Charcot neuroarthropathy of the knee due to idiopathic sensory peripheral neuropathy.

BACKGROUND: Charcot neuroarthropathy is a systemic disease that generates pathological changes in the musculoskeletal system, causing instability, dislocations, and deformities. Charcot neuroarthropathy of the knee, due to either diabetes mellitus or syringomyelia, is anecdotally reported with the epidemic of the diseases. However, idiopathic sensory peripheral neuropathy can inflict osteoarticular structures directly, inducing a dysfunctional Charcot neuroarthropathy. An early diagnosis and effective relief of the symptomatic deformity is essential for the treatment. CASE PRESENTATION: We report the case of a patient with idiopathic sensory peripheral neuropathy who presented with a swelling right knee, as well as distorted and painless gait disorder, diagnosed as Charcot neuroarthropathy of the knee. Partial weight bearing with a hinged knee brace was used to correct the abnormal alignment and gait posture, and bisphosphonates were prescribed to decrease pathological bone resorption. Although the alignment and Knee Society Score got a gradual deterioration, the combination of orthosis and pharmacy could alleviate the symptom to a certain extent. CONCLUSION: The diagnosis of Charcot neuroarthropathy of the knee is rare that requiring early diagnosis. The presence of features, including painlessness, numbness, and deformed arthropathy following chronic-onset algesthesia loss should be taken carefully.

A novel cerclage wiring technique in intertrochanteric femoral fractures treated by intramedullary nails in young adults.

BACKGROUND: Intertrochanteric femoral fractures (IFFs) in young adults, generally due to severe trauma, are increasingly presented. Different from IFFs in the geriatric population, these fractures in young adults are always comminuted and substantially displaced. Natural traction induced by musculature following IFFs determines closed reduction on a fracture table is extremely difficult. METHODS: To achieve anatomical reduction before intramedullary nail (IMN) fixation, we made an extended or a mini petrotrochantetic incision to facilitate temporary reduction using a pointed clamp. Subsequently, a curved and cannulated wire-passer was employed to pass through a multistrand cable to surround displaced fragments and strengthen intertrochanteric fixation. Afterward, a standard procedure was conducted to nail the fracture. RESULTS: We used the surgical technique in 9 young patients with an age range of 28~ 48 years old. The fractures were categorized as AO/OTA 31-A2.2 (3 cases) and 31-A2.3 (6 cases). The injury-to-surgery interval was 2.5 days on average. Mean operation time was 55 min. All fractures achieved anatomical reduction and healed within 14 weeks postoperatively without cable breakage, implant irritation or deep infection. CONCLUSIONS: In conclusion, the surrounding technique with cerclage wire in IFFs in young adults is an effective surgical technique with easily achieved anatomical reduction to facilitate operative maneuvers and fracture healing.

The Protective Effect of Cordycepin On Alcohol-Induced Osteonecrosis of the Femoral Head.

BACKGROUND: Alcohol abuse is known to be a leading risk factor for atraumatic osteonecrosis of the femoral head (ONFH), in which the suppression of osteogenesis plays a critical role. Cordycepin benefits bone metabolism; however, there has been no study to determine its effect on osteonecrosis. METHODS: Human bone mesenchymal stem cells (hBMSCs) were identified by multi-lineage differentiation. Alkaline phosphatase (ALP) activity, RT-PCR, western blots, immunofluorescent assay and Alizarin red staining of BMSCs were evaluated. A rat model of alcohol-induced ONFH was established to investigate the protective role of cordycepin against ethanol. Hematoxylin & eosin (H&E) staining and micro-computerized tomography (micro-CT) were performed to observe ONFH. Apoptosis was assessed by TdT-mediated dUTP nick end labeling (TUNEL). Immunohistochemical staining was carried out to detect OCN and COL1. RESULTS: Ethanol significantly suppressed ALP activity, decreased gene expression of OCN and BMP2, lowered levels of RUNX2 protein, and reduced immunofluorescence staining of OCN and COL1 and calcium formation of hBMSCs. However, these inhibitory effects were attenuated by cordycepin co-treatment at concentrations of 1 and 10 µg/mL Moreover, it was revealed that the osteo-protective effect of cordycepin was associated with modulation of the Wnt/ß-catenin pathway. In vivo, by micro-CT, TUNEL and immunohistochemical staining of OCN and COL1, we found that cordycepin administration prevented alcohol-induced ONFH. CONCLUSION: Cordycepin treatment to enhance osteogenesis may be considered a potential therapeutic approach to prevent the development of alcohol-induced ONFH.

