Its description, causes, symptoms, diagnosis and treatment (operative and non-operative)
The meniscus is cartilage that acts as a shock absorber between the femur (thigh bone) and tibia (shin bone). Each knee has two distinct menisci: the medial (inner aspect of the knee) and lateral (outer aspect of the knee). Medial meniscus tears are more common in general, and lateral meniscus tears are more common when the ACL is injured. Injuries to the meniscus may lead to eventual degenerative changes in the knee (aka – arthritis).
What are the causes?
The meniscus can be injured several ways. Acute meniscus tears result from a sudden twisting or pivoting maneuver. Acute meniscus tears are associated with ACL injuries. The meniscus can also undergo degeneration as patient age increases. The degenerative meniscus is susceptible to tearing with minimal trauma (i.e.-twisting the knee getting into the car).
What are the symptoms?
Meniscus tears, in the acute setting, cause immediate pain over the specific meniscus, potentially swelling and bruising and loss of motion and strength. The patient may feel clicking or catching with walking and increased pain with twisting on the affected foot. If the meniscus tears and gets stuck out of place, the knee may feel locked (aka - bucket handle meniscus).
How is it diagnosed?
Your surgeon will perform a thorough history and physical exam with X-rays. On exam, swelling and loss of motion and strength is present. The knee is painful to touch over the affected meniscus. Your surgeon may perform provocative maneuvers to test each meniscus, resulting in pain and clicking if the meniscus is torn. X-rays are usually normal. MRI is helpful to confirm the diagnosis and characterize the tear for surgical planning. Other injuries can also be identified on the MRI.
How is it treated?
Non-operative - Some meniscus tears are treated successfully without surgery. Your surgeon may prescribe anti-inflammatory medication, physical therapy, cryotherapy and activity modification to reduce pain and inflammation, as well as strengthen the muscles around the knee to decrease the force transmitted to the meniscus. Your surgeon may offer you an injection. Patients with continued symptoms (pain, clicking, etc.) may benefit from surgery. Bucket handle meniscus tears are not treated non-operatively and require surgery.
Operative - Meniscus tears can be treated in most cases with a minimally-invasive arthroscopic surgery. Depending on the size and type of tear, as well as the quality of the torn tissue, your surgeon may choose to remove the torn meniscus or repair it with a series of sutures. Removing large portions of the meniscus will lead to expedited degeneration of the joint cartilage (aka- arthritis). Postoperative rehabilitation is at your surgeon’s discretion.