Journal List > J Korean Soc Spine Surg > v.8(2) > 1035930

TOOLS
Lee, Choi, Kim, Seo, Ahn, Jeon, Shin, and Na: Survival Analysis of Posterior Short Fusion in Thoracolumbar Fracture - Significance of Load-Sharing Score and Bone Mineral Density -
Original Article

Journal of Korean Spine Surg 2001;8(2):113-120.

Published online: 21 February 2001

DOI: https://doi.org/10.4184/jkss.2001.8.2.113

Survival Analysis of Posterior Short Fusion in Thoracolumbar Fracture - Significance of Load-Sharing Score and Bone Mineral Density -

Changseop G. Lee, M.D., Jang Seok Choi, M.D., Young Chang Kim, M.D., Seong Suk Seo, M.D., Ki Chan Ahn, M.D., Jin Wook Jeon, M.D., Jae Hoon Shin, M.D., Chae Oh Na, M.D.

Department of Orthopedics, Paik Hospital, Inje University, Pusan, Korea

Address reprint requests to Changseop G. Lee, M.D. Department of Orthopedics, Paik Hospital, Inje University Gaegum-dong, Pusanjin-gu, Pusan, 633-165, Korea Tel : 82-51-890-6252, Fax : 82-51-892-6619, E-mail : osman64@unitel.co.kr

Copyright © 2001 Korean Society of Spine Surgery

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Study design

A retrospective study.

Objectives

To evaluate the fixation survival rate and the radiologic prognostic factors of posterior short fusion in thoracolumbar fracture.

Summary of background data

Posterior short fusion has the advantage of saving motion segments in spite of high fixation failure rate. The high Load-Sharing score is well known as a cause of fixation failure, but the effect of osteopenia is not evaluated.

Materials and Methods

A uthors evaluated 27 patients treated surgically with posterior short fusion using pedicle screws as thoracolumbar fractures from 1995 to 1999. The median followup was 20.5 months (6- 54). The survivorship using Kaplan-Meier method and the radiologic prognostic factors were evaluated.

Results

The sagittal index was preoperatively 16.7°(± 7.9 SD), immediate postoperatively 6.9°(± 4.6), and at last followup 10.6°(± 6.9). The fixation failures were detected in 4 patients, and the failure time was ranged from 6 months to 11(median 7.5). The overall survival rate was 82.3% at the last followup. The significant prognostic variables were Load-Sharing score, Jikei grade, compression percent and age in uni- variate analysis, but the Load-Sharing score and Jikei grade were significant prognostic factors in multi- variate analysis.

Conclusions

In decision to perform posterior short fusion, the Load-Sharing score and evidence of osteopenia should be considered as a prognostic factors to avoid fixation failure in thoracolumbar fracture.

Keywords: Thoracolumbar fracture, Posterior short fusion, Survival rate, Prognostic factors

