Efficacy of the Cross-Union Protocol in the Treatment of Congenital Tibial Pseudarthrosis: A Comparative Study

Efficacy of the Cross-Union Protocol in the Treatment of Congenital Tibial Pseudarthrosis: A Comparative Study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Efficacy of the Cross-Union Protocol in the Treatment of Congenital Tibial Pseudarthrosis: A Comparative Study Yanhui Jing, Dahui Wang, zhiqiang Zhang, Yueqiang Mo, Bo Ning, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5206533/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 02 Jan, 2025 Read the published version in BMC Musculoskeletal Disorders → Version 1 posted 11 You are reading this latest preprint version Abstract Background Congenital Pseudarthrosis of the Tibia (CPT) is a rare pediatric condition presenting substantial challenges for orthopedic surgeons aiming to achieve bone union, with subsequent complications such as refractures being common. The aim of the present study is to evaluate the results of our intentional cross-union protocol and to compare these outcomes with those obtained from our previously used techniques. Materials and Methods Sixteen patients, with a mean age of 4.8 years (range: 1-13.3 years), who were treated with the intentional cross-union protocol were included in Group A. Eleven patients, with a mean age of 3.5 years (range: 1.3-7.6 years), who primarily underwent intramedullary rodding with bone graft, were included in Group B. The intentional cross-union protocol involved cross-union of the tibia and fibula, autogenous iliac bone grafting, and the insertion of bone morphogenetic protein 2 (BMP-2) aimed at achieving tibia-fibula cross-union. Retrospective evaluation of serial radiographs was conducted, and the outcomes regarding union and any subsequent complications were analyzed. Results A total of 27 patients with CPT were included in the study. All 16 patients (100%) in Group A successfully achieved primary union. Among the 11 patients in Group B, only 4 cases achieved primary union, with a primary healing rate of 36.4%. Seven cases with delayed healing required 2-4 revision surgeries for final healing. The time to union was significantly shorter in Group A (3.37 ± 0.64 months) compared to Group B (8.67 ± 3.0 months). The cross-sectional area of union was also significantly larger in Group A (6.71 ± 0.58 cm²) compared to Group B (1.18 ± 0.19 cm²). In Group A, there were no cases of refracture, whereas in Group B, 7 cases (77.8%) experienced refracture, indicating a statistically significant difference. Conclusions Our study demonstrates that the Cross-union protocol is highly effective for achieving union and preventing refracture in CPT. With such significant improvement, it has notably altered the prognosis of this challenging condition. Level of Evidence: IV congenital pseudarthrosis of the tibia cross-union surgery child complication Figures Figure 1 Figure 2 Figure 3 Introduction CPT is a comparatively rare disorder, occurring in approximately 1 in 140,000 to 1 in 250,000 live births[ 1 , 2 ]. It is estimated that 50–90% of children with CPT are associated with Neurofibromatosis[ 1 , 3 ]. The clinical characteristics of CPT primarily include the abnormal development of certain tibial segments, leading to hindered osteogenesis. This results in tibial angulation deformities, pathological fractures, and nonunions, which significantly impact both appearance and functionality. Successfully treating CPT poses a considerable challenge. Currently, treatment outcomes vary widely across different regions and methodologies, and most are unsatisfactory. Children with CPT still face the risks of delayed healing, recurrent fractures, and in some cases, even amputation[ 4 , 5 ]. Surgical intervention is the only effective treatment, aimed at achieving and maintaining bone union of pseudarthrosis for a long time, restoring normal tibial alignment, and preventing complications like refracture, proximal tibia valgus, ankle valgus, and limb length discrepancy, while maximizing limb function preservation[ 6 – 8 ]. Choi (2011) and Paley (2012) published methods to intentionally create a cross-union in the treatment of CPT and discussed its advantages and higher success rate[ 9 , 10 ]. Paley's combination treatment involves an intentional cross-union between the tibia and fibula, autogenous iliac bone grafting, reliable internal fixation, zoledronic acid infusion, and bone morphogenic protein 2 (BMP-2) insertion. This method creates a favorable biological environment for bone healing, provides a wider and stronger area for bone healing at the pseudarthrosis site, improves the stability of the tibia and fibula, and reduces the risk of subsequent refracture[ 11 ]. Since 2018, our team has been utilizing the cross-union method to treat CPT. This retrospective study seeks to assess the outcomes of our intentional cross-union protocol and compare them with the results from our previously used techniques. Methods and Materials This was a retrospective observational study.The study included patients who were diagnosed and treated for CPT at our institution, with a requirement for a minimum of two years of follow-up after the index surgery. The index surgery was defined as the first surgical intervention conducted at our institute. For this retrospective analysis, data were collected using a standardized form from our hospital’s records. Prior to initiating the study, approval was obtained from both the hospital's review board and the Ethics Committee of the Children’s Hospital of Fudan University. Patients lacking complete documentation or radiographic evidence, as well as those not meeting the follow-up duration criteria, were not included. In total, 27 patients who had undergone surgical treatment for CPT at our hospital between 2010 and 2022 were reviewed. Among these patients, 11 who underwent surgery between 2010 and 2018, involving pseudarthrosis excision and intramedullary (IM) rodding combined with bone grafting, were categorized into Group B. In contrast, the remaining 16 patients, treated from 2018 to 2022 using the cross-union technique, were classified into Group A. Surgical Technique Group A An anterior curvilinear incision is made to expose the site of the pseudarthrosis (Fig. 1 A). The interosseous membrane and deep fascia are divided to expose the tibia and fibula. The hamartomatous periosteum, sclerotic bone, and surrounding pathological soft tissues are meticulously excised circumferentially (Fig. 1 B). Careful dissection is performed to protect the posterior tibial neurovascular bundle. The tibial bowing is straightened, and the medullary canal is opened from proximally to distally. The tibia is then fixed with an appropriately sized telescopic rod and a locking compression plate to ensure immobilization. The distal end of the telescopic growing rod is positioned within the distal tibial physis, taking care to avoid crossing the ankle or subtalar joints. If the fibula is malformed or presents with pseudarthrosis, the abnormal periosteum, sclerotic bone, surrounding pathological soft tissues, and the interosseous membrane are also removed (Fig. 1 C). The fibula is then fixed with an intramedullary (IM) K-wire. The bone grafts are harvested from three sources:(1)Cancellous graft are obtained from the ilium and the supra-acetabular area above the tri-radiate cartilage (Fig. 1 D).(2) An outer rectangular cortical segment is cut from the inner table of the iliac bone(Fig. 1 E).༈3༉The lateral periosteum is separated from the overlying muscle.The harvested iliac periosteum is used to cover the area surrounding the resection site of the pseudarthrosis in both the tibia and fibula. The harvested cortical graft is placed along the posterior surface of the tibia and fibula to separate the implanted bones from the neurovascular bundles behind (Fig. 1 F,See the blue arrow). The cancellous graft, mixed with BMP-2, is placed in the interosseous space (Fig. 1 G, See the blue arrow). The surgical wounds are then closed. Postoperative Management After surgery, negative pressure drainage and long leg plaster support were applied. Regular dressing changes were emphasized to prevent flap necrosis and compartment syndrome. The cast was replaced two weeks post-operation following wound healing. Postoperatively, the pseudarthrosis site was reviewed monthly until initial healing. Union is deemed to be achieved when there is continuity between the bony trabeculae of the proximal and distal segments in at least three cortices on both anteroposterior and lateral radiographic views. Outcome Analysis The study evaluated several outcome measures, including the primary union rate (defined as successful union following the initial surgery) and the number of surgeries required to achieve union. The cross-sectional area of union was calculated by multiplying the minimum diameters of the fusion mass observed in both anteroposterior and lateral radiographic views. Long-term outcomes assessed included the incidence of refractures, the lower limb alignment in the coronal plane, and any limb length discrepancies noted at the final follow-up. Complications were classified into two categories: minor and major. Minor complications were defined as those that did not require additional surgery or could