What is the Meniscus? – Blog By Ryan Harris
The meniscus is a crescent shaped disc of fibrocartilage that is located in the knee joint. The role of it is to distribute the weight of the body and absorb shock within the knee during movement. Each knee has two meniscus, one laterally and the other medially.
Mechanism of Injury
There are two main reasons for tearing this structure.
A Traumatic meniscus tear is more likely seen in the younger, more active population. It most commonly occurs when the foot is planted on the ground and a twisting force is applied upon the knee. This twisting force is often caused by another person.
In the older adult, a degenerative tear is most likely to occur. This may be due to the natural age related changes of the meniscus or arthritic changes of the femur tearing into the meniscus.
Signs and Symptoms
- An incident of a painful twist of the knee,
- Some people may describe a tearing sensation,
- Clicking, popping, or locking of the knee,
- Minimal immediate swelling which increases of the next 24hours
- Tenderness of the knee joint line.
The location of the meniscus tear will determine its capacity of healing.
The outer rim of the meniscus has a blood supply from the synovial capsule. This allows it to have a capacity to heal overtime with conservative treatment, depending on the size and type of the tear.
The central part of the meniscus has no blood supply, instead gaining its nutrients from the synovial fluid. Injuries to this area of the meniscus do not usually heal overtime and often require surgery.
Your Physiotherapist will perform a comprehensive physical examination and perform special test to diagnose your injury
It is important to undergo a thorough physiotherapy assessment as other knee injuries such as an ACL tear and/or medial and lateral collateral ligament tears may be present.
If a meniscus tear is suspected, your physiotherapist, doctor or surgeon may refer you for a MRI. This will aid in determining the location and type of tear and will help guide the appropriate treatment pathway.
Small tears and tears that occur in the outer ring that have no restriction of movement can be treated conservatively. Conservative treatment consists of:
- Eliminating swelling
- Restoring full range of motion
- Strengthening of the knee and lower limb,
- Enhancing pelvic stability
- Improving lower limb proprioception and jumping/landing strategies
- Sport specific activities,
- Gradual return to sport.
Surgical intervention may be required
Following a period of conservative treatment, surgical intervention may be required. This is performed arthroscopically (keyhole). During the surgery, the surgeon will inspect the meniscus and surrounding structures via a small camera. Once the tear is identified, the surgeon will remove the affected tissues and clean up the surrounding area. The aim of surgery is to protect as much of the meniscus as possible, although it may be necessary to have a complete removal of the meniscus.
The surgeon may decide to repair the tear in younger patients with a recent tear in the outer rim as these tears have a chance to heal over time. Rehabilitation for meniscal repairs are greater as time is needed to get the meniscus a chance to heal.
It is important to commence rehabilitation prior to surgery. “Prehabilitation” can increase the recovery speed post operatively and in some cases, the patient can avoid surgery all together.
Monitoring of the knee is crucial during rehabilitation as the remaining meniscus and underlying articular cartilage need to adapt to the new load that is being placed upon them. Your physiotherapist will continue to reassess your knee after each progression of exercises to ensure your knee is coping with the new stresses. If an increase in pain or swelling is seen, the rehabilitation program will be altered as a result.
The same rehabilitation principles apply for both, conservation and post surgical care. The principles are outline above. The exception being a meniscal repair which requires an initial period of rest to allow for healing to occur before commencing rehabilitation.
Post by Ryan Harris(Physiotherapist)