Osteochondritis dissecans is a rare condition that most often affects young people who are very active and sporty. What’s going on with this condition – and what are the implications if you have it? Here’s a brief guide.
What is osteochondritis dissecans?
Osteochondritis dissecans (OCD) is a condition that affects the joints. It can occur in ankles and elbows but is most common in the knees (about three quarters of all cases). It happens when a small section of bone begins to separate from the surrounding joint. In time, the fragment – and the protective cartilage attached to it – can deteriorate and loosen, and even drop out of the joint completely.
What causes OCD?
We can’t be completely sure. The immediate reason is that the blood supply to the bone becomes cut off. This could be due to previous trauma – for example a twisting injury in sport, or perhaps a series of repeated injuries that damaged the blood supply to the area. Because OCD can sometimes run in families, some experts have suspected a genetic component. But we can’t say for certain.
Who gets osteochondritis dissecans?
It usually occurs in children and adolescents between the ages of about 10 and 20. If there’s a common theme with OCD, it’s that patients are usually very active in sports and high-energy pursuits like football, gymnastics, basketball, dance, and so on. In most cases the affected part of the knee is the medial femoral condyle, the large outcrop of bone next to the kneecap, on the inside of the leg.
What does osteochondritis dissecans feel like?
OCD often first becomes noticeable when the area around the injury becomes tender or painful. Exercise or sport usually makes it worse. The knee can sometimes also swell up and it may be difficult to move or straighten the joint out properly. If any fragments break away from the surface, they can potentially get caught in the joint, causing the knee to catch or lock.
Can osteochondritis dissecans heal by itself?
Yes, in many cases the OCD lesion can recover naturally. But this usually happens in younger children whose bodies are still growing. It becomes harder in adults or older adolescents who are fully grown or nearing the end of their growth.
How do you treat osteochondritis dissecans?
It depends on several factors, including the size of the lesion, whether the fragment is partially or fully detached, and if it’s moving around or staying in place. This is something we can investigate in clinic with a physical examination, and often with an X-ray or MRI scan to get a closer look at the bone and cartilage.
If it’s a mild case of OCD, conservative treatment is usually the best approach. This is likely to mean complete rest, not putting any weight on the knee, taking simple pain relief, and potentially using a splint or brace to help the joint stay still in the early stages of recovery. That’s usually followed by physiotherapy, to strengthen the surrounding muscles, and a slow return to everyday activities.
What happens if conservative treatment doesn’t work?
Sometimes the painful symptoms persist even after months of rest. Sometimes, when the damage is more significant, the fragment can start to come loose and even detach completely. This is when we might consider surgery, particularly if the patient is fully grown and the injury is less likely to heal on its own. When it comes to surgery, there are several potential approaches. These include:
Fixation – surgical pins and screws to secure the loose fragment in place
Microfracture – drilling tiny holes in the lesion to stimulate regrowth of fibrocartilage
Osteochondral autologous transfer (OATS) – rebuilding the damaged area using small plugs of bone and cartilage from healthy parts of the joint
Allograft – removing the fragment and rebuilding the area with bone and tissue from a donor
Osteotomy – an operation to alter the alignment of the leg and remove pressure from part of the knee
The bottom line
If there’s a takeaway for OCD, it’s that diagnosing and treating the condition early – before the fragment loosens – produces the very best outcomes. With rest and rehab, particularly in younger patients, the damage can heal up and won’t necessarily create long-term issues. Healing becomes much more difficult if the fragment comes away from the joint. Although good surgical treatments are available for osteochondritis dissecans, they can’t recreate the natural condition of the joint surface, and will often require long-term management, and potentially repeat surgery, to relieve the symptoms as they occur.
