Meniscus Tears in the Knee

What is a Meniscus Tear?

The meniscus is a cartilage cushion between the femur (thigh bone) and tibia (large lower leg bone).  There are two menisci in each knee.  The lateral (outside) meniscus is small c-shaped cushion, whereas the medial (inside) meniscus is a larger c-shaped cushion.  Both menisci have poor blood supply and will not heal if they tear due to injury or degenerative causes.  A meniscus tear typically occur when the foot is in contact with the ground and there is a twisting motion in the knee.   Injury may also occur if the knee is forced to bend excessively (hyperflexion).  The initial injury may or may not have associated pain; swelling typically does not occur until 48 hours after accident, and may not occur at all.  Pain is generated after a tear when a piece of the meniscus folds on itself, causing catching, clicking, or popping in the knee joint.  Most patients have difficulty going up and down stairs, and some may not be able to fully straighten or bend the knee.

Meniscus Tear Diagram

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How are Meniscus Tears Diagnosed?

Many meniscus tears can be diagnosed clinically based on history and physical exam.  Special tests that are used for diagnosing meniscus injuries include McMurray Test, Bounce-Home Test, and Thessaly Test.  A physician may order x-rays and/or MRI to help diagnose, or verify clinical suspicion of, a meniscus tear. X-rays may show decreased joint space between the femur and tibia.  MRIs will show the location and type of meniscus tear and help the physician decide if the tear should be removed or repaired surgically.  The MRI can also help with the decision to choose conservative treatment verses aggressive surgical intervention.

What is Conservative Treatment of Meniscus Tears?

Conservative treatment typically includes anti-inflammatory medication, physical therapy, and possibly a steroid injection in the knee joint (intra-articular corticosteroid injection).  Conservative treatment will not repair a tear; this option manages symptoms.

What is Meniscus Surgery?

The majority of meniscus surgeries are menisectomies.  A menisectomy is an arthroscopic procedure that allows the surgeon to identify the tear and trim the meniscus until it meets the tear, thus creating a new meniscus edge.  Depending on the extent of tear and location of tear, the meniscus may also be repaired.  This procedure can also be done arthroscopically, as the surgeon will use sutures to repair the tear.  There is a risk that the meniscus may not heal due to limited blood supply.

Meniscus Tear in the KneeMeniscus Surgery Diagram

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Why Should I Consider Meniscus Surgery verses Conservative Treatment?

Meniscus tears will not heal on their own.  Conservative treatment is beneficial to patients that do not have a decrease in motion in their knee.  Anti-inflammatories can help control the pain that may be associated with the meniscus tear.  Surgical treatment will remove or repair the tear.

What are my restrictions after a Meniscus Surgery?

Removal of the meniscus tear leads to limited healing time.  Most people can be active in their normal routine within 6-8 weeks.  Physical therapy will start almost immediately following surgery, and crutches can be used for up to a week.  Repair of a meniscus tear has a longer return to activities of daily living.  There is a risk of tearing the sutures used to repair the meniscus, therefore the patient is usually in a straight leg brace and non-weight bearing using crutches for at least 3 weeks.  Hyperflexion or hyperextension (straight leg) can cause the sutures to catch on the femur and possibly ruin the repair.  Recovery after a meniscus repair may take 3-6 months.  Physical therapy for both surgical options involves strengthening of the quadriceps and hamstring muscles

What are the risks of Meniscus Surgery?

Complications are rare, but the potential does exist.  Common complications may include: infection, decrease range of motion in the knee, rupture of repair, and swelling.  Benefits of meniscus surgery commonly outweigh the risks.

 

Written By: Lisa Osterbrock, PA-C, ATC 9/18/14

Edited By: Robert Rolf, M.D.