Joshi Amit, Singh Nagmani, Pradhan Ishor, Basukala Bibek, Banskota Ashok Kumar
Shree Birendra Hospital, Nepalese Army Institute of Health Sciences, Kathmandu, Nepal.
B&B Hospital, Gwarko, Lalitpur, Nepal.
Orthop J Sports Med. 2019 Aug 29;7(8):2325967119866732. doi: 10.1177/2325967119866732. eCollection 2019 Aug.
Patients with anterior cruciate ligament (ACL)-deficient knees risk recurrent instability of the affected knee, which may predispose to meniscal injuries. Various studies have correlated the incidence of meniscal tear with elapsed time from ACL tear and number of instability events. However, it is not clear how significant an instability event needs to be to contribute to a meniscal tear.
PURPOSE/HYPOTHESIS: The purpose of this study was to (1) define a significant instability episode and (2) develop a checklist and scoring system for predicting meniscal tears based on significant instability episode. We hypothesized that patients with ACL-deficient knees who met the scoring threshold for a significant instability episode would have a higher incidence of meniscal tears compared with those who did not meet the threshold.
Cohort study (prognosis); Level of evidence, 2.
This retrospective study included patients with magnetic resonance imaging (MRI)-confirmed isolated ACL tear for longer than 3 months. We determined parameters for assessing instability episodes and defined any instability events between the MRI and ACL reconstruction as significant or insignificant. Patients were then grouped into a significant instability group (≥1 significant episode) and an insignificant instability group, and the incidence and types of meniscal tears found during surgery were compared between groups.
There were 108 study patients: 62 in the significant instability group and 46 in the insignificant instability group. During surgery, 58 meniscal tears (46 medial, 12 lateral) were recorded, for an overall meniscal injury rate of 53.70%. In the significant instability group, 47 patients (75.81%) had a meniscal tear and 15 (24.19%) had intact menisci ( < .001). In the insignificant instability group, 11 patients (23.91%) had a meniscal tear and 35 (76.08%) had intact menisci ( < .001). Regarding the 58 patients with a meniscal tear, 47 (81.03%) had ≥1 significant episode of instability before surgery, as compared with 11 (18.97%) who had insignificant or no instability. The odds of having a medial meniscal tear at ACL reconstruction was 10 times higher in the significant instability group versus the insignificant instability group.
The incidence of a medial meniscal tear was 10 times greater in patients with a significant episode of instability versus those with insignificant instability, as defined using a predictive scoring system. The incidence of lateral meniscal tear did not change with instability episodes.
前交叉韧带（ACL）损伤的膝关节患者存在患侧膝关节反复不稳定的风险，这可能易导致半月板损伤。多项研究已将半月板撕裂的发生率与ACL撕裂后的时间以及不稳定事件的数量相关联。然而，尚不清楚一次不稳定事件对导致半月板撕裂的影响程度有多大。
目的/假设：本研究的目的是（1）定义一次显著的不稳定发作，以及（2）基于显著的不稳定发作制定一份用于预测半月板撕裂的检查表和评分系统。我们假设，达到显著不稳定发作评分阈值的ACL损伤膝关节患者与未达到该阈值的患者相比，半月板撕裂的发生率更高。
队列研究（预后）；证据等级，2级。
这项回顾性研究纳入了磁共振成像（MRI）确诊为单纯ACL撕裂且病程超过3个月的患者。我们确定了评估不稳定发作的参数，并将MRI检查至ACL重建期间的任何不稳定事件定义为显著或不显著。然后将患者分为显著不稳定组（≥1次显著发作）和不显著不稳定组，并比较两组在手术中发现的半月板撕裂的发生率和类型。
共有108例研究患者：显著不稳定组62例，不显著不稳定组46例。手术期间，记录到58例半月板撕裂（内侧46例，外侧12例），总体半月板损伤率为53.70%。在显著不稳定组中，47例患者（75.81%）发生半月板撕裂，15例（24.19%）半月板完整（P<0.001）。在不显著不稳定组中，11例患者（23.91%）发生半月板撕裂，35例（76.08%）半月板完整（P<0.001）。在58例半月板撕裂患者中，47例（81.03%）在手术前有≥1次显著的不稳定发作，而11例（18.97%）有不显著或无不稳定发作。在ACL重建时发生内侧半月板撕裂的几率，显著不稳定组是不显著不稳定组的10倍。
使用预测评分系统定义的显著不稳定发作患者内侧半月板撕裂的发生率是不显著不稳定患者的10倍。外侧半月板撕裂的发生率并未随不稳定发作而改变。
