Long-term results of total hip arthroplasty for femoral neck fracture nonunion

Background: Hip arthroplasty for the treatment of nonunion at the site of a femoral neck fracture has provided good short-term results. The purpose of the present study was to evaluate the long-term results and complications of total hip arthroplasty for the treatment of femoral neck nonunion. Methods: The records of ninety-nine patients who had been managed with total hip arthroplasty with use of a cemented Charnley acetabular component and a cemented Charnley monoblock femoral component for the treatment of a femoral neck nonunion were retrospectively reviewed. The average age at the time of the arthroplasty was sixty-eight years. Eighty-four patients (85%) were followed until death, revision, or component removal or for at least two years (mean, 12.2 years) postoperatively. Results: Twelve patients were treated with revision (eleven) or resection arthroplasty (one), eleven were lost to follow-up, and four died less than two years postoperatively. Of the remaining seventy-two unrevised hips that were followed for at least two years, sixty-nine (96%) had no or mild hip pain at the time of the last follow-up. The rate of component survival free of revision or removal for any reason was 93% at ten years and 76% at twenty years. The risk factors that were significantly associated with revision for aseptic loosening included an age of less than sixty-five years at the time of the arthroplasty (p = 0.045), a body-mass index of greater than or equal to30 (p < 0.01), and male gender (p = 0.02). The second most common complication after loosening was dislocation, which occurred in nine patients (9%). Conclusions: Total hip arthroplasty is an effective method for the treatment of nonunion of the femoral neck and provides satisfactory long-term results. However, the rate of implant survival is poorer than that reported in most other studies of Charnley total hip arthroplasty in the general population. Level of Evidence: Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.