股骨颈保留型人工全髋关节置换后的应力分析

Stress distribution after total hip arthroplasty with a neck-retaining femoral prosthesis

背景:股骨颈保留型(Collum Femoris Preserving,C.F.P)假体为意大利骨科医生Pipino与德国LINK公司联合设计开发。该假体手术操作手册中推荐截骨平面是否适合国人股骨结构特点以及所采用截骨方式是否会引起假体以及股骨应力发生变化,目前尚未见研究报告。目的:通过临床病例回顾和三维有限元模型分析股骨颈保留型人工全髋关节置换的临床疗效以及应力分布变化。方法:①回顾分析36例股骨颈保留型全髋关节置换及36例普通生物型全髋关节置换患者临床资料,通过Harris评分、目测类比评分、置换前后偏心距变化、IDES-Engh放射学及并发症等指标评价疗效。②建立两种不同截骨平面股骨颈保留型全髋关节置换有限元分析模型,分析股骨转子间窝上1.5 cm及头颈交界处为截骨平面带来的偏心距差异、股骨以及假体应力分布变化。结果与结论:①头颈交界处为截骨平面的股骨颈保留型全髋关节置换,短期随访临床疗效优良,与普通生物型无明显差别。②有限元分析显示:头颈交界为截骨平面与转子间窝上1.5 cm为截骨平面比较,偏心距增大,假体及股骨所受应力增大,但应力分布相同。

BACKGROUND：Col um Femoris Preserving prosthesis is developed by Pipino, an Italian surgeon, and LINK （Germany）. Whether the femoral osteotomy plane recommended in the surgical manual is suitable for Chinese people and whether the osteotomy method can cause stress changes of the prosthesis and femur has not been yet reported. OBJECTIVE：Based on clinical reviews and three-dimensional finite element model, to analyze the clinical efficacy of total hip arthroplasty with Col um Femoris Preserving prosthesis and relevant stress distribution. METHODS：We retrospectively analyzed 36 patients undergoing total hip arthroplasty with neck-retaining femoral prosthesis and 36 patients receiving total hip arthroplasty with biotype prosthesis in terms of Harris scores, visual analog scale scores, preoperative and postoperative easurements of eccentricity changes, IDES-Engh radiological evaluation and the incidence of complications. Two different osteotomy plane finite element analysis models were created to analyze the eccentricity difference and changes in the stress distribution of prosthesis and femur when the osteotomy plane was set 1.5 cm above the intertrochanteric fossa or at the junction of femoral head and neck. RESULTS AND CONCLUSION：Neck-retaining total hip arthroplasty with the osteotomy plane set at the junction between the head and neck achieved good short-term outcomes, showing no difference from total hip arthroplasty with normal biological prosthesis. The finite element analysis showed that the eccentricity increased and the stress on the prosthesis and femur also increased when the osteotomy plane was set at the junction of femoral head and neck compared with that set 1.5 cm above the intertrochanteric fossa. But there was no difference in stress distribution between two osteotomy planes.