Vascularized Fibular Grafting In Treatment Of Femoral Neck Nonunion: A Prognostic Study Based On Long-term Outcomes

Objective: The purpose of this study was to evaluate the long-term efficacy and prognostic factors of revision surgery with free vascularized fibular grafting combined with internal fixation in treatment of femoral neck nonunion.Methods: We prospectively enrolled patients who underwent revision surgery with free vascularized fibular grafting combined with internal fixation between January 2001 and January 2013 in a tertiary hospital in China.A total of 98 patients with either minimum five-year follow up were included for analysis.Demographic information,preoperative neck shortening ratio(pre-NSR),fixation method and postoperative radiographic parameters including postoperative NSR(post-NSR),neck-shaft angle(NSA)were enrolled for prognostic analysis.Results: At an average follow-up of 9.8 ± 3.5 years(5 to 17 years),the overall success rate of this surgical procedure was 76.5%(75/98).The success and failure groups had no significant differences in age,fixation method,interval between initial fixation and revision surgery and postoperative NSA.NSR were significantly higher in success group(pre-NSR: 77.8% versus 62.4%,P<0.001;post-NSR: 87.6% versus 78.4%,P=0.001).The receiver operator curve(ROC)analysis revealed an optimal cut-off for pre-NSR at 60% to predict the outcome.For those patients with a pre-NSR >60%,the success rate was 90.7%(68/75).Conclusion: Free vascularized fibular grafting combined with internal fixation is an effective method and still an important treatment option for treating nonunion of the femoral neck in young patients without severe preoperative shortening and neck resorption(preoperative NSR >60%).