Meniscal Tears in Athletes. What Does the Research Say About Best Treatment and Time to Return to Sport?
Meniscal injuries or meniscus tears are the second most common injury to the knee and for athletes a considerable percentage will either not return to play or not be able to perform at pre-injury levels. The NBA has a long list of athletes with a history of a meniscus tear including Chris Paul, Jeremy Lin, Russell Westbrook, Dwyane Wade, and Meta World Peace. An internal 21 season NBA study found that there were 1-2 meniscus injuries for every 10,000 practices and games for a given athlete and an average return to play of 6 weeks. Of those athletes injured, 20% never returned. However, the good news is that those that did, generally returned to previous playing levels.
In young athletes, those that participate in football, wrestling, rugby, and soccer have been shown to have the highest incidence of tears. Unfortunately, in sports injuries, 20-30% of meniscal injuries are associated with other ligament injuries.
In this article, we’ll explore how meniscal tears are diagnosed, treated, and properly rehabbed.
Meniscus Injury Review
An acute mechanism usually involves torsional stress in weight bearing. The athlete will present with swelling and will report pain with rotation. They may also complain of the knee “locking” with difficulty fully extending the knee. Each meniscus can be divided into 3 zones: Red-Red Zone (the peripheral third and densely vascularized), Red-White Zone (central third), and White-White Zone (the inner third with no vascularization). This is a serious consideration when deciding treatment.
Another consideration is the classification of the tear.
Type of Lesion
|Vertical Longitudinal Lesion||Most frequent meniscal injury|
|Bucket-Handle Lesion||A complete longitudinal lesion can become a bucket-handle; can cause “locking” / “catching” sensation|
|Vertical Radial Lesion||Usually originates from the free side to the periphery|
|Horizontal Tears||Degenerative lesions; surgery usually not required|
|Oblique Tear (Flap)||Common with “locking”/ “catching” sensation|
|Complex Lesion||Due to repeated trauma|
Risk Factors for Getting a Meniscus Injury
Participating in sports involving twisting and pivoting increases your risk. There is minimal evidence showing that linear running is a risk factor. Weight is a consideration in athletes with a BMI of greater than 25 as they have a significantly increased risk. If an athlete suffers an ACL injury and waits longer than 12 months to have reconstruction surgery, there is strong evidence showing the risk of a subsequent meniscal tear is higher. Finally, there is moderate evidence linking systemic joint laxity (Beighton Score of 1 or higher) will increase your risk.
Diagnosing a Meniscus Tear
MRI is often referred to as the gold standard. However, incidental findings are common and are not always associated with pain. MRI scans are only 80-90% accurate at diagnosing meniscal tears with a high signal on the image indicating edema, degeneration, and/or an actual tear. Clinical examination has been shown to be as accurate or superior to MRI in diagnosing meniscus tears. However, it should be noted that location of pain does not correlate to location of pathology in meniscus tears.
Common special tests include Joint Line Tenderness, McMurray’s Test, and Apley’s Test. All of these have limited specificity and sensitivity, especially in the presence of other pathologies, such as an ACL tear. These tests are not diagnostic alone and will require a combination of findings. Other tests such as Thessaly’s, Merke’s Sign, Ege’s Test, and Dynamic Test/Steinmann I Sign have shown good initial diagnostic value, but limited research has been conducted to confirm their utility.
Non-surgical rehab is a valid option for a stable, incomplete tear located <3mm from the periphery as there is a higher likelihood of the meniscus healing on its own. Treatment involves managing the pain and swelling and progressively restoring strength with a relatively quick turnaround of a few weeks.
Surgical Options for Meniscus Tears
Indicated for flap tears, radial tears in the inner or vascular area, and horizontal cleavage tears. This procedure has a quick recovery, but there are some serious considerations. After the procedure, accelerated degenerative changes are likely to occur. This procedure has been shown to lead to a >350% increase in contact forces on the articular cartilage. In athletes, if they undergo a lateral partial meniscectomy, the risk of developing arthritis is greater than the equivalent for the medial side. One study found at an 8.5 year follow up that there was a reoperation rate of 22.8% and 53% of patients had arthritic changes compared to only 22% in the unaffected control knee.
This procedure is more suitable for younger patients with tears in the peripheral 2/3 of the meniscus. Those that elected to have the surgery within 3 months of injury had better results than late repair (91% vs. 58% success rate) and traumatic tears had better outcomes than chronic tears (73% vs. 42%). A 2010 AJSM study found that 94% of patients undergoing repair reached pre-injury sports levels at long-term follow up (8.8 years after surgery), while only 43.75% of patients undergoing partial meniscectomy reached the preinjury level.
Looking at patients younger than 20 years old, it was found that on an average follow up of 51 months, that 75% of the repairs were asymptomatic.
Meniscal Allograft Transplantation
Indicated for patients who have a history of partial or total meniscectomy and for those with compartmental pain. There are considerable difficulties for success and long-term function remains questionable as the transplant seems to undergo remodeling. In athletes, an indicated candidate is one with persistent femur-tibial pain following partial or total meniscectomy and a BMI <30. In a study of 13 professional athletes after a transplantation, the athletes returned to competitive activities an average of 16.5 months after surgery with 77% of them resuming pre-injury level of activity.
After this procedure, rehab can be relatively aggressive with no weight bearing or range of motion restrictions. Many surgeons will unfortunately not order physical therapy after this procedure. However, it has been shown that when patients received supervised rehab they had a more rapid recovery in strength than patients in the unsupervised control group. Strength levels need to be closely monitored and progressed as it has been shown that there are significant deficits in knee extensor strength compared to before and after surgery. Pre-operative strength levels have been shown to not return until 4-6 weeks after surgery and were still reduced compared to the non-injured limb for up to 12 WEEKS!
Linear running usually begins 4-6 weeks post-operatively with return to sport clearance after 3-6 weeks and return to competition usually after 5-8 weeks.
In most cases, the patient will have weight bearing and range of motion restrictions for 4-8 weeks after surgery depending on the procedure and surgeon as excessive weight bearing post-operatively can disrupt repairs. Early mobilization after surgery is important as it has been shown to lead to lower rates of arthritis at 12 months. There are accelerated rehab protocols out there with rapid return to full ROM (6 weeks vs. 10 weeks in standard group), higher quad strength at 2 months (82% vs. 71% in standard group), and accelerated return to activity (10 weeks vs. 20 weeks).
Regardless, if you didn’t personally perform the surgery, you don’t have the right to choose the rehab protocol. Work closely with the surgeon to develop the right plan for the patient.
Meniscal Allograft Transplantation
This has the longest recovery with the most restrictive precautions. In general, you can expect normal ambulation after 8-12 weeks, linear running at 6 months, and return to activity after 12 months. This is the least frequently performed surgery of the three with limited rehab recommendations. You will need to refer to case studies and to have good communication with the MD.
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