Meniscus (cartilage) tear
The meniscus is a piece of cartilage in the middle of your knee. The meniscus provides lining and cushioning to the surface of the joints due to its tough, rubbery nature. There is a meniscus on the inner side of your knee (the medial meniscus) and a meniscus on the outer side (the lateral meniscus). They attach to the top of the shin bone (tibia), make contact with the thigh bone (femur), and act as shock absorbers during weight-bearing activities.
In athletes the meniscus is commonly damaged during forced twisting movements of the knee. It is also quite common in athletes for there to be damage to other soft tissues in the knee (e.g. anterior cruciate ligament). In elderly people however non-traumatic damage can occur as the cartilage weakens and wears thin over time leading to degenerative tears.
You might experience a “popping” sensation when you tear the meniscus. Most people can still walk on the injured knee and many athletes keep playing. Over several hours the inflammation will set in and then for several days there will be:
• Stiffness and swelling.
• Tenderness in the joint line.
• Collection of fluid (“water on the knee”).
There may also be difficulty bending or straightening the knee. In some cases if a fragment of the meniscus drifts into the joint, the knee can become locked until you manually move it.
A chronic (old) meniscus tear may give you pain on and off during activities, with or without swelling. Your knee may occasionally lock and you may have stiffness in the knee.
Diagnosis and treatment
Through physical examination and an accurate history your physiotherapist will be able to diagnose this condition. Management of a meniscus tear depends on the type and severity of the tear and the involvement of other soft tissues.
If the knee is stable and does not lock then management will be conservative.
Blood vessels feed the outer edges of the meniscus, giving that part the potential to heal on its own. Small tears on the outer edges often heal themselves with rest. Conservative management would include physiotherapy. The initial physiotherapy would involve reducing pain and swelling. This may involve electrotherapeutic modalities, ice, compression, rest, and gentle massage. Following this treatment would move onto rehabilitation and return to sport. This may involve strengthening of knee stability muscles, stretching and decreasing activity of tight/overactive muscles, proprioceptive (balance) exercises and correction of any abnormal lower limb biomechanics. Your physiotherapist would also guide you in a gradual progression to sport and advise you on preventative measures such as wearing a knee guard/support for sport.
If your meniscus tear does not heal on its own and your knee becomes painful, stiff or locked, you may need surgical repair. Depending upon the type of tear, whether you also have an injured ACL, your age and other factors, your doctor may use an arthroscope to trim off damaged pieces of cartilage. Following the arthroscopic procedure a physiotherapy rehabilitation program would be commenced with its aim to return you to sport/activity as safely and as soon as possible. If other tissues such as the anterior cruciate ligament were damaged then management surgically may differ, however a physiotherapy program will still be required.