Background: Vertebroplasty with use of polymethylmethacrylate cement
is gaining popularity in the treatment of some specific painful lesions of the
spine. It remains unclear, however, what possible side effects this type of
cement might have upon the vertebral body. We performed a histologic and
radiographic analysis of the end plate and disc to determine whether there was
a difference between vertebroplasty with polymethylmethacrylate cement and
vertebroplasty with calcium phosphate cement in the surrounding tissue of the
goat spine. Furthermore, we assessed whether a defect in the end plate,
simulating end-plate fracture and allowing for direct contact of cement with
disc tissue, had any effect on end-plate or disc degeneration.
Methods: Twenty-four mature goats were divided between two follow-up
periods (six weeks and six months). All animals underwent a bilateral
transpedicular vertebroplasty at two lumbar levels, where one of the following
treatments was applied: vertebroplasty with calcium phosphate cement with or
without an end-plate defect, and vertebroplasty with polymethylmethacrylate
cement with or without an end-plate defect. The effect of the various
treatments on the integrity of the intervertebral disc, end plate, and
surrounding tissue was examined with semiquantitative histologic analysis and
Results: No sign of disc or end-plate degeneration was seen in any
of the analyzed sections. The mean disc height did not decrease from the
postoperative period to the time that the animals were killed in any group,
thereby supporting the histologic findings. A mild inflammatory reaction was
found in four vertebral bodies in the polymethylmethacrylate groups only.
Conclusions: Calcium phosphate cement and polymethylmethacrylate
cement both seem to be adequate bone-void fillers in terms of biological
behavior in the vertebral body.
Clinical Relevance: The results of this animal study suggest that
vertebroplasty with either of these cements can be performed without an
increased risk for disc or end-plate degeneration even when end-plate
discontinuity is present.