Introduction
Meniscal injuries (meniscal tear) is a common knee injury. There are two demographics of injury; young patients with sporting injuries, and older adults with degenerative conditions. Meniscus tear is the most common indication for knee surgery.
The decision on when to treat surgically will depend on n the age of the patient, their previous level of function, and the exact symptoms they are suffering.
The majority of cases involve the medial meniscus (ratio 3:1). In cases with an associated ACL injury, then the lateral side is more likely to be affected. In case of sporting injury, meniscus tear is usually the result of a twisting injury with the foot firmly affixed to the ground.
In older patients, it is most commonly the posterior horn of the meniscus that is affected.
Presentation
- Joint line pain / tenderness (50%)
- This is the most sensitive clinical sign
- Locking of the knee (17%)
- Knee effusion (14%)
- Reduced ROM – lost of last 10 degrees of extension and reduced flexion are possibilities
- Pain may. be aggravated by twisting of the joint (McMurray’s test or similar)
- Pain worse with activity
- Pain on hyperflexion or hyperextension of the knee (e.g. when squatting)
Imaging
- X-ray is usually normal
- MRI is diagnostic, but also has a high false positive rate
Management
- Conservative management
- First-line for degenerative tears
- Sometimes differentiating if it is a degenerative or acute tear is the difficult part – especially after injury in an older patient!
- Rest
- NSAIDs
- Rehabilitation (e.g. via physiotherapist)
- Graded return to physical activity
- First-line for degenerative tears
- Operative management
- Partial menisectiomy
- Suitable for tears that cannot be repaired or those that have failed >x2 previous repair attempts
- 80% have improvement at follow-up
- More likely to be successful if age <40, normal alignment, no arthritis, single tear
- Meniscal repair
- 70-95% successful
- More likely to be successful if any associated ACL injury is also repaired
- Only about 60% successful when ACL is intact, and 30% successful if a damaged ACL is left untreated
- Partial menisectiomy