Treatment of Advanced Osteoradionecrosis (ORN) of the Mandible (Resection/Disarticulation and Staged Reconstruction), a Protocol and Rationale

Abstract

For many reasons, reconstruction of the defect resulting from resection of mandibular ORN is not analogous to reconstructing a defect resulting from tumor ablation or trauma. Patients with mandibular ORN tend to have chronically exposed, infected bone in a bed of densely fibrotic, hypoxic, hypovascular, and hypocellular tissue. These tissue characteristics are much more harsh than those found after a primary tumor resection. Further, reconstruction after tumor ablation is more amenable to a combined one-stage procedure including the ablation with immediate reconstruction, typically using a microvascular free flap, because the host tissue is of better quality and often both hard and soft tissues are needed to correct the defect and close any intraoral communication. Additionally, in cancer surgery, it is rare to have involvement of the condylar ramus/head so as to necessitate a full disarticulation. Thus, the functional anatomy is maintained, and there is a surface to fixate the reconstruction plate carrying the fibula. It is important to appreciate that in an irradiated field, the region of affected bone very often extends a considerable distance from the site of pathologic fracture; often the extent of affected bone includes the hard tissue up to the condylar head. Experience has taught us that attempting to stabilize a reconstruction plate on this compromised bone often leads to failure of the entire reconstruction, resulting in pain and significant dysfunction. In this chapter we present a protocol that includes disarticulation of the joint in the setting of mandibular resection for ORN; this has been developed over time and with experience. This protocol is staged to allow for multiple stopping points if for any reason the sequence cannot be completed, but yet leaves the patient functional with minimal pain.