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

Abstract

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®.