Femoral Stem Selection Impact on Outcomes After Conversion Total Hip Arthroplasty

Overview

This retrospective study analyzed 51 patients undergoing conversion total hip arthroplasty (cTHA) after proximal femoral fracture fixation, assessing femoral stem types used and their association with patient outcomes and survivorship. The study found that stem selection correlated with patient age and prior fixation type, but no significant differences in survivorship or patient-reported outcomes were observed between stem types.

Background

Proximal femur fractures are common and often treated surgically with sliding hip screws (SHS) or cephalomedullary nails (CMN). Some patients subsequently require conversion to total hip arthroplasty (cTHA) due to complications such as osteoarthritis or nonunion. Compared to primary THA, cTHA has lower survivorship and higher complication rates, resembling revision THA more closely. Despite various femoral stem options available for cTHA, limited data exist on how stem type affects outcomes or how fracture patterns influence stem selection.

Data Highlights

Key Findings

• Cemented stems were preferentially used in older patients compared to uncemented stems.
• Most patients had prior fixation with cephalomedullary nails (86.3%), with fewer treated with sliding hip screws (13.7%).
• No significant differences in survivorship or patient-reported outcome measures (HOOS, JR.) were observed between different femoral stem types at mid-term follow-up.
• Radiographic osteoarthritis was present in 90% of patients prior to cTHA regardless of primary diagnosis.
• The study proposed a novel radiographic measurement (Stem to Screw distance) to guide femoral stem selection in cTHA, though detailed results were not provided in the excerpt.

Clinical Implications

Surgeons performing cTHA after proximal femoral fracture fixation can consider patient age and prior fixation type when selecting femoral stem type, with cemented stems favored in older patients. Given the lack of significant differences in outcomes between stem types, stem selection may be individualized based on patient and fracture characteristics. The novel radiographic measurement introduced may aid preoperative planning to optimize stem choice and implant longevity.

Conclusion

Femoral stem selection in conversion total hip arthroplasty after proximal femoral fracture fixation correlates with patient age and prior fixation method but does not significantly impact mid-term survivorship or patient-reported outcomes. The proposed radiographic protocol offers a promising tool to guide stem choice and improve surgical planning.

References

1. Arbeitsgemeinschaft für Osteosynthesefragen (AO)/Orthopaedic Trauma Association (OTA) system -- Fracture classification
2. Hip dysfunction and Osteoarthritis Outcome Score for Joint Replacement (HOOS, JR.) -- Patient-reported outcome measure