Pediatric-Specific Lesions in Unstable Pelvic Ring Fractures of Skeletally Immature Children: Impact on Diagnosis and Management Decisions.

Surgical fixation of pediatric pelvic ring injuries is gaining popularity to avoid the poor long-term outcomes of pelvic asymmetry. The surgical techniques and fixation choices depend on the individual injuries affecting the anterior and posterior pelvic ring areas. The immature bony pelvis of young children has anatomic differences including soft bones, elastic ligaments, and the presence of growth centers. Understanding the unique pediatric lesions with unstable pelvic fractures is essential for treatment decisions. Anterior lesions include pubic symphysis disruption through the pubic apophysis, single ramus fractures, pubic rami fractures through the triradiate cartilage, and/or the ischiopubic synchondrosis; ischiopubic ramus infolding injury; or the unstable superior and inferior quadrant lesions. Posterior pelvic lesions include iliac wing infolding and sacroiliac joint dislocation or transiliac (crescent) fracture/dislocations through the iliac apophysis growth plate. Pubic symphysis and sacroiliac disruptions are physeal injuries in children, and they have excellent healing potential. External fixation is an ideal choice for anterior ring fixation including bony and pubic symphysis injuries. Posterior lesions are mostly sacroiliac joint disruptions with iliac apophysis separation that can serve as a landmark for vertical displacement correction. Posterior lesions can be treated by percutaneous iliosacral screw fixation or open reduction techniques.

Is casting of displaced paediatric distal forearm fractures non-inferior to reduction under general anaesthesia? Study protocol for a pragmatic, randomized, controlled non-inferiority multicentre trial (the casting trial).

BACKGROUND: Treatment of displaced distal forearm fractures in children has traditionally been closed reduction and pin fixation, although they might heal and remodel without surgery with no functional impairment. No randomized controlled trials have been published comparing the patient-reported functional outcome following non-surgical or surgical treatment of displaced paediatric distal forearm fractures. METHODS: A multicentre non-inferiority randomized controlled trial. Children aged 4-10 years with a displaced distal forearm fracture will be offered inclusion, if the on-duty orthopaedic surgeon finds indication for surgical intervention. They will be allocated equally to non-surgical treatment (intervention) or surgical treatment of surgeon's choice (comparator). Follow-up will be 4 weeks and 3, 6, and 12 months. The primary outcome is the between-group difference in 12 months QuickDASH score. We will need a sample of 40 patients to show a 15-point difference with 80% power. DISCUSSION: The results of this trial may change our understanding of the healing potential of paediatric distal forearm fractures. If non-inferiority of non-surgical treatment is shown, the results may contribute to a reduction in future surgeries on children, who in turn can be treated without the risks and psychological burdens associated with surgery. TRIAL REGISTRATION: www. CLINICALTRIALS: gov (ID: NCT05736068). Date of registry: 17 February 2023.

Temporary Stabilization of Tibia Fractures: Does External Fixation or Temporary Plate Fixation Result in Better Outcomes?

Background: Provisional stabilization of high-energy tibia fractures using temporary plate fixation (TPF) or external fixation (ex-fix) prior to definitive medullary nailing (MN) is a strategy common in damage control orthopaedics. There is a lack of comprehensive data evaluating outcomes between these methods. This study compares outcomes of patients stabilized with either TPF or ex-fix, and with early definitive MN only, assessing complications including nonunion and deep infection. Methods: A retrospective review was performed on adult patients with tibia fractures treated with MN followed until fracture union (≥3 months) at a single level-1 trauma center from 2014 to 2022. Medical records were evaluated for nonunion and deep infection. Demographics, injury characteristics, and fixation methods were recorded. Significance between patients who underwent TPF and ex-fix was compared with a matched cohort of early MN using Pearson's exact tests, independent t-tests, and one-way ANOVA, depending on the appropriate variable. Results: 81 patients were included; 27 were temporized with TPF (n = 12) or ex-fix (n = 15). 54 early MN cases defined the matched cohort. All groups had similar patient and fracture characteristics. The difference in rates of nonunion between groups was significant, with TPF, ex-fix, and early MN groups at 17, 40, and 11% respectively (p = 0.027). Early MN had lower rates of nonunion (11% vs. 40%, p = 0.017) and deep infection (13% vs. 40%, p = 0.028) compared to ex-fix. Conclusion: Temporary ex-fix followed by staged MN was associated with higher rates of nonunion and deep infection. There was no difference in complication rates between TPF and early definitive MN. These data suggest that ex-fix followed by MN of tibia fractures should be avoided in favor of early definitive MN when possible. If temporization is needed, TPF may be a better option than ex-fix. Level of Evidence: IV.

