Park Jun-Gu, Bin Seong-Il, Kim Jong-Min, Lee Bum-Sik
Department of Orthopedic Surgery, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, Republic of Korea.
Knee Surg Sports Traumatol Arthrosc. 2021 Jun;29(6):1797-1804. doi: 10.1007/s00167-020-06214-y. Epub 2020 Aug 16.
To evaluate the effect of joint line obliquity of the knee on intrasubstance degeneration of isolated medial meniscus horizontal cleavage tear (HCT) in young patients.
Sixty knees of 50 patients aged < 40 years (mean age, 33.3 ± 5.5 years old), who underwent arthroscopic partial meniscectomy (APM) for HCT, were retrospectively reviewed. The radiologic parameters of alignment, including mechanical hip-knee-ankle (mHKA) angle, posterior tibial slope, and joint line obliquity, were measured on preoperative long-standing whole-leg radiographs. The patients were classified into two groups, simple horizontal type (type 1) and complicated type (type 2), according to the presence of diffuse intrasubstance degeneration of the meniscus on preoperative magnetic resonance imaging. The risk factors for intrasubstance degeneration of HCT were analyzed using multiple logistic regression analysis. Medial joint space width (JSW) on weight-bearing 45° flexion posteroanterior radiographs and the mHKA were measured to evaluate the radiographic outcomes. The clinical outcomes were evaluated using the modified Lysholm score. Among patients followed-up for > 5 years, the clinical and radiologic outcomes were compared between the two groups.
The joint line obliquity was significantly greater in the type 2 group than in the type 1 group (2.9 ± 1.3 vs. 0.9 ± 1.4, P < 0.001), and a significant risk factor for diffuse intrasubstance degeneration (P < 0.001; odds ratio, 2.88; 95% confidence interval, 1.27-6.54). The relative changes in the JSW in the type 2 group were greater than those in the type 1 group during the mean follow-up period of 7.9 ± 2.5 years (26% vs 10%, P = 0.045). The modified Lysholm score was not significantly different between the two groups (n.s).
The diffuse intrasubstance degeneration of medial meniscus HCTs in young patients is associated with increased joint line obliquity of the knee joints. The radiologic outcomes after APM were inferior in the patients with diffuse intrasubstance degeneration. However, the clinical outcomes were not different during the mid-term follow-up.
Level III.
评估膝关节关节线倾斜度对年轻患者孤立性内侧半月板水平劈裂（HCT）内部退变的影响。
回顾性分析50例年龄＜40岁（平均年龄33.3±5.5岁）因HCT接受关节镜下部分半月板切除术（APM）的患者的60个膝关节。在术前长期站立位全腿X线片上测量对线的放射学参数，包括机械髋-膝-踝（mHKA）角、胫骨后倾和关节线倾斜度。根据术前磁共振成像上半月板内部弥漫性退变的情况，将患者分为两组，单纯水平型（1型）和复杂型（2型）。采用多因素逻辑回归分析HCT内部退变的危险因素。在负重45°屈曲前后位X线片上测量内侧关节间隙宽度（JSW）和mHKA，以评估放射学结果。采用改良Lysholm评分评估临床结果。在随访超过5年的患者中，比较两组的临床和放射学结果。
2型组的关节线倾斜度显著大于1型组（2.9±1.3 vs. 0.9±1.4，P＜0.001），是内部弥漫性退变的显著危险因素（P＜0.001；比值比，2.88；95%置信区间，1.27 - 6.54）。在平均7.9±2.5年的随访期内，2型组JSW的相对变化大于1型组（26% vs 10%，P = 0.045）。两组间改良Lysholm评分无显著差异（无统计学意义）。
年轻患者内侧半月板HCT的内部弥漫性退变与膝关节关节线倾斜度增加有关。APM后，内部弥漫性退变患者的放射学结果较差。然而，在中期随访期间临床结果无差异。
Ⅲ级。
