Do you have a trick knee? If you're knee is catching, locking and stiffening with some degree of frequency, it might be more than acting up. The term "trick knee" was created to describe the instability and pain that accompanies a meniscal tear, a problem that is rapidly becoming more prevalent as the active population ages, and accounts for a significant percentage of all people with knee pain.
The behavior of a meniscal tear is predictable to a certain degree. Patients will have difficulty with extremes of bending and extending, and often describe their walking as stiff and painful, requiring several steps before being able to walk erect. Because there is an actual physical roadblock within the tissue, many people snap or force their knee into place, causing a pop or a crack in the joint. This action is not recommended because it can further fray or potentially rupture the meniscus, worsening the original problem.
A meniscus is a ring-shaped piece of cartilage that acts as a buffer for shock absorption between the weight-bearing bones of the leg. This ring will dampen forces incurred through the knee, preventing damage to the delicate cartilage surfaces of the femur and tibia. Menisci are found on both the inside and outside of the knee, but the medial (inside) meniscus is the one damaged in 95 percent of cases. The medial meniscus is situated in close proximity to a number of other important anatomic structures, and because trauma can bring with it a constellation of damage, it is important to have pain emanating from the inside of the knee examined in a timely fashion.
Meniscal tears occur predominantly in people under 55 years old. After 55, the meniscus loses much of its water content, and in turn begins to harden, losing its elasticity. Structures that do not have high elastic components tend to transmit forces in other directions, minimizing the frequency of tearing, which explains the incidence of occurrence in a younger population. While a meniscus does not require blunt force trauma to tear, the likelihood that a meniscus is damaged with direct contact increases exponentially.