Effect of vertebral cement augmentation with polymethylmethacrylate on intervertebral disc and bone tissue

Abstract

Vertebral cement augmentation is reported to be a safe and effective technique for providing stabilization and pain relief. However, adjacent intervertebral discs may be at risk of accelerated degeneration as a result of aggravated nutritional constraints. Therefore, we investigated the effects of injecting polymethylmethacrylate (PMMA) into three adjacent lumbar vertebrae on intervertebral disc and vertebral bone tissue in 12 skeletally mature sheep. After 6 and 12 months of augmentation, the sheep were euthanized and their spines were processes for histological evaluation. Semiquantitative histomorphological analysis of discs and endplates was conducted using published criteria. Histomorphological changes in the augmented bone were assessed qualitatively. Approximately 80% of the length of the endplates was in contact with PMMA. However, there was no significant difference between the histopathological score of the discs adjacent to augmented vertebrae and the score of the control discs. Bone tissue reaction to PMMA was characterized by a thin fibrous tissue layer and occasional foreign-body reactions. New bone formation was present in all augmented vertebrae. Concerns about aggravation of disc degeneration as a result of vertebral cement augmentation seem to be unsubstantiated. Furthermore, adverse effects of PMMA cement on bone biology do not seem to be a relevant issue.

Interference in the endplate nutritional pathway causes intervertebral disc degeneration in an immature porcine model

“…Because previous similar studies using PMMA cement in adult animals did not cause obvious abnormal histological changes [11][12][13], and the bone cement in our study was located at some distance from the endplate (Fig. 1), this effect might be minimal but can not be absolutely excluded.…”

“…This negative result might be attributable to the fact that the other side of the endplate pathway continued to provide adequate nutrition. Krebs et al [11], after injecting bone cement covering 80 % of the length of both sides of the endplates in the sagittal plane in a 7.2-year-old ewe model, found no significant IDD either. This might be because the cancellous bone mixed into the bone cement continuously provides a degree of blood supply for discs.…”

“…Similarly to the design of a previous study [11], disc 0 was kept intact and served as a normal control, and disc 4 or disc 5 was interfered with either by scalpel or cement as follows. One disc was stabbed with a no.…”

“…Blocking the endplate nutritional pathway with bone cement for a certain period (several months to 1.5 years) produced no obvious IDD in several adult animal models [11][12][13]. Interfering in the endplate pathway does not seem to affect the health of adjacent discs in mature animal models.…”

Bone defect reconstruction with a novel biomaterial containing calcium phosphate and aluminum oxide reinforcement

“…This temperature is higher than the critical level of protein denaturation in the body and could lead to osteonecrosis [ 4 – 6 ]. Additionally, foreign body reactions and the inhibition of endogenous bone formation have been described for PMMA-based cement materials [ 7 – 9 ].…”