be managed with minor interventions through outpatient care. Major complications were those that necessitated inpatient surgical intervention and had a negative impact on the ultimate surgical outcome. Statistical Methods Data were analyzed using SPSS version 19.0 statistical software. Quantitative data were presented as mean ± standard deviation (x̄ ± s), and intergroup comparisons were performed using independent samples t-tests. Categorical data were presented as numbers and percentages, and intergroup comparisons were conducted using chi-square (χ²) tests or Fisher's exact test. A p-value < 0.05 was considered statistically significant. Results All patients were followed up. There were 10 males and 6 females in Group A; 9 cases on the left and 7 cases on the right; 2 Crawford type III, and 14 type IV. The average age at the time of operation was 4.8 ± 2.78 months. Eleven cases were associated with neurofibromatosis type 1 (NF1). There were 5 males and 6 females in Group B; 3 on the left and 8 on the right; 3 Crawford type III, and 8 type IV. The average age at the time of surgery was 3.5 ± 1.93 months. Four cases were associated with NF1. The two groups were well-matched in terms of sex,age, type of CPT,the incidence of neurofibromatosis type 1 and associated fibula. The follow-up time for Group B was 78.45 ± 15.7 months, which is longer than the follow-up time for Group A, which was 45.31 ± 18.07 months (Table 1 ). Table 1 Demographic Data in Two Groups Characteristic Group A (Cross-union protocol) Group B (Previous protocol) P -value Age at index surgery (years) 4.8 ± 2.78 (2.0-13.3) 3.5 ± 1.93 (1.3–7.6) 0.165 Crawford classification 0.3705 Type III 2 3 Type IV 14 8 Side 0.202 Left 9 3 Right 7 8 Association with NF-1 11(68.8%) 4(36.4%) 0.1302 Associated fbula dysplasia 9 (56.3%) 7(63.6%) 0.368 Sex distribution 0.451 Male 10 5 Female 6 6 Number of previous surgeries 0.178 0 6 6 1 3 3 2 4 1 3 3 1 Total followup (months) 45.31 ± 18.07(24–70) 78.45 ± 15.7(48–105) < 0.0001 # NF-1 = Neurofibromatosis type 1 #=Statistically significant All 16 cases in Group A successfully completed the cross-union surgery and internal fixation with telescopic rod and plates. All of them achieved primary healing following their first cross-union surgery, with a primary union rate of 100%, and an average healing time of 3.37 ± 0.64 months. The cross-sectional area of union was 6.71 ± 0.58 cm². At the final follow-up, the medial proximal tibial angle was mildly increased in 5 patients, but it did not exceed 95°. Five cases (31%) had residual tibial valgus in the range of 10–20°. Nine cases (56%) had unequal tibia length, with an average difference of 3.2 ± 1.9 cm (range: 1.2 to 7 cm) (Table 2 ). None had refracture (Typical cases are shown in Figs. 2 and 3 ). Table 2 Comparative Outcomes Between Groups Outcome Measure Group A (Cross-union) Group B (Previous Protocol) P -value Primary union rate 16/16(100%) 4/11(36.4%) 0.0004 # Time to union (months) 3.37 ± 0.64(2.5-5) 8.67 ± 3.0(6–18) 0.001 # Number of surgeries to achieve union 1 2.1 ± 1.12(1–4) 0.0024 # Cross-sectional area of union (cm²) 6.71 ± 0.58 (2.25–8.41) 1.18 ± 0.19 (0.88–1.44) < 0.0001 # Refracture rate 0/16 7/11(63.6%) < 0.0001 # Knee, tibia, and ankle alignment at final follow-up MPTA (°) 90.5 ± 2.6 89.7 ± 3.9 0.36 LDTA (°) 89.4 ± 5.08 88.32 ± 4.83 0.57 MPTA = Media 3.2 ± 1.9 2.5 ± 2.5 0.24 MPTA = Medial proximal tibial angle, LDTA = Lateral distal tibial angle #=Statistically significant In Group B, the index surgery for the 11 patients involved IM rodding and onlay grafting. Among these, seven cases also utilized Ilizarov external fixation.Out of the 11 patients in Group B, four achieved primary healing, resulting in a primary healing rate of 36.4%. Seven cases with delayed healing required 2–4 revision surgeries for final healing. The average healing time was 8.67 ± 3.0 months. The cross-sectional area of union was 1.18 ± 0.19 cm². Seven cases (64%) had unequal tibia length, with an average difference of 2.5 ± 2.5 cm (range: 1.8–6.4 cm). Three cases (27%) presented with ankle valgus, with Lateral Distal Tibial Angles (LDTA) measuring 75°, 79°, and 80°.Proximal tibial valgus occurred in 2 cases (18%) with Medial Proximal Tibial Angle (MPTA) measuring 95° and 97° (Table 2 ). There was one case of skin necrosis requiring debridement and skin grafting in Group A, and no incidence of refractures. There were four cases of pin-site infections in Group B, which resolved with intravenous (IV) antibiotics. Seven cases (64%) experienced refractures that required surgical intervention; of these, five ultimately underwent a cross-union protocol to ensure proper healing. Discussion CPT is a rare and clinically diverse condition, posing significant challenges to pediatric orthopedic surgeons. The spectrum of presentations ranges from simple anterolateral bowing deformity to pronounced nonunion accompanied by extensive bone defects. To date, there remains no consensus on the optimal treatment approach for CPT, as evidenced by references [ 1 , 12 ]. Over the past three decades, a wide array of surgical techniques have been investigated. These methods include intramedullary (IM) rodding combined with bone grafting, Ilizarov external fixation, a combination of the Ilizarov technique and bone grafting, free vascularized fibular grafting, and, in certain cases, amputation. Paley [ 13 ] conducted a meta-analysis of union, refracture, and success rates (defined as union without refracture) across 25 published studies from 1990 to 2018. The studies were categorized into four main treatment groups: (1) rodding, which included 10 studies involving 196 patients; (2) the Ilizarov technique, which included 6 studies with 115 patients; (3) a combination of Ilizarov and rodding, which included 5 studies with 152 patients; and (4) free vascularized fibular graft, which included 4 studies with 84 patients. The primary union rates were 61% for the rodding group, 93.5% for the Ilizarov group, 72% for the combined Ilizarov and rodding group, and 66% for the vascularized fibula group. The refracture rates were 24% for rodding, 41% for the Ilizarov technique, 17% for the combined Ilizarov and rodding group, and 11% for the vascularized fibular graft group. Our initial results using the conventional technique of pseudarthrosis excision, IM rodding, and onlay cortical bone graft were unsatisfactory, with primary union achieved in only 4 out of 11 patients (36.4%). In Group B, the average number of surgeries required to achieve union was 2.1, and the average time from the primary surgery to union was 8.67 months, leading to considerable morbidity. In 2011, Choi et al. [ 9 ] suggested the use of a cross-union between the tibia and fibula for CPT, specifically in cases where the fibula was fractured but minimally proximally migrated. They described a technique called "4-in-1 Osteosynthesis," where the two fibula bone ends were aligned toward the tibia bone ends. This approach increased the effective bone area at the pseudarthrosis site, thereby enhancing the load-bearing capacity of both the tibia and fibula. They reported on eight patients treated at an average age of 6.3 years, all of whom achieved union with the cross-union to the fibula. No refractures occurred during an average follow-up of 7.4 years (range 2.7–12.4 years).However, a notable limitation of this technique is the potential for ankle valgus, as the proximal and distal ends of the fibula can become curved and close to the tibia. Additionally, inserting the tibial internal fixation nail from the distal to the proximal end, passing through the subtalar and ankle joints, may impede ankle joint movement. Paley published a large-sample study on the cross-union protocol with external fixation in 2017[ 13 , 14 ]. Primary union and cross-union were achieved in all 17 patients (100%) during the index procedure. The mean radiographic union time was 4 months, ranging from 1.5 to 6 months. Notably, none of these patients experienced refractures. Since 2018, we have chosen to use Paley's technique for the cross-union of the tibia and fibula. However, we have made some modifications to the grafting approach. The Paley cross-union protocol uses only autogenous cancellous bone as the graft material. We found that when placing cancellous bone in the gap between the tibia and fibula, it can be obstructed by the posterior muscle tissue. Therefore, we harvested a rectangular cortical graft from the iliac crest and placed it in front of the muscle tissue within the tibiofibular gap. This approach helps prevent the displacement of the grafted cancellous bone, increases its thickness, and enhances the stability of the grafted area. The most severe complication after healing in CPT is refracture. Maximizing the cross-sectional area of healing at the pseudarthrosis site is one of the most critical principles of treatment, as it helps prevent refracture [ 15 , 16 ]. A tibia with a larger cross-sectional area can better withstand mechanical stress, and the "cross-union" surgery appears to meet this essential criterion.In our study, the larger cross-sectional area of union in Group A (6.71 ± 0.58 cm²) compared to Group B (1.18 ± 0.19 cm²) suggests that the cross-union protocol leads to stronger and more stable unions. No patients