Constrained acetabular liner total hip arthroplasty versus conventional hemiarthroplasty for unstable comminuted femoral intertrochanteric fractures in elderly patients with neurological disorders

BACKGROUND: To evaluate whether constrained acetabular liners (CAL) used in total hip arthroplasty (THA) reduce the risk of dislocation and related complications in patients with neuromuscular disorders and unstable comminuted femoral intertrochanteric fractures (ITF). METHODS: This retrospective cohort study included patients diagnosed with Evans type III-V ITFs who underwent hemiarthroplasty or THA at our institution from July 2011 to July 2016. Patients were divided into two groups: a hemiarthroplasty group and a CAL group. Radiological data, clinical records, and laboratory test results were meticulously collected. Differences between the two groups were analyzed to support clinical decision-making regarding treatment strategies. RESULTS: Significant differences were observed between the two groups in operation duration (90.50 ± 25.12 vs. 110.10 ± 26.38 min, P = 0.008), intraoperative blood loss (205.12 ± 68.50 vs. 275.58 ± 83.36 mL, P = 0.003) and blood transfusion rate (16.67% vs. 30.87%, P = 0.012). Compared to hemiarthroplasty, CAL was associated with a significantly higher risk of heterotopic ossification (HO) (Odds ratio = 1.198, 95% CI: 1.020-1.850), a higher risk of aseptic loosening (Odds ratio = 1.155, 95% CI: 0.708-1.782), and a lower risk of dislocation (Odds ratio = 0.120, 95% CI: 0.022-0.552). CONCLUSIONS: Among patients with neurological disorders undergoing HA for unilateral unstable comminuted femoral ITF, CAL THA was correlated with a lower postoperative dislocation rate but increased risks of aseptic loosening and HO. Despite reducing dislocation risk, the overall clinical benefits of CAL appeared limited. Additionally, no significant differences in long-term hip function outcomes were observed between CAL and conventional hemiarthroplasty.