REFERENCES

1). Bradford DF, McBride GG. Surgical management of thoracolumbar spine fractures with incomplete neurologic deficits. Clin Orthop. 218:210–216. 1987.
crossref
2). Carl AL, Tromanhauser SG, Roger DJ. Pedicle screw instrumentation for thoracolumbar burst fractures and fracture-dislocation. Spine. 17(8S):s317–s324. 1992.
3). Dean JR, Ison KT, Gishen P. The strengthening effect of percutaneous vertebroplasty. Clin Radiol. 55:471–6. 2000.
crossref
4). Dvorak MF, Fisher CG. Revision spine surgery in the presence of osteoporosis. (in. Margulies JY, Aebi M, Farcy JP, editors. Revision spine surgery. 1st ed.Philadelphia: Mosby;p. 646. 1999. .).
5). Ebelke DK, Asher MA, Neff JR. S u r vivorshi p analysis of VSP spine instrumentation in the treatment of thoracolumbar and lumbar burst fractures. Spine. 16(8s):s428–432. 1991.
6). Fan KF, Tu YK, Hsu , Robert WW. Using the load sharing score to predict fixation failure of thoracolumbar burst fracture. abstract book, 12th WPOA. 1998.
7). Farcy JPC, Weidenbaum M, Galssman SD. Sagittal index in management of thoracolubar burst fracture. Spine. 15:958–965. 1990.
8). Graziano PG. Cotrel-Dubousset hook and screw combination for spine fractures. J Spinal Disord. 6:380–385. 1993.
crossref
9). Huler RJ. Thoracolumbar Spine Fracture. (in. John W. Frmoyer, editor. The adult spine-principles and practice. 2nd ed.Philadelphia: Lippincott-Raven;p. 1473. 1997.
crossref
10). Katonis PG, Kontakis GM, Loupasis GA, Aligizakis AC, Christoforakis JI, Veilvassakis EG. Treatment of unstable thoracolumbar and lumbar spine injuries using Cotrel-Dubousset instrumentation. Spine. 24:2352–2357. 1999.
crossref
11). Karaikovic EE, Gaines RW. Load-sharing classifi -cation-preventing implant failure following surgical treatment. (in. Margulies JY, Aebi M, Farcy JP, editors. Revision spine surgery, 1st ed. Philadelphia: Mosby;p. 354. 1999. .).
12). McCormack T, Karaikovic E, Gaines RW. Th e load sharing classification of spine fractures. Spine. 19:1741–1744. 1994.
13). McLain RF, Sparling E, Benson DR. Early failure of short segment pedicle instrumentation for thoracolumbar fractures. J Bone Joint Surg. 75:162–167. 1993.
14). Oleksik A, Ott SM, Vedi S. Bone structure in patients with low bone mineral density with or without vertebral fractures. J Bone Miner Res. 15:1368–1375. 2000; Successful short-segment instrumentation and fusion for thoracolumbar spine fractures: a consecutive 4 and 1/2year series. Spine,. 25:1157–1170. 2000.
crossref
16). Soshi S, Shiba R, Kondo H, Murota K. An experimental study on transpedicular screw fixation in relation to osteoporosis of the lumbar spine. Spine. 16:1335–1341. 1991.
crossref
17). Vanderschot P, Caluwe G, Lauteur L. The use of hybrid allograft in the treatment of fractures of the thoracolumbar spine. Eur Spine. 10:64–68. 2001.
18). Weinstein JN, Collalto P, Lehmann TR. Thora -columbar burst fractures treatment conservatively - A long term follow up. Spine. 13:33–38. 1988.

Figures and Tables%

Fig. 1-A.
Preoperative radiographs of 61 years-old male showed L2 stable burstfracture with more than 40% compression, load-sharing score 8 point and Jikei grade 1. Fig. 1-B. Immediate postoperative, 7 and 33 months followup lateral radiographs showed acceptable correction and fixation failure, but radiologic bone union.
jkss-8-113f1.tif
Fig. 2.
The fixation survival rates according to load-sharing scores. The survival rate of less than 7 score was higher than 7 or more score (p<0.05).
jkss-8-113f2.tif
Fig. 3.
The fixation survival rates according to Jikei grades. Jikei grade 0.5 or more showed significantly lower survival rate (p<0.05).
jkss-8-113f3.tif
Table 1.
Jikei grading scale
Grade 0 Normal trabecular pattern
Grade 0.5 Decreased bone density, thin trabeculars
Grade 1 Decreased transverse trabeculars, prominent vertical trabeculars and end plates
Grade 2 More decreased transverse trabeculars, decreased vertical trabeculars
Grade 3 Almost disappeared transverse trabeculars, unclear vertical trabeculars like a ground glass image
Table 2.
Summary of sagittal parameters at perioperative and last followup
Parameters preoperative immediate pop∗ last followup
Sagittal index (°) 16.7 96.9 10.6
Fused angle (°) 18.6 97.9 12.3
Vertebral compression % 38.5 19.5 23.7

∗ pop = postoperative

Table 3.
The survivorships of statistically non-significant factors
Factors (No. of Cases) Survival(%) p-value
Farcy instability grade ≤4 (22) 84.4 0.76
>4 (5) 75.0
Sagittal index (°) <15 (12) 78.8 0.56
≥15 (15) 85.1
Correction of <20 (15) 76.9 0.37
vert.* compression (%) ≥20 (12) 88.9
Correction of SI† (°) <10 (12) 78.8 0.56
≥10 (15) 85.1
Bone graft autograft (9) 87.1 0.56
allograft (18) 80.3
Fraccture level T11,T12(8) 75.0 0.51
L1,L2(19) dex 86.7

∗ vert. = vertebral, † SI = Sagittal Ind

TOOLS
Similar articles