One of the most common causes of knee popping, swelling, and pain is a meniscal tear. Many of us have either experienced or know someone who has undergone treatment for a meniscal tear. So, what’s the big deal? And what exactly is a meniscus?
Menisci are two semi lunar fibrocartilaginous disks that serve as the “shock absorbers” of the knee. There is one meniscus on the inner (medial) portion of the knee and another on the outer (lateral) portion. Together, they are able to withstand the daily twisting and pounding of our body’s experience. Mere walking, for instance, can generate forces across the knee ranging from two to five times body weight. When one considers that the average person takes more than 1 million steps a year, you start to realize how valuable these two little structures are!
The incidence of an acute meniscal tear has been reported to be 61 per 100,000, with an estimated 850,000 meniscal procedures performed in the United States yearly by orthopedist. Given the largely young, active population involved, a delay in the proper identification and treatment of meniscal injuries can have a tremendous socioeconomic impact.
As clinicians, it is important for us to distinguish between sports-related meniscal injuries in younger more active individuals versus degenerative tears in older individuals. Sports-related meniscal injuries account for roughly one third of all patients with torn menisci. Pivoting sports such as football and basketball are associated with the greatest numbers of injuries.
Most patients report an acute onset of sharp pain in 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. Of note, the onset of swelling is generally delayed a couple of days in isolated meniscal injuries, which differs from the immediate swelling seen with ACL (anterior cruciate ligament) tears.
A person with a symptomatic meniscal tear typically will present with recurrent knee effusions (swelling) and symptoms of locking and catching. Once the suspected diagnosis has been confirmed by thorough examination and appropriate imaging studies, the decision can be made whether to treat the meniscal disease operatively or non-operatively.
The guiding principle in the surgical treatment of a torn meniscus is to remove only the “unstable” meniscal fragments while preserving as much of the “shock absorber” as possible. Arthroscopic surgery affords the orthopedist an opportunity to do a large amount of work within the knee, through only a few small incisions.
Meniscal tears are extremely common, and if properly evaluated, can be properly diagnosed. Treatment can then be initiated with rehabilitation started almost immediately and the road to successfully recovery embarked upon.
