Ishii Orthopaedic & Rehabilitation Clinic, 1089 Shimo-Oshi, Gyoda, Saitama 361-0037, Japan.
Kouseiren Takaoka Hospital, 5-10 Eirakutyo Takaoka, Toyama 933-8555, Japan.
Osteoarthritis Cartilage. 2018 May;26(5):666-670. doi: 10.1016/j.joca.2018.01.027. Epub 2018 Feb 9.
An increase in coronal laxity is recognized as a risk factor for progression of knee osteoarthritis (OA). The purpose of this study was to evaluate coronal laxity, which was defined as the angular motion from the neutral, unloaded (baseline) position to the loaded position, in patients with advanced medial knee OA.
Preoperative coronal laxity was assessed using radiographs in patients with medial knee OA undergoing total knee arthroplasty by applying a force of 150 N with an arthrometer. A consecutive series of 211 knees with OA and 40 normal control knees were examined. A knee with OA was defined as clinically "balanced" when the difference between medial and lateral laxity was 3° or less. Values are expressed as median [25, 75 percentile].
The laxity was 4° [3, 5] from the baseline on the medial side and 3° [2, 4] on the lateral side. The distribution of medial and lateral laxity indicated that 90% (189/211) of patients fell within 3°. The equivalence test showed that the medial and lateral laxity was similar, with an equivalence margin of 3° (P < 0.001). In the control knees, the laxity was 3° [2, 4] from the baseline on the medial side and 2° [2, 4] on the lateral side. The differences between the knees with advanced OA and the controls were significant (P = 0.005, medial; P = 0.006, lateral).
This study showed that a clinically balanced knee was maintained even in patients with advanced medial knee OA.
冠状面松弛度增加被认为是膝关节骨关节炎（OA）进展的一个危险因素。本研究的目的是评估内侧膝关节 OA 患者的冠状面松弛度，其定义为从中立、无负荷（基线）位置到负荷位置的角度运动。
在接受全膝关节置换术的内侧膝关节 OA 患者中，使用关节测量仪在施加 150 N 力的情况下，通过 X 线评估术前冠状面松弛度。检查了连续 211 个膝关节 OA 和 40 个正常对照膝关节。当内侧和外侧松弛度的差异为 3°或更小，膝关节 OA 被定义为临床“平衡”。数值表示为中位数[25, 75 百分位数]。
内侧侧位松弛度为 4°[3, 5]，外侧侧位松弛度为 3°[2, 4]。内侧和外侧松弛度的分布表明，90%（189/211）的患者在 3°以内。等效性检验表明，内侧和外侧松弛度相似，等效边界为 3°（P<0.001）。在对照组中，内侧基线松弛度为 3°[2, 4]，外侧基线松弛度为 2°[2, 4]。与进展性 OA 膝关节相比，对照组的差异具有统计学意义（P=0.005，内侧；P=0.006，外侧）。
本研究表明，即使在患有严重内侧膝关节 OA 的患者中，临床平衡的膝关节仍能维持。
