An osteochondral fracture is caused by tearing of the articular cartilage. The articular cartilage is responsible for covering the endpoint of bone in a joint and is susceptible for tearing in case of a direct or forceful impact or a twisting movement.[1]
Osteochondral fractures are quite frequent in the knee joint. They often occur with certain other injuries like ACL tears.
About Osteochondral Fractures of Knee or Articular Cartilage Injury
Osteochondral fractures can also be given the name of articular cartilage injury, although it can also involve fracture of the bone. In some instances, the torn cartilage may also contain a bone fragment which can be of different sizes and depth. The larger fragments are more likely to cause difficulty. These are also called as loose bodies or loose fragments. General symptoms include pain, swelling, pain with weight bearing, locking or catching of the knee along with instability. The symptoms may come and go and depend on the movement of fragment in the joint. Alternately, patient may not experience any symptoms for many days and then the symptoms may start and continue for a few days continuously. These types of fractures are more frequent in children as well as young adults as their skeletal system is still in the development phase and their bones are soft. This makes them more susceptible for development of fractures.[2]
Causes of Osteochondral Fractures of Knee or Articular Cartilage Injury
The fracture may be caused due to a vigorous twist to the knee, more so when the individual is weight bearing. Direct impact or trauma to the knee like when an individual is tackled in contact sports or a fall may also result in osteochondral fracture.
How to Identify Osteochondral Fractures of Knee or Articular Cartilage Injury?
- Instant pain along with swelling.
- Pain with weight bearing.
- Locking of the knee.
- Instability of the knee.
- X-ray for confirmatory diagnosis osteochondral fracture.
- MRI or CT scan is also required for further establishing the diagnosis since the fragments cannot be seen clearly on x-rays.[3]
Classification or Grading of Subchondral Fracture
- Grade 1: Subchondral fracture.
- Grade 2: Chondral fracture.
- Grade 2a: Subchondral cyst.
- Grade 3: Chondral fracture with separated but undisplaced fragments.
- Grade 4: Chondral fracture with separated fragments which get displaced.
Treatment of Subchondral Fractures
- Physical therapy and a comprehensive rehab program is done for treatment of grade 1 and 2 injuries.
- Casting can be done to immobilize the joint.
- In case of severe injuries like in grade III or IV, usually the first line of treatment is arthroscopic surgery for removal or repair of the affected fragment.
- Patient should religiously follow the full rehabilitation program to facilitate restoration of strength, mobilization and functional balance.[4]
