Fixation of Unstable Osteochondritis Dissecans Lesions and Displaced Osteochondral Fragments Using New Biodegradable Magnesium Pins in Adolescents.

Abstract

Fixation of unstable osteochondritis dissecans (OCD) lesions and displaced osteochondral fragments are frequently performed procedures in pediatric orthopedic surgery. Since 2018, CE-certified MAGNEZIX pins are used in our institution in these cases. The aim of this study was (1) to analyze safety, efficiency, and limitations of magnesium-pin-based fixation of unstable OCD lesions and displaced osteochondral fragments and (2) to report clinical and radiological outcomes at short-term follow-up (FU). In this prospective cohort study, 19 patients (10 girls and 9 boys) were included. Inclusion criteria were (1) magnetic resonance imaging-confirmed unstable OCD lesion or displaced osteochondral fragment, (2) fixation with magnesium-based pins, and (3) minimum FU of 6 months. X-rays were taken 6 weeks and 6 months after operation and magnetic resonance imaging scans every 4 to 6 months to assess the healing progress. In total 67 pins were used, with a mean of 3.6 ± 1.4 per patient. Average age at surgery was 13.7 years (11-17 years). Mean time of operation was 56 ± 31 minutes, including arthroscopy, fixation, and patellar realignment (n = 6). No intraoperative complications occurred. Average FU was 11.3 ± 4.2 months (6-20 months). No redislocation or new dislocation occurred. Until now a complete radiographic healing occurred in 12 cases. Due to an implant failure in one case 11 weeks after the index surgery a revision became necessary. In short-term FU of 11 ± 4 months MAGNEZIX pins provide high stability after fixation of unstable OCDs and displaced osteochondral fragments leading to uncomplicated and timely healing.