Summary
Meniscal damage is common in primary ACL reconstructions with a predominance of lateral sided injuries. The frequent association of MM and LM injuries, as opposed to isolated LM injuries, may be an indication of the severity of an ACL injury. This would correlate with the fact that a high prevalence of BM injuries, particularly MMRL+LMPRT tears, has been observed in football.
Abstract
Purpose
The aim was to perform a detailed analysis of the sport-specific prevalence and type of meniscal injuries in primary ACL reconstructed knees of non-professional athletes. Particular attention was given to laterality as well as medial meniscus ramp lesions (MMRL), lateral meniscus posterior root tears (LMPRT) and lateral meniscus instability (LMI). It was hypothesized that this information would improve the mechanisms of ACL injuries.
Methods
A retrospective analysis of prospectively collected data from an institutional ACL registry was performed on patients undergoing primary ACL reconstruction. Patients with open physes, revision surgery, multiligament or complex reconstructions were excluded. Meniscus injuries were diagnosed arthroscopically by two experienced knee surgeons, including both the anterior and posterior compartments and an aspiration test to diagnose LMI. Meniscus lesions were first documented according to their laterality (lateral/medial meniscus; LM, MM) or on both menisci (BM). In addition, special attention was given to LMPRTs, LMIs and MMRLs.
Results
The cohort consisted of 406 patients (255 male / 151 female; 211 right / 195 left knees) with a median age of 27 years (Q1-Q3: 21-34). The median time from injury to surgery was 4.5 months (2.2- 9.5). The majority of injuries occurred in football (40%) and alpine skiing (20%).
A total of 460 meniscus injuries were recorded with a predominance of LM injury (61%). Four categories of patients were identified: 1. without an associated meniscus injury (n=78; 19%); 2. with LM injury (n=147; 36%); 3. with BM injuries (n=132; 33%); 4. with MM injury (n=49; 12%).
The overall prevalence of LMPRT, LMI and MMRL in patients undergoing a primary ACL reconstruction was 20% (n=80), 23% (n=93) and 21% (n=87), respectively. In group 2 (LM), the majority of injuries were LMPRTs or LMIs (n=91; 62%). In group 3 (BM), the majority were LMPRTs or LMIs (n=82; 62%) and 74 were MMRLs (56%). In group 4 (MM), only 13 were MMRLs (33%). Thus, MMRLs were more likely to be observed in association with a LM tear rather than appearing in isolation (OR: 3.5 [1.7-7.3]).
Meniscal damage differed according to the activity at the time of injury, particularly in football, handball and alpine skiing. Football injuries resulted in more BM than alpine skiing (40% vs 21%; p<0.05). 58% the MMRLs+LMPRTs occurred during football. A high prevalence of LMPRTs was observed in handball (30%) compared to alpine skiing (5%).
Summary
With 81% of ACL injured knees having at least one meniscal injury, meniscal damage is common in primary ACL reconstructions. The meniscus injury footprint reveals 3 different scenarios, ranging from a predominance of lateral sided injuries, either isolated or associated with MM injuries, to the rare isolated MM tears – including MMRLs. The frequent association of MM and LM injuries, as opposed to isolated LM injuries, may be an indication of the severity of an ACL injury. This would correlate with the fact that a high prevalence of BM injuries, particularly MMRL+LMPRT tears, has been observed in football, which may indicate a higher proportion of high-energy trauma mechanisms.