Arthroscopy & Meniscus Surgery
The meniscus is a crescent shaped structure that lies between the femur and the tibia on each side (inside and outside) of the knee. The principal functions of the meniscus are load sharing and shock absorption. The intact meniscus spreads load away from the cartilage of the bones, thereby protecting it. Damage to the cartilage leads to arthritis in the knee. The meniscus also contributes to knee joint position sense and joint stability. The outer third of the meniscus, known as the “red zone” is well supplied with blood, and has healing capacity. The inner two-thirds is known as the white zone and has no blood supply and has diminished ability to heal. Meniscus damage can be from injuries (acute) or from general wear and tear (chronic).
In most acute meniscus injuries repair or removal is advised through ‘key-hole’ surgery also known as arthroscopy. The factors influencing whether the meniscus should be repaired or removed include:
Patient age – younger patients are more likely to benefit from meniscal repair. They are also more prone to develop arthritis if the meniscus has to be removed.
Location of the tear – loss of the lateral meniscus is associated with poorer outcomes than loss of the medial meniscus. Repairing lateral meniscus tears may prevent these problems.
Type of tear – bucket handle tears are the most amenable to repair. Radial tears and parrot-beak tears can be fixed with special techniques, but are less successful. Degenerate and horizontal cleavage tears are usually best removed
Presence of arthritis – once degenerative changes in the joint are present, there is limited benefit from repairing the meniscus.
Meniscus root tears – in patients with tears of the meniscal root, where the remaining meniscus looks healthy on MRI scanning, and there is no signs of arthritis, repair is often advised.