Meniscus Tear
Tear of the knee's fibrocartilage shock absorber, from acute rotation in the young or degeneration in the older knee.
Mechanism
- Acute (under 40): twisting on a flexed, loaded knee (football, basketball, rugby, skiing), often with ACL injury. Hyperflexion causes posterior root tears.
- Degenerative (over 40): low-energy or no trauma, linked to osteoarthritis. A different disease.
Presentation
- Joint line pain and tenderness (most sensitive sign), worse on twisting and squatting
- Delayed effusion (hours), unlike the immediate haemarthrosis of ACL rupture
- Clicking, catching, giving way
- McMurray: moderate sensitivity, high specificity. Thessaly test at 20° flexion.
Locked knee is an emergency
A displaced bucket-handle tear blocks extension, with the knee held at 20 to 45° flexion. Refer urgently. Delay causes chondral damage and makes the tear irreparable. Do not “wait and see”.
Pseudo-locking (pain and spasm without a mechanical block) settles with analgesia and time.
Tear types
| Type | Repairable? |
|---|---|
| Longitudinal, peripheral | Good |
| Bucket-handle | Good if early |
| Radial, horizontal | Poor. Radial tears disrupt hoop function |
| Root | Repair. Functionally equals total meniscectomy if left |
| Degenerative | Usually no surgery |
Only the outer 10 to 30% (red-red zone) is vascularised, which determines healing.
MRI
Signal reaching the articular surface on two or more images. Bucket-handle: double PCL sign, absent bow-tie sign. Root tear: ghost meniscus, extrusion. Many asymptomatic middle-aged adults have meniscal tears, so treat the patient, not the image.
Management
- Operate: locked knee, repairable tear in a young patient, root tear, persistent mechanical symptoms after 6 to 12 weeks of conservative care, concurrent ACL reconstruction.
- Do not operate: degenerative tear without mechanical symptoms. Arthroscopic partial meniscectomy is no better than physiotherapy or sham surgery.
- Preserve the meniscus wherever possible. Meniscectomy gives short-term relief but worse long-term outcomes than repair.
Return to play
| Procedure | Timeline |
|---|---|
| Partial meniscectomy | Running 4 to 6 weeks, sport 6 to 8 weeks |
| Meniscal repair | 4 to 6 months (protected weight-bearing, 0 to 90° for about 6 weeks) |
| Repair with ACL reconstruction | Follows ACL timeline (9 to 12 months) |
References
- EU-US Meniscus Rehabilitation Consensus, KSSTA 2025, doi:10.1002/ksa.12689
- Clin Sports Med 2020, doi:10.1016/j.csm.2019.08.004
- Sports Med Arthrosc Rev 2021, doi:10.1097/jsa.0000000000000303
Related
Medical disclaimer: this article is general information, not personal medical advice. Always consult a qualified doctor about your own situation.