[Design and Testing of a Pressure Measurement and Adjustment Device for Fracture Ends].

Objective: To design and test a device which is capable of accurately measuring and dynamically adjusting the axial pressure at the fracture end in real-time. Methods: Upon completion of the design, the pressure measurement and adjustment device was implemented in a canine tibial fracture external fixation model. A pressure sensor was mounted at the fracture end, and the displayed values of the pressure sensor were used as the standard for comparison. The relationship between the displayed values of the measurement and adjustment device and the pressure sensor under identical conditions was examined. Results: The device was utilized in external fixation models of tibial fractures in five beagles. A linear correlation was observed between the displayed values of the device and the pressure sensor at the fracture end. The measurement values from the device could be transformed into fracture end pressure through the application of coefficients, thereby facilitating accurate measurement and dynamic adjustment of the fracture end pressure. Conclusion: The pressure measurement and adjustment device at the fracture end is easy to operate, enabling precise measurement and dynamic regulation of the pressure at the fracture end. It is well-suited for animal experiments aimed at investigating the impact of axial compression on fracture healing, demonstrating promising potential for experimental applications.

Current Concepts in Ankle Fracture Management.

Ankle fractures are one of the more common musculoskeletal injuries that are treated by foot and ankle specialists. A thorough understanding of managing these injuries requires the ability to differentiate between stable and unstable fractures. The current literature supports the nonoperative management of stable Weber B ankle fractures, whereas unstable fractures have much better outcomes with surgical intervention. Specifically, we review the fixation strategies for the lateral, medial, and posterior malleolar fractures respectively. Finally, we discuss the current trends in postoperative management of some of the more common fracture patterns, and the safety in early weight-bearing protocols.

Finite element analysis of modified Slongo's external fixation in the treatment of supracondylar humeral fractures in older children.

Older children over 8 years old are at higher risk of elbow joint stiffness after treatment of supracondylar humeral fractures. The objective of this study was to improve the Slongo's external fixation system for treating supracondylar humeral fractures in older children. This would be achieved by increasing fixation strength and providing a theoretical basis through finite element analysis and mechanical testing. A 13-year-old female patient with a history of previous fracture was selected for CT data processing to create a three-dimensional model of the distal humerus fracture. Two internal fixation models were established, using the Slongo's external fixation method with Kirschner wire (Group A) and modifying the Slongo's external fixation (Kirschner wire tail fixation) (Group B). The fracture models were then subjected to mechanical loading analysis using Finite Element Analysis Abaqus 6.14 software to simulate separation, internal rotation, and torsion loads. A PVC humeral bone model was used to create a supracondylar fracture model, and the A and B internal fixation methods were applied separately. The anterior-posterior and torsional stresses were measured using the Bose Electroforce3510 testing system, followed by a comparative analysis. The finite element simulation results showed that under the same tensile, torsion, and inversion forces, the osteotomy model fixed with Kirschner wire at the distal end in Group B exhibited smaller tensile stress and deformation compared to the unfixed osteotomy model in Group A. This indicated that the fixation strength of Group B was superior to that of Group A. According to the test results of the Bose Electroforce3510 testing system, a simple linear regression analysis was conducted using SPSS software. The K values of rotation angle-torque tests and front and rear displacement-stress tests were calculated for Groups A and B, with Group B showing higher values than Group A. The results of this study supported the significantly enhanced biomechanical reliability and stability of fracture fixation in Group B, which utilized the modified Slongo's external fixation (Kirschner wire tail fixation). This optimized method provides a new choice for the clinical treatment of supracondylar humeral fractures in older children, backed by both clinical evidence and theoretical basis.

