Adjacent vertebral body fracture following vertebroplasty with polymethylmethacrylate or calcium phosphate cement: biomechanical evaluation of the cadaveric spine.
METHODS
A biomechanical study using human cadaveric thoracolumbar spinal columns.


OBJECTIVE
To compare the effect of treatment by vertebroplasty (VP) with polymethylmethacrylate cement and VP with calcium phosphate cement on the creation of adjacent vertebral body fracture following VP.


BACKGROUND
Adjacent vertebral body fractures have been reported as a complication following VP.


METHODS
Twenty-four spinal columns (T10-L2) from human cadavers were subjected to dual energy radiograph absorptiometry to assess bone mineral density. They were divided into the P group and C group, and experimental vertebral compression fractures were created at T12 vertebrae. T12 vertebrae were augmented with polymethylmethacrylate and calcium phosphate cement in the P group and C group, respectively. Each spinal column was compressed until a new fracture occurred at any vertebra, and the location of newly fractured vertebra and failure load was investigated.


RESULTS
There was no significant difference in bone mineral density at each level within each group. In the P group, a new fracture occurred at T10 in 2 specimens, T11 in 8, and L1 in 2. In the C group, it occurred at T10 in 1 specimen, T11 in 2, L1 in 1, and T12 (treated vertebra) in 8. The failure loads of the spinal column were 1774.8+/-672.3 N and 1501.2+/-556.5 N in the P group and C group, respectively. There was no significant difference in the failure load of the spinal column between each group.


CONCLUSIONS
New vertebral fractures occurred at the vertebra adjacent to augmented vertebrae in the P group and in the augmented vertebrae in the C group. The difference in the fractured site may be because of the difference in strength between the 2 bone filler materials. Therefore, the strength of bone filler materials is considered a risk factor in developing adjacent vertebral body fractures after VP.
Nouda
Shinya
S
Department of Orthopedic Surgery, Osaka Medical College, Osaka, Japan. noudadesk@yahoo.co.jp
Tomita
Seiji
S
Kin
Akihiro
A
Kawahara
Kunihiko
K
Kinoshita
Mitsuo
M
D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000009:adverse effects* / Q000627:therapeutic use; D015519:Bone Density / Q000502:physiology; D001861:Bone Regeneration / Q000187:drug effects / Q000502:physiology; D002102:Cadaver; D002130:Calcium Phosphates / Q000009:adverse effects* / Q000627:therapeutic use; D050815:Fractures, Compression / Q000139:chemically induced / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008953:Models, Anatomic; D011109:Polymethacrylic Acids / Q000009:adverse effects* / Q000627:therapeutic use; D011183:Postoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D016059:Range of Motion, Articular / Q000502:physiology; D016103:Spinal Fractures / Q000139:chemically induced* / Q000503:physiopathology / Q000601:surgery*; D013131:Spine / Q000187:drug effects / Q000473:pathology / Q000601:surgery; D013314:Stress, Mechanical; D054854:Vertebroplasty / Q000009:adverse effects* / Q000379:methods; D016474:Weight-Bearing / Q000502:physiology
D001843:Bone Cements; D002130:Calcium Phosphates; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; C020243:calcium phosphate