The long term results of thoracolumbar burst fractures treated with short segment pedicle instrumentation
- VernacularTitle:经后路短节段椎弓根内固定治疗胸腰椎爆裂型骨折的远期疗效
- Author:
Baoshan XU
;
Tiansi TANG
;
Huilin YANG
- Publication Type:Journal Article
- Keywords:
Thoracic vertebrae;
Lumbar vertebrae;
Fractures;
Internal fixators;
Treatment outcome
- From:
Chinese Journal of Orthopaedics
2000;0(11):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the long term results of thoracolumbar burst fractures treated with short segment pedicle instrumentation. Methods Sixty eight cases of thoracolumbar burst fractures fixed with short segment pedicle instrumentation were followed up for at least 5 years (5-13 years, average 8 years). All of them were checked with radiography pre and post operation and before implant removal. At final follow up assessment, all were examined with radiography, 18 cases were checked with CT scan as well. Results 1) Neurological status improved at least 1 Frankel grade in 90.3% of the patients who had preoperative incomplete paraplegia, while no improvement was obtained in those who had preoperative complete paraplegia. Low back pain was evaluated according to Denis Pain Scale, the results showed P1 41 cases (60.3%), P2 24 cases (35.3%), P3 3 cases (4.4%). 2) The shortest distances between the upper and lower pedicle screws tips shortened for 0-6.5 mm (average 2.5 mm) before removal in contrast to that at post operative immediately. Of the 68 cases, nuts loosened in 1 case, pedicle screws loosened in 1 case, bent in 2 cases and broken in 5 cases. Of the 8 cases whose implants were not removed timely, screw broke in 2 cases, and seepage occurred through incision in 2 cases. 3) At final follow up, the correction of anterior vertebral body height averaged 30.5%, and Cobb angle 5.8?, despite a mean correction loss of Cobb angle 12.1?. Correction loss was most evident at the above disc spaces, then the below disc spaces. Correction loss of vertebral body height averaged 1.9% in the anterior, and 6.0% in the middle part. 4) The collapse of vertebral body was most serious in the middle part. The deformity of "codfish vertebrae" occurred in the superior part of vertebrae body in 21 cases, among them the upper adjacent vertebral body sank into the injured body in 5 cases, 3 of whom engendered kyphoses greater than 25?. Evident intra corporeal gaps were found in 16 of 18 patients who were checked with CT, and the gaps communicated with the above disc space. The fractured body could have a deformity of the "cup" after reduction. 5) Degeneration and narrowing of the disc spaces next to fractured vertebrae were very common, and the above space disappeared in 27 cases, while the lower space disappeared in 14 cases. The upper disc space adjacent to fixation levels degenerated in 1 of 8 cases whose implants were not removed timely. Five patients had Cobb angle greater than 20?, three of them had low back pain, and one had mild symptom of nerve compromise. Low back pain was not correlated with degeneration of discs. Conclusion Short segment pedicle instrumentation provides satisfying stability for thoracolumbar burst fractures. It helps physiologic postural contour restoration and facilitates neural recovery, but is associated with relatively high rates of implant failure and correction loss which is most evident at adjacent discs spaces. Deficiency of bone grafting and delayed implant removal are the most probable causes for correction loss.
