What is Osteochondritis Dissecans?
Osteochondritis dissecans is a joint condition in which a piece of cartilage, along with a thin layer of bone separates because of inadequate blood supply. The separated fragments are sometimes called “joint mice”. These fragments may be localised or may detach and fall into the joint space, causing pain and joint instability.
Osteochondritis dissecans can occur in any of the joints including your elbows, ankles, shoulders, and hips.
Osteochondritis dissecans is more common among boys and young men between 10 and 20 years who actively take part in sports. Athletes participating in sports such as gymnastics and baseball may develop osteochondritis dissecans.
What are the Causes of Osteochondritis Dissecans?
The exact cause for osteochondritis dissecans remains unknown and certain factors such as trauma, fractures, sprains or injury to the joint are considered as risk factors.
Osteochondritis dissecans may be caused by restricted blood supply to the end of the affected bone that usually occurs in conjunction with repetitive trauma. 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. This may initiate the healing process, however, by this time, articular cartilage will be compressed, flattened, and a subchondral cyst will develop. All these changes, in addition to increased joint pressure, cause failure of healing of the joint.
Symptoms of Osteochondritis Dissecans
Osteochondritis dissecans usually leads to elbow joint pain, swelling, stiffness and decreased range of motion. Pain usually increases after activity.
Diagnosis of Osteochondritis Dissecans
Your doctor will probably order an X-ray of both the right and left elbow to view any abnormality in the joint space and to compare them. You may also have a CT or MRI scan, which is useful in determining the location of loose fragments within the joint.
Treatment Options for Osteochondritis Dissecans
Your physician may recommend various treatments depending on the 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.
Non-surgical Treatment Options for Osteochondritis Dissecans
Conservative treatment approaches such as the wait-and-watch approach, pain medications and immobilisation for 1-2 weeks are recommended if the condition is diagnosed at an early stage and if the severity is mild. However, surgery is required if the condition is diagnosed at an advanced stage or the condition is severe.
Surgery to Treat Osteochondritis Dissecans
Surgical correction of osteochondritis dissecans can be done using the open technique or arthroscopic technique. Some of the surgical procedures include:
- Drilling: In this method, multiple small holes are drilled into the bone to allow the growth of new blood vessels and the flow of blood in the defective area. This initiates the healing response and formation of new cartilage cells inside the lesion.
- Open reduction internal fixation: Open surgery is performed in cases where the defective area is difficult to reach with an arthroscope. Hence, an open incision may be required. In this procedure, an incision is made in front of the joint to allow your surgeon to view 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: Grafting helps to fill the gap after removal of dead or necrotic bone. In this procedure, a bone graft is placed in the damaged site. This procedure may be performed to repair the damaged area or replace the missing bone. Autograft (harvested from your own body) or allograft (taken from a bone bank) may be required to help in the growth of new bone.
- Osteochondral grafting: The procedure involves transfer of healthy cartilage plugs from a non-weight-bearing area of the joint and transferring them to the damaged areas of the joint in a mosaic pattern. It allows the newly implanted bone and cartilage to grow in the defective area. Grafts may be taken from your own body (autograft), or a donor or bone bank (allograft).
- Autologous chondrocyte implantation (ACI): In this procedure, healthy cartilage cells are harvested from a non-weight-bearing joint and cultured in a laboratory. The cultured cartilage tissue patch will be implanted into the defective area to promote the growth of new cartilage.