Fixation of Juvenile Osteochondritis Dissecans Lesions of the Knee Using Poly 96L/4D-lactide Copolymer Bioabsorbable Implants

Background: The fixation of juvenile osteochondritis dissecans (OCD) lesions has been described using metal implants, staples, bone pegs, and bioabsorbable implants. Bioabsorbable fixation has potential benefits including not requiring a second surgery for implant removal, no interference on postoperative magnetic resonance imaging (MRI) scans, and a potentially lower incidence of prominent hardware. The possible complications of bioabsorbable fixation include synovitis, loss of fixation owing to noncompressive properties, and sterile abscess formation. The results of bioabsorbable fixation of juvenile OCD lesions of the knee have not been well studied. The purpose of this study was to evaluate the efficacy and safety of a bioabsorbable copolymer fixation in the management of unstable OCD lesions of the knee in adolescents. Methods: This is a retrospective case series of patients with unstable OCD lesions of the knee that were treated with poly 96L/4D-lactide copolymer bioabsorable implants. Information was gathered through 3 standardized and validated knee-function questionnaires, participants' medical records, plain films, MRIs, and pain level and satisfaction scale questionnaires. Results: Twenty-four knees in 24 patients were evaluated. The mean age at the time of surgery was 14.4 years. The mean follow-up was 39.6 months. The mean International Knee Documentation Committee score at follow-up was 84.9, the mean Lysholm score was 88.0, and the mean Tegner score was 7.9. Plain films at an average of 19.2 months postoperatively revealed interval healing in 9 patients, no significant change in 1 patient, complete healing in 13 patients, and loose bodies with no interval healing in 1 patient. MRIs were obtained postoperatively in 17 knees, with a mean follow-up of 22.4 months. Interval healing was present in 16 of 17 MRIs, consistent with the plain film findings. Twenty-two of 24 patients had good-to-excellent outcomes. Conclusion: Poly 96L/4D-lactide copolymer bioabsorable implants seem to be safe and effective for the management of unstable juvenile OCD lesions of the knee. They offer stability for the healing OCD lesions, with minimal reaction from degradation products.