Torn ACL & Torn Meniscus | Symptom, Surgery, Test & Walking Guide
What Is A Knee Torn Meniscus?
A torn meniscus is a tear in the knee’s cartilage and a common knee injury caused by trauma. This condition can occur when the knee is subjected to strong compressive or shearing forces. When this happens, these structures can rip, fray, or otherwise become damaged. Magnetic Resonance Imaging, or MRI, is the study of choice to diagnose this type of knee injury. This condition is commonly diagnosed by an orthopedist.
The menisci allow for load transmission and shock absorption through the tibial-femoral joint. When these are torn, the knee can become unstable, painful, and accumulate fluid, impairing function and causing pain. In addition, a tear in the knee can cause swelling and limitation of motion.
The menisci are wedge-shaped structures that rest on top of the tibia, known as the tibial plateau. Each knee has two menisci: one on the inner part of the knee called the medial meniscus and the other on the outer part of the knee called the lateral meniscus.
The medial meniscus is capital “U” shaped and covers about 60% of the medial compartment. In contrast, the lateral meniscus is capital “C” shaped and covers about 80% of the lateral compartment. The tops of the menisci are concave to enable sufficient articulation with their respective converse femoral condyles, and the inferior portions are flat to conform to the tibial plateaus. Strong ligaments, known as coronary ligaments, secure both menisci in place.
How Is A Torn Meniscus Caused?
One of the most common causes of a meniscal injury is the crushing or shearing forces caused between the upper leg, or femur, and the tibia when an increased downward load is placed through the menisci. This motion is quite common in car accidents, falls, and certain sports-related injuries.
Rapid acceleration/deceleration, change of direction, jumping, lifting heavy weights can also tear a meniscus. A tear in either of the menisci can occur in these situations since an undue force on the side or front of the knee can cause the type of movement that can damage a meniscus.
Degenerative, or age-related, changes to the knee can be a contributing factor to a tear in the meniscus. Menisci in a knee with degenerative changes will more likely be damaged when exposed to the same forces that might not otherwise damage a knee that has not degenerated. Occupations that involve kneeling or squatting can also strain the meniscus over time, resulting in a torn meniscus.
A torn meniscus in the knee presents usually with pain, inflammation, clicking, difficulty in deep knee bending, and a loss in partial flexion of the knee. Knee flexion is the backward movement of the lower leg towards the buttocks. Patients will usually complain of experiencing a popping sound with certain movements when a meniscus is torn.
Joint effusion, swelling, and joint-line tenderness are also common on examination. Your doctor will perform certain routine tests to assess whether you have a torn meniscus. These may include palpation of the femur, tibial plateau, and patellar region to evaluate soreness and ligament stability. Your doctor may also perform other common clinical maneuvers to assess your knee joint. These include the McMurray test and Aply grind test.
Although a clinical examination is important in assessing whether a patient has a torn meniscus, this condition is most easily diagnosed with Magnetic Resonance Imaging or MRI. With MRI, a torn meniscus is usually seen as a linear signal intensity that extends from a meniscal substance to a free edge.
What Treatment Is Available For a Torn Meniscus?
Initial treatment for acute knee trauma, including when a torn meniscus is suspected, includes the PRICE protocol (Protection, Rest, Ice, Compression, and Elevation). Physical therapy can help strengthen the knee and leg muscles to help support and stabilize the knee joint. At times, treatment may also include anti-inflammatory and analgesic medications, intra-articular injections, activity modification, quadriceps strengthening, and bracing.
At times, however, surgical management for a torn meniscus may be recommended by your doctor. Some common types of surgery for torn meniscus include:
- Meniscectomy. This procedure is usually performed arthroscopically and involves trimming damaged meniscus tissue to allow the joint to move smoothly.
- Meniscal repair. If the torn meniscus is large but enough blood supply is present, a meniscal repair can be performed by suturing the torn pieces together.
- Meniscal reconstruction. In the cases of total meniscectomy, meniscal reconstruction can be performed to fill the defect to restore the knee and lower extremity to its normal function. Meniscal reconstruction mainly consists of meniscal scaffolds and meniscal allograft transplantation (MAT) procedures.
What Is The Prognosis For A Tear In The Meniscus?
A torn meniscus is a common knee injury with a good prognosis. Patients can usually return to their pre-injury activities once their condition has been properly diagnosed, treated and an effective rehabilitation plan completed.