Osteochondral Autologous Transfer Surgery (OATS) is a surgical procedure to treat isolated cartilage defects which are 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.
This procedure is not indicated for wide spread damage of cartilage as seen in osteoarthritis.
The procedure is usually performed using arthroscopy. During the procedure the plugs taken are usually larger and therefore only one or two plugs are needed to fill the area of cartilage damage. The area of damaged cartilage is prepared using a coring tool which makes a perfectly round hole in the bone in the area of 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.
Possible complications of OATS include donor site morbidity causing pain, avascular necrosis, and fracture. Other complications such as haemarthrosis, effusion and pain may also occur. Following OATS rehabilitation is recommended by use of crutches and limiting the range of motion.