Vertebroplasty for treatment of thoracolumbar burst fractures
- VernacularTitle:椎体成形术对胸腰椎爆裂型骨折的治疗意义
- Author:
Baoshan XU
;
Tiansi TANG
;
Yongcheng HU
- Publication Type:Journal Article
- Keywords:
Spinal fractures;
Spinal puncture;
Biomechanics
- From:
Chinese Journal of Orthopaedics
1998;0(12):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective Short-segment pedicle instrumentation for thoracolumbar burst fracture was known to have a relatively high incidence of failure and correction loss, intracorporeal gap secondary to reduction being probable causes. The purpose of this study was to evaluate the intracorporeal gap after reduction and the biomechanical effect of vertebroplasty on thoracolumbar burst fractures. Methods Six fresh adult thoracolumbar specimens were collected, and 10 segmental specimens (T11-L1, L2-L4, T12-L2) were processed. Burst fracture was created using free-drop test. Then the fractures were reduced and augmented with injectable self-setting calcium phosphate cement. The intracorporeal gap and bone mineral density(BMD) were measured using spiral CT and dual energy X-ray absorptiometry(DEXA) before fracture, after reduction and after vertebroplasty respectively. The stiffness in middle vertebrae and above discs were measured under flexion, extension, lateral flexion and torsion stress before fracture and after augmentation. The ultimate strength against compression was tested in the augmented vertebrae and the integral vertebrae below it. Results Burst fractures were created in eight of ten specimens. 1) There was no evident intracorporeal gap before fracture, which appeared after reduction with average volume of 5.25 cm3 (13.9% of total corporal volume), and it decreased to normal level after vertebroplasty. 2) The BMD was normal in all specimens before fracture, which decreased significantly after fracture reduction, and it was significantly higher after vertebroplasty than that before fracture or after reduction. 3) There was no significant difference of stiffness in vertebrae before fractures and after augmentation. The mean value of ultimate strength against compression in the augmented vertebrae decreased slightly but not significantly in contrast to the vertebrae below it. In contrast to the value before fracture, the stiffness of above discs decreased significantly under flexion and extension stress but not significantly under lateral flexion stress after augmentation, while the stiffness of the specimen decreased significantly under torsion stress. Conclusion 1) Posterior reduction in thoracolumbar burst fracture can not reestablish intact corporeal structure, which may be an important cause of postoperative implant failure and correction loss. 2) Vertebroplasty with injectable self-setting calcium phosphate cement is helpful to reestablish intact corporeal structure, and restore stiffness and strength of the injured corpora nearly to its initial value.
