Total Hip Arthroplasty After In Situ Fixation of Minimally Displaced Femoral Neck Fractures in Elderly Patients

Background In situ screw fixation remains the most common treatment for minimally displaced femoral neck fractures (FNFs). Total hip arthroplasty (THA) can be used as a salvage procedure, but the results of conversion THA in this population have not been evaluated. The goals of this study were to evaluate (1) unique complications associated with conversion THA, (2) implant survivorship free of revision and reoperation, (3) radiographic results, and (4) clinical outcomes in patients undergoing conversion THA after in situ fixation of nondisplaced FNFs. Methods Between 2000 and 2014, 62 consecutive patients >65 years of age who underwent THA after in situ fixation of minimally displaced FNFs were identified. Indications were osteonecrosis (44%), post-traumatic/degenerative arthritis (35%), and nonunion (21%). Mean age was 78 years, and 73% patients were women. Mean follow-up was 5.5 years. Results One patient was revised for aseptic femoral loosening at 11 years. One patient underwent debridement and modular component exchange at 10 years for acute hematogenous periprosthetic joint infection. Two patients underwent acute reoperation without component exchange (one superficial wound infection, one hematoma evacuation). Survivorship free of reoperation for any indication was 97% at 5 years. No patients with surviving implants had radiographic evidence of loosening at 5 years. Harris hip scores improved from 35-85 (P <.01) after THA. Conclusion Conversion THA was associated with clinical improvement, a low rate of complications, and excellent implant durability. Risks of loosening, dislocation, and periprosthetic fracture can be minimized with appropriate operative strategies and perioperative management.