\u003eFollow-up was obtained in all patients, and the differences between the two groups in terms of gender, age, cause of injury, fracture classification, time from injury to surgery, intraoperative bleeding, and fixation method of the anterior ring and ilium were not statistically significant (P\u0026thinsp;\u0026gt;\u0026thinsp;0.05). The average length of the iliac segment of sacroiliac screws in group A was 3.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.85 cm, which was significantly longer than that in the control group (2.12\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47 cm, P\u0026thinsp;\u0026lt;\u0026thinsp;0.01).The shortest distance between the entry point of sacroiliac screws and the iliac fracture line in group A was 3.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.88 cm, which was significantly longer than that in the control group (1.22\u0026thinsp;\u0026plusmn;\u0026thinsp;0.64 cm, P\u0026thinsp;\u0026lt;\u0026thinsp;0.01). The quality of fracture reduction was assessed according to the Matta score based on the pelvic X-ray results in the first week after surgery: group A: 12 cases with excellent results, 7 cases with good results, 2 cases with acceptable results, and no poor results; group B: 6 cases with excellent results, 12 cases with good results, 5 cases with acceptable results, and no poor results; the quality of reduction in group A was better than that in group B (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05). The VAS score of sacroiliac joint pain at the last follow-up was 0 in 10 patients, \u0026lt;\u0026thinsp;3 in 7 patients, and 4\u0026ndash;6 in 4 patients in Group A. In Group B, there were 5 patients with a score of 0, 8 patients with a score of \u0026lt;\u0026thinsp;3, and 10 patients with a score of 4\u0026ndash;6. The relief of sacroiliac joint pain in Group A was better than that in Group B. (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05)\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eWhen the modified sacroiliac screw is used to treat Day type II crescent fracture of the pelvis, the screw entry point can avoid the iliac fracture line, and at the same time, the screw channel is long and the holding force is stronger than that of the traditional sacroiliac screw, which is worthy of popularization and application in the clinic.\u003c/p\u003e","manuscriptTitle":"A study of the modified sacroiliac screw technique in Day type II crescent fracture dislocation of the pelvis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-09-02 19:05:14","doi":"10.21203/rs.3.rs-4817453/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"97fbd326-1209-4dbc-81f0-62d06749d819","owner":[],"postedDate":"September 2nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-10-22T14:23:32+00:00","versionOfRecord":[],"versionCreatedAt":"2024-09-02 19:05:14","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4817453","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4817453","identity":"rs-4817453","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}