Conversion vs Primary Total Hip Arthroplasty After Failed Osteosynthesis for Femoral Neck Fractures: A Retrospective Cohort Study

Patients undergoing conversion total hip arthroplasty (cTHA) after failed osteosynthesis for femoral neck fractures (FNF) exhibit similar short-term complication and mortality rates compared with those undergoing primary total hip arthroplasty for FNF, according to the results of a retrospective cohort study. Despite longer surgical times in the cTHA group, hospital length-of-stay, 90-day complications, and 6-month and 1-year mortality rates did not significantly differ between the two groups, researchers found. Their study was presented at the American Academy of Orthopaedic Surgeons 2025 Annual Meeting in San Diego, CA.

Osteosynthesis failure following proximal femoral fractures presents a significant clinical challenge, often necessitating a salvage procedure such as THA to preserve joint mobility and stability. Previous studies have indicated higher complication rates in cTHA compared to primary elective THA; however, limited research has directly compared postoperative outcomes between cTHA and primary THA in the context of FNF. This study aimed to assess whether cTHA leads to higher complication and mortality rates compared with primary THA.

This retrospective cohort study analyzed 106 patients treated at a tertiary care center between 2015 and 2022, with a minimum follow-up of 1 year. Patients had undergone initial management with cannulated screws, dynamic hip screw (DHS), trochanteric femoral nail (TFN), or hybrid THA. Data collection included demographics, surgical details, fracture characteristics, reasons for conversion, and postoperative complications classified using the Clavien-Dindo system. The primary outcome was the 90-day complication rate, while secondary outcomes included 90-day unplanned readmissions and mortality.

Among the 106 patients, 31 underwent cTHA, while 75 had primary THA. The most common reasons for conversion were screw cut-through and nonunion. Surgical time was significantly longer in the cTHA group (94.9 minutes vs. 74.9 minutes, P = .002). However, length-of-stay did not differ significantly (5.48 vs. 6.9 days, P = .12). In-hospital complication rates (9.7% vs. 4%, P = .35) and 90-day complications (19% vs. 12%, P = .36) were similar between groups. Mortality rates at 6 months (3.2% vs. 4%, P = 1) and 1 year (3.2% vs. 6.7%, P = .66) also showed no significant differences.

Although complication rates are similar, the study underscores the importance of thorough preoperative planning for cTHA due to the increased surgical complexity. The study authors noted that clinicians should also provide comprehensive counseling to patients and their families, explaining the rationale behind initial fracture management and clarifying that conversion to THA, if required, does not necessarily result in poorer outcomes. Clear communication can help set realistic expectations and facilitate informed decision-making about treatment options.

“It is crucial to emphasize that the treatment of hip fractures should be guided by the specific fracture pattern rather than the assumption that conversion to THA will necessarily result in higher complication rates,” the study authors concluded. “Our findings suggest that biological healing should be given the opportunity to succeed, and if it fails, the outcomes of patients who undergo conversion to THA are comparable to those who undergo THA for FNF in terms of complications. Therefore, it is important to provide thorough preoperative counseling to patients and their families.”

Reference
Lucero CM, Albani AF, Camacho Terceros LA, et al. Comparative outcomes of conversion to total hip arthroplasty after failed osteosynthesis versus total hip arthroplasty following femoral neck fractures: a comprehensive analysis. Presented at: American Academy of Orthopaedic Surgeons Annual Meeting; 2025. Accessed March 7, 2025. https://submissions.mirasmart.com/AAOS2025/Itinerary/PresentationDetail.aspx?evdid=23.