What are the physical exams, expected findings, appropriate imaging, and initial treatment for a medial meniscus tear of the knee in a patient who has recently increased intensity and duration of running?

From the Guidelines

A medial meniscus tear in a runner who has recently increased training intensity can be diagnosed through specific physical exams and managed with appropriate treatment, prioritizing conservative management to minimize morbidity and mortality while improving quality of life. Physical examination should include the McMurray test (rotating the tibia while extending the knee from a flexed position), the Apley test (applying pressure to the knee while rotating the leg), and the Thessaly test (having the patient stand on the affected leg and rotate the knee) 1. Positive findings include joint line tenderness along the medial aspect of the knee, clicking or popping sensations during movement, and possibly knee effusion or limited range of motion.

Imaging and Diagnosis

MRI is the preferred imaging modality as it can visualize the meniscus and confirm the tear's location and severity, with a high sensitivity and specificity of 96% and 97% respectively for detecting meniscal tears 1. The use of MRI can help identify the extent of the injury and guide treatment decisions, potentially reducing the need for unnecessary surgical interventions and improving patient outcomes.

Initial Treatment

Initial treatment involves RICE protocol (rest, ice, compression, elevation), NSAIDs such as ibuprofen 400-600mg three times daily for pain and inflammation, and activity modification to reduce impact loading 1. Physical therapy focusing on quadriceps and hamstring strengthening exercises is essential for stability and can help reduce the risk of further injury. Most medial meniscus tears in runners result from repetitive microtrauma rather than acute injury, and many can heal with conservative management over 4-6 weeks.

Considerations for Surgery

If symptoms persist beyond 6 weeks or if mechanical symptoms like locking occur, orthopedic referral for possible arthroscopic intervention may be necessary 1. However, surgery should be considered a last resort, as it is associated with increased morbidity and mortality, and may not always improve quality of life. The decision to proceed with surgery should be made on a case-by-case basis, taking into account the individual patient's needs and circumstances.

Some key points to consider in the management of medial meniscus tears include:

• The use of oral nonsteroidal anti-inflammatory drugs (NSAIDs) and acetaminophen for pain management 1
• The potential benefits and risks of intra-articular injections, including corticosteroid, hyaluronic acid, and platelet-rich plasma 1
• The importance of physical therapy and activity modification in promoting healing and reducing the risk of further injury
• The need for careful consideration of the potential benefits and risks of surgical intervention, and the importance of making informed decisions based on individual patient needs and circumstances.

From the Research

Physical Exams for Medial Meniscus Tear

• The McMurray test, Apley test, and Thessaly test are commonly used to diagnose meniscal tears 2, 3, 4.
• Joint line tenderness is also a clinical sign used to diagnose medial meniscus tears 3.
• The sensitivity and specificity of these tests vary, with the Thessaly test showing statistical significance in diagnosing meniscal tears compared to McMurray and Apley tests 2.
• McMurray's test has a sensitivity of 54-79.7% and specificity of 61.7-79% in diagnosing medial meniscus tears 3, 4.
• Apley's test has a sensitivity of 83.7% and specificity of 71.4% in diagnosing meniscal tears 4.

Expected Findings

• Medial meniscus tears are the most common type of meniscal tear, accounting for 66-87% of cases 5, 2.
• Bucket-handle tears, longitudinal tears, and transverse tears are common types of meniscal tears 2.
• Meniscal tears can be caused by sports, twisting, or trauma, with sports being the most common cause 2.

Appropriate Imaging

• Magnetic Resonance Imaging (MRI) is commonly used to confirm clinical concern for meniscal tear and to review intra- and extra-articular anatomical structures 5, 2, 4.
• MRI has a sensitivity of 78.3% and specificity of 85.7% in diagnosing meniscal tears 4.
• Arthroscopy is considered the gold standard for diagnosing meniscal tears 2, 3, 4.

Initial Treatment

• The initial treatment for medial meniscus tears involves rest, rehabilitation, and physiotherapy 5.
• If the patient is not improving, referral to an orthopaedic surgeon may be necessary 5.
• Surgical repair or partial meniscectomy may be considered depending on the location and stability of the tear 6, 5.
• New experimental surgical techniques, such as meniscal allograft transplantation and biosynthetic scaffolds, are being developed to replace damaged tissue 5.