Internal fixation of juvenile osteochondritis dissecans lesions of the knee

Background: Operative techniques for the management of juvenile osteochondritis dissecans lesions of the knee include drilling, internal fixation, fragment removal, and chondral resurfacing. Purpose: To evaluate the functional and radiographic outcome of internal fixation of juvenile osteochondritis dissecans lesions of the knee. Study Design: Case series; Level of evidence, 4. Methods: The study design was a retrospective case series. Twenty-six knees in 24 skeletally immature patients underwent internal fixation of osteochondritis dissocans lesions. Mean follow-up was 4.25 years (range, 2-14.75 years). Mean patient age was 14.7 years (range, 11-16 years). There were 13 boys and 11 girls. Lesions were graded per the Ewing and Voto classification, with 9 stage 11 lesions (fissured), 11 stage III lesions (partially attached), and 6 stage IV lesions (detached). Methods of internal fixation included variable pitch scrows (n = 11), bioabsorbable tacks (n = 10), partially threaded cannulated screws (n = 3), and bioabsorbable pins (n = 3). Mean follow-up was 4.25 years (range, 2.0-14.75 years). Results: Healing occurred in 22 of 26 lesions (healing rate, 84.6%). There was no significant difference in healing rate for lesion location, fixation method, or lesion grade. In fact, all 6 stage IV (detached) lesions healed. The mean postoperative Lysholm score was 85.8, mean postoperative International Knee Documentation Committee score was 82.6, and mean postoperative Tegner activity level was 7.4. Mean time to healing was 6 months. Eight patients underwent additional procedures: 4 for nonunion, 1 for hemarthrosis, and 3 for elective screw removal. Conclusion: Given the relatively high healing rate, good functional outcome, and low complication rate, the authors advocate internal fixation of unstable juvenile osteochondritis dissecans lesions of the knee, even for detached lesions and in patients with a history of surgery for the osteochondritis dissecans lesion.