What is it?
The menisci are two C-shaped structures located within the knee, positioned between the femur and the tibia. The term “meniscus” originates from the Greek word “meniscos,” which means crescent moon, reflecting the semi-lunar shape of these smooth, collagenous structures.
Historically, the meniscus was believed to play no role in joint function, leading to its complete removal in cases of injury. However, recent discoveries highlight its crucial role in maintaining the health of the knee joint. The meniscus contributes significantly to load redistribution, shock absorption, lubrication and joint nutrition, knee stability and congruency between the femur and the tibia. It also plays a vital role in proprioception, sending signals to the brain about the knee’s spatial positioning, thus aiding in injury prevention.
The meniscus is poorly vascularized, with blood supply reaching only 10-20% of its periphery. This means that tears closer to the outer edge of the structure have a better chance of healing than those extending to the central part, where the blood supply and essential nutrients for healing are scarce.
Who could be affected?
Meniscus injuries primarily fall into two categories:
- Traumatic injuries:These are more common in young adults aged 28-40 years, with men being at a higher risk than women. Sports that apply excessive force to the knee and involve torsion movements, such as tennis, soccer, basketball, and contact sports, can be a cause for traumatic injuries to the meniscus. These injuries frequently occur in combination with ACL injuries.
- Degenerative changes:These are more prevalent than traumatic injuries and are typically found in the elderly population due to repetitive inappropriate movements.
It’s important to note that the medial meniscus (innermost side) is more frequently injured compared to the lateral one (outermost side of the knee).
Moreover, studies indicate that meniscal injuries can be asymptomatic, meaning individuals may not experience any pain or symptoms related to the injury. In fact, a study involving athletes revealed that 31% of asymptomatic individuals engaged in both pivoting and non-pivoting sports had an existing meniscus injury of which they were unaware.
What does it look like?
A meniscus injury typically results in pain and a locking sensation that prevents full knee bending. Furthermore, degenerative changes in the meniscus can affect the cartilage between the femur and tibia, causing pain at the end ranges of flexion or extension. Additionally, a sensation of knee instability and early onset of osteoarthritis can result from meniscus damage.
How can physiotherapy help?
During the evaluation, a physiotherapist will assess and determine if the discomfort and pain at the knee are caused by a meniscus injury. For most cases, a conservative approach, i.e., knee rehabilitation, is recommended over surgery. This approach includes strengthening the structures around the knee to compensate for the stability typically provided by the meniscus. Ensuring full range of motion of the knee and working on proprioception and balance are key factors in knee rehabilitation. If there are little to no changes in the signs and symptoms, even with rehabilitation, imaging might be necessary to assess the need for surgery based on the extent of the injury and the patient’s suitability for the operation. In such cases, intensive pre- and post-operative rehabilitation will be necessary to optimise post-surgery recovery.
