Prediction of Scoliosis Curve Correction Using Pedicle Screw Constructs in AIS: A Comparison of Fulcrum Bend Radiographs and Traction Radiographs Under General Anesthesia

Abstract

Study Design:Retrospective radiographic review.Objectives:Our objectives were to (1) compare the ability of fulcrum bend radiographs and traction radiographs under general anesthesia to predict correction of adolescent idiopathic scoliosis (AIS) using pedicle screw only constructs and (2) compare the fulcrum bend correction index (FBCI) with a new measurement: the traction correction index (TCI).Methods:This is a retrospective radiographic review of 80 AIS patients (62 female and 18 male), who underwent scoliosis correction with pedicle screw only constructs. The mean age at surgery was 14 years (range 9-20 years). Radiographic analysis was carried out on the preoperative and immediate postoperative posteroanterior standing radiographs and the preoperative fulcrum bend radiographs and traction radiographs under general anesthesia. FBCI is calculated by dividing the correction rate by the fulcrum flexibility and TCI is calculated by dividing the correction rate by the traction flexibility.Results:Preoperative mean Cobb angle of 63.9° was corrected to 25.8° postoperatively. The mean fulcrum bending Cobb angle was 37.6° and traction Cobb angle was 26.6°. The mean fulcrum flexibility was 41.1%, traction flexibility 58.4%, and correction rate 59.6%. The median FBCI was 137% and TCI was 104.3%.Conclusions:When comparing fulcrum bend and traction radiographs, we found the traction radiographs to be more predictive of curve correction in AIS using pedicle screw constructs. TCI takes into account the curve flexibility better than FBCI.

Perioperative outcome of severe rigid idiopathic scoliosis: Single-staged posterior spinal fusion utilizing a dual attending surgeon strategy. A report of 41 patients

“…Tokala et al studied 80 patients and reported traction radiographs under general anesthesia were more predictive than fulcrum bending (FB) radiographs. 26 Bekki et al compared supine with prone SB radiograph and found both to be similar. 27 Khodaei et al in a systematic review concluded that FB provided the best estimates for curves >45º but the quality of evidence was very low to low with moderate risk of bias.…”

Are We Looking at a Paradigm Shift in the Management of Adolescent Idiopathic Scoliosis? Comprehensive Retrospective Analysis of 75 Patients of Nonfusion Anterior Scoliosis Correction with 2–5-Year Follow-up: A Single Center Experience

“…In our center, we do awake traction X-rays. Preoperative traction radiographs help in reasonably estimating postoperative correction for AIS patients undergoing NFASC [ 16 ]. It guides the surgeon intraoperatively for appropriate tensioning for adequate correction [ 17 ].…”

Postoperative Correction in Idiopathic Scoliosis: Which Preoperative Imaging Technique Is Most Predictive?

“…Specifically, fulcrum bending radiographs are limited by patient discomfort and difficulty with proper positioning of the bolster, and push-prone radiographs are limited also by patient discomfort and difficulty with standardization of force applied at the apex of the curve. 8,11 TUGA radiographs were first described by Davis et al 7 in 2004 and offer the unique advantages of mitigating muscular factors affecting curve flexibility and are also not limited by patient compliance. Prior studies have demonstrated that TUGA radiographs better predict postoperative correction in large main thoracic curves > 60 degrees.…”

“…As with SB radiographs, these other methods are also have inherent advantages and disadvantages. Specifically, fulcrum bending radiographs are limited by patient discomfort and difficulty with proper positioning of the bolster, and push-prone radiographs are limited also by patient discomfort and difficulty with standardization of force applied at the apex of the curve 8,11…”