Department of Orthopaedics, Kantonsspital Baselland, Liestal, Switzerland.
Department of Orthopaedics, University of Utah, Salt Lake City, UT, USA.
Foot Ankle Int. 2020 Mar;41(3):275-285. doi: 10.1177/1071100719894528. Epub 2019 Dec 17.
Mobile-bearing total ankle replacement (TAR) potentially enables motion at the tibial implant-polyethylene insert (PI) interface. Such additional freedom of movement may overload periarticular ligaments and subsequently result in coronal translation of the talus. The aim of this study was to assess whether syndesmotic overload affects clinical and radiographic outcomes following mobile-bearing TAR and whether tibiofibular fusion is an effective treatment option.
Thirty-one patients who underwent revision surgery for syndesmotic overload after mobile-bearing TAR were retrospectively analyzed. Clinical and radiographic outcomes were assessed before and after index TAR, preoperatively to revision surgery, and at the last follow-up after revision surgery. Computed tomography scans were also analyzed.
Ankles with lateral talar translation prior to revision surgery were about 10 times more likely to have valgus tibial implant position ( = .003). A wide tibiofibular distance at the level of the syndesmosis after index TAR was associated with an increased hindfoot moment arm at revision surgery ( = .025). Decrease of PI height at revision surgery and a PI fracture were evident in 10 (32%) and 4 (13%) cases, respectively. Talar cyst formation at revision surgery was evident in 12 (39%) cases. Tibiofibular fusion was effective in restoring function of the replaced ankle and providing pain relief.
Syndesmotic overload impaired clinical and radiographic outcomes after mobile-bearing TAR. Proper implant positioning and additional realignment procedures may prevent overload of periarticular soft tissue structures after mobile-bearing TAR.
Level IV, retrospective case series.
带活动平台的全踝关节置换术（TAR）可使胫骨假体-聚乙烯衬垫（PI）界面活动。这种额外的运动自由度可能会使关节周围的韧带超负荷，随后导致距骨冠状面移位。本研究旨在评估距骨下关节（syndesmosis）超负荷是否会影响带活动平台的 TAR 后的临床和影像学结果，以及胫腓骨融合是否是一种有效的治疗选择。
回顾性分析了 31 例因带活动平台 TAR 后距骨下关节超负荷而行翻修手术的患者。在进行指数 TAR 之前、术前至翻修手术时以及翻修手术后的最后一次随访时，评估了临床和影像学结果。还对 CT 扫描进行了分析。
在翻修手术前有外侧距骨移位的踝关节，其胫骨假体有外翻的可能性约为 10 倍（ =.003）。指数 TAR 后距骨下关节水平的胫腓骨间隙增宽与翻修手术时后足力矩臂增加相关（ =.025）。翻修手术时 PI 高度降低和 PI 骨折分别在 10 例（32%）和 4 例（13%）中可见。12 例（39%）在翻修手术时出现距骨囊肿形成。胫腓骨融合可有效恢复置换踝关节的功能并缓解疼痛。
距骨下关节超负荷会影响带活动平台的 TAR 后的临床和影像学结果。适当的假体定位和额外的矫正程序可能会防止带活动平台的 TAR 后关节周围软组织结构超负荷。
IV 级，回顾性病例系列。
