Gaillard-Campbell Dani M, Gross Thomas P
Midlands Orthopaedics & Neurosurgery, 1910 Blanding Street, Columbia, SC 29201, USA.
Adv Orthop. 2019 Jul 4;2019:9315104. doi: 10.1155/2019/9315104. eCollection 2019.
We investigate the efficacy of a modified acetabular bone-preparation technique in reducing the incidence of two clinical problems identified in hip resurfacing arthroplasty. The first issue is failure due to lack of bone ingrowth into the acetabular component. The second is a newly recognized phenomenon of early cup shift. We hypothesize that these issues might be resolved by using a "wedge-fit method", in which the component wedges into the peripheral acetabular bone rather than bottoming out and potentially toggling on the apex of the cup. Prior to November 2011, all acetabula were reamed 1 mm under and prepared with a press-fit of the porous coated acetabular component. After November 2011, we adjusted reaming by bone density. In "soft bone" (T-score <-1.0), we underreamed acetabula by 1 mm less than the outer diameter of the cup, as was previously done in all cases. For T-scores greater than -1.0, we reamed line-to-line. Additionally, we began performing an "apex relief" starting June 2012 in all cases by removing 2 mm of apex bone with a small reamer after using the largest reamer. Failure of acetabular ingrowth occurred in 0.5% of cases before the wedge-fit method and <0.1% after. Rate of cup shift was reduced from 1.1% to 0.4%. The rate of unexplained pain between 2 and 4 years postoperatively also declined significantly from 2.6% to 1.3%. Our evidence suggests that wedge-fit acetabular preparation improves initial implant stability, leading to fewer cases of early cup shift, unexplained pain, and acetabular ingrowth failure.
我们研究了一种改良髋臼骨准备技术在降低髋关节表面置换术中发现的两个临床问题发生率方面的疗效。第一个问题是髋臼部件缺乏骨长入导致的失败。第二个是新认识到的早期髋臼杯移位现象。我们假设这些问题可能通过使用“楔入配合法”来解决，即部件楔入髋臼周边骨而非到底并可能在髋臼杯顶点处摆动。在2011年11月之前，所有髋臼均扩孔1毫米以下，并用多孔涂层髋臼部件压配制备。2011年11月之后，我们根据骨密度调整扩孔。在“软骨质”（T值＜-1.0）中，我们将髋臼扩孔比髋臼杯外径少1毫米，如同之前所有病例那样。对于T值大于-1.0的情况，我们逐线扩孔。此外，自2012年6月起，我们在所有病例中开始进行“顶点减压”，即在使用最大扩孔钻后用小扩孔钻去除2毫米顶点骨。在采用楔入配合法之前，髋臼骨长入失败发生率为0.5%，之后＜0.1%。髋臼杯移位率从1.1%降至0.4%。术后2至4年无法解释的疼痛发生率也从2.6%显著降至1.3%。我们的证据表明，楔入配合髋臼准备可提高初始植入物稳定性，从而减少早期髋臼杯移位、无法解释的疼痛和髋臼骨长入失败的病例。
