Background and objectives: The aim of this study was to compare the effectiveness and clinical performance of biodegradable osteosynthesis versus titanium osteosynthesis in maxillofacial surgery.

Methods: This RCT was performed in 4 different hospitals in the Netherlands from December 2006 to July 2009. Included were 230 patients who underwent mandibular- and/or Le Fort-I osteotomies and those with fractures of the mandible, maxilla, and zygoma. The patients were randomly assigned to a titanium control-group (plates and screws of KLS Martin) or to a biodegradable test-group (plates and screws of Inion CPS). Outcome measures were bone healing and plate/screws removal. Patients were evaluated until 2 years post-operative.

Results: In 25 biodegradable-randomized patients (‘switches’) the surgeon decided to switch to titanium intra-operatively. These switches were assessed as failures for bone healing in the Intention-To-Treat (ITT)-analysis. In the ITT-analysis bone healing of the 117 patients in the biodegradable group was significant less compared to bone healing of the 113 patients in the titanium group ( p < 0.001). In the Treatment-Received (TR)-analysis there were 2 patients in the biodegradable group with inadequate bone healing and zero patients in the titanium group ( p = 0.15). Regarding the removal of the plate/screws within the first 2 years post-operative in the TR-analysis there were 14 of the 134 patients (10.4%) operated with titanium and 20 of the 87 patients (23%) operated with the biodegradable system who needed a second operation to remove the plate/screws ( p = 0.007, Hazard Ratio (HR) biodegradable (95% CI) = 2.6 (1.3–5.1), HR titanium = 1).

Conclusions: Bone healing with Inion CPS was not inferior compared to titanium when it was possible to apply the plates and screws. There were more plate/screws removal when patients were operated with Inion CPS.

Key words: osteosynthesis; biodegradable; titanium; bone healing; plate removal