The knee joint is a synovial joint formed by the articulation of the femur, tibia, and patella. It is a hinge joint so it only allows flexion and extension of the knee.
The medial and lateral menisci are cartilaginous structures that cover the joint surface of the tibia.
The menisci have the following functions:
- They act as shock absorbers.
- They help stabilize the knee joint.
- They are involved in load transmission across the joint.
The adult menisci are divided into.
- An outer well-vascularized red zone that makes up one-third of the adult menisci.
- The inner avascular white zone that makes-up two-thirds of the adult menisci. (1)
Etiology and Epidemiology of Meniscal Tears
Excessive rotational force or increased axial load can damage the meniscus. Meniscal tears can occur alone or be associated with other injuries/diseases/disorders.
Conditions which can cause meniscal tears are as follows:
- Lifting heavy weights.
- Activities requiring speed, rapid change of position, and jumping
- Fall or sudden twisting injuries
- Occasionally they can occur gradually without a history of injury.
Individuals with degenerative diseases such as osteoarthritis are at an increased risk of damaging their menisci. Meniscal tears are also common in sports players, active soldiers, and military personnel. Males above 40 years can show an increased predisposition to meniscal injuries.
In general, medial meniscus tears occur more frequently than lateral meniscus tears as the medial meniscus has relatively limited mobility due to its attachment to the medial collateral ligament. (1)
Signs and Symptoms
The symptoms of meniscal tears depend on the mechanism of injury, degree of damage and the structures involved.
They can present in the following ways:
1. Isolated Meniscal Tear
- It can present within 24 - hours with symptoms worsening gradually
- It can present over a course of a few days.
An effusion, or joint swelling can develop slowly and the joint may feel stiff or painful despite no history of an inciting event.
2. Meniscus tears in association with a ligament tear or injury
This occurs immediately after a traumatic event with rapidly developing effusion and is associated with the sensation of a pop.
Pain is usually noted over the joint line. Depending on the type and extent of the meniscal lesion, there may also be signs of locking, clicking, catching, intermittent inability to fully extend the knee, or feeling that the knee is giving away.
Depending on the type of injury there may be a history of an acute traumatic event or the symptoms may have developed gradually without a history of trauma.
Several provocative tests are performed to assess the degree of injury and plan treatment.
Imaging studies are performed to diagnose the tear and visualize the concomitant structures to rule out associated injuries.
Often x-rays will first be obtained to assess for bony injury and evaluate levels of arthritis.
MRI can be a very useful imaging modality for diagnosing and classifying the type of meniscal injury. (1),(2)
The location of the tear can determine ability to heal.
Meniscal tears in the outer red zone have the highest possibility of spontaneous recovery and more chances of complete recovery after meniscus repair surgery.
The treatment can be conservative or surgical depending on the location of the lesion and degree of damage.
Initial treatment consists of the following:
Analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs) can be prescribed to relieve pain and reduce swelling.
Braces or wraps are sometimes used for compression of the knee joint. This aids with swelling
Simple exercises help preserve the range of motion and prevent joint stiffness. (1) Physical therapy can sometimes be incorporated to aid with motion and joint strength.
Patients unresponsive to conservative treatment may benefit from surgical intervention. Arthroscopic repair or tear debridement is performed for cases in which healing after simple conservative management is unlikely. This utilizes a camera called an arthroscope. This is performed as a same-day surgery with very small incisions and patients are generally able to walk on the operative leg the same day. Most patient return to normal activities 2-6 weeks after the procedure.
At Ascend Orthopaedics and Sports Medicine, Dr. Makani has expertise and experience in dealing with all aspects of meniscal and cartilage tears including nonoperative and minimally invasive surgical treatments.
Call us to see how we can help today. (727)498-8003.
- Raj MA, Bubnis MA. Knee Meniscal Tears. [Updated 2019 Mar 21]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan.
- Mohan, B. R., & Gosal, H. S. (2007). Reliability of clinical diagnosis in meniscal tears. International orthopedics, 31(1), 57–60.
- Doral, M. N., Bilge, O., Huri, G., Turhan, E., & Verdonk, R. (2018). Modern treatment of meniscal tears. EFORT open reviews, 3(5), 260–268.
<a href="https://www.freepik.com/free-photos-vectors/people">People photo created by kjpargeter - www.freepik.com</a>