# Incidence and geographic mapping of meniscal tears in acute ACL injuries with meticulous posterior arthroscopic evaluation: longitudinal tears at the posterior menisco-capsular junction are the most common tear pattern in acute ACL injuries

## TL;DR

This paper finds that longitudinal tears at the menisco-capsular junction are most common in acute ACL injuries, emphasizing the need for detailed posterior arthroscopic evaluation.

## Contribution

The study reveals a higher incidence of posterior menisco-capsular junction tears in acute ACL injuries than previously reported.

## Key findings

- Longitudinal tears at the menisco-capsular junction are the most common tear pattern in acute ACL injuries.
- Zones A0–A1 in the medial meniscus and Zones F0–F1 in the lateral meniscus are most commonly affected.

## Abstract

Meniscal injuries are commonly observed in acute anterior cruciate ligament (ACL) injuries, with varying reports on the incidence and location of meniscal tears. In particular, the incidence of posterior menisco-capsular tears may have been underestimated in previous literature owing to the technical challenges associated with posterior arthroscopic evaluation. This study aimed to determine the true incidence and location of posterior menisco-capsular junction tears in patients undergoing anterior cruciate ligament reconstruction (ACLR) up to 6 weeks of injury, hypothesizing a higher incidence than previously reported.

A retrospective analysis was conducted on patients who underwent primary ACLR between July 2015 and January 2023, including a total of 139 patients. Arthroscopic findings and surgical records were reviewed, and the posteromedial and posterolateral joint spaces were evaluated via intercondylar notch view with a 70-degree arthroscope or via a posteromedial/posterolateral portal as a viewing portal to confirm posterior menisco-capsular junctional tears in all patients. The Cooper’s classification system was used to document tear locations, and radial and longitudinal tear components were analyzed.

Meniscal tears were observed in 104 patients (74.8%). Medial meniscus tears occurred in 63 patients (45.3%), while lateral meniscus tears were found in 78 patients (56.1%). Bilateral meniscus tears were identified in 37 patients (26.6%). Radial tears were predominantly observed in the lateral meniscus (22.3%), with a significant portion being lateral meniscus root tears (15.1%). Longitudinal tears, particularly at the menisco-capsular junction, were the most common tear pattern, occurring in 64.7% of patients.The most commonly involved tear sites were Zone A0 (39.6%) and Zone A1 (42.4%) in the medial meniscus, and Zone F0 (36.7%) and Zone F1 (38.1%) in the lateral meniscus.

Longitudinal tears at the menisco-capsular junction are the most common tear pattern in acute ACL injuries, revealing a higher incidence than previously reported. In acute ACL injuries, Zones A0–A1 and F0–F1 should be meticulously evaluated using an intercondylar notch view with a 70-degree arthroscope or via a posteromedial/posterolateral portal as a viewing portal.