Poster 271: Descriptive Epidemiology of Surgically Treated Osteochondritis Dissecans of the Knee: Lessons Learned from a Large Pediatric Orthopedic Center

OBJECTIVES: Osteochondritis dissecans (OCD) lesions of the knee affect roughly 10-25 per 100,000 patients ages 6-19. This condition, which can cause pain, discomfort, and lead to arthritic changes, can be especially challenging for younger patients. The etiology is still not fully understood and treatment strategies, both non-operative and operative, can vary among clinicians. Although previous studies have begun to describe the prevalence and patterns of knee OCD lesions, there are very limited epidemiologic investigations of these lesions in surgically treated patients or from pediatric orthopedic centers at children’s hospitals. METHODS: Patients ages 0-18 who underwent operative treatment for OCD lesions of the knee from January 2015 to December 2021 at a large pediatric orthopedic center were identified using Current Procedural Terminology (CPT) codes. Patients who underwent exclusively nonoperative management of their OCD were excluded. Demographic data, growth plate status, sports participation, symptoms, lesions characteristics, and operative data were gleaned from patient charts. Descriptive statistical analysis was performed for outcomes of interest. RESULTS: A total of 375 knees in 354 patients across 5 surgeons were operated on; 64.4% were male. There was a mean age of 13.91 years (range 8.3-18.9 years), and 77.6% of patients had open growth plates. The most common sports played were basketball for males (28.6% of cases) and soccer for females (31.7% of cases). 55.7% of lesions were on the right with 22.7% of patients having bilateral OCD. Most lesions were on the medial femoral condyle (63.2%) with other locations including the lateral femoral condyle (17.6%), patella (10.4%), trochlea (8.3%), or tibial plateau (0.5%). The average time to surgery from initial presentation was 4.8 months (range 0.03-59.83 months) with 61.6% of patients having undergone some form of conservative treatment prior to surgery. The most common indication for surgery was failed healing response to conservative treatment (46.9% of cases). After diagnostic arthroscopy, patients either underwent drilling (67.7%), fixation with screws, sutures, or chondral darts (24.2%), grafting (33.3%), bone stimulation (14.1%), or cartilage biopsy for two-stage procedure (6.1%) (Table 1). 32% had some combination of surgical interventions. Transarticular drilling was the most common technique and the proximal tibia was the most common source of autograft. 19.4% of cases had additional procedures performed at the time of OCD repair. CONCLUSIONS: Overall, there is great variability in the presentation and management of surgically treated OCD lesions of the knee in pediatric and adolescent patients. While most patients trialed conservative therapy prior to operative treatment, there is a large cohort of patients who go to surgery sooner for other indications such as instability or additional injuries requiring operative repair. Although drilling is the most common form of fixation, the high prevalence of grafting suggests more lesions to be unstable than initially thought.