Fixation of Knee Osteochondral Lesions in Pediatric Patients with Magnesium-Based Implants.

PURPOSE OF THE STUDY Fixation of osteochondral fragments are relatively common procedures in pediatric orthopaedic surgery. The use of biodegradable magnesium implants in these indications appears to be a promising alternative to polymer implants due to their favorable mechanical properties and biological behavior. The purpose of this study is to evaluate the short-term clinical and radiological outcomes of the fixation of unstable or displaced osteochondral fractures and osteochondritis dissecans lesions in the knee joint using MAGNEZIX® screws and pins in pediatric patients. MATERIAL AND METHODS In this study, 12 patients (5 girls, 7 boys) were included. The inclusion criteria were as follows (1) age below 18 years; (2) unstable or displaced osteochondral fragments secondary to trauma or as a result of osteochondritis dissecans, Grades III and IV in the ICRS (International Cartilage Repair Society) score, confirmed by imaging methods and indicated for surgical fixation; (3) fixation performed using screws or pins made of the magnesium-based MAGNEZIX® alloy; (4) minimum postoperative interval of 12 months. X-rays and clinical evaluation were assessed 1 day, 6 weeks, 3, 6, and 12 months after the operation. MRIs were performed 1-year postoperatively for evaluation of bone response and degradation behavior of implants. RESULTS The mean age at surgery was 13.3 ± 1.6 years. A total of 25 screws were used in 11 patients, a mean of 2.4 ± 1 per patient, 4 pins were used in 1 patient. In 2 patients, fixation with screws was complemented with fibrin glue. The mean follow-up was 14.2 ± 3.3 months. All patients exhibited complete functional recovery while showing no signs of pain at 6 months postoperatively. No adverse local reactions were observed. At 1-year follow-up, no implant failure has been reported. Complete radiographic healing occurred in 12 cases. Mild radiolucent zones were observed around the implants. CONCLUSIONS The use of screws and pins MAGNEZIX® has been found to provide satisfactory outcomes in terms of fracture healing and very good functional outcomes at 1 year postoperatively. Key words: biodegradable implants, magnesium-based implants, osteochondral fracture, osteochondritis dissecans, MAGNEZIX®.