CPT® Code 29885

Arthroscopy, knee, surgical; drilling for osteochondritis dissecans with bone grafting, with or without internal fixation (including debridement of base of lesion)

Arthroscopy of the knee is a minimally invasive surgical procedure that allows for the examination and treatment of various knee joint conditions. In the context of CPT® Code 29885, the procedure specifically addresses osteochondritis dissecans, a condition characterized by the separation of a bone fragment and the overlying cartilage from the underlying bone, often leading to joint pain and dysfunction. This condition can result in loose bodies within the knee joint or cracks in the bone without complete detachment of the fragment. The procedure involves making small incisions, known as portal incisions, on the medial and lateral sides of the knee joint to facilitate access. An arthroscope, a specialized instrument equipped with a camera, is introduced through one of these portals to visualize the internal structures of the knee. A cannula is then inserted through a second portal to allow for the flushing of the joint with saline solution, which helps in cleaning the area and providing a clear view for examination. During the procedure, the surgeon locates the dissecans fragment and may perform debridement of the base of the lesion to remove any damaged tissue. The next step involves drilling small holes through the articular cartilage and into the underlying bone, creating channels that promote blood vessel infiltration and the regeneration of healthy tissue. In cases where the osteochondritis dissecans lesion is extensive or chronic, bone grafting may be necessary, with grafts typically harvested from the proximal tibia and packed into the drilled holes. Additionally, internal fixation may be employed to stabilize the dissecans fragment, either in conjunction with or independently of bone grafting. The procedure concludes with the removal of the arthroscope and instruments, followed by the closure of the portal incisions.