Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN; Indiana University Health Physicians, Orthopedics & Sports Medicine, IU Health Hip & Knee Center, Fishers, IN.
Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN.
J Arthroplasty. 2020 Jul;35(7):1868-1876. doi: 10.1016/j.arth.2020.02.024. Epub 2020 Feb 17.
Adequate interference fit and mechanical stability through optimal surgical technique are essential to prevent subsidence and loosening in cementless total hip arthroplasty. The purpose of this study is to determine the effect of surgical technique on radiographic subsidence and subsequent stability of a modern taper-wedge cementless stem.
A retrospective review of 250 consecutive cementless primary total hip arthroplasties performed by 2 surgeons was completed. Surgeon A vigorously broached, maximizing the mediolateral stem dimension and confirmed final broach stability with a torsional test, whereas Surgeon B did not. All patients received identical taper-wedge stems. Preoperative bone morphology (canal flare index), postoperative subsidence, and canal fill were radiographically assessed.
Canal flare index was not different between groups (P = .747). There was significantly less subsidence at 1 month for Surgeon A (0.3 vs 1.3 mm, P < .001). Additional subsidence at 1 year occurred in only 0.8% of Surgeon A (1/119) compared to 51.6% of Surgeon B stems (33/64, P < .001). Surgeon technique and canal fill measured at 60 mm below the lesser trochanter were the only variables predictive for subsidence, where Surgeon A and B had a mean canal fill of 95% and 86%, respectively. Surgeon B had 2 cases of aseptic loosening (2%) at 2 and 3 years postoperatively.
These observations support that maximizing mediolateral canal fill and avoiding under-sizing the femoral implant with meticulous broaching technique minimizes subsidence and optimizes stability of modern cementless taper-wedge stems. Failure to optimize canal fill with appropriate broaching and surgical technique may predispose femoral components to failure from aseptic loosening.
在无水泥全髋关节置换术中，为了防止下沉和松动，适当的干扰配合和通过优化手术技术获得的机械稳定性至关重要。本研究旨在确定手术技术对现代锥形骨水泥柄的放射学下沉和随后稳定性的影响。
对 2 名外科医生进行的 250 例连续无水泥初次全髋关节置换术进行回顾性研究。术者 A 剧烈扩髓，最大限度地扩大髓腔的内外径，并通过扭转试验确认最终扩髓的稳定性，而术者 B 则不这样做。所有患者均接受相同的锥形骨水泥柄。对术前骨形态（髓腔开口指数）、术后下沉和髓腔填充进行影像学评估。
两组间髓腔开口指数无差异（P=0.747）。术者 A 术后 1 个月的下沉量明显较少（0.3 毫米对 1.3 毫米，P＜0.001）。仅术者 A 组在 1 年内发生进一步下沉的患者比例为 0.8%（1/119），而术者 B 组为 51.6%（33/64，P＜0.001）。术者技术和小转子下 60 毫米处测量的髓腔填充是预测下沉的唯一变量，其中术者 A 和 B 的髓腔填充均值分别为 95%和 86%。术者 B 有 2 例在术后 2 年和 3 年发生无菌性松动（2%）。
这些观察结果支持通过精细扩髓技术最大限度地增加髓腔内外径填充并避免缩小股骨植入物的尺寸，可以减少下沉并优化现代骨水泥锥形骨水泥柄的稳定性。未能通过适当的扩髓和手术技术优化髓腔填充可能会使股骨部件易于发生无菌性松动导致失效。
