Conversion of failed hip hemiarthroplasties after femoral neck fractures

Hemiarthroplasty has been the preferred treatment for fractures of the femoral neck in elderly patients. The objective of the current study was to assess the outcome of revision of failed hemiarthroplasty to total hip arthroplasty in patients with a primary diagnosis of a femoral neck fracture. One hundred thirty-two conversions were done in 108 women and 24 men. One hundred two cemented and 30 uncemented hemiprostheses were revised to 88 cemented, 17 uncemented, and 27 hybrid total hip arthroplasties and the patients were followed up an average of 7.1 years (range, 5.1-15.3 years). Nine hips (6.8%) were revised for loosening and four additional hips (3%) were loose at the last followup. Survivorship free of revision was 96.5% (95% confidence interval, 93%-100%) at 5 years and 92% (95% confidence interval, 86%-98%) at 10 years. Major perioperative complications occurred frequently (45%), including 12 intraoperative femoral fractures (9%) and 13 dislocations (9.8%) Three of 12 (25%) of the intraoperative femoral fractures developed later femoral component loosening and all occurred during conversion of an uncemented Austin-Moore type hemiprosthesis. Conversion of endoprostheses to total hip arthroplasties after femoral neck fractures is fraught with high complication and loosening rates. Careful patient selection for each type of arthroplasty (hemiarthroplasty versus total hip arthroplasty) may help ameliorate the outcome of arthroplasty for patients with femoral neck fractures.