Radiographic outcome of vertebral bone bruise associated with fracture of the thoracic and lumbar spine in adults.

Bone bruising associated with long bone injury is a defined entity with known radiological, pathologic and clinical features. Vertebral bone bruise (VBB) has been described through magnetic resonance imaging (MRI) of the injured spine, but to date the consequences of this entity are unknown. The objective of this retrospective study was to describe the plain radiographic outcome of MRI-defined VBB associated with thoracic and lumbar spine fracture in adults, and to assess whether VBBs caused abnormalities of the bone-implant interface at instrumented levels. Levels of VBB were identified through analysis of the full spine MRI in a consecutive series of adult patients admitted to a spinal injuries unit for thoracic and lumbar spine fractures. The anterior wedge angles (AWAs) of thoracic and lumbar vertebrae demonstrating VBB were measured on radiographs taken at time of injury and at follow-up. Abnormalities of the bone--implant interface were recorded at instrumented levels associated with VBB on follow-up radiographs. Thirty VBBs were identified in 18 adult patients who had suffered 21 vertebral fractures. At an average follow-up of 19 months (range, 12--30 months), the mean AWAs of the VBB vertebrae at the time of injury and at the most recent follow-up were 3.5 degrees and 3.8 degrees , respectively (p=0.33, paired t-test). A total of 12 out of 30 (40%) bruised levels were instrumented in 13 out of 18 (72%) operated patients. No bone--implant interface failure was observed at these levels. It is concluded that VBB associated with thoracic and lumbar vertebral fracture in adult patients does not appear to cause significant progressive vertebral deformity or bone--implant interface failure.