Department of Orthopaedic Surgery, Service de Chirurgie Orthopédique, Hôpital de la Croix-Rousse, Centre Albert Trillat, 103 Grande Rue de La Croix Rousse, 69004 Lyon, France.
Clin Orthop Relat Res. 2011 Dec;469(12):3443-50. doi: 10.1007/s11999-011-1988-6. Epub 2011 Jul 26.
Postoperative varus alignment has been associated with lower IKS scores and increased failure rates. Appropriate positioning of TKA components therefore is a key concern of surgeons. However, obtaining neutral alignment can be challenging in patients with substantial preoperative varus deformity and it is unclear whether residual deformity influences revision rates.
QUESTIONS/PURPOSES: We asked: (1) in patients with preoperative varus deformities, does residual postoperative varus limb alignment lead to increased revision rates or lower IKS scores compared with correction to neutral alignment, (2) does placing the tibial component in varus alignment lead to increased revision rates and lower IKS scores, (3) does femoral component alignment affect revision rates and IKS scores, and (4) do these findings change in patients with at least 10° varus alignment preoperatively?
From a prospective database, we identified 553 patients undergoing TKAs for varus osteoarthritis. Patients were divided into those with residual postoperative varus and those with neutral postoperative alignment. Revision rates and International Knee Society (IKS) scores were compared between the two groups and assessed based on postoperative component alignment. Survival analysis was conducted with revision as the endpoint. The analysis was repeated in a subgroup of patients with at least 10° preoperative varus. Minimum followup was 2 years (median, 4.7 years; range, 2-19.8 years).
The two groups had similar survival rates to 10 years and similar IKS scores. Varus tibial component alignment and valgus femoral component alignment were associated with lower mean scores. Revision rates and scores were similar in a subgroup of patients with substantial preoperative varus.
Our data suggest residual postoperative varus deformity after TKA does not increase survival rates at medium-term in patients with preoperative varus deformities, providing tibial component varus is avoided. Tibial component varus negatively influences IKS score.
Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
术后内翻对线与较低的 IKS 评分和较高的失败率相关。因此，膝关节置换术（TKA）组件的适当定位是外科医生关注的关键。然而，对于术前存在严重内翻畸形的患者，获得中立对线可能具有挑战性，并且尚不清楚残余畸形是否会影响翻修率。
问题/目的：我们提出了以下问题：（1）在术前存在内翻畸形的患者中，与纠正为中立对线相比，残余术后内翻对线是否会导致翻修率增加或 IKS 评分降低；（2）将胫骨组件置于内翻对线是否会导致翻修率增加和 IKS 评分降低；（3）股骨组件对线是否会影响翻修率和 IKS 评分；（4）这些发现是否会在术前至少有 10°内翻对线的患者中发生变化？
我们从前瞻性数据库中确定了 553 例因内翻性骨关节炎接受 TKA 的患者。患者分为术后残余内翻和术后中立对线两组。比较两组间的翻修率和国际膝关节协会（IKS）评分，并根据术后组件对线进行评估。以翻修为终点进行生存分析。分析在术前至少有 10°内翻的患者亚组中重复进行。最低随访时间为 2 年（中位数，4.7 年；范围，2-19.8 年）。
两组患者在 10 年内的生存率相似，IKS 评分也相似。胫骨组件内翻和股骨组件外翻对线与平均评分较低相关。在术前存在严重内翻畸形的患者亚组中，翻修率和评分相似。
我们的数据表明，TKA 后残余的术后内翻畸形不会增加术前存在内翻畸形患者的中期生存率，只要避免胫骨组件内翻。胫骨组件内翻对线对线会对 IKS 评分产生负面影响。
III 级，治疗性研究。请参阅作者指南，以获取完整的证据水平描述。
