The document evaluates stabilization failure in the thoracolumbar spine. It analyzes 93 patients who underwent spinal stabilization surgery. 9 patients (8.37%) experienced implant failure, mostly screw breakage. Failure was likely due to inadequate bone grafting, poor surgical technique, use of undersized screws, low-quality implants, and inadequate rest after surgery. To prevent failure, the study recommends limiting stabilization to appropriate cases, improving surgical methods, using adequate bone grafts, proper implant selection, and considering spinal biomechanics.

1. Evaluation of Stabilization failure
in Thoracolumber spine
Dr. Md. Shafiul Alam
Dr. Ferdous Ara Islam
NINS&H

3. Introduction
Stabilization of Thoracolumber, Lumber and
Lumbosacral spine is a common surgical
procedures. This surgery become more
popular in our country for last two decades.
Stabilization by transpedicular screws and
rods through posterior approach are
preferred.

4. Indications of stabilization were
• Traumatic fracture
• Osteoporotic fracture
• Primary bone lession
• Secondaries in the spine
• Tuberculosis of the spine
• Spondylolisthesis

5. • Failure of transpedicular screws and rods are
not uncommon. Now it is a challenging
surgical issue.
• The purpose of study was to find out the
causes of failure and ways to avoid it as much
as possible.

6. Materials and Methods
Study Design
It was a retrospective study.
Study Period
January 2007 to December 2015

7. Patient selection criteria
All patient of stabilization of Thoracolumber,
Lumber and Lumbosacral spine by pedicle
screws and rods for different indications were
included in this study.

8. Evaluation of the patient
Implant status was assessed on the basis on
Intra-operative
immediate post-operative
and follow up X-Ray findings.
The mean duration of follow up was 2 years.
Range, 1month -3 years.

9. Implant failure and radiological analysis
• The postoperative plain radiological studies
includes the standard A/P and Lat. Views.
• Successful fusion was determined by
evaluating the radiographs for the presence
bridging bone between the fused segments.

10. The radiographs were interpreted for
– Manifestation of failure of fixation
– Effect of implant failure
– The point of implant failure
– Screw length and diameter
– Rod length and diameter
– Status of bone graft

11. The common complications were seen
– Screw misplacement
– Breakage of screws
– Breakage of rods
– Loosening of screws and rods

12. Results
Total No. of cases : 93
Male : 61
Female : 32
61
32
Sex
Male
Female

13. Total no. of failed cases :
9
• Male : 5
• Female : 4
5
4
Male
Female

14. Types of failure :
Breakage of screws - 8
Breakage of rods - 1
Loosening of screws -3 8
1
3
Breakage of
screws
Breakage of rods
Loosening of
screws

15. Probable causes of implant failure
• Absence of adequate bone graft
• Failure to bone fusion
• Poor surgical technique
• Use less diameter screws
• Poor quality of implants
• Inadequate rest after surgery
• Trauma after surgery
• Short fixation

16. Case no. – 1
F 46y, Spondylolisthesis, 5m

17. Case no. – 2
M 52y, HOF, 8m

18. Case no. – 3
F 43y, Spondylolisthesis, 3m

19. Case no. – 4
M 35, FFH, 12m

20. Case no. – 5
M 25y, RTA, 7m

21. Case no. – 6
F 52y, Osteoporotic, 12m

22. Case no. – 7
M 43y, RTA, 8m

23. Case no. – 8
M 32y, FFH, 6m

24. Case no. – 9
F 23y, TB, 15m

25. Results
• Among 93 cases 9 cases (8.37%) had
stabilization failure. And others had improved.
• Of these 5 cases were male (55.55%) and 4
were female (44.45%).

26. Flow chart of failed cases
Sl. No. Sex Age (yrs) Indication Followup
(Months)
1 F 46 Spondylolisthesis 5
2 M 52 Fall from Height 8
3 F 43 Spondylolisthesis 3
4 M 35 Fall from height 12
5 M 25 RTA 7
6 F 52 Osteoporotic fracture 12
7 M 43 RTA 8
8 M 32 Fall from Height 6
9 F 23 TB Spine 15

27. Prevention of Implant failure
• Limiting the use of stabilization
• Good surgical technique
• Adequate bone grafting
• Use of cages where indicated
• Proper choice of screw and rod
• Use of good quality implants
• Use of more screws in junctional regions
• Considering the biomechanics of the spine

28. Conclusion
Failure of implanted pedicle screws and rods are
not unavoidable complications. Failure to provide
adequate stabilization can necessitate additional
surgical procedures to achieve spinal fusion.
An understanding of fundamental biomechanical
principles of the spine, fixation strategies and good
surgical technique are essential to avoid
unnecessary subsequent failures.