Summary
The present findings demonstrate correlations between OCD lesion size and more symptomatic MRI findings for patient age in MFC and LFC lesions.
Abstract
OBJECTIVES:
The purpose of this study is to evaluate OCD lesion characteristics on magnetic resonance imaging based on age. We hypothesize that OCD lesion size and morphology correlate with age.
Methods
Patients with radiographic or magnetic resonance imaging evidence of an OCD lesion seen at one of the ROCK study group institutions between 2013 and 2024 were eligible for inclusion in this study. Exclusion criteria included age of 26 years or greater at the time of enrollment, incomplete screening forms, missing magnetic resonance imaging (MRI) readings, and missing data regarding OCD lesion location. Patient information was collected at baseline from each patient. MRIs were reviewed independently by each surgeon for information regarding lesion size and location, adjacent bone edema, omen sign, and physeal patency.
Descriptive statistics included mean ± standard deviation for scale variables, and counts and percentages for categorical variables. ANOVA, T-Tests and Pearson and Spearman correlations were performed as appropriate. Statistical significance was set to p ≤ 0.05.
Results
A total of 1599 patients were included. The average patient age was 13.5 ± 2.8 years, and the average BMI was 21.7 ± 5.1. Most patients were male (n = 1092, 68.3%). Most patients had only one OCD lesion (n=1,531, 95.7%), with 63 patients (3.9%) having 2 lesions and 5 patients (0.3%) having 3 OCD lesions. Most patients had lesions of the medial femoral condyle(MFC) (n=891, 55.7%), with the second most common site being the lateral femoral condyle(LFC) (n=279, 17.5%). Sixty-five percent of patients (n=1,042) had an open physis on sagittal MRI, while 147 (9.2%) had a closed physis and 195 (12.2%) had a closing physis.
Characteristics of MFC Lesions
There is a moderate correlation between age and coronal width of lesions for MFC lesions(r=0.39, 95%CI=[0.33,0.45]; p<0.001) and small correlation between sagittal length of lesion and age for MFC lesions (r=0.24, 95%CI=[0.18,0.31]; p<0.001). MFC lesions with omen signs had larger average coronal (16.2±4.6mm vs 13.8±4.7mm; p<0.001) and sagittal size (22.4±7.4mm vs 20.0±7.1mm; p<0.001). Patients with MFC lesions that had extensive edema of the epiphysis had larger average coronal (15.6±4.6mm vs 13.8±4.8mm; p<0.001)and sagittal (22.4±7.2mm vs 19.6±7.1mm; p<0.001) lesion sizes than their counterparts with no to minimal edema.
Characteristics of LFC Lesions
In lesions of the LFC, there was a moderate correlation between sagittal length of lesion and age (r=0.33, 95%CI=[0.21,0.43]; p<0.001) and between coronal width of lesion and age (r=0.34, 95%CI=[0.23,0.44]; p<0.001). LFC lesions with omen signs had larger average coronal (18.3±5.8mm vs 15.8±6.1mm; p=0.011) and sagittal size (22.5±7.8mm vs 18.8±7.0mm; p=0.002) than those without. Marrow edema with involvement of > 25% of the epiphysis was associated with higher average coronal lesion size (18.6±6.6mm vs 15.2±5.6; p<0.001) and sagittal lesion size (22.4±6.6 vs 18.6±7.6; p<0.001) than those with minimal/no edema.
Conclusion
The present findings demonstrate correlations between OCD lesion size and more symptomatic MRI findings for patient age in MFC and LFC lesions. This data may suggest that OCD lesions are generally sustained during a certain age range and progress as patients age.