Clinical Outcomes of Bipolar Hemiarthroplasty versus Total Hip Arthroplasty: Assessing the Potential Impact of Cement Use and Pre-Injury Activity Levels in Elderly Patients with Femoral Neck Fractures

PURPOSE: This study was performed to analyze the potential impact of cement use and favorable pre-injury activity on clinical outcomes of bipolar hemiarthroplasty (BHA) compared with total hip arthroplasty (THA) in elderly patients with femoral neck fractures. MATERIALS AND METHODS: Systematic review and meta-analysis of 12 clinical studies (5 randomized controlled trials and 7 comparative studies). Subgroup analysis was performed based on type of fixation method (cemented vs. cementless) and in the patient with independent ambulation, respectively. RESULTS: A significantly higher dislocation rate was observed in patients treated with THA compared with those treated with BHA in individuals capable of independent ambulation before injury (odds ratio [OR], 0.17; 95% confidence interval [CI], 0.05–0.62; P=0.05, Z=1.98). Also, the dislocation rate was significantly higher in patients treated with cemented THA compared with those treated with cemented BHA (OR, 0.18; 95% CI, 0.05–0.62; P=0.006, Z=2.73). EQ-5D was significantly higher in those treated with cemented THA compared with patients treated with cemented BHA. Lastly, HHS was significantly higher in patients treated with cementless THA compared with those treated with cementless BHA. CONCLUSION: An increase in the dislocation rate was observed when THA was performed in elderly patients with femoral neck fracture and who were pre-injury independent walkers. In addition, cemented THA was associated with a higher dislocation rate compared with cemented BHA. However, the dislocation rate in those treated with cementless THA were similar to patients treated with cementless BHA. With regards to functional score, THA was superior to BHA in both cementless and cemented fixation.