Deformity Secondary to Vertebral Body Metastases

Spinal metastases are the most common type of vertebral column tumor, affecting up to 70% of all patients with neoplastic disease. Though seldom the primary determinant of survival, these lesions are clinically important for the mass effect they exert on a patient’s neural elements as well as the mechanical instability they generate within affected vertebrae. Osteolytic lesions are of particular concern as they significantly decrease axial loading strength of the vertebral column, increasing the risk of fracture and subsequent deformity. Diagnosis of deformity is made using computed tomography imaging, which can also be used for surgical planning in patients indicated for operative management. Other interventions include prophylaxis against vertebral collapse using a combination of vertebral body cement augmentation and administration of anti-osteolytic agents, such as bisphosphonates and denosumab. In this chapter, we provide an overview of the biomechanics of the metastatic spine, give background on the pathophysiology of osteolysis in metastatic segments, and outline the therapeutic interventions for those with spinal deformity or mechanical instability in the context of disseminated cancer.