Changes of the adjacent discs and vertebrae in patients with osteoporotic vertebral compression fractures treated with or without bone cement augmentation

Abstract

BACKGROUND CONTEXTAlthough vertebral augmentation with bone cement has been commonly used to treat symptomatic osteoporotic vertebral compression fractures, relatively little is known about the impact of augmentation on the adjacent spinal components. PURPOSETo determine the imaging effects of vertebral augmentation on the adjacent discs, the augmented vertebra, and the involved spinal segment. STUDY DESIGNRetrospective radiographic study. PATIENT SAMPLEPatients with acute osteoporotic vertebral compression fractures who underwent vertebral augmentation or nonoperative treatments. OUTCOME MEASURESOn baseline and follow-up mid-sagittal T2W magnetic resonance images, quantitative measurements of disc degeneration, including disc height, bulging, and signal, vertebral height, wedge angle, and segmental kyphotic angle were acquired. METHODSLumbar spine magnetic resonance images of patients with acute osteoporotic vertebral compression fractures at a local hospital in Eastern China between 2010 and 2017 were reviewed. Student's t-tests and χ2 tests were used to examine the differences of baseline and changes over time between vertebrae underwent vertebral augmentation and those did not. Paired t-tests were used to examine the differences between baseline and follow-up to study the changes of adjacent disc degeneration, creep deformity of the vertebra and progression of segmental kyphosis. RESULTSThere were 112 acute vertebral compression fractures (72 treated with kyphoplasty and 40 with nonoperative treatments) in 101 subjects. At final follow-up (mean 21.5 months), the cranial disc of the augmented vertebra decreased in height (p<.001), and both cranial and caudal discs decreased in signal intensity (p≤.02). The discs in the nonoperative group did not undergo such degenerative changes. For the fractured vertebra, vertebral height significantly decreased (p<.01 for both) and vertebral wedge angle significantly increased (p≤.01 for both), regardless of augmentation treatment or not. Segmental kyphotic angle significantly increased in vertebral fractures that underwent vertebral augmentation (p<.001), but not in those underwent nonoperative treatments. CONCLUSIONSPatients that underwent vertebral augmentation had more advanced disc degeneration at adjacent disc levels as compared to those without augmentation. The fractured vertebral body height decreased and the wedge angle increased, regardless of vertebral augmentation treatment or not. Vertebral augmentation may be associated with increased creep deformity of the adjacent vertebra and the progression of segmental kyphosis.