How Are Meniscus Injuries Diagnosed?

The meniscus is a cartilaginous structure in a C or wedge shape, whose purpose is to act like a shock absorber between the thighbone and shinbone. Both knees have two menisci, one on the knee's interior (medial) and one on the outer (lateral) side. 

The menisci's primary function is absorbing pressure and distributing body weight. At the same time, they protect the bones from grinding against each other and causing osteoarthritis. Given that the knee joint can gradually deteriorate due to strenuous activity or aging, meniscal injuries can occur, requiring reparative treatment. 

Meniscal tears are most commonly caused by traumatic or sporting injuries involving an abnormal overextension or leg rotation that partially or fully ruptures the cartilage. Individuals that suffer a torn meniscus usually report the following symptoms:

• Pain near the torn area
• Sudden pain after the injury
• Slow symptoms onset
• Pain when moving
• Pain after resting
• Swelling from fluid accumulation
• Joint locking

These symptoms can vary for every individual depending on the tear's location, severity, patient health, and time that passed since the injury. Additional damage to surrounding structures like the ACL can also co-occur. 

Diagnostic physicians first establish if a meniscal tear is present or the symptoms have a different cause. If a tear is evident, they will determine which meniscus was affected and the extent of the damage. The diagnostic process focuses on:

• Patient history – Physicians usually ask if any other meniscal issues have occurred before, which can affect the nature of the subsequent treatment.
• Physical examination – Physicians determine which meniscus has been damaged and if joint locking is present and caused by torn pieces of cartilage inside the knee. They may employ either the McMurray or Apley's Compression test. 
• Imaging tests – X-rays, CT, and MRI scans enable a deeper view of the knee joint, helping physicians determine the location and extent of the tear and if any soft or hard tissue particulate is lodged in the joint.

The diagnosis also determines the type of meniscal tear, which include flap, degenerative, bucket handle, and radial tears. These factors allow physicians to determine which type of treatment is required. Light injuries may respond to conservative treatment methods, but more complex injuries may require surgical interventions to repair, remove or replace a torn meniscus.