Poor outcomes for osteoporotic patients undergoing conversion total hip arthroplasty following prior failed dynamic hip screw fixation: a nationwide retrospective cohort study

OBJECTIVES: This study was performed to compare the long-term clinical and radiological outcomes of conversion total hip arthroplasty (CTHA) following prior failed InterTan nail (IT) fixation or dynamic hip screw (DHS) fixation in Asian patients with osteoporotic intertrochanteric hip fractures (IHFs) and to clarify which implant tends to be more favourable for CTHA. METHODS: Records of consecutive Asian patients with osteoporosis who underwent conversion of failed primary unilateral IT or DHS fixation to THA from 2010 to 2013 were extracted from the comprehensive database of the China Pacific Insurance Company Ltd. All consecutive procedures were managed by high-volume surgeons. The primary endpoint was the clinical outcome. The secondary endpoint was the radiological outcome. RESULTS: In total, 447 Asian patients with osteoporotic IHFs (DHS, n = 223; IT, n = 224) were assessed during a median follow-up of 46 months (range, 39–53 months). The two groups showed a significant difference in the Harris hip score at final follow-up and in the orthopaedic complication rate (DHS, 20.2%; IT, 9.8%). CONCLUSION: Conversion to THA following prior failed DHS fixation tends to be associated with poorer clinical and radiological outcomes in Asian patients with osteoporotic IHFs than that following prior failed IT fixation.