Types of Meniscal Injury
Due to the absence of a blood supply to most of the meniscus, a tear is unlikely to heal by itself (a white-white tear).
If your symptoms are ongoing, and an MRI proven meniscal tear is seen, arthroscopic (keyhole) knee surgery is a very successful method of permanently curing the pain and instability that is felt.
This is done as a short day case procedure, and the torn part of meniscus which may be jamming the joint is trimmed and smoothened, so as to not catch and cause pain. Your surgeon will attempt to preserve as much normal meniscus as possible at this procedure.
Occasionally in the younger patient, the meniscus is torn within the zone of the meniscus which has a good blood supply (a red-red tear), and these tears may be suitable for surgical repair, preserving and regaining normal shock absorber function following successful healing.
Your surgeon will carefully go through the suitability and necessity of each procedure with you in clinic, prior to any planned surgery.
In older patients, we know that the lining of the articular surface of the joint may already be significantly diminished (osteoarthritis). In a known osteoarthritic knee, an MRI scan may reveal a crushed and macerated meniscus. This is often referred to as a “degenerate meniscal tear”. Keyhole surgery to treat a degenerate meniscal tear may not only fail to treat the symptoms, but can sometimes, actually aggravate the knee further.
Clearly, this can be disappointing for both patient and surgeon alike. Thus, when significant degeneration exists within the knee in addition to a meniscal tear, it is likely that your surgeon may advise you against keyhole surgery and seek alternative methods of treating the problem.
It is always your symptoms which should lead to consideration of an operation rather than just the presence of an MRI-proven tear alone.
If the decision has been made to proceed to surgery, this is a procedure known as an arthroscopic partial meniscectomy. This is a relatively straightforward keyhole operation carried out under general anaesthetic, lasting approximately 20-30 minutes under a light general anaesthetic.
The operation involves the insertion of a camera or “arthroscope” into the knee through two small 4mm incisions or “portals” in the front of the knee. The damaged part of the cartilage is trimmed and the residual rim of cartilage shaped. As little of the cartilage (usually approximately 20-25%) is removed as possible in order to preserve the function of the remaining healthy portion.
Once the whole of the inside of the joint cavity has been thoroughly inspected and any other defects/damage noted, the instruments are removed and the portals closed. After surgery, the knee is dressed with a woollen bandage and you will be encouraged to walk within an hour after you have woken up and have had a meal.
You will be able to walk without sticks or crutches but we advise that limiting walking to short distances initially and build up gradually to normal activity.
Driving is normally possible after two days and once you are confident enough to be able to do an emergency stop.