Autologous Osteochondral Transfer (Autolgous Mosaicplasty)
Cartilage is the smooth coating on the end of the bones that provides cushioning and support for comfortable, fluid movement. Cartilage damage occurs as a result of injury or degeneration and can lead to severe pain and arthritis. The cartilage eventually wears away and leaves the bone unprotected. Fortunately, there are now several techniques used to repair damaged cartilage and restore normal movement.
One of these methods is mosaicplasty, which is a transferring of cartilage from a healthy part of a joint to the area that has experienced damage. It is a form of osteochondral autograft transplantation. Developed in Hungary in the early 1990s, this technique has been used with increasing frequency in the past two decades because of the advantages it can provide. In this procedure, the healthy cartilage is removed from a portion of bone that does not bear weight. This graft tissue is taken out using a specialized tool that withdraws a plug of cartilage and subchondral bone. These plugs are quite small, typically less than one centimeter in diameter.
This technique is quite successful when the patient has some bone necrosis taking place within the joint. Mosiacplasty can relieve the related discomfort as well as stop the progression of the cartilage disease that is causing the difficulties. The number of plugs used will vary by patient, depending on the extent of the damage in the joint. This can be assessed prior to the procedure through imaging testing such as diagnostic X-rays.
During a mosaicplasty, several plugs of material will be removed for transfer. The plugs are then placed in the damaged area of cartilage, leaving a full, smooth cushion of cartilage in the joint to protect the bones. This technique is typically best suited to smaller areas of defective cartilage. Only a limited amount of healthy cartilage can be removed from within the same joint and transferred successfully. If the damage is more extensive, a procedure called an osteochondral allograft transplant will often be chosen instead to prevent furthering the potential damage in the joint.
The Mosaicplasty Procedure
Mosaicplasty is a minimally invasive procedure that can be performed using an arthroscope. This enables the surgeon to make tiny incisions to access the joint in question. The arthroscope is actually a camera tube that is inserted into one of the incisions while small surgical instruments are inserted into the other incisions. The arthroscope allows the surgeon to visually examine the joint and guide the instruments to the precise area for treatment.
The mosaicplasty procedure is performed under general anesthesia. The surgeon examines the interior of the joint and removes any debris. The cartilage is withdrawn from non-weight bearing portions of the joint and then grafted into the damaged area. A new layer of cartilage is thus created that is a combination of existing cartilage and these transplanted plugs.
The small incisions made when a mosaicplasty is done arthroscopically help to greatly reduce the recovery time needed from this procedure, and allow patients to return to work and other regular activities much sooner. Many mosaicplasties can be performed on an outpatient basis, but in other cases an overnight stay in the hospital may be required. Patients are typically told to remain on bed rest for two weeks following the surgery. When cleared by the surgeon to begin walking again, patients may require an assistive device such as crutches to prevent putting too much pressure on the joint. Exercise and other strenuous activities should be avoided for approximately eight weeks after a mosaicplasty.
Cartilage repair is a relatively new field and long-term results are still not fully known. This procedure aims to restore movement with the best possible tissue and to prevent further cartilage damage.
Although mosaicplasty is considered a safe procedure for most patients, there are certain risks associated with all surgical procedures. Some of the potential complications may include infection, blood clots, weakening of muscles, limited range of motion and developing arthritis. These risks are considered uncommon, as most patients are able to achieve substantial pain relief as well as stop the deterioration of cartilage through this safe procedure. Your doctor will discuss the risks of surgery with you prior to your procedure to ensure complete patient understanding for the most effective results.