Abstract
Background:
Osteochondritis dissecans (OCD) is a focal, idiopathic alteration of subchondral bone with potential for instability and disruption of adjacent articular cartilage that may result in premature (early secondary) osteoarthritis.
Purpose:
The purpose of this study was to evaluate differences in clinical, radiographic, and treatment outcomes in weightbearing (WB) versus non-weightbearing (NWB) lateral femoral condyle (LFC) OCDs.
Methods:
An IRB-approved retrospective review of 62 patients with LFC OCD lesions, 26 of which were weightbearing and 36 non-weightbearing (defined as Cahill and Berg sagittal zones B and C, respectively), treated at a single institution between 2004 and 2019 was performed. All participants were 18 years of age or younger at the time of diagnosis. Demographic and clinical characteristics, radiographic features, treatment modalities, and outcomes were evaluated. Continuous variables were analyzed using a Mann-Whitney test and a Kruskal-Wallis test when comparing across various groups. A Chi-square test was used to compare categorical variables.
Results:
The study cohort consisted of 40 (64.5%) male and 22 (35.5%) female participants, with an average age at diagnosis of 12.86 ± 2.74 years, and an average follow-up of 24 months. WB and NWB LFC OCDs had no differences in symptom chronicity or the presence of mechanical symptoms. NWB lesions were more likely to present with distinct ossification of the progeny bone segment (70.0% vs. 25.0%; p = 0.044) and were deeper lesions (MRI sagittal depth 7.11 vs. 5.96; p = 0.046).
Across a variety of treatment modalities, NWB lesions were significantly more likely than WB lesions to demonstrate full radiographic healing at final follow-up (52.8% vs. 24.0%; p = 0.033). There was no difference in the likelihood of initial non-operative versus operative treatment selection or in the outcomes of non-operative treatment between the two lesion types. Additionally, OCDs in either zone were equally likely to be pain-free at final follow-up.
Conclusion:
Lateral femoral condylar OCD lesions in weightbearing and non-weightbearing zones have similar clinical presentation. However, lesions in non-weightbearing zones demonstrate improved radiographic healing at final follow-up. These data may aid in clinical decision-making and counseling during treatment of children and adolescents presenting with lateral femoral condylar OCD.
Comparison of healing in non-weightbearing (Cahill and Berg sagittal zone C) and weightbearing (zone B) LFC OCD lesions (arrows).