School of Biomedical Engineering, Western University, London, Ontario, Canada.
Imaging Research Laboratories, Robarts Research Institute, Western University, London, Ontario, Canada.
Bone Joint J. 2020 Dec;102-B(12):1654-1661. doi: 10.1302/0301-620X.102B12.BJJ-2019-1428.R1.
The direct anterior (DA) approach has been associated with rapid patient recovery after total hip arthroplasty (THA) but may be associated with more frequent femoral complications including implant loosening. The objective of this study was to determine whether the addition of a collar to the femoral stem affects implant migration, patient activity, and patient function following primary THA using the DA approach.
Patients were randomized to either a collared (n = 23) or collarless (n = 26) cementless femoral stem implanted using the DA approach. Canal fill ratio (CFR) was measured on the first postoperative radiographs. Patients underwent a supine radiostereometric analysis (RSA) exam postoperatively on the day of surgery and at two, four, six, 12, 26, and 52 weeks postoperatively. Patient-reported outcome measures (Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index, the 12-item Short Form Health Survey Mental and Physical Score, and University of California, Los Angeles (UCLA) Activity Score) were measured preoperatively and at each post-surgery clinic visit. Activity and function were also measured as the weekly average step count recorded by an activity tracker, and an instrumented timed up-and-go (TUG) test in clinic, respectively.
Comparing the RSA between the day of surgery baseline exam to two weeks postoperatively, subsidence was significantly lower (mean difference 2.23 mm (SD 0.71), p = 0.023) with collared stems, though these patients had a greater CFR (p = 0.048). There was no difference (p = 0.426) in subsidence between stems from a two-week baseline through to one year postoperatively. There were no clinically relevant differences in PROMs; and there was no difference in the change in activity (p = 0.078) or the change in functional capacity (p = 0.664) between the collared stem group and the collarless stem group at any timepoint.
Presence of a collar on the femoral stem resulted in reduced subsidence during the first two postoperative weeks following primary THA using the DA approach. However, the clinical implications are unclear, and larger studies examining patient activity and outcomes are required. Cite this article: 2020;102-B(12):1654-1661.
直接前侧（DA）入路与全髋关节置换术（THA）后患者的快速康复有关，但可能与更频繁的股骨并发症相关，包括植入物松动。本研究的目的是确定在使用 DA 入路进行初次 THA 时，股骨柄加颈圈是否会影响植入物迁移、患者活动度和功能。
患者随机分为带颈圈（n = 23）或无颈圈（n = 26）非骨水泥股骨柄组，采用 DA 入路植入。术后第 1 天测量管腔填充比（CFR）。术后当天、术后 2、4、6、12、26 和 52 周时，患者接受仰卧位放射立体测量分析（RSA）检查。术前及术后每次就诊时采用 Western Ontario and McMaster Universities Osteoarthritis（WOMAC）指数、12 项简明健康调查量表精神和身体评分以及加利福尼亚大学洛杉矶分校（UCLA）活动评分进行患者报告的结果测量。活动度和功能也分别通过活动追踪器记录的每周平均步数和诊室中带仪器的起立行走测试进行测量。
与术后两周 RSA 基线检查相比，带颈圈组的下沉量显著降低（平均差异 2.23mm（SD 0.71），p = 0.023），但颈圈组 CFR 更高（p = 0.048）。从术后两周基线到术后 1 年，两组的下沉量没有差异（p = 0.426）。两组患者的 PROM 没有明显差异（p = 0.426）；在任何时间点，颈圈组和无颈圈组的活动度变化（p = 0.078）或功能能力变化（p = 0.664）均无差异。
在使用 DA 入路进行初次 THA 后，股骨柄带颈圈可减少术后前两周的下沉量。然而，其临床意义尚不清楚，需要更大的研究来检查患者的活动度和结局。
