Arthroscopic Surgery for Meniscus Tears

As November ushers a cooler change in weather, orthopedic surgeons often see an increased amount of outdoor activities that can cause injury to our joints.  One of the most commonly encountered knee injuries is a meniscal tear.  Fortunately, not all meniscal tears are created equally, and some are fairly well tolerated by individuals.  At best, they can cause some painless clicking and a little soreness, but the more severe ones typically result in mechanical catching, swelling and pain. 

Within the knee there are two distinct rubbery menisci that serve as tough shock absorbers to lessen the shock transmitted across the knee with daily activities.  Mere walking, for instance, can generate forces across the knee ranging from two to five times the body weight.  When one considers that the average person takes more than one million steps a year, you start to realize how durable these structures are meant to be.  Unfortunately, the meniscal tissue tends to degenerate and dry out as we age in a process called myxoid degeneration.  This degenerative process is a radiographic finding commonly noted on MRI scans and does not in itself represent a tear, but renders the meniscus tissue susceptible to injury or breakdown. 

Most patients report an acute onset of sharp pain in the inner aspect of the knee, usually following a twisting injury in which the knee is flexed and the foot firmly planted on the ground.  Typical symptoms may include swelling, catching, and pain when squatting or climbing stairs.  The onset of swelling is generally delayed a couple of days in isolated meniscal injuries, which differs from the immediate swelling seen with ligament tears such as the ACL (anterior cruciate ligament). 

A thorough clinical examination would rule out any ligamentous instability.  Traditional weight-bearing knee x-rays can rule out any underlying arthritis that would present as joint space narrowing or bone spurs.  Once a meniscal tear diagnosis is confirmed via MRI, individuals are left with the decision to monitor symptoms or to surgically stabilize the torn tissue.

Meniscus tissue is mostly devoid of blood supply and if torn, the best case scenario is a small rent in the tissue that is not grossly unstable or painful.  Symptomatic tears will often flare-up with unpredictability and if neglected, generally result in the formation of larger tears and more destruction of the non-regenerative tissue. Arthroscopic surgery allows direct visualization of the entire knee joint to identify the tear and trim the damaged portion back to a stable rim.  The guiding principal in the surgical treatment of a torn meniscus is to remove ONLY the torn unstable meniscal fragments while preserving as much of the intact tissue as possible. 

The arthroscopic surgery is done as an outpatient procedure and patients go home the same day with crutches.  Soreness after debridement of a torn meniscus lasts anywhere from five to ten days and a post-operative course of physical therapy is started immediately to regain motion and decrease swelling. 

Meniscal tears are extremely common, and once they become symptomatic, they can be properly diagnosed and treated.  Arthroscopic surgery is a safe and reliable way to trim the irritating meniscal tissue in order to initiate rehabilitation and a return to normal activities.