Development of Scoliocorrector Fatma-UI to aid correction of adolescent idiopathic scoliosis in Indonesia

Background: Adolescent idiopathic scoliosis (AIS) is a three-dimensional spine deformity and many techniques have been conducted to correct scoliosis. This study aims to develop a set of tools named Scoliocorrector Fatma-UI to aid in the correction of adolescent idiopathic scoliosis, to evaluate them in finite element analysis and biomechanical test, as well as to apply them in a real patient. Methods: Needs, principles, and ways to achieve the needs of an ideal corrector of scoliosis were listed, and a design was developed. Finite element analysis was performed with static structural, no separation contact, automatic mesh, and a force of 800 N. The design was modified until it passed the finite element test, and the prototype was fabricated. The prototype was biomechanically tested using a universal testing machine. The modulus of elasticity of the tools was recorded. The pull was continued until the point of failure, and the response was recorded. After ethical clearance, the tools were applied to a 15-year-old girl with Lenke 1a- adolescent idiopathic scoliosis. Postoperatively, we measured the radiological profile (coronal, sagittal, and rotational) and neurological profile (motor-evoked potential, somatosensory evoked potential, and postoperative motor power). Results: The correction tools consist of pulleys, wires, correction screws, correction houses, and pulling boards. In finite element analysis, the highest number of nodes and elements were found in the correction board, while the highest stress was in the wire. In biomechanical analysis, we found that the modulus elasticity of the correction tool is 95 613.24 +/- 6 332.77 MPa. The failure point occurred at 800 Nm, at which point the wire was slowly detached from the correction screw. In clinical application, we found that the coronal and sagittal angles improved from 53 to 1 degree and 19 to 26 degrees. Axial rotation enhanced from 10 to 4 degrees. Motor-evoked and somatosensory-evoked potential were similar to baselines, and postoperative motor function was normal. Conclusion: We have developed a set of correction tools that have been evaluated in finite element and biomechanical analysis and clinically applied to an actual patient