Purpose
This study aimed to elucidate the clinical characteristics of isolated meniscal injuriesduring sports activities among young athletes with intact ligaments.
Methods
From January 2007 to December 2021, 183 patients under 30 years of age underwent arthroscopic surgery for isolated meniscal injuries with clear injury mechanisms during sporting activities. They were 131 males and 52 females with a mean age of 18 years old (range: 8¬–29 years). They were divided into three groups: medial meniscus (MM), semilunar LM (SLM), and discoid lateral meniscus (DLM). Injury mechanisms were divided into contact and non-contact mechanisms. Contact injuries were categorized as being hit, tackled, or thrown by other players. Non-contact injuries were categorized as stepping, landing, kicking, crouching, running, collapsing, sliding, and others. Tear type and radial/circumferential location in each meniscal tear was assessed based on the medical report and intraoperative arthroscopic image. The tear types were classified into vertical, radial, flap, horizontal, and complex tear. A bucket-handle tear was included in the vertical type. A complex tear was defined as the one involving two or more tear types (e.g. horizontal and radial tears). The radial zones were classified as anterior, middle, and posterior segments. The circumferential zones were classified as white-white, red-white, and red-red zones.
Results
Overall, vertical tear was the most frequent (n = 107, 58.5%), followed by radial tear (n = 31, 16.9%). Considering the circumferential/radial location, vertical tear involving red-red zone was the most frequent tear occupying 57.4% (n = 105). Of the 31 radial tears, 25 tears involved white-white zone to red-red zone in the middle segment. Concerning sport genre, soccer occupied 54 (29.5%), followed by basketball (n = 23, 12.6%) and rugby/American football (n = 23, 11.4%). There was no significant relationship between sport genre and meniscus type or tear type. However, there was a significant relationship between tear type and injury mechanism (P < 0.001): 66.7–100% cases caused by crouching, kicking, sliding, or being hit presented vertical tears while 44.4%–50.0% cases caused by stepping, collapsing, or being tackled presented radial or flap tears. In the MM group (n = 47), it was notable that all of the 15 cases caused by kicking motion during soccer presented vertical tears involved anterior–middle segment in the red-red zone. In the SLM group (n = 86), 51 cases with vertical tears involved posterior segment in the red-red zone and were mainly caused by crouching (n = 16) or stepping (n = 8). In the DLM group (n = 50), although vertical tear was the most frequent (n = 23), radial tear in the middle segment occupied 17 cases (34.0%) and there was a significant difference in the distribution of tear type comparing SLM group (P = 0.015).
Conclusion
The characteristics of isolated meniscal tears including DLM with regard to the injury mechanism, sport, and tear location and type is useful information for clinicians in knee injury management.