Meniscus tear: symptoms, treatment, and when knee arthroscopy helps

Meniscal tears are among the most common reasons patients are referred for knee arthroscopy. But not all meniscal tears are alike, and the treatment that is right for one type of tear is not necessarily right for another.

For the right patient with the right diagnosis, keyhole surgery is highly effective. For others, particularly those with degenerative knee pain, it may offer little benefit. The difference matters enormously, and it begins with an accurate diagnosis.

What the meniscus does

The meniscus is a C-shaped disc of fibrocartilage that sits between the thigh bone (femur) and the shin bone (tibia) on each side of the knee. The menisci act as shock absorbers, spreading load across the joint surface, and they contribute to stability and lubrication.

Meniscus tear symptoms

When the meniscus is torn, it can cause pain, swelling, clicking, and sometimes locking, where the knee becomes stuck and cannot fully straighten. Whether surgery is likely to help depends significantly on the type of tear.

How it is diagnosed

MRI is the most useful investigation for diagnosing a meniscal tear. X-rays do not show the meniscus but are useful for assessing joint space and identifying arthritis. Dr Mooney will review your MRI and clinical examination to determine the best approach.

When a patient presents with a degenerative meniscal tear, Dr Mooney’s first step is to understand the full picture: the nature and severity of symptoms, any mechanical features, the degree of associated arthritis on imaging, and what the patient has already tried. An MRI showing a meniscal tear is not, by itself, an indication for surgery.

Traumatic tears: when knee arthroscopy helps

Traumatic meniscal tears typically occur in younger, active patients, often as a result of a twisting injury, a pivot while playing sport, or a fall. Many cause mechanical symptoms: catching, locking, or a sense that the knee is not moving smoothly. A displaced flap tear, in which a fragment of the meniscus folds into the joint and physically blocks movement, is a classic example. In these cases, arthroscopic surgery is usually appropriate.

Preserving the meniscus, where technically possible, is always the preferred goal. It is what protects the joint in the long term.

Meniscal repair, stitching the tear back together rather than removing the torn tissue, is the preferred approach when it is technically possible. Preserving the meniscus protects the joint from long-term arthritic change. Recovery after repair is longer than after debridement, but the benefit to the joint over a lifetime is significant.

Degenerative tears: treatment without surgery first

Degenerative meniscal tears are a fundamentally different entity. They occur in older patients, typically over 45, and are a feature of the ageing knee rather than a discrete injury. The critical question is whether the symptoms are caused by the meniscal tear specifically, or whether they reflect underlying arthritis.

Multiple high-quality randomised controlled trials have compared arthroscopic partial meniscectomy with physiotherapy for degenerative meniscal tears, and the results are consistent: for most patients with degenerative tears, surgery offers no significant advantage over a well-structured exercise programme. This does not mean surgery is never appropriate: patients with true mechanical symptoms that have not responded to rehabilitation may benefit, but surgery is not the default first step.

Root tears

Meniscal root tears warrant particular attention. A root tear disrupts the attachment of the meniscus to the tibia, causing the entire meniscus to effectively extrude from the joint. This significantly increases load on the articular cartilage and can accelerate arthritis substantially. Root tears in appropriately selected patients may be repaired using a bone tunnel technique. Dr Mooney is experienced in this procedure.

Knee arthroscopy for a meniscus tear

Arthroscopy means looking inside a joint using a camera. In knee arthroscopy, the surgeon makes two or three small incisions, each about the size of a buttonhole, around the knee. A thin camera (the arthroscope) is inserted through one of these incisions, and fine instruments through the others.

The procedure is performed under general or spinal anaesthesia and typically takes between 20 minutes and an hour. Most patients go home the same day.

Seeing a knee specialist

Dr Mooney consults at Eastwood, Tea Tree Gully (North East Health Centre), Woodville, Naracoorte and Mount Gambier. Dr Mooney will review your MRI and clinical examination to determine the best approach.

Common questions