Reverse Transfer of the Proximal Vascularized Fibula to Reconstruct the Lateral Malleolus: A Case Report and Literature Review.

Defects of the lateral malleolus and distal fibula occur occasionally, mainly because of severe trauma or wide resection of fibular neoplasms. These bony defects should be reconstructed to avoid persistent pain and to prevent an abnormal gait induced by ankle instability. Various methods of repair have been developed, including allografting, autologous iliac crest transplantation, scapular apophysis transplantation, and arthrodesis and prosthetic reconstruction. A reverse transfer of the proximal vascularized fibula is also effective. Its morphologic advantage is apparent, and the surgery is simple and direct, with no need for vascular anastomosis. We treated recurrent fibrous dysplasia in the distal fibula of a young male with wide resection and reconstruction using reverse transfer of the proximal, vascularized fibula. At the 6-year follow-up examination, the patient had an American Orthopaedic Foot and Ankle Society ankle-hindfoot score of 100, without any apparent complications. Additionally, we critically reviewed other methods for reconstructing the lateral malleolus and distal fibula and have concluded that reverse transfer of the proximal vascularized fibula compares favorably and could be the treatment of choice.

Transarticular fixation by hook plate versus coracoclavicular stabilization by single multistrand titanium cable for acute Rockwood grade-V acromioclavicular joint dislocation: a case-control study.

BACKGROUND: Hook plate (HP) is popularly used for acute and severely displaced acromioclavicular (AC) dislocations. However, subacromial impingement and acromion osteolysis induced by transarticular fixation are notorious. The current case-control study was to compare transarticular fixation by HP to coracoclavicular (CC) stabilization by single multistrand titanium cable (MSTC). METHODS: Between January 2006 and August 2009, 24 patients with acute AC dislocations were surgically treated by open reduction and transarticular fixation with HP. These patients were matched to a series of 24 patients, who were managed by CC stabilization with MSTC in the same period. All AC dislocations were graded as Rockwood type V. Implant was removed 8-12 months after the primary operation in all patients, and 12 months at least were needed to assess the maintenance of AC joint. Functional results were evaluated before implant removal as well as in the last follow-up based on Constant-Murley criteria. RESULTS: There were no differences of demographic data including age, dominant gender and side, injury-to-surgery interval, operation time and follow-up period. In terms of functionality, Constant score was 95.8 ± 4.1 in MSTC group, while 76.7 ± 8.0 in HP group before implant removal (P < 0.001). In detail, MSTC was superior to HP in pain, ROM and activities. Constant score was significantly improved to 86.1 ± 5.7 after hardware removal for patients in HP (P < 0.001). Degenerative change of acromioclavicular joint presented in 16 patients (66.7%) in patients treated by HP, while it was found in only 3 patients (12.5%) treated by MSTC (P < 0.001). CONCLUSIONS: MSTC is superior to HP for the treatment of Rockwood type-V acromioclavicular dislocation both before and after removal of the implant. Hardware removal is of great benefits for functional improvement in patients treated by HP.

Late surgery for acetabular fractures in a Chinese level I trauma centre: surgical experience and outcomes.

PURPOSE: Delayed surgical management of acetabular fractures, often necessary due to life-threatening concomitant injuries, is a great challenge because delays may potentially increase complications and decrease outcomes. We report clinical outcomes of 61 acetabular fractures treated by delayed open reduction and internal fixation (ORIF) with an injury-to-surgery interval (ISI) of 22-399 days. METHODS: Operations were performed between April 2001 and December 2008. There were 61 cases (42 men 19 women), with an average age of 38 years. All patients were followed for an average of 82 months. Demographic data, fracture pattern, ISI, concomitant injuries, surgical approach, complications and clinical outcomes were recorded and analysed. There were 16 simple fractures (26.2%) and 45 associated fractures (73.8%). Matta criteria were used to evaluate reduction quality. The Merle d'Aubigné and Postel scoring system was employed to assess post-operative functionality. RESULTS: Anatomical reduction was achieved in 45 cases (73.8%). The clinical result was excellent in 38 cases, good in 13, fair in six and poor in four. Osteonecrosis of the femoral head was observed in three cases, and heterotopic ossification was found in 28 cases. Four patients had transient palsy of the sciatic nerve. CONCLUSIONS: ORIF for fresh acetabular fractures might yield a better prognosis; however, for delayed acetabular fractures, clinical outcomes are also predictable when sophisticated surgical techniques are employed. Our results indicate that delayed ORIF could yield satisfactory clinical outcomes in the majority of patients with acetabular fractures.

