Children are involved in sports more than ever before. Year-round practice and competitive play have increased the number of orthopedic conditions and injuries reported. One of those conditions is osteochondritis dissecans (OCD) or JOCD when juveniles (children and teens) are affected.
OCD mostly affects the femoral condyles of the knee. The femoral condyle is the rounded end of the lower thighbone, or femur. Each knee has two femoral condyles, referred to as the medial femoral condyle (on the inside of the knee) and the lateral femoral condyle (on the outside). Like most joint surfaces, the femoral condyles are covered in articular cartilage. Articular cartilage is a smooth, rubbery covering that allows the bones of a joint to slide smoothly against one another.
The problem occurs where the cartilage of the knee attaches to the bone underneath. The area of bone just under the cartilage surface is injured, leading to damage to the blood vessels of the bone. Without blood flow, the area of damaged bone actually dies. This area of dead bone can be seen on an X-ray and is sometimes referred to as the osteochondritis lesion.
The lesions usually occur in the part of the joint that holds most of the body’s weight. This means that the problem area is under constant stress and doesn’t get time to heal. It also means that the lesions cause pain and problems when walking and putting weight on the knee. It is more common for the lesions to occur on the medial femoral condyle, because the inside of the knee bears more weight.
Parents of active children with JOCD are faced with an interesting challenge. The nonoperative treatment is rest and inactivity until the bone heals. But the physical, social, and emotional downside of inactivity for these sports-minded youth can be a problem.
Is there some way to preserve the bone without prolonged immobility that gets these athletes back on their feet and playing or performing again? In this study, sports medicine physicians and surgeons from the University of Michigan (Ann Arbor) look to see if drilling into the lesion might speed up the healing process.
Drilling is done using arthroscopy and fluoroscopy. These techniques allow the surgeon to see inside the joint while guiding surgical tools and completing the drilling process. Drilling is done with K-wires that poke holes through the hardened rim of bone that develops around the softened bone.
Once the hard shell around the lesion has been breached, new blood supply to the area starts the healing process. The surgeon must be careful not to drill into the knee joint or into areas of healthy knee joint cartilage. That type of drilling approach is referred to as intraarticular technique. The drilling used in this study avoided the cartilage and is called extraarticular drilling.
One of the advantages of the extraarticular drilling technique is that motion is not restricted. The patients were allowed to stand and walk with crutches. Weight-bearing was limited on that side for six weeks. Physical therapy to restore motion and stimulate bone healing through the proper exercises and activities was started. When signs of healing were observed on X-ray, the exercise program was progressed to include light resistance and gradual impact loading.
Swimming and cycling were allowed but running, jumping, and twisting were limited until MRI or CT scan showed evidence of good healing. Once the patient was pain free with good leg muscle strength, then the training program was stepped up to include full return to activities.
How well did this treatment approach work? Fifteen children were included in the study. All were active athletes in year-round training and competition. Ages ranged from nine to 15. Everyone had open physes. That means they were still growing and the growth plate had not yet hardened and turned into bone. Their bone lesions were soft and did not extend down into the deeper bone.
Surgery to perform the drilling technique was done without any follow-up problems or complications. Everyone was able to return to full sports participation. Some were back on the field sooner than others. The earliest return-to-play was five months. The longest time period for recovery was 14.5 months.
The results of this and other studies may challenge the current practice of treating JOCD nonoperatively for at least six months before attempting surgery. There’s evidence that early surgical treatment may provide a better result. This is especially true in older children who are close to bone maturity. Operative treatment after the growth plates have closed is not as successful as when it’s done in skeletally immature patients.
Conservative care with prolonged immobilization can result in muscle weakness and atrophy, joint stiffness, and worse cartilage degeneration. Delaying surgery too long may not be the best idea.
The authors suggest that extraarticular drilling for JOCD is best used when there are unstable lesions, when the child is close to bone maturity, or for children who have tried nonoperative treatment for stable lesions without success.
Extraarticular drilling is a good treatment option for the active athlete with JOCD who might otherwise make the lesion worse with high-impact activities. This may be an acceptable treatment plan for the young athlete who refuses to reduce activity level and risks further damaging the joint.