Outcomes of Total Hip Replacement for Failed Hemiarthroplasty.

Abstract

Our study aims to analyze the outcomes of conversion total hip replacement (THR) done for failed hemiarthroplasty. We retrospectively analyzed 104 consecutive patients who underwent conversion THR for failed hemiarthroplasty between January 2012 and December 2018. The patient's records were analyzed for demographic information, index surgery details, preoperative functional status, and perioperative complications. Patients were analyzed according to the various modes of failure of hemiarthroplasty. The radiographs were analyzed for any progressive osteolysis, cup migration and stem subsidence. All the patients were evaluated using the modified Harris hip score (HHS) for clinical outcome. Complications, revision or reoperation in the follow-up period was recorded. A total of 73 patients were included in the study for final analysis after exclusion criteria. The average follow-up was 48.2 ± 29.6months. There was a significant improvement in mean HHS from 38.5 ± 9.1 preoperatively to 80.9 ± 4.3 at the last follow-up (p < 0.05). The different modes of failure had no statistically significantdifference in the postoperative Harriship score (p = 0.393). None of the patients had progressive radiolucent lines more than 2mm or significant subsidence in the final follow-up compared to the initial postoperative radiograph. There was one deep infection, one patient had grade 2 heterotopic ossification, intraoperative calcar fracture was fixed with cerclage wiring in 11 patients, and postoperative periprosthetic fracture in two patients was treated with plate osteosynthesis. There were no neurovascular complications or dislocation during the follow-up. Conversion THR for failed hemiarthroplasty is a challenging procedure and results in good functional outcome and provides reliable pain relief. Conversion THA for septic loosening by two stage revision have comparable postoperative outcomes like THA for aseptic loosening. Caution is required owing to high incidence of peri-prosthetic fracture during conversion THA. Dislocation rate is negligible even with smaller head provided the prosthesis is implanted in the proper orientation and adequate soft tissue balancing is achieved.