Outcomes of bioabsorbable fixation in the treatment of osteochondral lesions of the knee in adolescent patients

Background: Bioabsorbable fixation in managing osteochondral lesions is increasing in popularity. The purpose was to report on outcomes using bioabsorbable fixation nails for osteochondral lesions of the knee in a pediatric and adolescent population. Methods: A retrospective review of pediatric patients undergoing surgery with bioabsorbable fixation for knee osteochondral lesions was performed. Demographic, clinical, and surgical data was collected including symptom duration, lesion location, size, use of bone grafting, and number of implants. Return to activities was documented. Patients recommended revision surgery were compared to those who were not. Results: 47 patients with median age 13.9 years and 25.5% female were included with median clinical follow-up of 47.3 weeks. 87.2% of patients were cleared for full activities. Four male patients (8.5%) were recommended revision surgery, of whom three underwent surgery including removal of loose bioabsorbable fixation. Demographic data did not differ between the group with successful versus failed primary surgery (p > 0.05). Symptom duration was more acute (<1 month) in the four recommended revision surgery (75% versus 9.3%, p = 0.008). The group recommended revision also had larger lesion size (median 5.4 cm² versus 2 cm², p = 0.04). Distal femoral physeal status, lesion location, necessity for bone grafting, and number of implants did not differ between groups. Conclusions: Adolescents had a high return to activity following bioabsorbable fixation for knee osteochondral lesions with 87.2% cleared for full return. In the 8.5% of patients who were deemed to have failed primary fixation, symptoms were more likely to be acute in nature with larger lesion sizes.