Anatomy and Function of the Knee
Before you start, it will be very helpful to read our information to better understand knee anatomy, where the menisci are located, and how the knee works. You can always refer to this information later in the article.
A torn meniscus is a common injury in the knee. A tear can happen in any age group. In young people, the meniscus is fairly tough, and tears usually happen from a very forceful twisting injury—such as planting your foot and pivoting or twisting when playing tennis or squatting. In older people, the meniscus has grown weaker with age, and tears of the meniscus can happen from a minor injury, such as the simple motion of squatting. Sports injuries aren’t the only causes of tears; tears can also happen with lifting.
There is a meniscus on either side of the knee joint. The meniscus fills the space between the femur and the tibia and use pressure to fit the two bones together. A meniscus can be torn in several ways. The entire inner rim of the medial meniscus can be torn, called a bucke thandle tear because the torn area looks like a handle. The meniscus can also have a flap torn at the inner rim, or the tear can be a degenerative tear where a portion of the meniscus is frayed and torn in several directions.
Symptoms of a Meniscus Tear
The most common problem from a torn meniscus is pain on the side or center of the knee. The pain may be felt where the meniscus is located or may involve the whole knee. If the torn portion of the meniscus is large enough, locking of the knee can occur. The torn fragment of meniscus gets caught when the knee bends and won’t allow the leg to completely straighten. You may not be able to fully bend your knee. Pain can come and go along with clicking or popping in the knee.
A torn meniscus can cause long-term problems. The constant rubbing of the torn meniscus on the articular cartilage can cause wear and tear on the cartilage surface, leading to osteoarthritis of the knee joint and possibly replacement of the knee joint.
How to Diagnose a Torn Meniscus
Diagnosis begins with your story of how and when the injury happened (a history), where you are having pain, and physical exam. The exam will try to find out where the pain is located, if there is any locking in your knee, and if there are clicks or pops when your knee is bent or straightened. A regular xrays won’t show a torn meniscus since the tissue is not dense enough. Xrays are mainly useful to find problem with bones. An MRI scan is very good at showing the meniscus and tears. If the history and physical exam strongly suggest that your have a torn meniscus, then arthroscopy may be done to confirm the diagnosis and repair the problem at the same time.
Treatment for a Torn Meniscus
Initial treatment for a torn meniscus is mean to reduce the pain and swelling in the knee. Rest and ice packs are a first treatment. If the tear is located on the outer 1/3 of the meniscus, the tear may heal on its own since there is a good blood supply. The inner 2/3 of the meniscus does not have a good blood supply and surgery may needed to repair a tear in this area. If symptoms continue and the tear interferes with your everyday activities, surgery will be needed either to remove the torn part of the meniscus or repair the tear and prevent further injury to your knee. Most meniscus surgery is done using an arthroscope. The orthopedic surgeon makes small incisions are made in the knee to allow the insertion of a small TV camera into the joint. Through another small incision, special instruments are used to remove the torn portion of meniscus while the arthroscope is used to see what is happening.
Sometimes the meniscus tear can be repaired using arthroscopy. The arthroscope is used to view the torn meniscus. Sutures are used to sew up the tear. Not ever meniscus tear can be repaired. Young people with relatively recent tears are the most likely candidates for repair. Degenerative type tears in the meniscus of older people cannot be repaired.