Prosthetic Condyle with Concurrent Microvascular Reconstruction for Mandibular Disarticulation Defects: A Retrospective Series

Introduction Reconstruction of mandibular disarticulation defects is a challenging area of head and neck surgery, with a variety of options available for replacement of the condylar head. The gold standard is autogenous reconstruction of the condyle-ramus unit. The use of a prosthetic condylar head is controversial, but in challenging cases, and those with a likely poor prognosis it may be considered and can achieve a good functional result. The objective of this study is to evaluate the outcomes of its use in a high volume head and neck reconstructive unit. Materials and methods A retrospective analysis of all patients treated at the Queen Elizabeth Hospital, Birmingham who underwent mandibular disarticulation resections and prosthetic condylar reconstruction from January 2008 to December 2019 were included. Results This retrospective review included 25 patients; 16 for malignant disease (16), osteoradionecrosis (4), osteomyelitis (2), medication related osteonecrosis (1), and secondary reconstruction(2). Free flap reconstruction was performed in 23 cases; 18 bony composite free flaps, 3 patients required double flap reconstruction, and 2 underwent soft tissue flaps only. Mean follow up was 43 months. Prosthesis related complications were encountered in 6 patients, all malignant cases. Four prosthetic condyles required removal due to recurrent infections and glenoid fossa perforation, This appeared to be related to significant surrounding dead space, and limited bony reconstruction. Rate of complications was lowest for non-malignant cases, and patients who had concurrent bony reconstruction extending up the ascending ramus. Functional outcomes were good with majority of patients having a balanced occlusion and oral intake. Conclusion Prosthetic condyle outcomes are best when concurrent bony free flap reconstruction is performed with ascending ramus reconstruction. Avoid prosthetic condyles in cases where the articular disc is removed, and cases where a large amount of dead space is expected around the prosthesis. Careful attention to occlusal factors and vertical support of the reconstruction plate can lead to good functional outcomes. A review of the literature and potential future advances is also presented.