A meniscal tear can be caused by trauma or degenerative changes in the knee joint. Traumatic meniscal tears are usually associated with physical activity and typically result from rotation coupled with axial loading of the knee joint. The affected meniscus may be medial or lateral, with the medial frequently torn because of its relative immobility. Clinical features include pain and limited range of movement of the affected knee. Key features are slow onset joint effusion and a characteristic popping or clicking sensation during joint maneuvers. MRI is used to confirm the diagnosis. Arthroscopy enables simultaneous surgical intervention, especially in patients with persistent symptoms, inner zone tears, and functional limitations. Conservative treatment (i.e., rest, ice, leg elevation, and analgesia) may be considered in small meniscal tears of the outer vascular zone and patients with pre-existing degenerative changes.
- Young, active patients: traumatic (i.e., axial loading and rotation action with a fixed foot during physical activity)
- Older patients: degenerative (e.g., continuous work in a squatting position)
Location of the tear
- White zone: inner third, avascular area
- Red-white zone: middle third, poorly vascularized area
- Red zone: outer/peripheral third, vascularized area
Type of tear
- Longitudinal tear (vertical tear): perpendicular to the tibial plateau
- Radial tear: perpendicular to the tibial plateau and the longer axis of the meniscus
- Horizontal tear: parallel to the tibial plateau
- Displaced tears
- Tears may also be simple or complex.
- Knee pain: exacerbated by weight‑bearing or physical activity
- Joint line tenderness (medial or lateral)
- Restricted knee extension with possible knee instability
Intermittent joint effusions
- Tears in the medial, white zone → serous effusion
- Tears in the red zone near the base of the meniscus → bloody effusion (hemarthrosis)
Patellar tap test: a maneuver used to assess knee joint effusion
|Signs of meniscus injury|| |
|McMurray test || || |
|Apley grind test|| |
|Payr test|| |
- X-ray : to exclude degenerative joint changes
- MRI: imaging modality of choice
- Both diagnostic and therapeutic with a sensitivity and specificity of ∼ 100%
- Diagnostic step of choice if MRI is contraindicated (e.g., patient with metal prostheses)
|Clinical features|| || |
The differential diagnoses listed here are not exhaustive.
- Conservative treatment
- Persistent disabling symptoms/effusions, functional limitations
- Complex tears
- Postoperative care: physical therapy followed by gradual return to active physical activity.
We list the most important complications. The selection is not exhaustive.