Abstract
Aim:
To compare the ability of fulcrum bend and traction radiographs to predict correction of AIS using pedicle screw only constructs and to compare the fulcrum bending correction index (FBCI) with a new measurement: the traction correction index (TCI).
Method:
Retrospective radiographic analysis of eighty patients, average age 14 yrs, who underwent posterior correction of scoliosis using pedicle screw only construct. Analysis was carried out on the pre-op and immediate post-op PA radiographs and the pre-op fulcrum bend and traction radiographs. Correction rate, fulcrum flexibility, traction flexibility, FBCI and TCI was calculated.
Results:
Preoperative mean Cobb angle of 63.9 degrees was corrected to 25.8 degrees postoperatively. The mean fulcrum bending Cobb angle was 37.6 degrees and traction Cobb angle 26.6 degrees. The mean fulcrum flexibility was 41.1%, traction flexibility 58.4% and correction rate 59.6%. The mean FBCI was 144.9% and TCI was 102.1%.
Discussion:
Radiographic correction of scoliosis based on correction rate does not take into consideration the curve flexibility. It has been suggested by Cheung et al, that fulcrum bending radiographs predict curve correction in AIS. Ibrahim et al, have questioned this, and they suggested that traction radiographs are more predictive in a mixed group of patients with hybrid and screw only constructs.
Conclusions:
When comparing fulcrum bend and traction radiographs, we found the latter to be more predictive of curve correction in AIS using pedicle screw constructs. The TCI better takes into account the curve flexibility than the FBCI.
Conflict Of Interest Statement: No conflict of interest.
