For patients undergoing ACL surgery, the presence of a medial collateral ligament(MCL) injury may significantly influence recovery.
This article is based on the study “Outcomes following anterior cruciate ligament injury with concomitant damage to the medial collateral ligament: ananalysis from the registry of the francophone arthroscopic society” by Prof. Cavaignac and his team.It explores the results of a large-scale, prospective French cohort comparing isolated ACL injuries and combined ACL + MCL lesions.
Combined ACL + MCL lesions lead to poorer outcomes
ACL tears are common in sports-related knee injuries, but when they occur alongside damage to the MCL, recovery becomes more complex. The MCL plays a key role instabilising the inner side of the knee, and while low-grade injuries can often heal with conservative treatment, high-grade tears (grade II or III) are more severe and may require surgery.
This large multi-centre French study followed 722 patients who underwent ACL reconstruction. Of them, 408 had a combined ACL + MCL lesion, while 314 had an isolated ACL injury. Patients were monitored using clinical follow-up and validated functional scores (IKDC, Tegner, ACL-RSI, and SKV), and surgical outcomes were analysed.
Key findings:
- The reoperation rate was significantly higher in the ACL + MCL group (7.4%) compared to the ACL-only group (3.2%).
- Functional recovery, as measured by IKDC and SKV scores, was significantly lower in the ACL + MCL group at final follow-up.
- Stiffness requiring secondary arthrolysis was the most frequent cause of reoperation in the ACL + MCL cohort.
These findings confirm the study’s hypothesis: the presence of an MCL lesion negatively impacts recovery following ACL surgery.
MCL lesion severity affects treatment strategy
A crucial point in the study was the severity and location of the MCL injury, which influenced both treatment choice and patient outcome.
Non-surgical treatment yields better results in low-grade MCL lesions
For low-grade MCL injuries (grade I or II without major laxity), conservative treatment (brace, physiotherapy) was often sufficient. In this subgroup, functional scores at follow-up were similar to those seen in isolated ACLcases. This supports the use of non-operative management in acute, low-grade MCL injuries accompanying ACL tears.
Surgery is needed for high-grade or chronic lesions
When MCL surgery was required, outcomes varied based on the type of procedure:
- Ligament reinsertion (typically used in acute cases) produced significantly better functional scores than reconstruction (usually reserved for chronic cases).
- Chronic injuries that required multi-ligament reconstruction consistently led to poorer outcomes.
This highlights the importance of early diagnosis and appropriate treatment strategy for the MCL lesion. Failure to identify and treat high-grade injuries promptly may compromise ACL reconstruction results and lead to persistent instability or pain.
Treating the MCL matters for ACL success
This landmark study provides high-level evidence (Level II) that concomitant MCL injuries are not benign when associated with ACL rupture. The presence of a medial lesion, especially if left untreated or improperly managed, significantly increases the risk of poor functional outcomes and reoperation.
For patients with ACL + MCL lesions:
- Early recognition and individualised treatment of the MCL lesion are key.
- Non-surgical MCL management offers good results when the injury is low grade.
- In severe cases, early surgical reinsertion outperforms delayed reconstruction
For patients seeking expert advice and comprehensive care for ACL or multiligament knee injuries, Professor Cavaignac is a recognised specialist whose scientific work is shaping clinical practice.