Brodie's abscess as a late complication of external fixation of the distal radius: A case report.

CASE: A 41-year-old male presented with an insidious onset of pain and swelling about the dorsal wrist, and was found to have a Brodie's abscess in the distal radius. The patient had a history of a distal radius fracture, treated with external fixation, nineteen years prior, which we believe contributed to the infection. The patient was treated surgically with abscess irrigation, debridement, bony curettage, bioactive glass S53P4 allograft, with concurrent antibiotic therapy. CONCLUSION: Brodie's abscesses can have atypical presentations, and a thorough history must be obtained from patients to identify any potential sources of infection.

3D printing feasibility of a controlled dynamization device for external circular fixation.

AIM: to assess the small-scale 3D printing feasibility and cost estimation of a device for controlled dynamization. MATERIALS AND METHOD: The two-part device previously developed by our research group was printed with a carbon fiber-reinforced nylon filament (Gen3 CarbonX™ PA6+CF, 3DXTECH Additive Manufacturing) by a professional 3D printer (FUNMAT HT, Intamsys). Electricity, material, and labor costs for production in a Brazilian city in the Santa Catarina state were calculated. RESULTS: The devices for controlled dynamization were successfully printed in accordance with the planned design and dimensions. Six out of 38 printed devices presented defects in the bolt hole and were discarded. The average printing time per device was 1.9 h. The average electricity, material, and labor costs per printed device were respectively US$0.71, US$13.55, and US$3.04. The total production cost per device reaches approximately US$20 by adding the average cost of defective devices (15 %). CONCLUSION: 3D printing of the controlled dynamization device is feasible and its cost seems affordable to most healthcare services, which could optimize the consolidation of diaphyseal fractures and reduce treatment time for patients.

In vivo axial load-share ratio measurement using a novel hexapod system for safe external fixator removal.

BACKGROUND: External fixation is widely used in the treatment of traumatic fractures; however, orthopedic surgeons encounter challenges in deciding the optimal time for fixator removal. The axial load-share ratio (LS) of the fixator is a quantitative index to evaluate the stiffness of callus healing. This paper introduces an innovative method for measuring the LS and assesses the method's feasibility and efficacy. Based on a novel hexapod LS-measurement system, the proposed method is to improve the convenience and precision of measuring LS in vivo, hence facilitating the safe removal of external fixators. METHODS: A novel hexapod system is introduced, including its composition, theoretical model, and method for LS measurement. We conducted a retrospective study on 82 patients with tibial fractures treated by the Taylor Spatial Frame in our hospital from September 2018 to June 2020, of which 35 took LS measurements with our novel method (Group I), and 47 were with the traditional method (Group II). The external fixator was removed when the measurement outcome (LS < 10%) was consistent with the surgeon's diagnosis based on the clinical and radiological assessment (bone union achieved). RESULTS: No significant difference was found in the fracture healing time (mean 25.3 weeks vs. 24.9 weeks, P > 0.05), frame-wearing duration (mean 25.5 weeks vs. 25.8 weeks, P > 0.05), or LS measurement frequency (mean 1.1 times vs. 1.2 times, P > 0.05). The measurement system installation time in Group I was significantly shorter compared to Group II (mean 14.8 min vs. 81.3 min, P < 0.001). The LS value of the first measurement in Group I was lower than that of Group II (mean 5.1% vs. 6.9%, P = 0.011). In Group I, the refracture rate was 0, but in Group II it was 4.3% (2/47, P > 0.05). CONCLUSION: The novel hexapod LS-measurement system and involved method demonstrated enhanced convenience and precision in measuring the LS of the external fixator in vivo. The LS measurement indicates the callus stiffness of fracture healing, and is applicable to evaluate the safety of removing the fixator. Consequently, it is highly recommended for widespread adoption in clinical practice.

