99m-Technetium phosphate compound joint scintigraphy in the management of juvenile osteochondritis dissecans of the femoral condyles.

The known sensitivity of joint scintigraphy in following the course of fracture healing caused the authors to believe that this radiologic technique might be valuable in the management of osteochondritis dissecans (OCD). Accordingly, 99mTc-diphosphonate joint scintigraphy was used on 18 patients with OCD of the knee. The average age was 13 1/2 years. The scintigrams were repeated at 6-week intervals until healing had occurred. When the diagnosis of OCD was established by standard roentgenograms and joint scintigraphy, the patients were placed on an activity restriction program, attempting to reach a symptom-free level. The patients were followed for an average of 18 months. Ninety-five scans were categorized according to their level of scintigraphic activity. This led to a discrete four-part scintigraphic classification that is indicative of the extent of healing or progression of this condition, and precedes changes seen on standard x-rays by months. Joint scintigraphy also rules out anomalies of ossification in the diagnosis of OCD since an anomaly should have a normal scintigraphic appearance. We have concluded that joint scintigraphy is valuable in the management of OCD because of its superior sensitivity to changes in the activity of the lesion. As experience is gained with this technique, those cases that should be prophylactically surgically stabilized may be indicated.