Functional and three-dimensional radiographic outcomes after open reduction and internal fixation of condylar head fractures using magnesium alloy cannulated screws – a retrospective long-term follow-up

Condylar head fractures are common in facial trauma and can result in significantly impaired mandibular function. Open Reduction and internal fixation overall produce better functional outcomes than closed treatment. Multiple methods of fixation have been proposed, including the use of biodegradable magnesium-based cannulated bone screws. This study aims to investigate the long-term efficacy of this fixation method using three-dimensional radiographic imaging and clinical outcomes. This retrospective cohort study of a single centre included patients who underwent surgical intervention for a condylar head fracture using a cannulated magnesium lag screw. Clinical parameters and three-dimensional radiographic scans were collected during follow-up, and virtual model analysis was conducted after segmentation. Fifty-eight patients received an osteosynthesis with a magnesium alloy implant. The functional results of the final assessment were excellent. Significant changes in volume, surface area, and signs of condylar remodelling were observed during the healing process. Complication rates were low. No implant had to be removed. Cannulated compression screws using biodegradable magnesium-based alloys show good clinical results despite reduced condylar volume and surface area, as well as significant proof of three-dimensional incongruency of healing mandibular condyles. No patient complained of subjective problems connected to the resorption process, and no mechanical failure prior to fracture healing was recorded. Overall, this method verifies excellent long-term results. Surgical implants comprised of magnesium alloys provide adequate fixation of fractures of the condylar head with excellent clinical results without the need for a second intervention to remove the implant.