A new ring fixator system for automated bone fixation.

BACKGROUND: In the field of orthopaedics, external fixators are commonly employed for treating extremity fractures and deformities. Computer-assisted systems offer a promising and less error-prone treatment alternative to manual fixation by utilising a software to plan treatments based on radiological and clinical data. Nevertheless, existing computer-assisted systems have limitations and constraints. METHODS: This work represents the culmination of a project aimed at developing a new automatised fixation system and a corresponding software to minimise human intervention and associated errors, and the developed system incorporates enhanced functionalities and has fewer constraints compared to existing systems. RESULTS: The automatised fixation system and its graphical user interface (GUI) demonstrate promising results in terms of accuracy, efficiency, and reliability. CONCLUSION: The developed fixation system and its accompanying GUI represent an improvement in computer-assisted fixation systems. Future research may focus on further refining the system and conducting clinical trials.

Implementation of supplemental physiotherapy following hip fracture surgery: a protocol for the process evaluation of a randomised controlled trial.

BACKGROUND: Patient outcomes following low-trauma hip fracture are suboptimal resulting in increased healthcare costs and poor functional outcomes at 1 year. Providing early and intensive in-hospital physiotherapy could help improve patient outcomes and reduce costs following hip fracture surgery. The HIP fracture Supplemental Therapy to Enhance Recovery (HIPSTER) trial will compare usual care physiotherapy to intensive in-hospital physiotherapy for patients following hip fracture surgery. The complex environments in which the intervention is implemented present unique contextual challenges that may impact intervention effectiveness. This study aims to complete a process evaluation to identify barriers and facilitators to implementation and explore the patient, carer and clinician experience of intensive therapy following hip fracture surgery. METHODS AND ANALYSIS: The process evaluation is embedded within a two-arm randomised, controlled, assessor-blinded trial recruiting 620 participants from eight Australian hospitals who have had surgery for a hip fracture sustained via a low-trauma injury. A theory-based mixed method process evaluation will be completed in tandem with the HIPSTER trial. Patient and carer semi-structured interviews will be completed at 6 weeks following hip fracture surgery. The clinician experience will be explored through online surveys completed pre- and post-implementation of intensive therapy and mapped to domains of the Theoretical Domains Framework (TDF). Translation and behaviour change success will be assessed using the Reach Effectiveness-Adoption Implementation Maintenance (RE-AIM) framework and a combination of qualitative and quantitative data collection methods. These data will assist with the development of an Implementation Toolkit aiding future translation into practice. DISCUSSION: The embedded process evaluation will help understand the interplay between the implementation context and the intensive therapy intervention following surgery for low-trauma hip fracture. Understanding these mechanisms, if effective, will assist with transferability into other contexts and wider translation into practice. TRIAL REGISTRATION: ACTRN 12622001442796.

Cost-effectiveness analysis of soft bandage and immediate discharge versus rigid immobilization in children with distal radius torus fractures.

Aims: The aim of this trial was to assess the cost-effectiveness of a soft bandage and immediate discharge, compared with rigid immobilization, in children aged four to 15 years with a torus fracture of the distal radius. Methods: A within-trial economic evaluation was conducted from the UK NHS and personal social services (PSS) perspective, as well as a broader societal point of view. Health resources and quality of life (the youth version of the EuroQol five-dimension questionnaire (EQ-5D-Y)) data were collected, as part of the Forearm Recovery in Children Evaluation (FORCE) multicentre randomized controlled trial over a six-week period, using trial case report forms and patient-completed questionnaires. Costs and health gains (quality-adjusted life years (QALYs)) were estimated for the two trial treatment groups. Regression was used to estimate the probability of the new treatment being cost-effective at a range of 'willingness-to-pay' thresholds, which reflect a range of costs per QALY at which governments are typically prepared to reimburse for treatment. Results: The offer of a soft bandage significantly reduced cost per patient (saving £12.55 (95% confidence interval (CI) -£5.30 to £19.80)) while QALYs were similar (QALY difference between groups: 0.0013 (95% CI -0.0004 to 0.003)). The high probability (95%) that offering a bandage is a cost-effective option was consistent when examining the data in a range of sensitivity analyses. Conclusion: In addition to the known clinical equivalence, this study found that the offer of a bandage reduced cost compared with rigid immobilization among children with a torus fracture of the distal radius. While the cost saving was small for each patient, the high frequency of these injuries indicates a significant saving across the healthcare system.

