Outcomes of salvage total hip arthroplasty after failed cannulated screw fixation of fractured neck of femur

Introduction

In a UK setting, cannulated hip screws (CHS) are frequently used to fix femoral neck fractures. Although often a relatively quick procedure and one that is delegated to more junior surgeons, failure rates of up to 23 % have been reported. The salvage procedure is total hip arthroplasty (THA). In this paper we report the outcomes of a series of THA for failed cannulated screw fixation.

Methods

Retrospective analysis of one of the largest reported single cohort of 600 CHS procedures spanning 14 years from 2007 to 2020 from a single centre was performed. This identified 55 patients who went on to have total hip arthroplasty, 36 women, 19 men, mean (SD) age: 71.5 (13.6) years. Patient characteristics, reason for fixation failure and complications were recorded. Oxford hip scores were available for 47 patients. Comparison was made with a series of patients who underwent primary THA for fracture.

Results

Failure rate of CHS was 9.2 % in our cohort. Mean (SD) time from fixation to arthroplasty was 15.5 (12.4) months. Two patients (3.6 %) patients had a postop complication, one requiring further surgery. Mean (SD) preoperative Oxford hip score was 11.4 (8.0). This improved to 38.8 (10.4) at 1 year and 32.1 (14.9) at 5 years postoperatively. This compares to a mean (SD) of 39.7 (8.6) at 1 year and 39.4 (8.1) at 5 years in a group of 185 patients undergoing primary THA for hip fracture. Displaced fractures that went on to failure had better postop scores than nondisplaced fractures.

Discussion

The failure rate of CHS is relatively low and the salvage procedure of THA has a minimal complication rate and outcomes as good as primary THA for hip fracture.