Concave or convex rod translation first in adolescent idiopathic scoliosis instrumentation with differential rod contouring?
The objective was to assess deformity correction and bone-screw force associated respectively with concave manipulation first, convex manipulation first, and different differential rod contouring configurations. Instrumentation scenarios were computationally simulated for 10 AIS cases with mean thoracic Cobb angle (MT) of 54±8°, apical vertebral rotation (AVR) of 19±2° and thoracic kyphosis of 21±9°. Instrumentations with major correction maneuvers using the concave side rod were first simulated; instrumentations with major correction maneuvers using the convex side rod were then simulated. Simulated correction maneuvers were concave/convex rod translation followed by apical vertebral derotation and then convex/concave rod translation. There were no significant differences in deformity corrections and bone-screw forces between concave rod translation first and convex rod translation first with differential rod contouring. Increasing differential rod contouring angle and concave rod diameter improved AVR correction and increased the TK and bone-screw forces; the effect on the MT Cobb angle was not clinically significant.
Studies in health technology and informatics
Adolescent; Bone Screws; Humans; Kyphosis; Scoliosis; Spinal Fusion; Treatment Outcome
Cobb angle; bone-screw force; computer simulation; concave rod; contour; convex rod; derotation; translation
Wang X, Aubin CE, Schwend RM. Concave or convex rod translation first in adolescent idiopathic scoliosis instrumentation with differential rod contouring?. Stud Health Technol Inform. 2021;280:150-152. doi:10.3233/SHTI210455