[Treatment reality of distal radius fractures in a center]. / Versorgungsrealität distaler Radiusfrakturen in einem Zentrum.

Distal radius fractures are the third most common type of fracture in Germany after fractures of the femoral neck and peritrochanteric femoral fractures. In 2019 a total of 72,087 cases were registered with an incidence of 106 cases per 100,000 inhabitants (81,570 fractures of the femoral neck, 73,785 peritrochanteric fractures). Many of these fractures are surgically treated also in this hospital but with controversial views on the optimal treatment. Against the background of the coronavirus disease 2019 (COVID-19) pandemic, disappearing personnel resources and the political pressure to form centers and a switch to outpatient treatment, the authors ask the question what the treatment reality in this hospital looks like and whether the general changes in the framework conditions also have an affect in this context. This is not a strictly scientific study but a stocktaking without any claims of completeness and the retrospective evaluation of a larger data pool with all its weaknesses. On the contrary, the data provide interesting aspects that are explained in detail in the individual sections.

Functional and union outcome of combined column tibial plateau fracture treated with hybrid external fixator.

Objective: To determine the combined column tibial plateau fracture treated with a hybrid external fixator in terms of knee functionality, union outcome and complications. METHODS: The quasi-experimental study was conducted at the Department of Orthopaedic Surgery, Mayo Hospital, Lahore, Pakistan, from July 5, 2019, to December 31, 2021, and comprised patients of either gender aged 20-50 years who presented with 2-column or 3-column fractures of proximal tibia classified according to the 3-column classification system after being diagnosed using radiographs and three-dimensional computed tomography scan. Knee function, union and complications, like neural, vascular, infection, delayed union, nonunion, malunion and implant failure, were evaluated. The Knee Society Score was used to assess knee function, and modified Rasmussen score for the union, while complications were assessed clinically on the 2nd, 6th, 12th, 16th, 24th, 36th weeks and one year post-operatively. Data was analysed using SPSS 26. RESULTS: Of the 113 patients, 91(80.53%) were males and 22(19.47%) were females. The overall mean age was 35.56±9.00 years. From the 12th week to the 24th week 45(39.83%) patients had good and 59(52.21%) patients had excellent functional outcomes. Union outcome in the 16th and 24th week was good in 57(50.44%) patients and excellent in 47(41.59%) patients. No neurovascular injury was observed. Superficial pin tract infection was observed in 21(18.6%) cases that healed with wound debridement and antibiotics. No delayed union, malunion and implant failure was observed. CONCLUSIONS: Good to excellent functional and union outcomes with minimum complications were observed with the hybrid external fixator.

Short-term outcome after treatment of talocrural instability in cats using modified type II transarticular external skeletal fixation.

Transarticular external skeletal fixation (TESF) is repeatedly used for temporary stabilisation of tarsal joint in cats. Hence, this study aimed to evaluate the use of temporary modified type II TESF for management of talocrural instability (TCI) in cats without joint arthrodesis and to rate short-term outcomes and complications. Medical records of all cats treated for TCI between January 2012 and December 2021 were reviewed. Information was collected including signalment, degree of lameness, type of TCI, accompanying soft tissue and bone injuries, and post-operative follow-up assessment including time of frame removal, complications, degree of lameness, range of joint motion and ankylosis. Surgical management didn't involve debridement of the articular cartilage. Eighty-five percent of cats had satisfactory joint stability at the time of frame removal. Eighteen cats exhibited minor complications, six cats had major complications, and 8 cats showed persistent lameness. All cats showed reduction of joint motion range by 20°-30° directly after frame removal while returned to normal in 79% of cats 4 weeks later. Variable degrees of joint ankylosis were reported. In conclusion, this study supports the use of temporary modified type II TESF for management of TCI in cats without joint involvement as an excellent alternative to tarsal arthrodesis.

