Conversion total hip arthroplasty following failed proximal femoral fixation: current concepts review
Amaan Merchant1, Elliot Onochie2, Babar Kayani2,3
1University College London - UCLMS, London, UK.
Introduction:
Failed internal fixation of proximal femoral fractures is associated with significant morbidity, mortality, and financial burden. Conversion total hip arthroplasty (THA) is a technically demanding salvage procedure associated with high risks of periprosthetic joint infection and instability.
Methods:
Independent searches of MEDLINE, EMBASE, and the Cochrane library were performed for studies published from 1990 onwards regarding conversion THA in adults following failed proximal femur fixation. Following screening, 34 studies were included in this review.
Results:
Predictors of failure include female sex, smoking, and tip-apex distance >25 mm. Preoperative screening for occult, extra-articular infection is vital, as pathogens often reside near hardware rather than within the joint. CT, ultrasound, and SPECT-CT are essential for assessing bone stock and identifying fluid collections. Dual-mobility cups effectively reduce dislocation rates to 0-3%. Functional scores improve significantly, though 10-year survivorship is approximately 86%.
Discussion:
Conversion THA provides substantial functional recovery but carries a 7-fold higher infection risk than primary THA. Success requires meticulous screening tailored to previous hardware sites and selecting femoral fixation based on bone quality and cortical defects. Specialised implants are essential for optimising long-term outcomes in this high-risk population.
