The knee is the largest joint in the body, comprised of the tigh bone (femur), shin bone (tibia) and the kneecap (patella). Unlike the hip and shoulder ball and socket joints, the knee does not have a lot of inherent stability and relies heavily on the quadracep and hamstring muscle groups for support..
The femoral end of the articulation has 2 rounded surfaces called condyles and the inner condyle is slightly longer than the outer condyle which gives the knee the ability to twist however it also means that the inner cartilage is more vulnerable to injury.
The menisci are 3/4 moon shaped pieces of cartilage with a thicker outer rim which enhances the concavity of the tibial end of the joint and so gives the knee a bit more stability.
The cartilages act as sacrificials and are slowly worn over time depending on your activities and are particularly susceptible to damage when twisting on a bent knee which is why meniscal tears are so often seen in football, squash and snowboarding.
The menisci cannot be seen on X Ray but any narrowing in between the gap of the inner or outer joint compartment spaces between the femur and the tibia is a good indication that there may be cartilage damage.
The only way to fully establish a cartilage (meniscal) tear is with a Magnetic Resonance Scan.
There are many different types of meniscal tears and they are named according to location and shape. Loose cartilage floating around in the joint space is called a “foreign body”.
Many of us probably have existing tears and foreign bodies and not even know it as they are not producing any diverse symptoms. Tiny slivers of cartilage are worn off all the time just like fingernails. It is only when these slivers or tears get caught in the mechanics of the knee joint that the symptoms will occur.
Symptoms of cartilage tear include pain after exercise accompanied by swelling and/or locking of the knee, usually when standing up from sitting, or the knee may give way which is particularly noticeable when walking downhill or descending stairs.
Physiotherapy treatments can help resolve the symptoms and often gentle manipulation can free up the mechanism. I have had patients who have had few if any problems since the original diagnosis and subsequent treatment .
The menisci, like a broken finger nail, cannot repair themselves as they have little to no blood supply and so if the symptoms persist then surgery may be required.
Your surgeon will likely choose to perform an Arthroscopy which is “keyhole” surgery and the recovery is much faster.
There are normally 2 small incisions used for a camara and tools to clean away any floating slivers of cartilage and “hoover up” any foreign bodies in the joint space.
There is usually an overnight stay in hospital although can also be done as day surgery. The patient will wake up to a thick compression bandage from mid thigh to the ankle to aid in reducing post-operative swelling and then return home on crutches. The patient will have a follow up appointment with the surgeon to remove any sutures. Physiotherapy rehabilitation programme is important for 2 to 3 weeks after surgery to help regain full movement and ensure that the patient is not fully weight bearing too early as this can delay healing.