Predictors of early failure of fixation in the treatment of displaced subcapital hip fractures.

ABSTRACT

OBJECTIVE: To examine predictors of fixation failure in the treatment of displaced subcapital hip fractures. DESIGN: Retrospective study. METHODS: All patients aged sixty-five years and older discharged from a large teaching hospital after treatment for displaced subcapital fracture between April 1, 1989 and February 29, 1995 were identified (n = 344). Of these, 108 patients treated with internal fixation became the study group. Clinical information included demographics, implant, comorbidity, complications, mortality, surgeon' s assessment of reduction, and need for revision. Preoperative x-ray information Garden grade, Singh Index, Pauwel's angle, medial neck and femoral shaft cortex width, and displacement of fracture fragments. Postoperative Quality of reduction, a visible gap or step, evidence of union, fracture collapse, and failure. RESULTS: The failure rate was 31 percent. The two most important predictors were varus reduction and perceived difficulty in achieving reduction. If the patient had a varus reduction or the surgeon had difficulty achieving a satisfactory reduction, fixation was 4.3 times more likely to fail (p = 0.007). If the patient had a varus reduction and reduction was difficult, fixation was 13.6 times more likely to fail (p = 0.04). Under this latter scenario, 75 percent of the fixations failed. CONCLUSION: In a fracture of the neck of the femur, if difficulty is encountered in obtaining a closed reduction or there is residual varus angulation, the chance of subsequent fixation failure is high. Hemiarthroplasty may be considered in these cases.