The menisci are now recognized to be integral parts of the knee and not the vestigial and dispensable remains of evolution as once thought.
Because the meniscus was thus thought to be trivial structures, tears in the meniscus often meant that the surgeon simply cut away the torn part or removed the meniscus altogether. But we now know that the meniscus is a very significant structure within the knee.
The meniscus or semilunar cartilage is a paired structure composed of cartilaginous tissue. It is situated in the knee between the thigh and leg bones. The main function of the menisci (plural) is one of load transmission. The menisci also play a role in knee stability. They deepen the socket of the tibia to better conform to the ovoid shape of the femoral condyles; they act act as secondary stabilisers in the anterior cruciate ligament-deficient knee. The meniscus also has a role in joint lubrication, which significantly reduces the coefficient of friction in the knee.
More than 50% of the body’s weight is transmitted through the menisci. Loss of all or part of a meniscus increases point loading and results in premature wear of the knee due to altered mechanical forces. Meniscal tears are a common and important source of knee dysfunction, particularly in younger, active individuals who place significant demand on their knees.
Over the last two decades, there has been an improvement in surgical techniques to assess and treat meniscal pathology and have led to a shift towards preservation of the menisci.
Meniscal preservation includes leaving small or partial tears, performing partial menisectomy where appropriate, and meniscus repair techniques. It is crucial to preserve as much functional meniscus as possible. Repair of a torn meniscus restore the loading profiles of the joint and the ability of the meniscus to absorb hoop stress and eliminate joint space narrowing, possibly decreasing the risk of degenerative disease.
Dr (Prof) Raju Vaishya represented India in a recently held cadaveric workshop at National University Hospital, Singapore. In this unique workshop, various techniques of meniscal repair were discussed and practiced.
Dr (Prof) RAJU VAISHYA
MBBS, MS, MCh (Liverpool), FRCS (Lon) Indraprastha Apollo Hospitals,
New Delhi, INDIA
email: [email protected]
The arrangement of the fibres in the meniscus divert vertical compressive forces into circumferential stresses - like the hoop of a barrel.
The meniscus fills the space between the two long bones. When it is damaged or absent this space narrows, and the delicate joint cartilage covering the ends of the bones can become damaged.
This is removal of damaged meniscus tissue, but attempting to retain as much as possible of the important outer part.
Meniscal repair preserves torn meniscus by opposing it to the healthy remnant with stitches or other devices until a blood supply is re-established.