in Group A experienced refractures, whereas 7 out of 11 patients (63.6%) in Group B did (p < 0.0001). The adjunctive use of a tibial telescopic rod offers enhanced stability. As a form of center-based internal fixation, the telescopic rod (TR) is capable of maintaining the tibia's mechanical axis, adapting to the child's growth, and serving as a continuous preventive measure against refractures. This principle aligns with the rationale for using flexible dynamic (FD) devices in the management of osteogenesis imperfecta [ 17 ]. All of these factors highlight the long-term stability and effectiveness of the cross-union protocol in preventing refractures. Currently, similar results have been reported in accounts of the cross-union protocol. Shannon et al. (2021) [ 18 ] reported on 39 cases of CPT treated using the cross-union protocol with all internal fixation. All 39 cases achieved union at the tibia and developed a cross-union to the fibula, with no refractures observed during the follow-up period of up to 7 years (range: 24–85 months). Wu et al. (2022) [ 19 ] described 18 patients with refractory CPT treated using the Paley cross-union protocol with all internal fixation. All 18 patients achieved union, and none experienced refractures during a mean follow-up of 4.3 years (range: 1.5–6.3 years). In our group, 16 patients with CPT underwent treatment by cross-union protocol. All patients (100%) obtained primary union at the pseudarthrosis site. During a mean follow-up of 45.31 months, the primary union and refracture rate in our patients (100% union, 0% refractures) were consistent with those reported in existing literature [ 11 , 18 , 19 ]. Ankle valgus has been reported after several surgical procedures for CPT in previous studies. In Group A, 5 (31%) cases had residual tibial valgus ranging from 10–20° at the final follow-up. This condition is regarded to be linked to insufficient lateral support provided by the shortening or bone defect of the fibula, a view supported by Vanderstappen's observations [ 20 ], which highlighted that patients with fibular pseudarthrosis often exhibit this complication. Dobbs et al. [ 21 ] also found a high incidence of ankle valgus in patients with fibular pseudarthrosis in their long-term follow-up study. In the cross-union protocol, the tibia was secured using a telescopic growing rod, while the fibula was fixed with K-wires, maintaining a normal interosseous distance between the two bones and reducing the incidence of ankle valgus. The telescopic rod in the tibia is inserted from the proximal end to the distal end, avoiding the ankle and subtalar joints and thus preserving ankle mobility [ 18 ]. In this group, 9 cases (56.3%) had pre-existing fibular pseudarthrosis, which likely contributed to the high incidence of ankle valgus. The Lateral Distal Tibial Angle (LDTA) was 89.4° ± 5.08° in Group A, compared to 88.32° ± 4.83° in Group B (p = 0.57), indicating no significant statistical difference. Future studies may require larger sample sizes to demonstrate the advantages of cross-union surgery in improving knee, tibia, and ankle malalignment. There are a few limitations to our study. First, the current sample size is still relatively small, and the follow-up duration is relatively short; longer follow-up would be needed to comment on the occurrence of late complications. Second, we did not examine functional outcomes. Further quantification and analysis of motor function should be included in subsequent studies. Conclusions Our study demonstrates that the Cross-union protocol, although demanding, is highly effective for achieving union and preventing refracture in CPT. With such significant improvement, it has notably altered the prognosis of this challenging condition. Abbreviations CPT congenital pseudarthrosis of the tibia LLD limb length discrepancy NF1 neurofibromatosis type 1 Declarations Ethics approval and consent to participate Our study was approved by The Ethics Committee approval of Children’s hospital of Fudan university and conducted according to the Helsinki Declaration and its later amendments. Informed consent was obtained from all patients’ parents who participated in this study. Consent for publication All participants were informed about the purpose of the study and informed consent was obtained for all patient images from a parent and/or legal guardian. Availability of data and material The datasets generated and/or analysed during the current study are not publicly available due to limitations of ethical approval involving the patient data and anonymity but are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding Supported by the National Natural Science Foundation of China(nos.82272441) and Technology Commission of Shanghai Municipality (CN) (nos.22Y11912200). Authors ’ contributions YH J made substantial contributions to the conception, reviewed the case, collected the data, carried out the initial analyses, and drafted the initial manuscript. CX W, ZQ Z and DH W reviewed the case, collected the data and B N performed the surgeries. YQ M and B N coordinated and supervised data collection, and critically reviewed the manuscript. All authors read and approved the final manuscript. Clinical trial number Not applicable Acknowledgements Not applicable References Grill, F.; Bollini, G.; Dungl, P.; Fixsen, J.; Hefti, F.; Ippolito, E.; Romanus, B.; Tudisco, C.; Wientroub, S. Treatment Approaches for Congenital Pseudarthrosis of Tibia: Results of the EPOS Multicenter Study. J. Pediatric Orthop. Part B 2000, 9, 75–89. Crawford AH, Schorry EK. Neurofibromatosis in children: The role of the orthopaedist. J Am Acad Orthop Surg 1999;7:217-30. Shah H, Doddabasappa SN, Joseph B. Congenital pseudarthrosis of the tibia treated with intramedullary rodding and cortical bone grafting: a follow-up study at skeletal maturity. J Pediatr Orthop. 2011;31(1):79-88. doi:10.1097/BPO.0b013e318202c45d. Inan M, El Rassi G, Riddle EC, Kumar SJ. 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Choi IH, Lee SJ, Moon HJ, et al. “4-in-1 osteosynthesis” for atrophictype congenital pseudarthrosis of the tibia. J Pediatr Orthop. 2011; 31:697–704. Paley D. Congenital pseudarthrosis of the tibia: combined pharmacologic and surgical treatment using biphosphonate intravenous infusion and bone morphogenic protein with periosteal and cancellous autogenous bone grafting, tibio-fibular cross union, intramedullary rodding and external fixation. In Zorzi A (ed.), 2012: 91-106; InTech, Available from: https:// www.intechopen.com/books/bone-grafting/treatment-of-congenital-pseudarthrosiswith-periosteal-and-cancellous-bone-grafting- Packer D, Robb J, Liu R, Robbins C, Paley D. Combined pharmacologic and biological treatment of congenital pseudoarthrosis of the tibia; 100 % union; no refractures! J Child Orthop 2016;10:S19-S20 Kesireddy, N.; Kheireldin, R.K.; Lu, A.; Cooper, J.; Liu, J.; Ebraheim, N.A. Current treatment of congenital pseudarthrosis of the tibia: A systematic review and meta-analysis. J. Pediatr. Orthop. B 2018, 27, 541–550 Paley, D. Congenital pseudarthrosis of the tibia: Biological and biomechanical considerations to achieve union and prevent refracture. J. Child. Orthop. 2019, 13, 120–133. Paley D. Congenital pseudarthrosis of the tibia. In: Current Progress in Orthopaedics.Johari A and Waddell J (eds). Mumbai: Tree Life Media; 2017:318-348. Choi IH, Cho T-J, Moon HJ. Ilizarov treatment of congenital pseudarthrosis of the tibia. A multi-targeted approach using the Ilizarov technique. Clin Orthop Surg. 2011;3:1–8. Cho T-J, Choi IH, Lee SM, et al. Refracture after Ilizarov osteosynthesis in atrophic-type congenital pseudarthrosis of tibia. J Bone Joint Surg Br. 2008;90:488–493. Fassier, F.R. Osteogenesis imperfecta. In Pediatric Lower Limb Deformities; Springer: Berlin/Heidelberg, Germany, 2016;pp. 255–265. Shannon CE, Huser AJ, Paley D. Cross-Union Surgery for Congenital Pseudarthrosis of the Tibia. Children (Basel). 2021;8(7):547. doi:10.3390/children8070547 Wu C, Zheng G, Wang D, Paley D, Ning B. Combination Treatment by Cross-Union of the Tibia and Fibula, Autogenic Iliac Bone Grafting, Reliable Fixation and Bone Morphogenetic Proteins for the Treatment of Refractory Congenital Pseudarthrosis of the Tibia. J Pediatr Orthop. 