Outcomes of Conversion Total Hip Arthroplasty From Free Vascularized Fibular Grafting

Conversion total hip arthroplasties (THAs) from prior free vascularized fibular grafting (FVFG) are infrequently reported in the literature. We characterized the perioperative outcomes of patients undergoing conversion THA and compared them with those of a matched cohort of patients undergoing primary THA for osteonecrosis of the femoral head and neck (ONFHN).

The institutional database was queried for patients with FVFG requiring conversion to THA. This cohort was then matched 1:1 for age, gender, and American Society of Anesthesiologists (ASA) score for patients with ONFHN undergoing primary THA. Medical records were reviewed for intraoperative and postoperative complications, which were then compared between conversion and primary THA patient cohorts.

Two hundred eighty-eight THA patients were included for analysis (144 patients with FVFG matched to 144 patients with ONFHN and no prior FVFG). Patients with prior FVFG who underwent THA had significantly greater operative time and blood loss (P < .001). Although not significant, there were more intraoperative fractures in the FVFG cohort (P = .053). Postoperatively, patients with FVFG had significantly greater blood transfusions (P < .001) and hematoma formation (P = .004) than the matched cohort. There was no difference in length of stay, discharge disposition, or venous thromboembolism; however, patients who underwent conversion THA showed increased deep infection (P = .044) and rate of return to the operating room (P = .010).

Although there are numerous treatment strategies for patients with ONFHN, many patients will ultimately require THA. Patients undergoing conversion after FVFG are more likely to have complications including increased blood loss, hematoma formation, and intraoperative fractures. Consequently, surgeons should concentrate on preoperative optimization and prepare for specific technical challenges.