Purpose: Drilling is the most common operative treatment for stable juvenile osteochondritis dissecans (OCD) of the knee. However, prognostic factors remain unclear because of lack of precise radiographic and histopathologic investigations. The purpose of this study was to evaluate the clinical results and prognostic factor of the arthroscopic drilling for juvenile OCD lesions at the medial femoral condyle (MFC), using computed tomography (CT) images.
Methods: Eighteen skeletally immature patients (boys, n = 16; girls, n = 2, mean age, 12 years) underwent arthroscopic antegrade transarticular drilling for a total of 19 OCD lesions of MFC. Functional outcomes were evaluated with the Lysholm score at follow-up (mean, 30 months). Preoperative osteochondral condition and postoperative healing were evaluated by CT images.
Results: All 18 patients returned to their previous level of sports activity and showed excellent functional outcomes (mean Lysholm score, 77.2 ± 9.4 preoperative vs. 99.5 ± 1.6 postoperative). There were 10 osteochondral lesions and 9 subchondral bone defect lesions under preoperative CT examination. Postoperatively, 15 of 19 lesions healed completely at a mean of 6 months; however, the remaining four lesions (all osteochondral types) did not achieve complete radiographic healing after 2 years.
Conclusion: Transarticular drilling for stable juvenile OCD produced excellent functional outcomes. However, the osteochondral type may influence radiographic outcome.
Level of evidence: Case series, Level IV.