Osteochondritis dissecans is a joint condition in which a piece of cartilage, along with a thin layer of the bone separates from the end of the bone because of inadequate blood supply. These fragments may be localized or may detach and fall into the joint space causing pain and joint instability.
Osteochondritis dissecans occurs within the lateral aspect of the medial femoral condyle. The condition can also occur in other joints, including your elbows, ankles, shoulders, and hips. Exact cause for osteochondritis dissecans remains unknown and certain factors such as repetitive trauma, fractures, sprains, or injury to the joint are considered to increase the risk of developing the condition. Following the injury or trauma, the bones in the area may be deprived of blood flow leading to necrosis and finally the bone fragment may break off following an injury or trauma.
Diagnosis
Patients with osteochondritis dissecans usually have joint pain, swelling, stiffness, decreased range of motion, and joint popping or locking. Pain usually increases after activity.
The physician may order an X-ray of both the right and left knee to see the abnormality in the joint space and to compare them. A Cat Scan or MRI scan may be ordered in addition to determine the location of loose fragments within the joint.
Treatment
Your physician may recommend various treatments depending on the reports of diagnostic scans, age, severity, stability of the cartilage and other factors. Goals of treatment are to relieve the symptoms and stop or impede the progression of degeneration of the joint.
Conservative treatment approaches include wait & watch, pain medications, and immobilization for 1-2 weeks are recommended if the condition is diagnosed at early stages and if the severity is mild.
Surgery is required if the condition is diagnosed at advanced stage or if the condition is severe.
Surgical correction of osteochondritis dissecans can be done using by open technique or arthroscopic techniques. Some of the surgical procedures include drilling, bone grafting, open reduction internal fixation, osteochondral grafting, or autologous chondrocyte implantation (ACI).
- Drilling –multiple small holes are drilled into the bone which allows the growth of new blood vessels in the defect area.
- Open reduction internal fixation –This surgery performed in cases where the defected area is difficult to reach with arthroscope. Hence an open incision may be required. In this procedure, an incision is made in front of the joint to allow the surgeon to see the joint and the loose bodies are removed. Internal fixation involves fixing the fragments using internal fixators such as metal screws, pins, or wires.
- Bone grafting helps to fill the gap after removal of the dead or necrotic bone. In this procedure bone graft is placed on the damaged site. This procedure may be performed to repair the damaged area or replace the missing bone. Auto graft (harvested from the same individual) or allograft (taken from bone bank) may be required to help in the growth of a new bone
- Osteochondral grafting - The procedure involves transfer of healthy cartilage plugs from the non-weight bearing areas of the joint and transferring into the damaged areas of the joint in mosaic pattern. It allows the newly implanted bone and cartilage to grow in the defected area. Grafts may be taken from the same individual (auto graft) or from a donor or bone bank (allograft)
- Autologous chondrocyte implantation (ACI) – In this procedure healthy cartilage cells are harvested from the non-weight-bearing joint of the patient and cultured in laboratory. The cultured cartilage tissue patch will be implanted into the defected area which also promotes