I mentioned in my ACL tear story that my husband, James, has had two surgeries for a torn meniscus on his right knee in the past two years. The first tear occurred while he was repairing a roof at his father’s house. Thankfully, he didn’t fall, but he took a misstep and twisted the knee. Nearly a year later, he took another misstep in the yard. He didn’t step into a hole — just a slight indentation in the yard — and the twist was enough to cause another tear. It was a painful injury. The surgeries, both for medial meniscus tears, were almost to the day a year apart.
Knee meniscus definition and anatomy
The meniscus (plural, menisci) is composed of both a medial and a lateral component situated between the corresponding femoral condyle and tibial plateau of the knee joint. Both are crescent-shaped fibrocartilaginous structures that act as shock absorbers for the knee joint.
The vascularization of the meniscus is quite interesting. In the developing fetus, the meniscus has a complete blood supply, but in the adult, that goes down to 10% to 25% for the medial meniscus and 10% to 30% for the lateral meniscus. This occurs in the periphery, supplied by the popliteal artery. Nutrition is supplied by joint movement and synovial diffusion. The knee is innervated by the femoral, sciatic and obturator nerves. While the meniscus is involved in proprioception, only the posterior and anterior horns of the medial meniscus have mechanoreceptors, which detect touch, pressure, and stretch of the tissues.
The meniscus is important to overall homeostasis of the knee, providing lubrication, stability, and helping to distribute the weight load borne by the joint. Injury to the meniscus can result in premature onset of arthritis.
Although people tend to think of the meniscus in relation to the knee, there are menisci in other parts of the body, including the wrist, temporomandibular joint, sternoclavicular joint, and acromioclavicular joint. Unlike an articular disk, a meniscus only partially divides a joint cavity.
Medial meniscus tear causes
Meniscus tears are classified as traumatic or degenerative based on the tear pattern. A traumatic tear is a vertical tear, while a degenerative tear is a complex, horizontal, or flap tear. Sudden meniscal tears often happen during sports. Tears in the meniscus can occur when twisting, cutting, pivoting, or being tackled. Degenerative meniscal tears may occur as a result of arthritis or aging; any awkward twist of the knee can cause a tear.
Medial vs. lateral meniscus tear symptoms
A 2019 review of the literature pertaining to meniscus tears does not seem to differentiate between medial meniscus tear symptoms vs. lateral meniscus tear. The main complaints in either case are sudden locking of the joint and knee pain. Either tear may produce a “popping” sound, inflammation, stiffness, swelling, clicking when walking, and instability.
Risk factors of getting a medial meniscus tear
A systematic review including meta-analysis identified risk factors for meniscus tear but does not differentiate in specific risk factors of medial meniscus tears vs. lateral meniscus tears, with one exception: waiting longer than 12 months to have surgery to repair a torn anterior cruciate ligament is a strong risk for a medial meniscus tear but not a lateral meniscus tear.
Risk factors include those who play contact sports that involve sudden pivoting like soccer and rugby, men are more likely than women to have traumatic tears; those over the age of 60, and those whose work involves kneeling, squatting, and stair-climbing of more than 30 flights of stairs (urban firefighters come to mind).
Medial meniscus tear test
An MRI (magnetic resonance imaging) is used most often to confirm diagnosis of a torn meniscus, but physicians would not order that prior to gathering a health history and doing a physical examination. There are several non-invasive physical tests that are commonly used for preliminary diagnosis of a meniscus injury. However, none of the physical tests have enough diagnostic accuracy to be of routine clinical value as an alternative to MRI.
The McMurray test is performed with the patient supine and relaxed. The examiner grasps the patient’s heel with one hand and the joint line of the knee with the other hand. The knee is flexed maximally, with external tibial rotation (medial meniscus) or internal tibial rotation (lateral meniscus). The knee is brought to full extension while maintaining rotation.
A positive test produces a pop or click. Pain in a reproducible portion of the range of motion is described as part of the McMurray test, which has an accuracy rating of 54%, as does the Thessaly test. The patient stands flat footed on one leg while the examiner supports the patient by holding their outstretched hands.
