Abstract
The FBCI has been shown to be a better method for describing scoliosis correction because it takes spinal flexibility into consideration. 1
Objective: To use FBCI prospectively to compare the efficacy of four different posterior instrumentations in the correction of thoracic scoliosis.
Method: 123 idiopathic scoliosis patients with thoracic curves were surgically treated prospectively using 4 different posterior instrumentations: TSRH (n=35); ISOLA (n=33); CD-Horizon (CD-H: n=32); and Moss-Miami (MM: n=23). All the operations were performed by the same team of surgeons using standard techniques. The curve was measured using the Cobb’s method on the pre-operative PA standing, fulcrum bending and 1-week post-operative PA standing radiographs. The conventional correction rate and the FBCI were calculated. One-way ANOVA and independent sample t-test were used for statistical analysis.
Results: (1) There were no significant differences between any of the 4 instrumentations when assessed using the FBCI, however, the correction rate was better in CD-H than in ISOLA and TSRH (Table 1). (2) Higher FBCIs were observed in the stiff curve group (fulcrum flexibility £ 50%) compared with those in the flexible group (fulcrum flexibility > 50%), while the correction rates were lower in the former than in the latter (Table 2).
Discussion: Better correction rate obtained in the CD-H group was attributed to the more flexible curves rather than the instrumentation itself. In the flexible curve group, the instrumentations have been able to take up all the flexibility revealed by the fulcrum-bending radiograph. Although the correction rate was less in the stiff curve group, the FBCI showed that the deformity correction was actually more than that indicated by the fulcrum bending radiographs. One possible explanation of this phenomenon may be that the fulcrum-bending radiograph is less effective in eliciting all the flexibility in the stiff curves.
Conclusion: All 4 instrumentations were EQUALLY effective in correction of thoracic scoliosis when the curve flexibility was taken into consideration.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