Audio Distraction for Traction Pin Insertion: A Prospective Randomized Controlled Study.

BACKGROUND: Insertion of a skeletal traction pin in the distal femur or proximal tibia can be a painful and unpleasant experience for patients with a lower-extremity fracture. The purpose of this study was to determine whether providing patients with audio distraction (AD) during traction pin insertion can help to improve the patient-reported and the physician-reported experience and decrease pain and/or anxiety during the procedure. METHODS: A prospective randomized controlled trial was conducted at 2 level-I trauma centers. Patients ≥18 years of age who were conscious and oriented and had a medical need for skeletal traction were included. Patients were randomized to receive AD or not receive AD during the procedure. All other procedure protocols were standardized and were the same for both groups. Surveys were completed by the patient and the physician immediately following the procedure. Patients rated their overall experience, pain, and anxiety during the procedure, and physicians rated the difficulty of the procedure, both on a 1-to-10 Likert scale. RESULTS: A total of 54 patients met the inclusion criteria. Twenty-eight received AD and 26 did not. Femoral fractures were the most common injury (33 of 55, 60.0%). Baseline demographic characteristics did not differ between the 2 groups. The overall patient-reported procedure experience was similar between the AD and no-AD groups (3.9 ± 2.9 [95% confidence interval (CI), 3.1 to 4.7] versus 3.5 ± 2.2 [95% CI, 2.9 to 4.1], respectively; p = 0.55), as was pain (5.3 ± 3.2 [95% CI, 4.4 to 6.2] versus 6.1 ± 2.4 [95% CI, 5.4 to 6.8]; p = 0.28). However, anxiety levels were lower in the AD group (4.8 ± 3.3 [95% CI, 3.9 to 5.7] versus 7.1 ± 2.8 [95% CI, 6.3 to 7.9]; p = 0.007). Physician-reported procedure difficulty was similar between the groups (2.6 ± 2.0 [95% CI, 2.1 to 3.1] versus 2.8 ± 1.7 [95% CI, 2.3 to 3.3]; p = 0.69). CONCLUSIONS: AD is a practical, low-cost intervention that may reduce patient anxiety during lower-extremity skeletal traction pin insertion. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

The Clinical Application of Double Taylor Spatial Frame in Segmental Tibial Fracture.

OBJECTIVES: Multi-planar external fixation has been used for the management of segmental tibial fractures with severe soft tissue injuries. However, fewer specialized studies have been reported. The primary aim of this study was to describe our experience of treating fractures of this type using the Taylor Spatial Frame and Ilizarov external fixation methods. METHODS: We retrospectively analyzed 33 patients with segmental tibial fracture treated at our institution between January 2016 and December 2020. The patients were divided into double Taylor Spatial Frame (D-TSF) and Ilizarov groups based on the external fixation structure. Baseline demographic data included sex, age, injury side and cause, open or closed fracture, time from injury to surgery, complications, and external frame removal and fracture healing time. The hip-knee-ankle angle (HKA) was measured from preoperative, immediate postoperative, and final follow-up full-length X-rays of bilateral lower limbs. We determined the degree of deviation in the HKA by calculating the difference between the measured angle and the ideal value of 180°; the absolute value was used to assess recovery of the lower limb force line. At the final follow-up, Johner-Wruhs tibial fracture outcome criteria (J-W TFOC) were used to classify the postoperative function of the affected limb as excellent, good, moderate, or poor. Count data were analyzed with the chi-square test or Fisher's exact test; the Mann-Whitney U test was used for rank data. RESULTS: No statistically significant differences were observed between the two groups in terms of sex, age, side of injury, cause of injury, closed or open fracture, or time between injury and surgery, which indicates that the groups were comparable (p > 0.05). A statistically significant difference was observed in external frame removal and fracture healing time between the D-TSF and Ilizarov groups (36.24 ± 8.34 vs 45.42 ± 10.21 weeks, p = 0.009; 33.33 ± 8.21 vs 42.00 ± 9.78 weeks, p = 0.011). The Johner-Wruhs criteria were used to assess the function of the affected limb, the D-TSF group performed better in correcting the lower limb force line than the Ilizarov group. A statistically significant difference in terms of excellent ratings was observed between the two groups (18/2/1/0 vs 5/5/1/1, p = 0.010). Postoperative follow-up X-rays demonstrated a significant improvement in the HKA in both groups immediately after surgery and at the final follow-up compared to the angle before surgery. At the final follow-up, a statistically significant difference was observed in the degree of deviation in the HKA between the two groups (1.58° ± 0.84° vs 2.37° ± 1.00°, p = 0.023). CONCLUSION: The D-TSF treatment is associated with minimal secondary damage to soft tissue, a straightforward and minimally invasive procedure, multiplanar stable fracture fixation, and optimization of fracture alignment and lower limb force lines, therefore, it is highly effective therapeutic option for segmental tibial fracture.

