Model of Induced Leakage of Polymethylmethacrilate Inside Epidural Space and Prevertebral Muscles During Vertebroplasty in Pigs: Clinical, Macroscopical, and Histological Study

rilate. Methods: We performed vertebroplasty on six pigs. We performed a leakage of cement into the epidural space and into prevertebral muscles. Two weeks later we performed an anatomic evaluation regarding the spreading of polymethylmetacrilate and a histological analysis of soft tissues that came into contact with it. Results: No clinical alterations were observed. We observed a laminar distribution of the cement surrounding dura mater, and creating a fusiform cavity inside muscles. Spinal cord was normal in all the animals. In dura mater, we observed: synovialmetaplasia, inflammatory reaction, crystal deposits, and giant-cell-reaction. In muscles, we observed: inflammatory reaction, crystal deposits, giantcell-reaction, muscular atrophy, fibrosis, and synovial metaplasia. Conclusions: The spinal cord was normal; it is likely that dura mater and cerebrospinal fluid are responsible to isolate neural struc tures from cement. Dura mater and muscle showed similar histological changes than other publications. Synovial metaplasia was observed in dura mater and muscles that came into contact with cement. The pulsatile rubbing between the tissue and cement could be responsible of this phenomenon.