442 - Tilt on Traction: A New Parameter to Decide the Lower Instrumented Ver...

General Session: Pediatric Spine

Presented by: P. Sudarsan - View Audio/Video Presentation (Members Only)


H. Suthar(1), M. Yarlagadda(1), C. Chikhale(1), M. Jindal(1), S. Hegde(1), P. Sudarsan(2)

(1) Apollo Hospitals, Orthopaedics, Chennai, India


Background: The selection of distal fusion level remains controversial in adolescent idiopathic scoliosis. Description of Lenke in his classification is widely used in selecting fusion levels. We have postulated a new parameter, tilt of vertebrae on traction x-ray view to decide lower instrumented vertebrae.

Methods: Prospective cohort of 26 adolescent idiopathic scoliosis patients who were operated in our institute by single surgeon during June 2013 to July 2014 with minimum two years follow up were included in our study. Preoperative traction x-rays were taken in all patients with standard anteroposterior, lateral and bending films. Tilt of vertebra were measured on anteroposterior and traction view. The vertebrae whose tilt came down ≤ 10 degree on traction x-ray were taken as lower instrumented vertebrae. Post operative x-rays were taken at 1 week, 6 months and 2 years. Post operative x-rays were analysed for coronal imbalance, lower instrumented vertebrae tilt.

Results: Among the 26 patients with mean age of 14.1 years 23 patients were females. 16 patients with lenke 1, one with lenke 2, 3 with lenke 3, 6 with lenke 5 curves. The vertebra with an average tilt of 19.3 degree on anteroposterior x-ray which came down to 8.4 on traction image was selected as lower instrumented vertebra. Cobb angle correction was 74±6.7%. All patients had maintained coronal balance up to recent follow up. Lowest instrumented vertebrae tilt of more than 10 degree was found in 2 patients but none of them required revision surgery (no adding on).

Conclusion: Tilt of vertebrae on traction x-ray can be used as one of the parameters to decide lower instrumented vertebrae in adolescent idiopathic scoliosis that may restrict the level of fusion to some extent. Large case series with comparative study require proving this hypothesis.