A meniscus tear is a common injury, but even more so in athletes. There are modifiable and non-modifiable risk factors that can increase a meniscus injury. Prevention is the key to reducing meniscus tears, and it is more cost-effective than surgery. However, if the injury requires surgery, proper rehabilitation will help the person return to normal activities.
Menisci ensure proper stress distribution and absorb axial, rotational, and shear forces in the knee joint.
Meniscus tears can affect all ages across all physical activity levels.
BMI, sports, and occupational activities are modifiable risk factors for the meniscus tear.
A good warm-up session can reduce knee injury.
After meniscus repair, meniscectomy, or other surgery, the patient must follow the rehabilitation process. After that, they are able to return to normal activities.
The menisci are located inside and outside the knee joint, mainly described as a plate between the femur and tibia. Menisci secure the cartilage from damage. However, the loss of the meniscus can cause progressive wear of the knee joint.
About 850,000 meniscus surgeries are performed in the United States of America every year. Perhaps, not surprisingly, meniscus injuries in high school athletes during games and competitions occur at higher rates compared with practice training.
Menisci ensure the long and qualitative life of the knee joint. Moreover, they are responsible for many tasks, including:
- Reducing stress between the femur and tibia.
- Absorbing axial, rotational, and shearing forces in the knee joints while we are moving or training.
- Lubricating the knee joint.
- Providing nutrition to the knee joint.
- Increasing stability.
What causes meniscus damage?
Unfortunately, everyone is susceptible to a meniscus tear. It can affect all ages and sexes and occur across all physical activity levels.
Age, gender, mechanical axis malalignment, hyperlaxity, and other anatomical structures are non-modifiable risk factors. However, many modifiable risk factors include body mass index (BMI), tobacco use, sports participation, and occupational activities.
The prevention of modifiable risk factors is essential and can potentially reduce the number of meniscus tears.
Body mass index
As mentioned above, the meniscus absorbs the forces and reduces stress on the knee joint. For example, when we walk on a flat surface, our knee joints absorb about two to three times our body weight. However, that force doubles when we squat or move up and down. That is why body mass index (BMI) is so important in preventing a meniscus injury.
Studies showed that people with BMI > 30 have a strongly increased risk of a meniscus tear or chondral defects compared with those who have BMI < 30.
Interestingly, tobacco use does not increase meniscus tears. However, the length of rehab and recovery increases after a meniscus injury for tobacco smokers.
Sports activities place higher loads on the meniscus, especially when athletes need to jump, squat, cut, change direction, or lift heavy loads. Moreover, contact sports have a higher risk of meniscus injuries, such as football, basketball, wrestling, and soccer.
Occupational activities which require workers to kneel or squat for more than one hour a day increase the risk of meniscus injury. Furthermore, people who carry loads more than 22 lbs or climb more than 30 stairs per day have a higher meniscus injury rate.
Furthermore, eight out of 1000 active duty soldiers per year suffer a meniscal injury, and about 81.5% of them return to work after meniscus repair and rehab.
Meniscus tear–related injuries and conditions:
There are a number of injuries closely related to the meniscus that should be taken into account.
Anterior cruciate ligament injury
The anterior cruciate ligament (ACL) tear has the potential to cause meniscus injury. Acute ACL injury can cause a lateral meniscus tear, while chronic ACL injury — causes a medial meniscus tear. Moreover, delayed ACL reconstruction has the potential to increase medial meniscus tear.
The tear in the posterior horn of the medial meniscus is sometimes not diagnosed, so it causes instability in the knee joint and increases tension on the ACL graft. Therefore, treating ACL injuries in the early stages is important, even in children. That's because if ACL reconstruction is delayed for 3 to 6 months, it can cause medial meniscus tears.
Nowadays, complete meniscectomy is avoided because it increases the rate of knee osteoarthritis. Osteoarthritis is diagnosed in 50%–80% of patients after 10–20 years for those who had undergone partial meniscectomy.
When comparing non-athletes and athletes, the latter have a higher risk for joint degeneration because athletes maintain high-stress levels on the knee joint after partial meniscectomy.
Knee varus and knee valgus
Knee varus means bowleg knees, while knee valgus means knock knees. Knee varus malalignment causes medial meniscus extrusion and increases the risk of meniscus tears compared with knee valgus.
How to avoid meniscus tears
Studies show that a good warm-up session can reduce knee injury. Proper landing
biomechanics, hamstring strengthening, and proprioception reduce acute knee
Moreover, some studies showed that prophylactic bracing could help to stabilize the knee joint and increase peak knee flexion moment. Bracing might reduce medial collateral ligament and meniscus injuries. However, it should be worn with caution.
Meniscus tear treatment options
The main surgical treatment options are arthroscopic partial meniscectomy or meniscus repair.
Meniscus repair offers several advantages compared with meniscectomy. In some studies, it leads to less risk of osteoarthritis, a higher level of activity, and higher patient satisfaction in the long term.
Recovery after meniscus repair
Meniscus preservation has long-term advantages because the cartilage can be saved, which means delaying osteoarthritis.
Returning to usual activities after meniscus repair or meniscectomy is individualized to the person's needs and athletic ability, and is pathology dependent.
After meniscus, partial meniscectomy. Rehabilitation is needed. This recovery and rehab can last from 8 to 12 weeks. During rehabilitation, the main goals are to restore the range of motion, reduce pain, and increase quadriceps strength, proprioception, and balance. Additionally, prescribed exercises are designed to restore normal gait patterns, normalize plyometric movements, and return to normal activities. After strict rehabilitation protocol, patients are able to run and train.
After meniscus repair. Rehabilitation can last up to 16 weeks, and the person can return to sports after 16–24 weeks. Depending on the type of meniscus tear, and the repairs made, rehabilitation protocol ranges from no weight-bearing and partial range of motion in the first few weeks to toe-touch weight-bearing and 90 degrees range of motion in the first two weeks.
Therefore, a rehabilitation regiment is vital for an athlete because it is designed to ready a patient for running, training, squatting, jumping, and contact sports activities.
How can elite athletes prevent injury?
When talking about athletes, especially contact-sport athletes, it is important to do a pre-injury evaluation. Professional sports clubs are very interested in an athlete's quick return. However, even more, they are interested in the absence of injury. That is why professional sports clubs do pre-injury evaluations. They check every athlete's landing and jumping biomechanics, physiological capacity, etc.
First, coaches want to see athletes' baseline functional status. Screening can include a squat jump and countermovement jump on force plates to see strength asymmetries. Additionally, team physicians measure the athlete's maximum oxygen intake while exercising under stress.
Furthermore, they also measure body balance because it is also very important for injury prevention. All these tests are relevant when athletes want to return to play after an injury. If coaches know the athlete’s baseline biomechanics and other parameters before the injury, it is easier to seek the same results in post-injury assessment.
Nowadays, functional assessment can get almost everybody who is interested in their body and trauma prevention, from beginners and amateurs to advanced athletes.
- Sports Medicine and Arthroscopy Review. The Epidemiology of Meniscus Injury.
- Current Reviews in Musculoskeletal Medicine. Treatment, Return to Play, and Performance Following Meniscus Surgery.
- The Archives of Bones and Joint Surgery. The Prevalence, Zone, and Type of the Meniscus Tear in Patients with Anterior Cruciate Ligament (ACL) Injury; Does Delayed ACL Reconstruction Affects the Meniscal Injury?
- BMJ Open Sport and Exercise Medicine. Rehabilitation following meniscal repair: a systematic review.