2022;42(6):e623-e629. doi:10.1097/BPO.0000000000002138 Vanderstappen J, Lammens J, Berger P, Laumen A. Ilizarov bone transport as a treatment of congenital pseudarthrosis of the tibia: a long-term follow-up study. J Child Orthop. (2015) 9(4):319–24. doi: 10.1007/s11832-015-0675-7 Dobbs MB, Rich MM, Gordon JE, Szymanski DA, Schoenecker PL. Use of an intramedullary rod for treatment of congenital pseudarthrosis of the tibia. A long-term follow-up study. J Bone Joint Surg Am. (2004) 86(6):1186–97. doi: 10.2106/00004623-200406000-00010 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 02 Jan, 2025 Read the published version in BMC Musculoskeletal Disorders → Version 1 posted Editorial decision: Revision requested 03 Dec, 2024 Reviews received at journal 03 Dec, 2024 Reviewers agreed at journal 03 Dec, 2024 Reviews received at journal 23 Nov, 2024 Reviewers agreed at journal 11 Nov, 2024 Reviewers agreed at journal 06 Nov, 2024 Reviewers invited by journal 30 Oct, 2024 Editor invited by journal 10 Oct, 2024 Editor assigned by journal 09 Oct, 2024 Submission checks completed at journal 09 Oct, 2024 First submitted to journal 04 Oct, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5206533","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":385550328,"identity":"1a457f5a-e323-4344-bb3e-f38cd6e6b6b7","order_by":0,"name":"Yanhui Jing","email":"","orcid":"","institution":"National children’s medical center \u0026 Children’s Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"Yanhui","middleName":"","lastName":"Jing","suffix":""},{"id":385550329,"identity":"6960cd11-ebd7-4ae4-bb43-922c4827b793","order_by":1,"name":"Dahui Wang","email":"","orcid":"","institution":"National children’s medical center \u0026 Children’s Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"Dahui","middleName":"","lastName":"Wang","suffix":""},{"id":385550331,"identity":"40853dae-fee9-46fe-b3c0-156f8b19faab","order_by":2,"name":"zhiqiang Zhang","email":"","orcid":"","institution":"National children’s medical center \u0026 Children’s Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"zhiqiang","middleName":"","lastName":"Zhang","suffix":""},{"id":385550333,"identity":"c9d6b08f-b97f-4f6a-bb5e-edd45bdce485","order_by":3,"name":"Yueqiang Mo","email":"","orcid":"","institution":"National children’s medical center \u0026 Children’s Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"Yueqiang","middleName":"","lastName":"Mo","suffix":""},{"id":385550334,"identity":"aea1b15d-98d9-4539-9b45-ac0deb876a1d","order_by":4,"name":"Bo Ning","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAz0lEQVRIiWNgGAWjYDACZjCy4WdgSIByidSSJtlAvBaIssMkaDFn5z38uqDivITB8eRnDxgqrBMb2M8ewKvFspkvzXrGmdsSBmeemRswnElPbODJS8CrxeAwj5kxb9vtOoMbCWYSjG2HExskeAyI0XJOwuBG+jcJxn/EaTF+zNt2AKglB2hLA5G2MM84kywheeZNmUTCsXTjNp4cAlrOnzH+XFBhJ8F3PH2bxIcaa9l+9jP4tQABmwScmQDiElIPBMwfiFA0CkbBKBgFIxkAANr4QetoNDC/AAAAAElFTkSuQmCC","orcid":"","institution":"National children’s medical center \u0026 Children’s Hospital of Fudan University","correspondingAuthor":true,"prefix":"","firstName":"Bo","middleName":"","lastName":"Ning","suffix":""},{"id":385550337,"identity":"1fa58775-6da8-473e-8665-234d920ccfe2","order_by":5,"name":"Chunxing Wu","email":"","orcid":"","institution":"National children’s medical center \u0026 Children’s Hospital of Fudan University","correspondingAuthor":false,"prefix":"","firstName":"Chunxing","middleName":"","lastName":"Wu","suffix":""}],"badges":[],"createdAt":"2024-10-05 02:08:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5206533/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5206533/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s12891-024-08257-5","type":"published","date":"2025-01-02T15:57:23+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":70999543,"identity":"1e042462-991f-4b2f-8570-19533c12d23e","added_by":"auto","created_at":"2024-12-10 05:27:18","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":307407,"visible":true,"origin":"","legend":"\u003cp\u003e(A) Operative steps of cross-union: Anterior curvilinear incision to expose both tibia and ffbula. (B) Ciricumferential excision of hamartoma at pseudarthrosis site.(C)Dissect and expose the space between the tibia and fibula. (D，E) Harvested bone graft, cancellous bone from iliac crest, rectangular cortico-cancellous graft from lilac crest. (F) Rectangular cortico-cancellous graft placed along posterior surface of tibia and ffbula after intra-medullary fixation. See the blue arrow.(G) Cancellous graft placed in tibia-ffbula interosseous space.See the blue arrow.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5206533/v1/3f9b55b731f842b1f7e72bc4.png"},{"id":70999541,"identity":"33d4ad92-9904-4dd8-b0a7-1d487bcbae5c","added_by":"auto","created_at":"2024-12-10 05:27:18","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":121453,"visible":true,"origin":"","legend":"\u003cp\u003eRadiographic Progression in a 2.5-Year-Old Girl with crawford type IV CPT\u003c/p\u003e\n\u003cp\u003eA (Preoperative): Anteroposterior and lateral radiographs displaying the tibial condition prior to surgery.\u003c/p\u003e\n\u003cp\u003eB (Intraoperative): Radiographic images captured during the surgical procedure, showing the initial stages of the modified cross-union protocol.\u003c/p\u003e\n\u003cp\u003eC (3.5 Months Post-Surgery): Radiographs illustrating initial bone healing. At this stage, the patient began exercising under the protection of a brace.\u003c/p\u003e\n\u003cp\u003eD (1.5 Years Post-Surgery): Images showing successful cross-union of the tibia and fibula, demonstrating the long-term efficacy of the treatment.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5206533/v1/7cb36648257e0395976e5fff.png"},{"id":70999540,"identity":"17f3bd14-2570-499b-8fbe-7ca628d85003","added_by":"auto","created_at":"2024-12-10 05:27:17","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":109093,"visible":true,"origin":"","legend":"\u003cp\u003eRadiographic Evolution of a 2.5-Year-Old Boy, crawford type IV CPTwith large bone defect of the tibia\u003c/p\u003e\n\u003cp\u003eA (Preoperative): Anteroposterior (AP) and lateral radiographs depicting a significant bone defect and small distal metaphyseal segments of the tibia and fibula , accompanied by a limb length discrepancy (LLD) of 5 cm.\u003c/p\u003e\n\u003cp\u003eB (Postoperative – Initial Stage): Images showing the tibia and fibula fixed using the cross-union protocol, illustrating the immediate postoperative condition.\u003c/p\u003e\n\u003cp\u003eC (3 Months Post-Surgery): AP and lateral radiographs demonstrate a well-healed cross-union with effective bridging between the tibia and fibula.\u003c/p\u003e\n\u003cp\u003eD (One Year Post-Surgery): AP and lateral radiographs reveal the development of ankle valgus, with LDTA 78 °.\u003c/p\u003e\n\u003cp\u003eE (Post-Deformity Correction): A medial hemiepiphysiodesis was performed to correct the valgus deformity. The images show ongoing LLD of 4 cm after the corrective procedure.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5206533/v1/338f17c769abc6316436ea55.png"},{"id":73093253,"identity":"2da20bf3-3c4f-4423-bb67-a46f835c9a2d","added_by":"auto","created_at":"2025-01-06 16:12:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1202594,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5206533/v1/efc4e5cd-0846-4e82-8390-7fb61026ec89.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Efficacy of the Cross-Union Protocol in the Treatment of Congenital Tibial Pseudarthrosis: A Comparative Study","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCPT is a comparatively rare disorder, occurring in approximately 1 in 140,000 to 1 in 250,000 live births[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. It is estimated that 50\u0026ndash;90% of children with CPT are associated with Neurofibromatosis[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. The clinical characteristics of CPT primarily include the abnormal development of certain tibial segments, leading to hindered osteogenesis. This results in tibial angulation deformities, pathological fractures, and nonunions, which significantly impact both appearance and functionality. Successfully treating CPT poses a considerable challenge. Currently, treatment outcomes vary widely across different regions and methodologies, and most are unsatisfactory. Children with CPT still face the risks of delayed healing, recurrent fractures, and in some cases, even amputation[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSurgical intervention is the only effective treatment, aimed at achieving and maintaining bone union of pseudarthrosis for a long time, restoring normal tibial alignment, and preventing complications like refracture, proximal tibia valgus, ankle valgus, and limb length discrepancy, while maximizing limb function preservation[\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eChoi (2011) and Paley (2012) published methods to intentionally create a cross-union in the treatment of CPT and discussed its advantages and higher success rate[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Paley's combination treatment involves an intentional cross-union between the tibia and fibula, autogenous iliac bone grafting, reliable internal fixation, zoledronic acid infusion, and bone morphogenic protein 2 (BMP-2) insertion. This method creates a favorable biological environment for bone healing, provides a wider and stronger area for bone healing at the pseudarthrosis site, improves the stability of the tibia and fibula, and reduces the risk of subsequent refracture[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSince 2018, our team has been utilizing the cross-union method to treat CPT. This retrospective study seeks to assess the outcomes of our intentional cross-union protocol and compare them with the results from our previously used techniques.\u003c/p\u003e"},{"header":"Methods and Materials","content":"\u003cp\u003eThis was a retrospective observational study.The study included patients who were diagnosed and treated for CPT at our institution, with a requirement for a minimum of two years of follow-up after the index surgery. The index surgery was defined as the first surgical intervention conducted at our institute. For this retrospective analysis, data were collected using a standardized form from our hospital\u0026rsquo;s records. Prior to initiating the study, approval was obtained from both the hospital's review board and the Ethics Committee of the Children\u0026rsquo;s Hospital of Fudan University. Patients lacking complete documentation or radiographic evidence, as well as those not meeting the follow-up duration criteria, were not included.