Department of Orthopaedics, Mayo Clinic Arizona, Phoenix, AZ, USA.
Department of Orthopaedics, Mayo Clinic Rochester, Rochester, MN, USA.
Hip Int. 2022 Nov;32(6):724-729. doi: 10.1177/1120700020988723. Epub 2021 Feb 10.
Cementless fixation is the standard for acetabular fixation in primary total hip arthroplasty (THA). There are various surface finishes thought to improve osteointegration, although literature regarding the long-term survival of some of these surfaces is limited. Regardless of design, primary stability is essential to allow for osteointegration. Previous studies have suggested an increased rate of radiolucency and compromised short-term functional outcomes using the Tritanium primary acetabular component (Stryker, Mahwah, NJ). The purpose of this study was to compare the primary Tritanium acetabular component to another contemporary acetabular component as a control group with an established clinical record.
444 consecutive, primary THAs performed by a single surgeon from 2008 to 2012 were reviewed. Patients were included if they had a minimum 1-year follow-up. Implant survivorship and modified Harris Hip Scores (mHHS) were recorded for all patients at final follow-up. Radiographs were evaluated by 2 surgeons at 6 weeks, 1 year, and the most recent follow-up for evidence of radiolucency and migration. Components were considered to have evidence of radiographic lucency if they had radiolucency in 2 or more DeLee zones.
198 patients met criteria for inclusion (96 Pinnacle, 102 Tritanium). Average follow-up was 28 (12-72) months. At final follow-up 6.2% of the Pinnacle cups and 29.4% of the Tritanium cups had radiographic evidence of loosening ( < 0.01). The average mHHS for the Tritanium group was 83.1, and 88.4 for the Pinnacle group ( < 0.01). Radiographic evidence of loosening also correlated with a lower mHHS: 75.5 versus 86.4 ( < 0.01). In patients that received Tritanium cups without screw fixation 44.6% showed radiographic evidence of loosening versus 8% that received screw fixation ( < 0.01). In total, 6 patients in the Tritanium group required revision for aseptic loosening of the acetabular component.
The 30% rate of radiographic loosening in the Tritanium group was significantly higher than the Pinnacle group and correlated with an inferior clinical outcome. Interestingly the use of screw augmentation was protective against radiographic evidence of loosening. This suggests that the Tritanium component may be prone to fibrous in-growth because of inadequate primary stability.
在初次全髋关节置换术（THA）中，骨水泥固定是髋臼固定的标准。有各种表面处理方法被认为可以改善骨整合，尽管关于其中一些表面的长期存活率的文献有限。无论设计如何，初始稳定性对于允许骨整合都是至关重要的。先前的研究表明，使用 Tritanium 初次髋臼组件（Stryker，Mahwah，NJ）会增加放射性不透明度并影响短期功能结果。本研究的目的是将初次 Tritanium 髋臼组件与另一个作为对照组的当代髋臼组件进行比较，该对照组具有既定的临床记录。
对 2008 年至 2012 年间由一名外科医生进行的 444 例连续初次 THA 进行了回顾性研究。如果患者有至少 1 年的随访，则将其纳入研究。所有患者在最后一次随访时均记录了植入物存活率和改良 Harris 髋关节评分（mHHS）。在最后一次随访时，由 2 名外科医生在 6 周、1 年和最近的随访时评估 X 光片，以评估放射性不透明度和迁移的证据。如果 DeLee 区有 2 个或更多区域存在放射性不透明度，则认为组件存在放射性不透明度的证据。
198 名患者符合纳入标准（96 个 Pinnacle，102 个 Tritanium）。平均随访时间为 28（12-72）个月。在最后一次随访时，6.2%的 Pinnacle 杯和 29.4%的 Tritanium 杯有影像学松动的证据（ < 0.01）。Tritanium 组的平均 mHHS 为 83.1，而 Pinnacle 组为 88.4（ < 0.01）。影像学松动的证据也与较低的 mHHS 相关：75.5 与 86.4（ < 0.01）。在未接受螺钉固定的 Tritanium 杯患者中，44.6%的患者有影像学松动的证据，而接受螺钉固定的患者为 8%（ < 0.01）。在 Tritanium 组中，共有 6 名患者因髋臼组件无菌性松动而需要翻修。
Tritanium 组 30%的影像学松动率明显高于 Pinnacle 组，与较差的临床结果相关。有趣的是，螺钉增强的使用可预防影像学松动的证据。这表明，由于初始稳定性不足，Tritanium 组件可能容易发生纤维内生长。
