The meniscus in the knee works by “Hoop Stresses” – by being attached at the front and back of knee, and with its triangular cross section, it spreads the load through that compartment of the knee, protecting the knee from arthritis. A particular problem for the medial meniscus is a popping sensation, where the posterior horn becomes detached. It usually isn’t major trauma, but squatting, or walking up stairs can do it in middle age and above. The “pop” has a very high specificity (99% in a Korean study) but not sensitivity (35%). The natural history is poor – most patients go on to develop osteoarthritis. If there is bone marrow oedema, or a subchondral fracture, the arthritis may be rapid in evolution.

Fortunately, meniscal roots can be repaired if the tear is within 10mm of the root with a surprisingly high success rate.

But, typically we require six weeks of non weight bearing after the surgery, use of knee braces to restrict motion, minimal arthritis, and our patient needs to be on board with the plan. Being heavy isn’t too much of a problem, but if significantly bow legged, a realignment osteotomy is also required. When this surgery was initially advocated, an age limit of 65 was proposed, but in the Australian Knee Society group, plenty of orthopaedic surgeons are operating on folk older than that – if they can tolerate the recovery requirements.

Mr David Mitchell
Orthopaedic Surgeon
MBBS (Melb), FRACS (Orth), FAOrthA, GAICD