Injury-to-surgery interval does not affect the occurrence of osteonecrosis of the femoral head: a prospective study in a canine model of femoral neck fractures.

BACKGROUND: It is controversial whether an early reduction and internal fixation can reduce the occurrence of femoral neck fracture-induced osteonecrosis of the femoral head (ONFH). This prospective study was designed to reflect the relationship between injury-to-surgery interval (ISI) and traumatic ONFH based on a canine model of femoral neck fractures. MATERIAL/METHODS: Twenty-four dogs were equally divided randomly into 3 groups. A lateral L-shape approach centered left great trochanter was used for exposure of the femoral neck. A low-speed drill was used for making displaced fractures in the narrow femoral neck, with the femoral head kept in situ with ligamentum teres intact. In Group A, the fracture was immediately reduced and fixed with 3 parallel pins; while the operation was done 3 days later in Group B, and 3 weeks later in Group C. Another 2 dogs had their fractures untreated. Postoperatively, all dogs were fed separately and received regular x-ray examination. Left femoral heads were harvested for histological examination with a postoperative follow-up of 3.5 months. RESULTS: The canine model of femoral neck fractures could be achieved successfully. Radiological signs of post-fracture ONFH could not be detected at intervals of 2 weeks, 4 weeks, 1 month and 2 months. Histologically, there were 2 cases with ONFH in Group A, 1 case in Group B, and 2 cases in Group C. The difference had no statistical significance. For untreated fractures, obvious ONFH could be found radiologically. CONCLUSIONS: A shorter ISI may not reduce the incidence of fracture-induced ONFH, which suggests that intrinsic factors play an important role in the occurrence of ONFH.

Pain relief following osteonecrosis of the femoral head treated by free vascularized fibular grafting.

BACKGROUND: Pain is the core and basic problem in the treatment of osteonecrosis of the femoral head (ONFH). However, it is unclear about the status of pain relief following ONFH treated by free vascularized fibular grafting (FVFG) and the level of pain relief contributed to clinical results. Therefore, we designed a consecutive and prospective study to investigate post-operative pain relief in the treatment of osteonecrosis of the femoral head by FVFG. METHODS: One hundred and fifty-one patients with unilateral osteonecrosis of the femoral head were enrolled consecutively for current prospective study from January to August of 2006. Patients were managed by modified technique of free vascularized fibular grafting. Pre-operative, post-operative Harris hip score (HHS) and Harris pain score (HPS) were recorded and compared statistically, meanwhile, correlation between disease severity and Harris hip score, Harris pain score were revealed. RESULTS: All patients had an average follow-up of 54.3 months. Post-operative Harris hip score could be improved from 73.7 to 83.5 averagely in stage-II patients, 64.6 to 78.9 in stage-III, and 53.6 to 72.4 in stage-IV. As for Harris pain score, it was elevated from 28.8 to 38.6 in stage-II patients, 25.5 to 36.6 in stage-III, and 21.8 to 34.2 in stage-IV. Taken together, HHS was improved from 67.7 to 80.3 (ΔHHS = 12.6), and HPS was improved from 26.6 to 37.3 (ΔHPS = 10.7) averagely. CONCLUSIONS: Harris pain score could be employed to monitor prognosis of osteonecrosis of the femoral head treated by free vascularized fibular grafting. Improvement of HPS was the heaviest contributor to elevation of HHS, and both of them conceived of a close relationship with disease severity.

Treatment of aseptic nonunion after intramedullary nailing fixation with locking plate.

OBJECTIVE: To evaluate the safety and efficacy of locking plate combined with bone grafting in the treatment of aseptic nonunion following intramedullary nailing fixation of fractures of the long bones. METHODS: Thirty-eight consecutive patients treated in our hospital between January 2004 and December 2006 were included in this retrospective study. The nonunions included 20 femurs, 15 tibias, and 3 humeri. The duration of non-union ranged from 6 to 84 months and 21 (55.3%) of them were located around the metaphysis of the affected long bones. There were 12 women and 26 men with a mean age of 39.2 years (range, 9-70 years). Locking plate combined with bone grafting was the procedure chosen to treat every case of nonunion in this series. The clinical outcomes were evaluated. RESULTS: All patients were followed up for 6-20 months (average 11.6 months). After locking plate fixation combined with bone grafting, union was achieved in all cases, the average healing time being 5.3 months (range, 4-8 months). Infection of the superficial incision occurred in three cases (7.9%) and delayed healing of the incision in one case, all of which healed with no further complications. The function of the adjacent joints was excellent to good in 30 patients (78.9%), fair in 7 (18.4%) and poor in 1 (2.6%) after follow-up. CONCLUSION: Locking plate fixation combined with bone grafting is a highly effective treatment for aseptic nonunions of the long bones after intramedullary nailing fixation, especially in the case of metaphyseal nonunion.

[The surgical technique and follow-up of the treatment with locking internal fixation on long bone nonunion of extremities].

OBJECTIVE: To report the outcome of long bone nonunion of humerus, femur and tibia treated with locking internal fixation and bone graft. METHODS: From February 2003 to October 2006, locking internal fixation and bone grafting were employed to treat 5 cases at humerus, 33 cases at femur, 23 cases at tibia. Forty-four of the patients were men, and 17 were women. The mean age was 38 years (range 7-70 years). The nonunion had resulted from failure of internal fixation in 47 cases, failure of external fixation in 5 cases, infection in 9 cases. The history of nonunion lasted from 10 to 156 months (mean 19 months). There were 42 patients treated with locking compression plate (LCP), and 19 patients with less invasive stabilization system (LISS). For bone grafting, autogenous ilium was used in 55 patients, autogenous ilium and allograft bone was used in 3 patients, allograft bone and Wright DBM artificial bone was used in 3 patients. RESULTS: All the 61 patients were followed up for an average 12 months (range 6-24 months) only to reveal solid bone union in all the fracture, with a mean healing time of 4.8 months (ranged from 4 to 6 months). No loosening or breakage of the implants occurred in this series. The Knee Society Scores (KSS) was used to evaluate knee function in 47 patients with peri-knee joint nonunion, excellent result were seen in 35 patients, good in 7 patients, fare in 1 patients, poor in 4 patients. CONCLUSION: Locking internal fixation can be used to treat effectively bone nonunion at the humerus, femur and tibia.