1st Ortopaedic-Traumatologic Clinic, Istituto Ortopedico Rizzoli, University of Bologna, Via Pupilli 1, 40136, Bologna, Bo, Italy,
Knee Surg Sports Traumatol Arthrosc. 2014 Dec;22(12):3157-62. doi: 10.1007/s00167-014-3147-6. Epub 2014 Jun 28.
Unicompartmental knee arthroplasty (UKA) has shown a higher rate of revision compared with total knee arthroplasty. The success of UKA depends on prosthesis component alignment, fixation and soft tissue integrity. The tibial cut is the crucial surgical step. The hypothesis of the present study is that tibial component malalignment is correlated with its risk of loosening in UKA.
This study was performed in twenty-three patients undergoing primary cemented unicompartmental knee arthroplasties. Translations and rotations of the tibial component and the maximum total point motion (MTPM) were measured using radiostereometric analysis at 3, 6, 12 and 24 months. Standard radiological evaluations were also performed immediately before and after surgery. Varus/valgus and posterior slope of the tibial component and tibial-femoral axes were correlated with radiostereometric micro-motion. A survival analysis was also performed at an average of 5.9 years by contacting patients by phone.
Varus alignment of the tibial component was significantly correlated with MTPM, anterior tibial sinking, varus rotation and anterior and medial translations from radiostereometry. The posterior slope of the tibial component was correlated with external rotation. The survival rate at an average of 5.9 years was 89%. The two patients who underwent revision presented a tibial component varus angle of 10° for both.
There is correlation between varus orientation of the tibial component and MTPM from radiostereometry in unicompartmental knee arthroplasties. Particularly, a misalignment in varus larger than 5° could lead to risk of loosening the tibial component.
Prognostic studies-retrospective study, Level II.
与全膝关节置换相比，单髁膝关节置换的翻修率更高。单髁膝关节置换的成功取决于假体组件的对线、固定和软组织完整性。胫骨截骨是关键的手术步骤。本研究的假设是胫骨组件的对线不良与其在 UKA 中的松动风险相关。
本研究纳入了 23 例接受初次骨水泥单髁膝关节置换的患者。使用放射立体测量分析在术后 3、6、12 和 24 个月时测量胫骨组件的平移和旋转以及最大总点运动（MTPM）。在手术前后还进行了标准的放射学评估。胫骨组件的内翻/外翻和后倾角以及胫骨-股骨轴与放射立体测量微运动相关。通过电话联系患者，还进行了平均 5.9 年的生存分析。
胫骨组件的内翻对线与 MTPM、胫骨前沉、内翻旋转以及从放射立体测量获得的前侧和内侧平移显著相关。胫骨组件的后倾角与外旋相关。平均 5.9 年的生存率为 89%。接受翻修的两名患者的胫骨组件内翻角均为 10°。
在单髁膝关节置换中，胫骨组件的内翻方向与放射立体测量的 MTPM 之间存在相关性。特别是，内翻大于 5°的对线不良可能会导致胫骨组件松动的风险。
预后研究-回顾性研究，II 级。
