Magnesium alloy based implants represent relatively new generation of bioabsorbable materials appearing to be a promising alternative to the currently most widely used polymers. The purpose of this study was 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.
12 patients (5 girls, 7 boys) were included in the study. Inclusion criteria were 1 / age < 18 years; 2 / unstable or displaced osteochondral laesions caused by injury or due to osteochondritis dissecans, classified according to ICRS; 3 / fixation with MAGNEZIX implants; 4 / minimum FU 12 months. X-rays and clinical evaluation were performed 1 day, 6 weeks, 3, 6, and 12 months after the operation, MRI scans 12 months after the surgery.
The mean age at surgery was 13.3 ± 1.6 years. A total of 25 screws were used in 11 patients, mean 2.4 ± 1 per patient, 4 pins were used in 1 patient. In 2 patients the fixation was combined with fibrin glue. The mean FU was 14.2 ± 3.3 months. No intraoperative complications occurred. VAS for pain demonstrated significant improvement (from 4.8 before surgery to 1.2 after surgery). All patients showed full recovery of function and showed no signs of pain 6 months after surgery. No adverse local reactions were observed during follow-up. Complete radiographic (x-ray and MRI) healing occurred in all cases. Mild radiolucent zones were observed around the implants in the range of 6 weeks - 3 months. Areas of hypodensity suggesting new bone deposition corresponding with the former implant sites were observed on MRI at 12 months.
Fixation of osteochondral fragments by MAGNEZIX screws and pins during short-term FU provides sufficient stability and leads to uncomplicated healing.