\u003c/p\u003e \u003cp\u003eIn total, 27 patients who had undergone surgical treatment for CPT at our hospital between 2010 and 2022 were reviewed. Among these patients, 11 who underwent surgery between 2010 and 2018, involving pseudarthrosis excision and intramedullary (IM) rodding combined with bone grafting, were categorized into Group B. In contrast, the remaining 16 patients, treated from 2018 to 2022 using the cross-union technique, were classified into Group A.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSurgical Technique Group A\u003c/h2\u003e \u003cp\u003eAn anterior curvilinear incision is made to expose the site of the pseudarthrosis (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). The interosseous membrane and deep fascia are divided to expose the tibia and fibula. The hamartomatous periosteum, sclerotic bone, and surrounding pathological soft tissues are meticulously excised circumferentially (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). Careful dissection is performed to protect the posterior tibial neurovascular bundle. The tibial bowing is straightened, and the medullary canal is opened from proximally to distally. The tibia is then fixed with an appropriately sized telescopic rod and a locking compression plate to ensure immobilization. The distal end of the telescopic growing rod is positioned within the distal tibial physis, taking care to avoid crossing the ankle or subtalar joints. If the fibula is malformed or presents with pseudarthrosis, the abnormal periosteum, sclerotic bone, surrounding pathological soft tissues, and the interosseous membrane are also removed (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eC). The fibula is then fixed with an intramedullary (IM) K-wire.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe bone grafts are harvested from three sources:(1)Cancellous graft are obtained from the ilium and the supra-acetabular area above the tri-radiate cartilage (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eD).(2) An outer rectangular cortical segment is cut from the inner table of the iliac bone(Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eE).༈3༉The lateral periosteum is separated from the overlying muscle.The harvested iliac periosteum is used to cover the area surrounding the resection site of the pseudarthrosis in both the tibia and fibula. The harvested cortical graft is placed along the posterior surface of the tibia and fibula to separate the implanted bones from the neurovascular bundles behind (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eF,See the blue arrow). The cancellous graft, mixed with BMP-2, is placed in the interosseous space (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eG, See the blue arrow). The surgical wounds are then closed.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePostoperative Management\u003c/h3\u003e\n\u003cp\u003eAfter surgery, negative pressure drainage and long leg plaster support were applied. Regular dressing changes were emphasized to prevent flap necrosis and compartment syndrome. The cast was replaced two weeks post-operation following wound healing. Postoperatively, the pseudarthrosis site was reviewed monthly until initial healing. Union is deemed to be achieved when there is continuity between the bony trabeculae of the proximal and distal segments in at least three cortices on both anteroposterior and lateral radiographic views.\u003c/p\u003e\n\u003ch3\u003eOutcome Analysis\u003c/h3\u003e\n\u003cp\u003eThe study evaluated several outcome measures, including the primary union rate (defined as successful union following the initial surgery) and the number of surgeries required to achieve union. The cross-sectional area of union was calculated by multiplying the minimum diameters of the fusion mass observed in both anteroposterior and lateral radiographic views. Long-term outcomes assessed included the incidence of refractures, the lower limb alignment in the coronal plane, and any limb length discrepancies noted at the final follow-up.\u003c/p\u003e \u003cp\u003eComplications were classified into two categories: minor and major. Minor complications were defined as those that did not require additional surgery or could be managed with minor interventions through outpatient care. Major complications were those that necessitated inpatient surgical intervention and had a negative impact on the ultimate surgical outcome.\u003c/p\u003e\n\u003ch3\u003eStatistical Methods\u003c/h3\u003e\n\u003cp\u003eData were analyzed using SPSS version 19.0 statistical software. Quantitative data were presented as mean\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (x̄ \u0026plusmn; s), and intergroup comparisons were performed using independent samples t-tests. Categorical data were presented as numbers and percentages, and intergroup comparisons were conducted using chi-square (χ\u0026sup2;) tests or Fisher's exact test. A p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered statistically significant.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eAll patients were followed up. There were 10 males and 6 females in Group A; 9 cases on the left and 7 cases on the right; 2 Crawford type III, and 14 type IV. The average age at the time of operation was 4.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.78 months. Eleven cases were associated with neurofibromatosis type 1 (NF1). There were 5 males and 6 females in Group B; 3 on the left and 8 on the right; 3 Crawford type III, and 8 type IV.\u003c/p\u003e \u003cp\u003eThe average age at the time of surgery was 3.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.93 months. Four cases were associated with NF1. The two groups were well-matched in terms of sex,age, type of CPT,the incidence of neurofibromatosis type 1 and associated fibula. The follow-up time for Group B was 78.45\u0026thinsp;\u0026plusmn;\u0026thinsp;15.7 months, which is longer than the follow-up time for Group A, which was 45.31\u0026thinsp;\u0026plusmn;\u0026thinsp;18.07 months (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDemographic Data in Two Groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"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\u003eCharacteristic\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup A (Cross-union protocol)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup B (Previous protocol)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge at index surgery (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.8\u0026thinsp;\u0026plusmn;\u0026thinsp;2.78 (2.0-13.3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.5\u0026thinsp;\u0026plusmn;\u0026thinsp;1.93 (1.3\u0026ndash;7.6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.165\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCrawford classification\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.3705\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType III\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\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\u003eType IV\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8\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\u003eSide\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\u003e0.202\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLeft\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\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\u003eRight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8\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\u003eAssociation with NF-1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11(68.8%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4(36.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.1302\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAssociated fbula dysplasia\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9 (56.3%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7(63.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.368\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex distribution\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\u003e0.451\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10\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 \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemale\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6\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\u003eNumber of previous surgeries\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\u003e0.178\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6\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\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\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\u003e2\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\u003e1\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\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\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\u003eTotal followup (months)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e45.31\u0026thinsp;\u0026plusmn;\u0026thinsp;18.07(24\u0026ndash;70)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e78.45\u0026thinsp;\u0026plusmn;\u0026thinsp;15.7(48\u0026ndash;105)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003csup\u003e\u003cb\u003e#\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eNF-1\u0026thinsp;=\u0026thinsp;Neurofibromatosis type 1\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e#=Statistically significant\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eAll 16 cases in Group A successfully completed the cross-union surgery and internal fixation with telescopic rod and plates. All of them achieved primary healing following their first cross-union surgery, with a primary union rate of 100%, and an average healing time of 3.