Simultaneous bilateral fractures of the femoral neck caused by high energy: A case report and literature review.

Simultaneous bilateral fractures of the femoral neck are rare injuries, which are reportedly induced by low-speed energy with predisposing factors including systemic diseases, medications and eclamptic seizures. Those caused by high energy are even rarer. High energy-induced bilateral fractures of the femoral neck conceive of high incidence of mortality and present great challenges in the early management. We report one case of a 52-year-old man with simultaneous bilateral fractures of the femoral neck which resulted from a motor pedestrian accident. One-stage closed reduction and internal fixation was done following the emergent resuscitation and neurosurgical management for concomitant brain injuries. The fractures united. There was no pain in the hips, and they had a normal range of motion. The treatment protocol, mechanism of the injury and possible postoperative complications were discussed to expand a comprehensive understanding about these infrequent types of fractures.

Subtrochanteric femur fracture treated by intramedullary fixation.

PURPOSE: To discuss surgical technique, operative efficacy and clinical outcome of intramedullary fixation in the treatment of subtrochanteric femur fractures. METHODS: From February 2011 to February 2013, 76 cases of subtrochanteric femur fractures were treated by intramedullary fixation in our hospital, including 53 males and 23 females, with the age range of 37 -72 years (mean 53.5 years). According to Seinsheimer classification, there were 2 cases of type I, 7 type II, 15 type III, 23 type IV and 29 type V. Firstly, all patients underwent closed reduction with the guidance of C-arm fluoroscopy in a traction table. Two cases of type I and 3 cases of type III fractures had ideal closed reduction followed by internal fixation. The others needed additional limited open reduction. Radiographic examination was used to evaluate callus formation and fracture healing in postoperative 1, 3, 6 and 12 months follow-up. Functional recovery was evaluated by Harris Hip Scoring (HHS) system. RESULTS: Patients were followed up for 6-12 months. All fractures were healed except one patient with delayed union. The average bone union time was 4.5 months. According to HHS system, 65 cases were considered as excellent in functional recovery, 8 good, 2 fair and 1 poor. The proportion of the patients with excellent and good recovery was 96.05%. CONCLUSION: Intramedullary fixation is feasible for the treatment of subtrochanteric femur fracture. The accuracy of intraoperative reduction and surgical skill are important for the clinical outcome and the patients' prognosis.

Femur performed better than tibia in autologous transplantation during hemipelvis reconstruction.

BACKGROUND: Pelvic reconstruction after hemipelvectomy can greatly improve the weight-bearing stability of the supporting skeleton and improve patients' quality of life. Although an autograft can be used to reconstruct pelvic defects, the most suitable choice of autograft, i.e., the use of either femur or tibia, has not been determined. We aimed to analyze the mechanical stresses of a pelvic ring reconstructed using femur or tibia after hemipelvectomy using finite element (FE) analysis. METHODS: FE models of normal and reconstructed pelvis were established based on computed tomography images, and the stress distributions were analyzed under physiological loading from 0 to 500 N in both intact and restored pelvic models using femur or tibia. RESULTS: The vertical displacement of the intact pelvis was less than that of reconstructed pelvis, but there was no significant difference between the two reconstructed models. In FE analysis, the stress distribution of the intact pelvic model was bilaterally symmetric and the maximum stresses were located at the sacroiliac joint, arcuate line, ischiatic ramus, and ischial tuberosity. The maximum stress in each part of the reconstructed pelvis greatly exceeded that of the intact model. The maximum von Mises stress of the femur was 13.9 MPa, and that of the tibia was 6.41 MPa. However, the stress distribution was different in the two types of reconstructed pelvises. The tibial reconstruction model induced concentrated stress on the tibia shaft making it more vulnerable to fracture. The maximum stress on the femur was concentrated on the connections between the femur and the screws. CONCLUSIONS: From a biomechanical point of view, the reconstruction of hemipelvic defects with femur is a better choice.

Osteogenic induction protects rat bone marrow-derived mesenchymal stem cells against hypoxia-induced apoptosis in vitro.

