Purpose

The concept of medial stabilizing technique total knee arthroplasty (MST-TKA) is to minimize the medial release without the superficial layer of medial collateral ligament (MCL). However, it is unclear at what stage the proper medial laxity is obtained during surgery. The purpose of this study was to investigate the implication of deep layer of MCL (dMCL) and osteophyte resection on medial laxity during MST-TKA.

Methods

A total of 103 consecutive patients who underwent cruciate-retaining TKA using the navigation system were included. The intraoperative hip–knee–ankle (HKA) angle was recorded under three conditions (no stress, valgus, and varus stress) at four time points after the resection of the anterior cruciate ligament (ACL) and meniscus (1st evaluation), after the dMCL release (2nd evaluation), and after osteophyte resection on both the femoral and tibial side (3rd evaluation). To assess valgus laxity, the differences in intraoperative HKA angle between 1st and 2nd evaluation (stage 1) and between 2nd and 3rd evaluation (stage 2) were calculated.

Results

Under the valgus stress condition, the intraoperative HKA angle change in stage 2 was significantly larger than that in stage 1 in full extension (stage 1; − 0.5 ± 1.0°, stage 2; − 2.0 ± 1.3°, p < 0.001) and 30° flexion (stage 1; − 0.8 ± 1.4°, stage 2; − 1.5 ± 2.0°, p = 0.008). There were no significant differences at 60° and 90° of knee flexion. Under the no stress and varus stress conditions, there were no significant differences in knee flexion at all angles.

Conclusion

The medial laxity during MST-TKA increased significantly more after dMCL release and osteophyte resection than after just dMCL release at full extension and 30° flexion, and it was, therefore, considered that osteophyte resection is a key procedure for a successful MST-TKA.

Level of evidence

Level II, therapeutic prospective cohort study.

中文翻译：

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内侧副韧带松解和骨赘切除术对全膝关节置换术内侧松弛的影响。

目的

内侧稳定技术全膝关节置换术 (MST-TKA) 的概念是在没有内侧副韧带 (MCL) 表层的情况下最大限度地减少内侧松解。然而，目前尚不清楚在手术过程中在哪个阶段获得适当的内侧松弛。本研究的目的是研究 MCL 深层 (dMCL) 和骨赘切除术对 MST-TKA 期间内侧松弛的影响。

方法

共纳入了 103 名连续使用导航系统接受交叉固位 TKA 的患者。在前交叉韧带 (ACL) 和半月板切除术 (第一次评估) 后的四个时间点，在三种条件下 (无应力、外翻和内翻应力) 记录术中髋 - 膝 - 踝 (HKA) 角度。 dMCL 释放（第二次评估），以及股骨和胫骨侧骨赘切除后（第三次评估）。为了评估外翻松弛度，计算了第一次和第二次评估（阶段 1）之间以及第二次和第三次评估（阶段 2）之间的术中 HKA 角度的差异。

结果

在外翻应力条件下，第 2 阶段的术中 HKA 角度变化明显大于第 1 阶段完全伸展（第 1 阶段；- 0.5 ± 1.0°，第 2 阶段；- 2.0 ± 1.3°，p  < 0.001）和 30 ° 屈曲（第 1 阶段；- 0.8 ± 1.4°，第 2 阶段；- 1.5 ± 2.0°，p  = 0.008）。膝关节屈曲 60° 和 90° 没有显着差异。在无应力和内翻应力条件下，各角度膝关节屈曲度均无显着差异。

结论

MST-TKA 过程中的内侧松弛在 dMCL 松解和骨赘切除后比仅在完全伸展和 30°屈曲时松解 dMCL 后显着增加，因此，认为骨赘切除是 MST-TKA 成功的关键程序。

证据水平

II 级，治疗性前瞻性队列研究。