Sacral insufficiency fracture complicated by epidural haematoma and cauda equina syndrome in a patient with multiple myeloma

We report the case of a patient with multiple myeloma (MM) and extensive lytic bone disease who presented with a short history of back pain and leg weakness. Magnetic resonance imaging (MRI) of the lumbar spine revealed a sacral insufficiency fracture complicated by an epidural haematoma. Bleeding tendency in this case can be accounted for by platelet function defects, often described in plasma cell disorders in the absence of obvious coagulation abnormalities. Surgical intervention was contraindicated as a result of poor overall patient performance status (poor surgical candidate due to extensive myelomatous bone disease, previous vertebral compression fractures requiring orthopaedic stabilisation, and requiring opiate analgesia for bone pain) and management was conservative. Patients presenting with back pain and documented bone disease in the setting of myeloma should be managed with a high index of clinical suspicion and considered for urgent MR imaging to avoid missing this serious and potentially reversible complication. We report the undescribed causative association between sacral insufficiency fracture and lumbo-sacral epidural haematoma. We illustrate the MRI signal and contrast enhancement pattern of an acute presentation of epidural haematoma.