BACKGROUND: Bone marrow-derived mesenchymal stem cells (BMSCs) undergo hypoxia-induced apoptosis when cells are transplanted from a normoxic to a hypoxic microenvironment in vivo. The effect of the osteogenic microenvironment on BMSCs under hypoxic conditions has not yet been revealed. MATERIALS AND METHODS: In the current study, we investigated the effects on BMSCs of hypoxia and osteogenic induction (OI) individually and in combination. We isolated BMSCs from rat bone marrow and confirmed them by recognition of surface antigens using cytometry. After passaging the BMSCs to the third generation, we treated them with the following conditions: 1% oxygen and OI, normoxia and OI, and 1% oxygen without OI; normoxia without OI was the control condition. On days 3, 7, 14, and 21, we detected the expression levels of hypoxia inducible factor-1α and alkaline phosphate via Western blotting. Cellular apoptosis was detected by Hoechst staining and terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine, 5'-triphosphate nick end labeling; caspase activity was also detected. RESULTS: The expression of hypoxia inducible factor-1α was induced and up-regulated when BMSCs were grown under 1% oxygen. The incidence of terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine, 5'-triphosphatenick end labeling-positive cells in the hypoxia plus OI group was much lower than that in the hypoxia group without OI. Caspase activity increased on days 3, 7, 14, and 21. The absolute value of caspase was statistically higher in the BMSC hypoxia group than in the other three groups, whose values were similar to each other. CONCLUSIONS: Osteogenic induction could protect BMSCs against hypoxia-induced apoptosis. Bone marrow-derived mesenchymal stem cells may be appropriate candidate cells for cytotherapy for skeletal diseases.

A novel rat model of osteonecrosis of the femoral head induced by periarticular injection of vascular endothelial growth factor receptor 2 antibody.

BACKGROUND: Traditional methods to establish animal model of osteonecrosis of the femoral head (ONFH) are not satisfactory because of the undefined underlying mechanism, low rate of the disease, and high incidence of mortality. The present study was to induce ONFH in a rat model through periarticular injection of vascular endothelial growth factor (VEGF) receptor 2 antibody. MATERIALS AND METHODS: Eighty Sprague-Dawley rats were divided into four groups randomly and equally. VEGF receptor 2 antibody solution with a concentration of 50 µg/mL (group A), 25 µg/mL (group B), and 12.5 µg/mL (group C) was injected periarticularly to the capsular attachment to proximal femur, respectively. The injection lasted 4 continuous days, with a total volume of 2 mL. The rats in the fourth group were treated by saline for control (group D). Two weeks after the first injection, histologic and micro-computed tomographic examinations were used to investigate the presence of ONFH. RESULTS: Histologically, there were 90% of rats that developed ONFH in group A, 60% in group B, and 20% in group C, whereas no ONFH was found in group D. The density of intraosseous vessels was suppressed significantly by the antibody. Radiologically, the features of ONFH including deformation of the femoral head were revealed. There was no occurrence of lethal complications. CONCLUSIONS: VEGF receptor 2 antibody can induce ONFH in the rat with a high incidence of the disease. Local blockage of angiogenesis can be used as an effective method to establish animal model of ONFH.

Unilateral free vascularized fibula shared for the treatment of bilateral osteonecrosis of the femoral head.

Between June 2007 and May 2008, 21 patients with bilateral osteonecrosis of the femoral head were surgically treated with implantation of free vascularized fibula obtained from the unilateral donor site. All patients were followed up clinically and radiographically for an average of 3.5 years. The evaluation included operative duration, blood loss, Harris hip score, incidence of complications, and radiological examinations. The time for fibular harvesting was 20min on average. Total operative duration was 100-240min, with an average of 150min. Blood loss averaged 300ml. All transplanted fibula integrated well to the femoral head 3.5years postoperatively with no severe complications observed. The results revealed that unilateral free vascularized fibula is effective for the treatment of bilateral osteonecrosis of the femoral head.

Modified surgical techniques of free vascularized fibular grafting for treatment of the osteonecrosis of femoral head: results from a series of 407 cases.