Then the patient flexes the knee at 20 degrees and rotates their body three times, internally and externally. The test is considered positive for a medial meniscus tear if the patient experiences medial or lateral joint line discomfort or a sense of locking/ catching in the knee. Another commonly used test, Apley’s test, has an accuracy rate of 53%.
The examiner places the patient’s knee into 90 degrees of flexion and applies a firm grasp at the patient’s heel. While applying a downward axial loading force, the examiner rotates the leg medially and laterally. There are other tests, but these are frequently used.
Do you need torn meniscus surgery?
Meniscus tears are one of the most common knee injuries among all age groups in the US, but there is a lot of disparity when it comes to surgical repair of a torn meniscus. A meniscectomy, or surgical removal of the meniscus, may be total or partial, depending on the extent of the injury, and whether the injury is traumatic or degenerative.
Surgical repair of the meniscus, basically suturing it back together, is also an option. A 2016 study of middle-aged patients with degenerative meniscal injury who were followed for two years post-injury found that there was no clinically significant difference in the outcomes for those who received surgery and those who utilized supervised exercise as a treatment.
Several different options exist for torn meniscus surgery. The choice of which method to use is dependent upon whether or not the meniscus can actually be repaired, whether it may heal, and whether it will regain mechanical function once repaired.
Debridement is arthroscopic surgery of the torn area of the meniscus, basically filing it down and leaving the rest intact; it is usually performed for degenerative tears that cannot be repaired. Trephination is another method, in which a circular section of the meniscus is removed, also leaving the rest intact.
Meniscectomy, or removal of the meniscus, may be partial or complete, depending on the severity of the injury, how symptomatic the patient is, and their level of physical activity. It is more likely to be performed on younger people who have sudden injuries and high levels of physical activity.
In younger athletes, the decision to debride instead of repair a meniscus depends on tear pattern, location, and the patient’s willingness to comply with postoperative restrictions. Repair, rather than meniscectomy, has been the preferred option for younger patients not suffering from degenerative disease.
Meniscal allograft (harvested from a cadaver) transplantation is an option for symptomatic meniscal deficiency in young, active patients.
There’s a lot of disagreement on just how effective meniscectomy is, if at all. One study comparing patients who had surgery for a degenerative medial meniscus tear to patients having sham surgery concluded that there was no significant difference in outcomes, while pointing out that it is one of the most frequently used procedures in spite of the lack of evidence of its efficacy.
Paul Ingraham has plenty to say about knee surgery in general, including meniscectomy. According to Ingraham, the evidence is now overwhelming that meniscectomy just does not do what surgeons have assumed for a long time.
A 2020 study concluded, “Save the meniscus is the principle. Meniscal repair is almost always the best option in repairable lesions. We believe it is wise to take the risk to repair all the repairable meniscal tears, even if it does not always work. For a given patient, 25% of failure risk is better than 100% meniscectomy.”
Although most meniscectomy is performed arthroscopically as outpatient surgery, there is more risk than one might think. A 2018 review of 700,000 arthroscopic medial meniscus surgeries from England’s Hospital Episode Statistics database reviewed surgeries performed between April 1997 through March 2017. Within 90 days of surgery, 546 patients suffered pulmonary embolism, and 944 patients developed infections requiring further surgery. Although the risk is statistically low, the researchers found that the risk had not lowered over time.
One known factor with meniscectomy, whether full or partial, is that it increases the possibility of developing osteoarthritis of the knee joint in many cases. Patients who experience painful catching or locking might need surgical treatment with meniscal repair, and it can relieve the pain associated with the torn meniscus. However, the possibility of an increased risk of osteoarthritis if functional meniscal tissue is removed cannot be overlooked.
Medial meniscus tear exercises
Exercise at home and/or with the aid of a physical therapist, may be prescribed instead of surgery, or may be prescribed post-surgery.
Frequently used/prescribed exercises include
- Passive knee extension. This may be done sitting in a chair or on the floor.
- Hip extensions while prone, bending the knee and bringing up toward the glutes.
- Straight leg raise, lifting from the hip.
- Calf stretch, using a wall for support.
- Hamstring stretch, lying supine against a wall.
There are exercises that should be avoided when the meniscus is torn, such as those which mimic the actions that may have torn it in the first place like pivoting and twisting. It should be clear that no exercise is going to restore the meniscus to its uninjured state, but exercise post-surgery can help build the surrounding muscle and help with the pain.
