Effect of vertebroplasty filler materials on viability and gene expression of human nucleus pulposus cells.
Consequences of intradiscal cement leakage--often occurring after vertebral cement augmentation for the treatment of vertebral compression fractures--are still unknown. In this study, we have investigated the influences of vertebroplasty filler materials (polymethylmethacrylate-, calcium phosphate- and calcium sulfate-based bone cement) on isolated nucleus pulposus cells. Cell viability of cultured human nucleus pulposus cells were measured after treatment with vertebroplasty filler materials. Gene expression profile of selected genes was determined with quantitative real-time PCR. The widely used polymethylmethacrylate and calcium phosphate cement significantly decreased cell number in a dose- and time-dependent manner while calcium sulfate cement affected cell viability less. Expression of genes involved in matrix metabolism of nucleus pulposus--aggrecan, collagens, small proteoglycans--as well as important transcription factors have also significantly changed due to treatment (e.g., 2.5-fold decrease in aggrecan expression was determined in cultures due to polymethylmethacrylate treatment). Our results suggest that vertebroplasty filler materials--depending on the type of applied material--can accelerate the degeneration of nucleus pulposus cells resulting in a less flexible disc in case of intradiscal cement leakage. This process may increase the risk of a subsequent new vertebral fracture, the main complication of vertebral augmentation.
Lazáry
Aron
A
1st Department of Medicine, Semmelweis University, Korányi S. u. 2/a, Budapest, H-1083 Hungary. lazaron@bel1.sote.hu
Speer
Gábor
G
Varga
Péter Pál
PP
Balla
Bernadett
B
Bácsi
Krisztián
K
Kósa
János P
JP
Nagy
Zsolt
Z
Takács
István
I
Lakatos
Péter
P
D000328:Adult; D001843:Bone Cements / Q000494:pharmacology*; D002130:Calcium Phosphates / Q000494:pharmacology; D002133:Calcium Sulfate / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007403:Intervertebral Disc / Q000187:drug effects*; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008297:Male; D019904:Polymethyl Methacrylate / Q000494:pharmacology; D013997:Time Factors; D054854:Vertebroplasty / Q000009:adverse effects*
D001843:Bone Cements; D002130:Calcium Phosphates; D019904:Polymethyl Methacrylate; C020243:calcium phosphate; D002133:Calcium Sulfate