Meniscus Injuries

One of the most common injuries we see related to the knee in an outpatient physical therapy clinic is meniscal injuries.   The meniscus in the knee is an important load-bearing anatomical structure that stabilizes, lubricates, nourishes, and transmits load in the joint.  Injuries to the structure can be acute—meaning a direct result of an injury, or degenerative—meaning it happens over time with normal wear and tear.  Both acute and degenerative injuries can cause very specific clinical presentations including:

• Pain at the medial and lateral joint lines
• Swelling in the front of the knee
• Difficulty bending or straightening the knee
• Pain when pivoting/twisting in a weight bearing position
• Pain with squatting
• Clicking, catching, or locking in the joint

The mechanism of injury for acute meniscal injuries is typically a plant and pivot movement in a weight bearing environment.  It can be paired with other structural injuries-most commonly ACL ( anterior cruciate ligament) tears.  However, oftentimes happen in isolation without other structural damage.  One study showed that a trained physical therapist can accurately diagnose mensical tears with up to 92% accuracy without the use of a MRI.  Once diagnosed, the overall goal of treatment is to reduce inflammation and initiate gentle exercise, allowing the meniscus to heal independently.  This process may take 6-8 weeks to occur and is most likely to be successful if the injury is present in the outer third of the meniscus.  This area receives the most blood flow and is most able to successfully heal. 

We can’t escape this discussion without touching on the option of surgery to manage meniscal injuries.  The two primary choices for surgical management for meniscal injuries are meniscal repairs and meniscectomies.  In cases of injury to the outer third of the meniscus where blood flow and healing are more prevalent and likely, meniscal repairs are a better option.  The goal is always to maintain as much of the meniscus as possible as it can help to slow down the degeneration in the joint and the need for future knee replacement surgeries.  However, not all tears are repairable and there are patients who will have poorer outcomes from surgical management than others.  Some characteristics which may encourage you to second guess a recommendation to receive surgery are:

• Pain without other physical signs/symptoms
• Lack of presence of swelling or locking in the joint
• Associated articular cartilage injury
• BMI > 26 kg/m2
• Osteoarthritis in the patellofemoral joint
• Previous meniscus repair or other knee surgery

Let me reiterate, PAIN ALONE IS NOT AN INDICATION FOR SURGERY!  Typically, we will refer out to a surgeon if the knee is catching/locking and giving way causing a patient to fall or have a fear of falling.  This is a result of physical tissue getting stuck within the joint space and causing instability in the knee.  Or, in some cases surgery may be indicated if the joint is unable to resume normal range of motion after 6-8 weeks of therapy, meaning the tissue is physically blocking the knee from fully straightening or bending causing abnormal wear and tear on the joint.  The results of the effectiveness of meniscectomy at long term follow-up are alarming in some sense.  Oftentimes patients have the same results at 1 year follow-up with or without surgery.   And in individuals age 60+ who do choose to undergo meniscectomy, 75-100% of these patients end up with osteoarthritis at 1 year follow-up. 

In summary, a trained physical therapist can accurately diagnose your meniscus tear without imaging, 6-8 weeks of therapy should be the first line of defense for pain management and resuming normal daily function, surgery is oftentimes not the best option and can in some cases accelerate the need for additional surgeries—mainly a total knee replacement, and the body has a remarkable way of healing injuries with time, exercise, and a great PT. 

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