This page discusses osteochondritis of the knee. For osteochondritis of the ankle, please see Osteochondral Lesion of the Talus.
Osteochondritis dissecans (OCD) of the knee is an often-painful condition in which the cartilage and underlying bone loses blood supply, leading a small segment of bone to crack and separate.
Pain, swelling, tenderness, and locking, catching, and/or giving way of the knee are common symptoms of OCD and may cause inability to walk or run comfortably.
Osteochondritis dissecans most often affects the knees of young people. It is most prevalent between 10 and 18 years old.
The cause is not well understood, including why it most often affects younger people. It may be multifactorial and often due to repeated small stress injuries. It is believed that an area of bone underlying the knee joint cartilage does not form or respond to stress normally. This can affect the way that joint cartilage functions and shares loads across the knee.
X-rays of the knee are used to diagnose OCD. Generally, four different views of the knee are obtained while the affected knee is in straight and bent positions. The other knee is often imaged as well, because OCD is bilateral (affecting bone knees) approximately 30% of the time. A magnetic resonance image (MRI) often is ordered after radiographs to help confirm the diagnosis and determine the stability of the OCD (needed to guide treatment).
An orthopedic surgeon specializing in pediatric sports medicine treats OCD. Osteochondritis dissecans of the knee must be diagnosed as soon as possible in order to be successfully treated.
For OCD lesions that are stable (overlying joint cartilage is intact), rest from high impact activities (for up to six months), NSAIDs, bracing, and physical therapy are the mainstays of treatment. In about 50% of cases, the lesions can heal with conservative treatment and surgery is unnecessary.
The patient's bone development, symptoms, and stability of the affected area all play a role in determining whether surgery is necessary. The primary objectives for surgery are to stabilize the joint surface, increase the blood supply to the injured area, maintain strong fixation, and allow for early movement to protect the bone and cartilage fragment. If the fragment cannot be salvaged, the precise location of the damage and the patient's overall health will influence the decision of whether to use cartilage repair methods.
Surgery is performed for an unstable OCD (breach in the overlying joint cartilage), a stable lesion that does not heal with nonoperative intervention, or if nonoperative approaches have a low likelihood to be successful based on the size and characteristics of the OCD lesion shown on an MRI. There are various procedures, which are used for different types of cases, including arthroscopic condylar drilling, fixation, debridement, grafting, or cartilage regeneration.
In stable lesions, knee arthroscopy is utilized to assess the OCD and then make multiple holes in the lesion using a drill. This generates blood flow which provides stem cells required for healing the OCD.
In the more severe, unstable lesions, fixation of the loose segments of bone with screws or tacks of the lesions is necessary, and this procedure has high success rates in children and adolescents.
Approximately 50% of children with OCD will recover with nonoperative treatment but it often takes six months to a year for significant healing to occur.
Updated: 7/3/2024
Reviewed and updated by Shevaun Mackie Doyle, MD and Daniel W. Green, MD, MS, FAAP, FACS