THE PROGNOSTIC VALUE OF QUANTITATIVE BONE-SCAN IN KNEE OSTEOCHONDRITIS-DISSECANS - A PRELIMINARY EXPERIENCE

We reviewed the records of 12 patients ages 9 to 16 years with knee os teochondritis dissecans, All patients had clinical histories and exami nations, four radiographic views of the knee, and technetium-99m dipho sphonate quantitative bone scans. Scan results (symmetric, increased, or decreased activity), clinical course, healing time, and final outco me were correlated to determine the prognostic value of the scan. We d ivided the patients into those with open physes (distal femoral and pr oximal tibial) and those with closed physes. Four of the six patients with open physes had increased activity on the bone scan, Ail four of these knees healed with nonsurgical treatment. The other two patients had decreased activity on bone scan, and both required surgical treatm ent after nonsurgical treatment failed, Of the six patients with dosed physes, all had increased activity on the bone scan, but only two pat ients had healing of the osteochondral lesion without surgery. Quantit ative bone scanning had a 100% predictive value for the prognosis in o steochondritis dissecans patients with open physes, but for those with closed physes the predictive value was less. Because the natural hist ory in the adolescent group is less predictable, it is in this group t hat the quantitative scan would be most helpful, In this small group o f patients, quantitative bone scanning had limited prognostic value.