The American Academy of Orthopaedic Surgeons provided an illustrated guide of recommended exercises. These exercises are good for general strengthening of the legs and knee area in those who have never been injured, but that is not a guarantee that an injury would not occur, especially among those who play sports that involve pivoting and sudden stops.
Can a medial meniscus tear heal without surgery?
There are several options for treating a torn meniscus without surgery, including traumatic injuries where the anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) and meniscus were torn at the same time, as sometimes happens to athletes.
One study followed 32 patients with an ACL tear and torn meniscus, treated with bracing. In a three month period, 58% of the medial menisci healed completely and none healed partially. Twenty of 25 anterior cruciate ligaments and 3 of 7 posterior cruciate ligaments healed satisfactorily. This study indicated that acute tears of the meniscus, even when they occur in association with a cruciate ligament injury, can heal morphologically with nonsurgical treatment.
A study of degenerative meniscus tears concluded that patients treated with non-steroidal anti-inflammatory drugs (NSAIDS) and physical therapy compared to patients who were treated with partial meniscectomy resulted in similar results over the long term.
Use of orthobiologics, such as platelet-rich plasma and mesenchymal (self-renewing) stem cells, have shown promise in augmenting surgical repairs or as standalone treatments for torn meniscus, but to date ,there has been limited research performed on humans in this area (although a search through PubMed reveals numerous such studies on animals). Limited research has not kept orthopedic doctors from jumping on the stem cell bandwagon since there are numerous clinics advertising it as an available therapy.
Gel injections containing hyaluronic acid (also called hyaluronan), a substance that naturally occurs in the joints, fascia, and skin of the human body, is being used to treat osteoarthritis of the knee. It was offered to my husband at the time of his second torn meniscus, but after reading the side effects, which are muscle pain, joint pain and stiffness, redness, and swelling, he declined to have it injected.
He felt that since he was already suffering from those things, he would be adding fuel to the fire to have the injection. The orthopedic doctor braced him and gave him exercises to do at home, and scheduled him for re-evaluation in six weeks.
At the follow-up visit, he had a second MRI and the doctor scheduled him for surgery a week later. After the surgery, when the doctor came out to inform me of how it had gone, he showed me the before and after pictures from the arthroscopy, and said, “That was much worse than it looked on the MRI.” Nothing is exact; “second look” arthroscopy is a common procedure to see how a meniscus injury has healed, rather than depending on an MRI.
Medial meniscus tear and massage therapy
The intake interview should cover pertinent information about the client’s current condition, including specifics about the torn meniscus and any recent (or scheduled, if it hasn’t happened yet) surgeries or other interventions that the physician is recommending, such as icing, bracing, exercise, and injections. If the client has had any injections at the site, whether anti-inflammatory or gel, avoid the area for several days.
Massage therapists should always be mindful of the client’s comfort level and pain tolerance. If the client has had recent surgery to repair, remove, or graft that has not yet healed, avoid the area altogether until it has healed. Although the surgery is usually arthroscopic and performed on a relatively small area, you should treat it like any other surgery and avoid massaging directly on the surgical site(s) until the client gets permission from their physician.
If the knee is still inflamed or swollen from the injury, don’t aggravate that problem with aggressive techniques. Swedish massage, light nerve stroking, and lymphatic drainage massage, if you are trained in that, may assist the client to feel better.
Although many massage therapists still espouse the theory that massage increases circulation, the meniscus has very little vascularization, as mentioned at the beginning of this article. If the client is being treated without surgery, remember that while massage therapists are not allowed to do joint manipulations, they are allowed to do joint mobilizations. Gentle passive movements directed to the quads and hamstrings can be beneficial, while deep tissue massage is fine above and below the surgical sites, as the client desires.
Client comfort is the goal, so be accommodating. They may feel better side-lying with the injured knee on top and a pillow between the legs. Bolster or use a pillow under the knees when supine, and under the ankles when prone. In a chair massage, the client may not want to rest their knee on the knee pad if the injury is very recent or painful.
We cannot repair a torn meniscus, but we can help the client feel better and hopefully help with the stress that goes along with being injured.