Evaluation of supine fulcrum pressurized radiograph for predicting spinal flexibility in adolescent idiopathic scoliosis / 中华放射学杂志

ABSTRACT

Objective To examine supine fulcrum pressurized radiograph to predict spinal flexibility in adolescent idiopathic scoliosis (AIS). Methods 1. Empirical study: put two points (A and B) on one side of the plastic stick and one point on the other side ( C), pressurize on the plastic stick when point C is in the middle of A and B, and then measure the projection shifting of point A. Repeat the pressure test when the distance between A and C doubled. Analyze the effect of increasing distance on diminishing pressure. 2.Clinical study :45 patients ( 16 males and 29 females) underwent standing anteroposterior radiograph ,fulcrum lateral flexion radiograph, supine lateral flexion radiograph. The Cobb's angles were measured and the flexibility ratio was determined on preoperative fulcrum radiograph. Results (1) If the length of A and C was 25 cm, pressurize on point C, when pressure quantitative scale number located 1 scale and 2 scale of the rule, projection shifting of point A were 5 cm and 10 cm. If the length of A and C was 50 cm, pressurize on point C, when pressure quantitative scale number located 1 scale and 2 scale of the rule, projection shifting of point A were 8 cm and 15 cm. The longer the distance, the lesser the pressure force of plastics stick. (2)The Cobb angles and curve flexibility provided by fulcrum lateral flexion radiograph had significant difference from that provided by supine lateral flexion radiograph in male group and female group. Cobb angles of male group was 28. 6°± 4. 1 °, 16. 7°± 4. 6° respectively (t= 7. 438, P ＜ 0. 01 )and curve flexibility was 47. 6% ±8. 1% ,69. 4% ± 8. 5% respectively( t = 7. 438, P ＜ 0. 01 ). Cobb angles of female group was 24.5°± 2. 7°,12. 6°±2. 4° respectively(t = 17. 540,P ＜0. 01 )and curve flexibility was 53.4% ±5.2% ,76. 0% ±4. 7% respectively(t = 17. 54, P ＜ 0. 01 ). The flexibility of spinal main curve of female patients was obviously higher than male patients. Conclusions Supine fulcrum pressurized technique can make up for the insufficiency of supine lateral flexion technique, and provide a convenient, safe, precise and useful method for evaluation of spinal flexibility in AIS.