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.64 months. The cross-sectional area of union was 6.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58 cm\u0026sup2;. At the final follow-up, the medial proximal tibial angle was mildly increased in 5 patients, but it did not exceed 95\u0026deg;. Five cases (31%) had residual tibial valgus in the range of 10\u0026ndash;20\u0026deg;. Nine cases (56%) had unequal tibia length, with an average difference of 3.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9 cm (range: 1.2 to 7 cm) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). None had refracture (Typical cases are shown in Figs.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e and \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\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\u003eComparative Outcomes Between Groups\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" 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\u003eOutcome Measure\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroup A (Cross-union)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGroup B (Previous Protocol)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eP\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrimary union rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16/16(100%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4/11(36.4%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0004\u003csup\u003e\u003cb\u003e#\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTime to union (months)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.64(2.5-5)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8.67\u0026thinsp;\u0026plusmn;\u0026thinsp;3.0(6\u0026ndash;18)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.001\u003csup\u003e\u003cb\u003e#\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNumber of surgeries to achieve union\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.12(1\u0026ndash;4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0024\u003csup\u003e\u003cb\u003e#\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCross-sectional area of union (cm\u0026sup2;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58 (2.25\u0026ndash;8.41)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 (0.88\u0026ndash;1.44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003csup\u003e\u003cb\u003e#\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRefracture rate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0/16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e7/11(63.6%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.0001\u003csup\u003e\u003cb\u003e#\u003c/b\u003e\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eKnee, tibia, and ankle alignment at final follow-up\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMPTA (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e90.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e89.7\u0026thinsp;\u0026plusmn;\u0026thinsp;3.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLDTA (\u0026deg;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e89.4\u0026thinsp;\u0026plusmn;\u0026thinsp;5.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e88.32\u0026thinsp;\u0026plusmn;\u0026thinsp;4.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMPTA\u0026thinsp;=\u0026thinsp;Media\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.24\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eMPTA\u0026thinsp;=\u0026thinsp;Medial proximal tibial angle, LDTA\u0026thinsp;=\u0026thinsp;Lateral distal tibial angle\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e#=Statistically significant\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn Group B, the index surgery for the 11 patients involved IM rodding and onlay grafting. Among these, seven cases also utilized Ilizarov external fixation.Out of the 11 patients in Group B, four achieved primary healing, resulting in a primary healing rate of 36.4%. Seven cases with delayed healing required 2\u0026ndash;4 revision surgeries for final healing. The average healing time was 8.67\u0026thinsp;\u0026plusmn;\u0026thinsp;3.0 months. The cross-sectional area of union was 1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 cm\u0026sup2;. Seven cases (64%) had unequal tibia length, with an average difference of 2.5\u0026thinsp;\u0026plusmn;\u0026thinsp;2.5 cm (range: 1.8\u0026ndash;6.4 cm). Three cases (27%) presented with ankle valgus, with Lateral Distal Tibial Angles (LDTA) measuring 75\u0026deg;, 79\u0026deg;, and 80\u0026deg;.Proximal tibial valgus occurred in 2 cases (18%) with Medial Proximal Tibial Angle (MPTA) measuring 95\u0026deg; and 97\u0026deg; (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThere was one case of skin necrosis requiring debridement and skin grafting in Group A, and no incidence of refractures. There were four cases of pin-site infections in Group B, which resolved with intravenous (IV) antibiotics. Seven cases (64%) experienced refractures that required surgical intervention; of these, five ultimately underwent a cross-union protocol to ensure proper healing.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eCPT is a rare and clinically diverse condition, posing significant challenges to pediatric orthopedic surgeons. The spectrum of presentations ranges from simple anterolateral bowing deformity to pronounced nonunion accompanied by extensive bone defects. To date, there remains no consensus on the optimal treatment approach for CPT, as evidenced by references [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Over the past three decades, a wide array of surgical techniques have been investigated. These methods include intramedullary (IM) rodding combined with bone grafting, Ilizarov external fixation, a combination of the Ilizarov technique and bone grafting, free vascularized fibular grafting, and, in certain cases, amputation. Paley [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] conducted a meta-analysis of union, refracture, and success rates (defined as union without refracture) across 25 published studies from 1990 to 2018. The studies were categorized into four main treatment groups: (1) rodding, which included 10 studies involving 196 patients; (2) the Ilizarov technique, which included 6 studies with 115 patients; (3) a combination of Ilizarov and rodding, which included 5 studies with 152 patients; and (4) free vascularized fibular graft, which included 4 studies with 84 patients. The primary union rates were 61% for the rodding group, 93.5% for the Ilizarov group, 72% for the combined Ilizarov and rodding group, and 66% for the vascularized fibula group. The refracture rates were 24% for rodding, 41% for the Ilizarov technique, 17% for the combined Ilizarov and rodding group, and 11% for the vascularized fibular graft group.\u003c/p\u003e \u003cp\u003eOur initial results using the conventional technique of pseudarthrosis excision, IM rodding, and onlay cortical bone graft were unsatisfactory, with primary union achieved in only 4 out of 11 patients (36.4%). In Group B, the average number of surgeries required to achieve union was 2.1, and the average time from the primary surgery to union was 8.67 months, leading to considerable morbidity.\u003c/p\u003e \u003cp\u003eIn 2011, Choi et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] suggested the use of a cross-union between the tibia and fibula for CPT, specifically in cases where the fibula was fractured but minimally proximally migrated. They described a technique called \"4-in-1 Osteosynthesis,\" where the two fibula bone ends were aligned toward the tibia bone ends. This approach increased the effective bone area at the pseudarthrosis site, thereby enhancing the load-bearing capacity of both the tibia and fibula. They reported on eight patients treated at an average age of 6.3 years, all of whom achieved union with the cross-union to the fibula. No refractures occurred during an average follow-up of 7.4 years (range 2.7\u0026ndash;12.4 years).However, a notable limitation of this technique is the potential for ankle valgus, as the proximal and distal ends of the fibula can become curved and close to the tibia. Additionally, inserting the tibial internal fixation nail from the distal to the proximal end, passing through the subtalar and ankle joints, may impede ankle joint movement.