The goal for treatment of osteonecrosis of the femoral head (ONFH) is to relieve pain, preserve the contour of the femoral head, and delay the need for total hip arthroplasty. The free vascularized fibular grafting (FVFG) has been shown to support the subchondral architecture as well as restore local circulation for the necrotic femoral head in treatment of ONFH. This report aimed to present the clinical results of the use of a modified surgical technique of FVFG for treatment of ONFH. Four hundred and seven patients with 578 hips of ONFH were included. The patients' average age was 36.7 years old (ranging 19-55 years old). The disease was staged from II to V based on the Steinberg classification system. By the modified procedure, the vascularized fibular graft was harvested via a lateral incision with fibular osteotomy prior to the exposure of the vascular pedicle, and the removal of necrotic tissue and inset of graft were performed through an anterior approach. The operative time averaged 90 min for unilateral ONFH (ranging 75-110 min) and 190 min for simultaneous treatment of bilateral ONFH (ranging 160-230 min). The average length of follow-up was 5.0 years (ranging 3-10 years). The complications included one infection in one case, temporary loss of sensation of the thigh in eleven cases, and restricted motion of the great toe in nine cases. The Harris hip score of patients improved from 65.0 to 86.9 on average. Radiographic evaluation showed no changes in 331 hips (57.3%), improvement in 195 hips (33.7%) and necrosis progression in 52 hips (9.0%). Twenty-three hips (4.0%) in 20 patients had total hip arthroplasty during the period. These results show that the modified technique of the use of FVFG for treatment of ONFH yields similar postoperative results in comparison to the traditional method.

The effect of postoperative corticosteroid administration on free vascularized fibular grafting for treating osteonecrosis of the femoral head.

Free vascularized fibular grafting (FVFG) has been reported to be an effective method of treating osteonecrosis of the femoral head (ONFH). This study evaluated whether postoperative maintenance doses of corticosteroids had an adverse effect on FVFG outcomes in patients with corticosteroid-induced ONFH. We retrospectively reviewed the records of 39 patients (67 hips) who had received maintenance doses of corticosteroids following FVFG. This group was matched to a group of patients who had not received corticosteroids treatment after operation. The mean follow-up duration was 5.4 years for the postoperative corticosteroid administration group (PCA group) and 5.0 years for the control group. At the latest follow-up, the average increase in Harris hip score was 11.1 ± 8.7 points for all hips in the PCA group and 12.6 ± 7.4 points for all hips in the control group (P > 0.05). In the PCA group, through radiographic evaluation, 49 hips were improved, 10 hips appeared unchanged, and 8 hips appeared worse. In the control group, 47 hips were improved, 13 hips appeared unchanged, and 7 hips appeared worse. The results suggested that postoperative maintenance doses of corticosteroids do not have an adverse effect on FVFG outcomes in patients with corticosteroid-induced ONFH.

Logistic regression analysis of factors associated with avascular necrosis of the femoral head following femoral neck fractures in middle-aged and elderly patients.

BACKGROUND: Risk factors for femoral neck fracture-induced avascular necrosis of the femoral head have not been elucidated clearly in middle-aged and elderly patients. Moreover, the high incidence of screw removal in China and its effect on the fate of the involved femoral head require statistical methods to reflect their intrinsic relationship. METHODS: Ninety-nine patients older than 45 years with femoral neck fracture were treated by internal fixation between May 1999 and April 2004. Descriptive analysis, interaction analysis between associated factors, single factor logistic regression, multivariate logistic regression, and detailed interaction analysis were employed to explore potential relationships among associated factors. RESULTS: Avascular necrosis of the femoral head was found in 15 cases (15.2 %). Age × the status of implants (removal vs. maintenance) and gender × the timing of reduction were interactive according to two-factor interactive analysis. Age, the displacement of fractures, the quality of reduction, and the status of implants were found to be significant factors in single factor logistic regression analysis. Age, age × the status of implants, and the quality of reduction were found to be significant factors in multivariate logistic regression analysis. In fine interaction analysis after multivariate logistic regression analysis, implant removal was the most important risk factor for avascular necrosis in 56-to-85-year-old patients, with a risk ratio of 26.00 (95 % CI = 3.076-219.747). CONCLUSION: The middle-aged and elderly have less incidence of avascular necrosis of the femoral head following femoral neck fractures treated by cannulated screws. The removal of cannulated screws can induce a significantly high incidence of avascular necrosis of the femoral head in elderly patients, while a high-quality reduction is helpful to reduce avascular necrosis.

Free vascularized fibular grafting benefits severely collapsed femoral head in concomitant with osteoarthritis in very young adults: a prospective study.

