Limitation of in-situ arthroscopic fixation for stable juvenile osteochondritis dissecans in the knee.

UNLABELLED: Current treatment algorithms for stable juvenile osteochondritis dissecans (JOCD) of the knee have not been established. For arthroscopically stable lesion, in-situ arthroscopic fixation with bioabsorbable pins was introduced as a more desirable approach because of less surgical morbidity and faster recovery. However, there is a paucity of literature that concludes on its efficacy. The aim of this study is to determine the efficacy and limitation of in-situ arthroscopic fixation on stable JOCD lesion in the knee. Ninety-six patients with 110 affected knees were reviewed. Subsequently, patients who underwent in-situ arthroscopic fixation for arthroscopically stable JOCD lesions were grouped for further analysis. Arthroscopic lesion stability was graded according to the Guhl's grading system from the surgical description of each lesion. The grade I and II were defined as 'stable' lesions. The lesion status was also evaluated with the MRI grading system described by Dipaola in preoperative images retrospectively. The grade I and II lesions were also defined as 'stable' and more than III as 'unstable'. Clinical outcomes were evaluated by the Lysholm score at the final office visit. If the patient had a revision surgery, the case was classified as a complete failure. There were 13 lesions in 13 patients with open physis treated with in-situ arthroscopic fixation using bioabsorbable pins. In this population, radiographical lesion status and the Lysholm score were significantly improved in 10 cases (preoperative: 77.5±11.2, postoperative: 98.9±3.1, P=0.002); however, we found three revision cases (failure rate, 23%). Of these revision cases, all lesions were graded as 'unstable' in MRI. In this series, the failure rate was 23% for in-situ arthroscopic fixation for arthroscopically stable JOCD lesion of the knee. Because of the potential risk for underestimation of lesion instability, we strongly suggest that this less invasive approach should be chosen with great care for the lesion that presents arthroscopically stable, but as unstable status on MRI.

LEVEL OF EVIDENCE: Level IV, case series.