\u003c/p\u003e \u003cp\u003ePaley published a large-sample study on the cross-union protocol with external fixation in 2017[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Primary union and cross-union were achieved in all 17 patients (100%) during the index procedure. The mean radiographic union time was 4 months, ranging from 1.5 to 6 months. Notably, none of these patients experienced refractures.\u003c/p\u003e \u003cp\u003eSince 2018, we have chosen to use Paley's technique for the cross-union of the tibia and fibula. However, we have made some modifications to the grafting approach. The Paley cross-union protocol uses only autogenous cancellous bone as the graft material. We found that when placing cancellous bone in the gap between the tibia and fibula, it can be obstructed by the posterior muscle tissue. Therefore, we harvested a rectangular cortical graft from the iliac crest and placed it in front of the muscle tissue within the tibiofibular gap. This approach helps prevent the displacement of the grafted cancellous bone, increases its thickness, and enhances the stability of the grafted area.\u003c/p\u003e \u003cp\u003eThe most severe complication after healing in CPT is refracture. Maximizing the cross-sectional area of healing at the pseudarthrosis site is one of the most critical principles of treatment, as it helps prevent refracture [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. A tibia with a larger cross-sectional area can better withstand mechanical stress, and the \"cross-union\" surgery appears to meet this essential criterion.In our study, the larger cross-sectional area of union in Group A (6.71\u0026thinsp;\u0026plusmn;\u0026thinsp;0.58 cm\u0026sup2;) compared to Group B (1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.19 cm\u0026sup2;) suggests that the cross-union protocol leads to stronger and more stable unions. No patients in Group A experienced refractures, whereas 7 out of 11 patients (63.6%) in Group B did (p\u0026thinsp;\u0026lt;\u0026thinsp;0.0001). The adjunctive use of a tibial telescopic rod offers enhanced stability. As a form of center-based internal fixation, the telescopic rod (TR) is capable of maintaining the tibia's mechanical axis, adapting to the child's growth, and serving as a continuous preventive measure against refractures. This principle aligns with the rationale for using flexible dynamic (FD) devices in the management of osteogenesis imperfecta [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. All of these factors highlight the long-term stability and effectiveness of the cross-union protocol in preventing refractures.\u003c/p\u003e \u003cp\u003eCurrently, similar results have been reported in accounts of the cross-union protocol. Shannon et al. (2021) [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] reported on 39 cases of CPT treated using the cross-union protocol with all internal fixation. All 39 cases achieved union at the tibia and developed a cross-union to the fibula, with no refractures observed during the follow-up period of up to 7 years (range: 24\u0026ndash;85 months). Wu et al. (2022) [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] described 18 patients with refractory CPT treated using the Paley cross-union protocol with all internal fixation. All 18 patients achieved union, and none experienced refractures during a mean follow-up of 4.3 years (range: 1.5\u0026ndash;6.3 years). In our group, 16 patients with CPT underwent treatment by cross-union protocol. All patients (100%) obtained primary union at the pseudarthrosis site. During a mean follow-up of 45.31 months, the primary union and refracture rate in our patients (100% union, 0% refractures) were consistent with those reported in existing literature [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAnkle valgus has been reported after several surgical procedures for CPT in previous studies. In Group A, 5 (31%) cases had residual tibial valgus ranging from 10\u0026ndash;20\u0026deg; at the final follow-up. This condition is regarded to be linked to insufficient lateral support provided by the shortening or bone defect of the fibula, a view supported by Vanderstappen's observations [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], which highlighted that patients with fibular pseudarthrosis often exhibit this complication. Dobbs et al. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] also found a high incidence of ankle valgus in patients with fibular pseudarthrosis in their long-term follow-up study. In the cross-union protocol, the tibia was secured using a telescopic growing rod, while the fibula was fixed with K-wires, maintaining a normal interosseous distance between the two bones and reducing the incidence of ankle valgus. The telescopic rod in the tibia is inserted from the proximal end to the distal end, avoiding the ankle and subtalar joints and thus preserving ankle mobility [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In this group, 9 cases (56.3%) had pre-existing fibular pseudarthrosis, which likely contributed to the high incidence of ankle valgus. The Lateral Distal Tibial Angle (LDTA) was 89.4\u0026deg; \u0026plusmn; 5.08\u0026deg; in Group A, compared to 88.32\u0026deg; \u0026plusmn; 4.83\u0026deg; in Group B (p\u0026thinsp;=\u0026thinsp;0.57), indicating no significant statistical difference. Future studies may require larger sample sizes to demonstrate the advantages of cross-union surgery in improving knee, tibia, and ankle malalignment.\u003c/p\u003e \u003cp\u003eThere are a few limitations to our study. First, the current sample size is still relatively small, and the follow-up duration is relatively short; longer follow-up would be needed to comment on the occurrence of late complications. Second, we did not examine functional outcomes. Further quantification and analysis of motor function should be included in subsequent studies.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eOur study demonstrates that the Cross-union protocol, although demanding, is highly effective for achieving union and preventing refracture in CPT. With such significant improvement, it has notably altered the prognosis of this challenging condition.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCPT \u0026nbsp; \u0026nbsp; \u0026nbsp;congenital pseudarthrosis of the tibia\u003c/p\u003e\n\u003cp\u003eLLD \u0026nbsp; \u0026nbsp; limb length discrepancy\u003c/p\u003e\n\u003cp\u003eNF1 \u0026nbsp; \u0026nbsp; neurofibromatosis type 1\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur study was approved by The Ethics Committee approval of Children\u0026rsquo;s hospital of Fudan\u003c/p\u003e\n\u003cp\u003euniversity\u0026nbsp;and conducted according to the Helsinki Declaration and its later amendments.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from all patients\u0026rsquo;\u0026nbsp;parents who participated in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll participants were informed about the purpose of the study and informed consent was\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eobtained for all patient images from a parent and/or legal guardian.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analysed during the current study are not publicly available due to limitations of ethical approval involving the patient data and anonymity but are available from\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ethe corresponding author on reasonable request.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSupported by the National Natural Science Foundation of China(nos.82272441) and Technology\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCommission of Shanghai Municipality (CN) (nos.22Y11912200).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u003c/strong\u003e\u003cstrong\u003e\u0026rsquo;\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003econtributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eYH J made substantial contributions to the conception, reviewed the case, collected the data,\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ecarried out the initial analyses, and drafted the initial manuscript. CX W, ZQ Z and DH W reviewed the case, collected the data and B N performed the surgeries. YQ M and B N coordinated and supervised data collection, and critically reviewed the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical trial number\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eGrill, F.; Bollini, G.; Dungl, P.; Fixsen, J.; Hefti, F.; Ippolito, E.; Romanus, B.; Tudisco, C.; Wientroub, S. Treatment Approaches for Congenital Pseudarthrosis of Tibia: Results of the EPOS Multicenter Study. J. Pediatric Orthop. Part B 2000, 9, 75\u0026ndash;89.\u003c/li\u003e\n\u003cli\u003eCrawford AH, Schorry EK. Neurofibromatosis in children: The role of the orthopaedist. J Am Acad Orthop Surg 1999;7:217-30. \u003c/li\u003e\n\u003cli\u003eShah H, Doddabasappa SN, Joseph B. Congenital pseudarthrosis of the tibia treated with intramedullary rodding and cortical bone grafting: a follow-up study at skeletal maturity. J Pediatr Orthop. 2011;31(1):79-88. doi:10.1097/BPO.0b013e318202c45d.\u003c/li\u003e\n\u003cli\u003eInan M, El Rassi G, Riddle EC, Kumar SJ. Residual deformities following successful initial bone union in congenital pseudoarthrosis of the tibia. J Pediatr Orthop 2006;26:393-9.