Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi Abeno-ku, Osaka, 545-8585, Japan.
Department of Orthopaedic Surgery, Shiraniwa Hospital, 6-10-1 Shiraniwadai Ikoma, Nara, 630-0136, Japan.
Knee Surg Sports Traumatol Arthrosc. 2022 Feb;30(2):734-739. doi: 10.1007/s00167-021-06448-4. Epub 2021 Jan 25.
Research has shown that a cemented mobile-bearing component has a favorable effect on the bone mineral density (BMD) of the distal femur at 2 years after total knee arthroplasty (TKA). This study was performed to determine whether the advantage on BMD of a cemented mobile-bearing TKA over a conventional cemented fixed-bearing TKA changes with time. This report is an update of a matched cohort study initiated in 2004 and for which the 2-year results have been published.
Twenty-eight knees that were treated with a fixed-bearing posterior stabilized (PS) prosthesis and 28 matched knees from a database of 76 knees that were treated with a mobile-bearing PS prosthesis in the same period were investigated. All knees underwent dual-energy X-ray absorptiometry (DEXA) scans around the femoral component preoperatively, 2 weeks postoperatively, 5 years postoperatively, and annually thereafter. Eighteen knees with a cemented mobile-bearing PS prosthesis and 20 knees with a cemented fixed-bearing PS prosthesis were investigated for more than 6 years. The mean follow-up period was 11 years.
The range of motion, Knee Society Score, BMD of the lumbar spine, and follow-up period were not significantly different preoperatively and postoperatively in the two groups. In the fixed-bearing group, the BMD of the anterior part of the femoral condyle decreased postoperatively. In the mobile-bearing group, the BMD of the posterior part of the femoral condyle increased postoperatively. The postoperative change in the BMD at 5 years and the latest follow-up period was statistically significant in the two groups.
This DEXA study revealed that a cemented mobile-bearing component had a favorable effect on the BMD of the distal femur after TKA even at a mean of 11 years postoperatively.
Therapeutic study, level II, prospective comparative study.
研究表明，全膝关节置换术（TKA）后 2 年，骨水泥固定的活动衬垫组件对股骨远端骨密度（BMD）有积极影响。本研究旨在确定骨水泥固定的活动衬垫 TKA 相对于传统骨水泥固定的固定衬垫 TKA 在 BMD 方面的优势是否随时间而改变。这是对 2004 年启动的匹配队列研究的更新，该研究的 2 年结果已经发表。
28 例膝关节采用固定衬垫后稳定型（PS）假体治疗，同期数据库中有 76 例膝关节采用活动衬垫 PS 假体治疗，各选择 28 例匹配的膝关节进行研究。所有膝关节在术前、术后 2 周、术后 5 年和此后每年均行股骨组件周围双能 X 线吸收法（DEXA）扫描。18 例骨水泥固定活动衬垫 PS 假体和 20 例骨水泥固定固定衬垫 PS 假体的膝关节进行了超过 6 年的研究。平均随访时间为 11 年。
两组术前和术后的关节活动度、膝关节协会评分、腰椎 BMD 和随访时间均无显著差异。在固定衬垫组，术后股骨髁前部的 BMD 下降。在活动衬垫组，术后股骨髁后部的 BMD 增加。两组术后 5 年和末次随访时的 BMD 变化均有统计学意义。
这项 DEXA 研究表明，即使在平均 11 年的随访后，骨水泥固定的活动衬垫组件对 TKA 后股骨远端的 BMD 仍有积极影响。
治疗性研究，II 级，前瞻性比较研究。
