J Korean Soc Spine Surg.  2008 Mar;15(1):23-30. 10.4184/jkss.2008.15.1.23.

The Comparison of the Results Between AO Internal Fixator (Long lever-arm) and Screw-Rod System (Short lever-arm) Through Posterior Approach in Unstable Thoracolumbar Fractures

• Kim YT
• Kim MC
• Kang SJ
• Kim CW
• Kim SY
• Sohn DW
• Lee CS
• Lee DH

• KMID: 1482840
• DOI: http://doi.org/10.4184/jkss.2008.15.1.23

Abstract

STUDY DESIGN: Prospective study.
OBJECTIVES
To analyze the outcome of posterior reduction and fixation with the AO internal fixator and with the screw-rod system in unstable thoracolumbar fractures and to investigate differences in effectiveness between the two methods. SUMMARY OF LITERATURE REVIEW: In unstable thoracolumbar fractures, fixation with the AO internal fixator is an effective method for posterior reduction. However, the results of correction are quite variable.
MATERIALS AND METHODS
We analyzed 51 patients with unstable thoracolumbar fractures who underwent correction through posterior approach between 1997 and 2003. We divided the patients into two groups: Patients in Group A (25 cases) were treated with the AO internal fixator, and patients in Group B (26 cases) were treated with the screw-rod system. We added transpedicular bone grafts for 17 patients in Group A. We evaluated correction of deformity (anterior and posterior height of vertebral body, sagittal index, disc height), loss of correction, spinal canal clearance, and neurological recovery.
RESULTS
Comparing correction of deformity, we saw better results in Group A than in Group B in regards to sagittal index and anterior height of vertebral body. However, we saw a higher degree of correction loss in the anterior height of the vertebral body in Group A. We grafted autogenous bone into the fracture site by transpedicular approach for 17 patients in Group A. We saw less correction loss in the anterior vertebral body height and sagittal index. In regard to spinal canal clearance, we saw better results in Group A (18%) than in Group B (10%). As for neurological recovery, we could not find any statistically significant difference between the two groups.
CONCLUSIONS
Through an operative procedure, we could achieve better results in restoration of anterior vertebral height and canal clearance with the AO internal fixator system. Further study is necessary to keep the reduced state of vertebral height.

Keyword

Thoracolumbar fractures; AO internal fixator; Screw-rod system; Transpedicular bone graft

MeSH Terms

Body Height
Congenital Abnormalities
Humans
Internal Fixators
Prospective Studies
Spinal Canal
Surgical Procedures, Operative
Transplants

Reference

1). Bohlman HH. Treatment of fractures and dislocation of the thoracic and lumbar spine. J Bone Joint Surg Am. 1985; 67:165–169.

2). Holdsworth F. Fracture, dislocations and fracture-dislocation of the spine. J Bone Joint Surg Am. 1970; 52:1534–1551.

3). Daniaux H, Seykora P, Genelin A, Lang T, Kathrein A. Application of posterior plating and modifications in thoracolumbar spine injuries. Indication, techniques, and results. Spine. 1991; 16:125–33.

4). Kuner EH, Kuner A, Schlickewei W, Mullaji AB. Liga-mentotaxis with an internal spinal fixator for thoracolumbar fractures. J Bone Joint Surg Br. 1994; 79:107–111.

5). Mclain RF, Sparling E, Benson DR. Early failure of short-segment pedicle instrumentation for thoracolumbar fractures. J Bone Joint Surg Am. 1993; 75:162–167.

6). Olerud S, Karlstrom G, Sjostrom L. Transpedicular fixation of thoracolumbar vertebral fractures. Clin Orthop. 1988; 227:44–51.

7). Benson DR, Burkus JK, Montesano PX, Sutherland TB, Mclain RF. Unstable thoracolumbar and lumbar fractures treated with AO fixateur interne. J spinal disorders;. 1992; 5:335–343.

8). Oda T, Panjabi MM. Pedicle screw adjustments affect stability of thoracolumbar burst fracture. Spine. 2001; 1(26):2328–2333.

9). Oda T, Panjabi MM, Kato Y. The effects of pedicle screw adjustments on the anatomical reduction of thoracolumbar burst fractures. Eur Spine J. 2001; 10:505–511.

10). Kim YT, Lee CS, Kim CH, Joo KM. Surgical treatment of unstable thoracolumbar fractures with posterior approach. J Korean Orthop Assoc. 1999; 34:651–658.

11). Cho HO, Kwak KD, Cho SD, Ryoo CS, Baek JD, Yang IJ. Operative treatment of thoracolumbar spine fractures with AO internal fixator. J Korean Orthop Assoc. 1995; 30:926–932.

12). Aklm S, Kis M, Benli T, Citak M, Mumcu EF, Tuzuner M. Results of the AO spinal internal fixator in surgical treatment of thoracolumbar burst fractures. Eur Spine J. 1994; 3:102–106.

13). Esses SI, Botsford DJ, Wright T, Bednar D, Bailey S. Operative treatment of spinal fractures with the A-O internal fixator. Spine. 1991; 15-3:146–150.

14). Aebi M, Etter C, Kehl T, Thalgott J. Stabilization of the lower thoracic and lumbar spine with the internal skeletal fixation system. Indications, techniques and first results of treatment. Spine. 1987; 12:544–551.

15). Esses SI. The A-O spinal internal fixator. Spine. 1989; 14:373–378.

16). DeweiZou MD, Yoo JU, Edwards T, et al. Mechanics of anatomic reduction of thoracolumbar burst fractures. 1991; 12:195–212.

17). Lim BY, Cheong HY, Shin DB, Tsung YT. Clinical analysis of posterior spinal instrumentation in unstable thoracolumbar fracture and fracture dislocation. J Korean Orthop Assoc. 1990; 25:142–150.

18). Handel SF, Twiford TW Jr, Reigel DH, Kaufman HH. Posterior lumbar apophyseal fractures. Radiology. 1979; 130:629–633.

19). Lindahl S, Willen J, Irstam L. Computed tomography of bone fragments in the spinal canal. Spine. 1993; 8:181–186.

20). Doerr TE, Montesano PX, Burkus JK, Benson DR. Spinal canal decompression in traumatic thoracolumbar burst fractures: posterior distraction rods versus transpe- ducular screw fixation. J Orthop trauma. 1991; 5:403–411.

21). Lindahl S, Willen J, Norswall A, Irstam L. The crush-cleavage fracture. Spine. 1983; 8:559–569.

22). Aebi M, Etter C, Kehl T, Thalgott J. Stabilization of the lower thoracic and lumbar spine with the internal spinal skeletal fixation system: indications, techniques, and first results of treatment. Spine. 1987; 12:544–551.

23). Park HJ, Rah JH, Yoo KJ. Operative treatment of thoracolumbar spine fractures with AO internal fixator. J Korean Orthop Assoc. 1996; 31:1116–1123.

24). Hergwig D, Peter S, Alexander G, Thomas L and Anton K. Application of posterior plating and modifications in thoracolumbar spine injuries. Spine. 1991; 16:125–133.

25). Park HJ, Lee DH, Lim MH. The effectiveness of transpedicular bone graft in burst fracture, J Kor Soc Spine Surg. 2000; 7:625–631.

26). Knop C, Fabian HF, Bastian L, Blauth M. Late results of thoracolumbar fractures after posterior instrumentation and transpedicular bone grafting. Spine. 2001; 6:88–99.