Partial knee replacement is an alternative to total knee replacement in patients with arthritis on only one side of the knee. Partial knee replacement is a surgical procedure which involves resurfacing and replacement of only the diseased surface of the joint instead of the entire joint. Partial knee resurfacing may be an option depending on the affected surface. During the procedure, your surgeon removes only the damaged area of the bone in the affected knee and fits the implant to that bone.
Unicompartmental knee resurfacing is a procedure that resurfaces the affected inner aspect of the femur and tibia. During the procedure, a small incision is made along the affected knee exposing the knee joint. The damaged portion of the meniscus along with a part of bone may be removed to create space for the new plastic component. The plastic component is fixed into the new created area. Now the damaged part of the femur along with little bone is removed to create room for the new femoral component.
The new metal component is fixed with cement. After fixing the femoral and tibial components the knee is taken through a range of movements.
Patellofemoral knee resurfacing is a procedure that resurfaces only the worn-out kneecap or patella and the groove in the thighbone (trochlea). The procedure is performed using an arthroscope, a small fiber-optic instrument with a tiny lens and a video camera. Through the tiny incisions, the damaged part of the patella and trochlea will be removed to create room for the artificial component. The new component is fixed in place with the use of bone cement and the knee is taken through a range of movements.
Advantages of partial knee resurfacing include:
- Minimal incisions
- Minimal hospitalization
- Reduced blood loss
- Less scarring
- Quick recovery
- Less post-operative pain
Although partial knee resurfacing is an effective method in repairing the damaged part of the knee, it is associated with certain complications such as infection, blood clot formation, damage to nerves and blood vessels, wear, dislocation, and ligament injuries.
Cartilage Repair and Restoration
Articular Cartilage is the white tissue lining the end of bones where these bones connect to form joints. Cartilage acts as cushioning material and helps in smooth gliding of bones during movement. An injury to the joint may damage this cartilage which cannot repair on its own. Cartilage can be damaged with increasing age, normal wear and tear, or trauma. Damaged cartilage cannot cushion the joints during movement and the joints may rub over each other causing severe pain and inflammation.
Non-Surgical Treatment: Dietary supplements such as glucosamine and chondroitin are the non-surgical treatment options for cartilage restoration. Chrondroitin sulphate and glucosamine are naturally occurring substances in the body that prevent degradation of cartilage and promote formation of new cartilage. Chrondroitin sulphate and glucosamine obtained from animal sources are available as over the counter products and are recommended for cartilage restoration. Apart from these various other nutritional supplements are also recommended such as calcium with magnesium and vitamin D as a combination. S-Adenosyl-Methionine and Methylsulfonylmethane supplementation may also be recommended by your physician
Surgical Treatments
Cartilage restoration: a surgical procedure where orthopedic surgeons stimulate the growth of new cartilage that restores the normal function. Arthritic conditions can be delayed or prevented through this procedure.
Microfracture: In this method, numerous holes are created in the injured joint surface using a sharp tool. This procedure stimulates healing response by creating new blood supply. Blood supply results in growth of new cartilage.
Drilling: In this method, a drilling instrument is used to create holes in the injured joint surface. Drilling holes creates blood supply and stimulate growth of new cartilage. Although the method is like microfracture, it is less precise, and the heat produced during drilling may damage other tissues.
Abrasion Arthroplasty: High speed metal-like object is used to remove the damaged cartilage. This procedure is performed using an arthroscope.
Osteochondral Autograft Transplantation: Healthy cartilage tissue (graft) is taken from the bone that bears less weight and is transferred to the injured joint place. This method is used for smaller cartilage defects.
Osteochondral Allograft Transplantation: A cartilage tissue (graft) is taken from a donor and transplanted to the site of the injury. Allograft technique is recommended if larger part of cartilage is damaged.
Autologous Chondrocyte implantation: In this method, a piece of healthy cartilage from other site is removed using arthroscopic technique and is cultured in laboratory. Cultured cells form a larger patch which is then implanted in the damaged part by open surgery.
Osteoarticular transfer system (OATS): Osteoarticular transfer system (OATS) is a surgical procedure to treat isolated cartilage defects which usually 10 to 20mm in size. The procedure involves transfer of cartilage plugs taken from the non-weight bearing areas of the joint and transferring into the damaged areas of the joint and is not indicated for widespread damage of cartilage as seen in osteoarthritis. The procedure is usually performed using arthroscopy. The area of damaged cartilage is prepared using a coring tool which makes a perfectly round hole in the bone in damage. The hole is drilled to a size that fits the plug. Next the plug of normal cartilage is harvested from a non-weight bearing area of the knee, is then implanted into the hole that was created in the damaged area. The size of the plug used should be slightly larger than the hole so that it fits into the position. This procedure allows the newly implanted bone and cartilage to grow in the defected area. Usually only one or two plugs are transplanted.
Possible complications of OATS such as hemarthrosis, effusion and pain may occur. Following OATS rehabilitation is recommended. This includes the use of crutches and limiting the range of motion.