Correlations between the femoral neck osteotomy angle and radiologic and clinical outcomes analyzed in patients undergoing total hip replacement with metaphyseal fixation.

OBJECTIVE: This study will explore whether the femoral neck osteotomy angle (FNOA) has an effect on hip anatomical functional reconstruction and clinical outcomes after total hip arthroplasty (THA). PATIENTS AND METHODS: The study included 254 patients (296 hips) who underwent primary total hip arthroplasty using the same uncemented short stem (Tri-Lock BPS) between December 2018 and December 2019. Correlations between FNOA and the radiologic and clinical outcomes of patients were analyzed. RESULTS: Patients were divided into 3 groups according to different FNOA. FNOA ≤50° is Group A, 50°< FNOA <55° Group B, and FNOA ≥55° Group C. There were significant differences among the three groups in distal D1 (p=0.029), sitting proud (SP) (p<0.001), varus and valgus alignment (p<0.001), FO (p=0.001), and caput-collum-diaphysis angle (CCD) (p<0.001). There were significant differences in the incidence of complications among the three groups (p<0.007). There was a significant linear correlation with D1 (B=0.005, CI=0.002 to 0.008, p=0.004), SP (B=-0.266, CI=-0.286 to 0.166, p<0.001), the femoral stem varus-valgus alignment angle (B=-0.359, CI=-0.422 to -0.297, p<0.001), femoral offset (FO) (B=-0.500, CI=-0.795 to -0.205, p=0.001), and CCD (B=0.696, CI=0.542 to 0.849, p<0.001). In logistic regression analysis, inappropriate FNOA increased the risk of dislocation (OR=0.892, CI=0.812 to 0.979, p=0.016) and thigh pain (OR=0.920, CI=0.851 to 0.995, p=0.037). CONCLUSIONS: The study demonstrates the relationship between FNOA and short-term radiological and clinical outcomes of patients after THA using a Tri-Lock femoral prosthesis. Inappropriate FNOA was significantly associated with failure of hip anatomical reconstruction and a higher risk of complications. [ABSTRACT FROM AUTHOR]