Although free vascularized fibular grafting (FVFG) has been successfully employed for precollapsed osteonecrosis of the femoral head (ONFH), there are few reports concerning its radiographic and functional results for ONFH concomitant with osteoarthritis (OA) of the hip. In the current study, 12 patients with OA induced by traumatic ONFH were enrolled, with FVFG employed as the treatment protocol. The collapsed step of the cartilage surface was measured and compared with the postoperative value, and the Merle d'Aubigné scoring system was used to evaluate preoperative and postoperative status of the hip joint. The collapsed step disappeared, and sphericity of the femoral head could be restored at an average duration of 56 months postoperatively in seven patients. With regard to the severity of hip OA, six were improved to Grade 1 and one to Grade 2. In terms of functionality, all patients with a restored femoral head experienced postoperative improvement in pain relief, mobility, and functional capacity. The average Merle d'Aubigné score increased from 6.0 to 16.9 postoperatively (p < 0.001). In conclusion, for traumatic ONFH concomitant with OA, FVFG can confer benefits in the form of restoration of the contour of the femoral head and improvement in joint function.

Total hip arthroplasty in a 17-year-old girl with progressive pseudorheumatoid dysplasia.

Progressive pseudorheumatoid dysplasia is an autosomal recessively inherited skeletal disease. Progressive pseudorheumatoid dysplasia can involve multiple synovial joints, which then develop structural deformity and articular dysfunction. We report a case of progressive pseudorheumatoid dysplasia with polyarthropathy in a 17-year-old girl. Total hip arthroplasty was performed to treat persistent pain and stiffness by reconstructing a functional joint. Although we found arthroplasty to be an effective way of reconstructing a functional joint, treatment of the underlying cause is urgently required for this disease in the future.

Chronic calcaneal osteomyelitis associated with soft-tissue defect could be successfully treated with platelet-rich plasma: a case report.

Chronic osteomyelitis associated with soft-tissue defect following surgical management is a severe complication for orthopaedic surgeons. Traditionally, the treatment protocol for the notorious complication involved thorough debridement, bone grafting, long-term antibiotic use and flap surgery. Alternatively, platelet-rich plasma (PRP), a high concentration of platelets collected via centrifugation, has been successfully used as an adjuvant treatment for bone and soft-tissue infection in medical practices. PRP has numerous significant advantages, including stypsis, inflammation remission and reducing the amount of infected fluid. It increases bone and soft-tissue healing and allows fewer opportunities for transplant rejection. Through many years of studies showing the advantages of PRP, it has become preferred organic product for the clinical treatment of infections, especially for chronic osteomyelitis associated with soft-tissue defect. To promote the clinical use of this simple and efficacious technique in trauma, we report the case of a patient with chronic calcaneal osteomyelitis associated with soft-tissue defect that healed uneventfully with PRP.

Injury-to-surgery interval does not affect postfracture osteonecrosis of the femoral head in young adults: a systematic review.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) is a common and severe complication following femoral neck fractures in young adults. Despite significant advances in surgical techniques, radiological evaluation and comprehensive treatment for the prevention of ONFH, the incidence of traumatic ONFH has remained unchanged at approximately 20% in recent decades. The injury-to-surgery interval is considered as a principal factor affecting the occurrence of ONFH, and traditionally, femoral neck fractures are treated emergently. However, the relationship between the injury-to-surgery interval and ONFH occurrence is poorly understood, and previous reviews have not provided a precise explanation due to the lack of strict selection criteria for studies. METHODS: We reviewed previously published articles and included in current systematic review those studies with accurate multivariate analyses that included age, fracture type, operation method, follow-up, ONFH occurrence and injury-to-surgery interval. RESULTS: Six case studies were included and reevaluated. The studies included 263 hips for final analysis, with an overall incidence of postfracture ONFH of 17.5%. Patients were categorized into groups of less/more than 8 h, less/more than 24 h, less/more than 48 h and less/more than 3 weeks based on the individual injury-to-surgery interval. The postfracture ONFH incidence ranged from 13.3% (<8 weeks) to 21.7% (>3 weeks). Operations performed within 3 weeks of injury resulted in a lower ONFH incidence compared with operations performed after 3 weeks; however, this difference was not statistically significant. The ONFH incidence remained relatively stable when the operations were performed within 3 weeks of injury. CONCLUSIONS: The injury-to-surgery interval did not significantly affect the incidence of postoperative ONFH.