\u003c/li\u003e\n\u003cli\u003eBorzunov DY, Chevardin AY, Mitrofanov AI. Management of congenital pseudarthrosis of the tibia with the Ilizarov method in a paediatric population: Influence of aetiological factors. Int Orthop. (2016) 40(2):331\u0026ndash;9. doi:10.1007/s00264-015-3029-7\u003c/li\u003e\n\u003cli\u003eSinger D, Johnston CE. Congenital Pseudarthrosis of the Tibia: Results, at Skeletal Maturity, of the Charnley-Williams Procedure. JB JS Open Access. 2019;4(2):e0004. Published 2019 Jun 20. doi:10.2106/JBJS.OA.19.00004\u003c/li\u003e\n\u003cli\u003eEl-Gammal TA, El-Sayed A, Kotb MM, et al. Crawford Type IV Congenital Pseudarthrosis of the Tibia: Treatment With Vascularized Fibular Grafting and Outcome at Skeletal Maturity. J Pediatr Orthop. 2021;41(3):164-170. doi:10.1097/BPO.0000000000001751 \u003c/li\u003e\n\u003cli\u003eShabtai L, Ezra E, Wientroub S, et al. Congenital tibial pseudarthrosis, changes in treatment protocol. J Pediatric Orthop B. 2015;24: 444\u0026ndash;449. \u003c/li\u003e\n\u003cli\u003eChoi IH, Lee SJ, Moon HJ, et al. \u0026ldquo;4-in-1 osteosynthesis\u0026rdquo; for atrophictype congenital pseudarthrosis of the tibia. J Pediatr Orthop. 2011; 31:697\u0026ndash;704. \u003c/li\u003e\n\u003cli\u003ePaley D. Congenital pseudarthrosis of the tibia: combined pharmacologic and surgical treatment using biphosphonate intravenous infusion and bone morphogenic protein with periosteal and cancellous autogenous bone grafting, tibio-fibular cross union, intramedullary rodding and external fixation. In Zorzi A (ed.), 2012: 91-106; InTech, Available from: https:// www.intechopen.com/books/bone-grafting/treatment-of-congenital-pseudarthrosiswith-periosteal-and-cancellous-bone-grafting-\u003c/li\u003e\n\u003cli\u003ePacker D, Robb J, Liu R, Robbins C, Paley D. Combined pharmacologic and biological treatment of congenital pseudoarthrosis of the tibia; 100 % union; no refractures! J Child Orthop 2016;10:S19-S20\u003c/li\u003e\n\u003cli\u003eKesireddy, N.; Kheireldin, R.K.; Lu, A.; Cooper, J.; Liu, J.; Ebraheim, N.A. Current treatment of congenital pseudarthrosis of the tibia: A systematic review and meta-analysis. J. Pediatr. Orthop. B 2018, 27, 541\u0026ndash;550\u003c/li\u003e\n\u003cli\u003ePaley, D. Congenital pseudarthrosis of the tibia: Biological and biomechanical considerations to achieve union and prevent refracture. J. Child. Orthop. 2019, 13, 120\u0026ndash;133.\u003c/li\u003e\n\u003cli\u003ePaley D. Congenital pseudarthrosis of the tibia. In: Current Progress in Orthopaedics.Johari A and Waddell J (eds). Mumbai: Tree Life Media; 2017:318-348.\u003c/li\u003e\n\u003cli\u003eChoi IH, Cho T-J, Moon HJ. Ilizarov treatment of congenital pseudarthrosis of the tibia. A multi-targeted approach using the Ilizarov technique. Clin Orthop Surg. 2011;3:1\u0026ndash;8.\u003c/li\u003e\n\u003cli\u003eCho T-J, Choi IH, Lee SM, et al. Refracture after Ilizarov osteosynthesis in atrophic-type congenital pseudarthrosis of tibia. J Bone Joint Surg Br. 2008;90:488\u0026ndash;493.\u003c/li\u003e\n\u003cli\u003eFassier, F.R. Osteogenesis imperfecta. In Pediatric Lower Limb Deformities; Springer: Berlin/Heidelberg, Germany, 2016;pp. 255\u0026ndash;265.\u003c/li\u003e\n\u003cli\u003eShannon CE, Huser AJ, Paley D. Cross-Union Surgery for Congenital Pseudarthrosis of the Tibia. Children (Basel). 2021;8(7):547. doi:10.3390/children8070547\u003c/li\u003e\n\u003cli\u003eWu C, Zheng G, Wang D, Paley D, Ning B. Combination Treatment by Cross-Union of the Tibia and Fibula, Autogenic Iliac Bone Grafting, Reliable Fixation and Bone Morphogenetic Proteins for the Treatment of Refractory Congenital Pseudarthrosis of the Tibia. J Pediatr Orthop. 2022;42(6):e623-e629. doi:10.1097/BPO.0000000000002138\u003c/li\u003e\n\u003cli\u003eVanderstappen J, Lammens J, Berger P, Laumen A. Ilizarov bone transport as a treatment of congenital pseudarthrosis of the tibia: a long-term follow-up study. J Child Orthop. (2015) 9(4):319\u0026ndash;24. doi: 10.1007/s11832-015-0675-7\u003c/li\u003e\n\u003cli\u003eDobbs MB, Rich MM, Gordon JE, Szymanski DA, Schoenecker PL. Use of an intramedullary rod for treatment of congenital pseudarthrosis of the tibia. A long-term follow-up study. J Bone Joint Surg Am. (2004) 86(6):1186\u0026ndash;97. doi: 10.2106/00004623-200406000-00010\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"congenital pseudarthrosis of the tibia, cross-union surgery, child, complication","lastPublishedDoi":"10.21203/rs.3.rs-5206533/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5206533/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCongenital Pseudarthrosis of the Tibia (CPT) is a rare pediatric condition presenting substantial challenges for orthopedic surgeons aiming to achieve bone union, with subsequent complications such as refractures being common. The aim of the present study is to evaluate the results of our intentional cross-union protocol and to compare these outcomes with those obtained from our previously used techniques.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSixteen patients, with a mean age of 4.8 years (range: 1-13.3 years), who were treated with the intentional cross-union protocol were included in Group A. Eleven patients, with a mean age of 3.5 years (range: 1.3-7.6 years), who primarily underwent intramedullary rodding with bone graft, were included in Group B. The intentional cross-union protocol involved cross-union of the tibia and fibula, autogenous iliac bone grafting, and the insertion of bone morphogenetic protein 2 (BMP-2) aimed at achieving tibia-fibula cross-union. Retrospective evaluation of serial radiographs was conducted, and the outcomes regarding union and any subsequent complications were analyzed.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 27 patients with CPT were included in the study. All 16 patients (100%) in Group A successfully achieved primary union. Among the 11 patients in Group B, only 4 cases achieved primary union, with a primary healing rate of 36.4%. Seven cases with delayed healing required 2-4 revision surgeries for final healing. The time to union was significantly shorter in Group A (3.37 ± 0.64 months) compared to Group B (8.67 ± 3.0 months). The cross-sectional area of union was also significantly larger in Group A (6.71 ± 0.58 cm²) compared to Group B (1.18 ± 0.19 cm²). In Group A, there were no cases of refracture, whereas in Group B, 7 cases (77.8%) experienced refracture, indicating a statistically significant difference.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur study demonstrates that the Cross-union protocol is highly effective for achieving union and preventing refracture in CPT. With such significant improvement, it has notably altered the prognosis of this challenging condition.\u003c/p\u003e\n\u003cp\u003eLevel of Evidence: IV\u003c/p\u003e","manuscriptTitle":"Efficacy of the Cross-Union Protocol in the Treatment of Congenital Tibial Pseudarthrosis: A Comparative Study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-10 05:27:13","doi":"10.21203/rs.3.rs-5206533/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2024-12-03T08:05:52+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-12-03T07:23:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"173773096387628088956924166275155174317","date":"2024-12-03T07:18:13+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2024-11-24T01:26:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"105932065521316151677374336534304908367","date":"2024-11-12T00:03:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"326931705924325571557106383552622232782","date":"2024-11-06T09:50:34+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-10-30T14:25:39+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-10-10T13:22:56+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-10-09T10:11:08+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-10-09T10:08:08+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Musculoskeletal Disorders","date":"2024-10-05T02:06:28+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-musculoskeletal-disorders","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmsd","sideBox":"Learn more about [BMC Musculoskeletal Disorders](http://bmcmusculoskeletdisord.biomedcentral.com/)","snPcode":"","submissionUrl":"https://author-welcome.nature.com/12891","title":"BMC Musculoskeletal Disorders","twitterHandle":"BMC_series","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"a31bc96f-00d4-4d1e-99ea-780d119d990a","owner":[],"postedDate":"December 10th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-01-06T16:01:24+00:00","versionOfRecord":{"articleIdentity":"rs-5206533","link":"https://doi.org/10.1186/s12891-024-08257-5","journal":{"identity":"bmc-musculoskeletal-disorders","isVorOnly":false,"title":"BMC Musculoskeletal Disorders"},"publishedOn":"2025-01-02 15:57:23","publishedOnDateReadable":"January 2nd, 2025"},"versionCreatedAt":"2024-12-10 05:27:13","video":"","vorDoi":"10.1186/s12891-024-08257-5","vorDoiUrl":"https://doi.org/10.1186/s12891-024-08257-5","workflowStages":[]},"version":"v1","identity":"rs-5206533","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5206533","identity":"rs-5206533","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}