Biomechanical comparative study on external fixators of new configurations in the treatment of Tile C pelvic injury.

To compare the biomechanical properties of several anterior pelvic ring external fixators with two new configurations in the treatment of Tile C pelvic fractures, in order to evaluate the effectiveness of the new configurations and provide a reference for their clinical application. A finite element model of a Tile C pelvic ring injury (unilateral longitudinal sacral fracture and ipsilateral pubic fracture) was constructed. The pelvis was fixed with iliac crest external fixator (IC), anterior inferior iliac spine external fixator (AIIS), combination of IC and AIIS, combination of anterior superior iliac spine external fixator (ASIS) and AIIS, and S1 sacroiliac screw in 5 types of models. The stability indices of the anterior and posterior pelvic rings under vertical longitudinal load, left-right compression load and anterior-posterior shear load were quantified and compared. In the simulated bipedal standing position, the results of the vertical displacement of the midpoint on the upper surface of the sacrum are consistent with the displacement of the posterior rotation angle, and the order from largest to smallest is IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. The longitudinal displacement of IC is greater than that of the other models. The displacements of ASIS + AIIS and IC + AIIS are similar and the latter is smaller. In the simulated semi-recumbent position, the vertical displacement and posterior rotation angle displacement of the midpoint on the upper surface of the sacrum are also consistent, ranking from large to small: IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. Under the simulated left-right compression load state, the lateral displacements of the highest point of the lateral sacral fracture end are consistent with the highest point of the lateral pubic fracture end, and the order from large to small is S1 screw, IC, AIIS, ASIS + AIIS and IC + AIIS, among which the displacements of S1 screw and IC are larger, and the displacements of ASIS + AIIS and IC + AIIS are similar and smaller than those of other models. The displacements of IC + AIIS are smaller than those of ASIS + AIIS. Under the simulated anterior-posterior shear load condition, the posterior displacements of the highest point of the lateral sacral fracture end and the highest point of the lateral pubic fracture end are also consistent, ranking from large to small: IC, AIIS, ASIS + AIIS, IC + AIIS and S1 screw. Among them, the displacements of IC and AIIS are larger. The displacements of ASIS + AIIS and IC + AIIS are similar and the latter are smaller. For the unstable pelvic injury represented by Tile C pelvic fracture, the biomechanical various stabilities of the combination of IC and AIIS are superior to those of the external fixators of conventional configurations. The biomechanical stabilities of the combination of ASIS and AIIS are also better than those of the external fixators of conventional configurations, and slightly worse than those of the combination of IC and AIIS. Compared with sacroiliac screw and conventional external fixators, the lateral stabilities of IC + AIIS and ASIS + AIIS are particularly prominent.