Development of a Computer Simulation Tool for Application in Adolescent Spinal Deformity Surgery

Abstract

Abstract. Scoliosis is a three-dimensional spinal deformity which requires surgical correction in progressive cases. In order to optimize correction and avoid complications following scoliosis surgery, patient-specific finite element models (FEM) are being developed and validated by our group. In this paper, the modeling methodology is described and two clinically relevant load cases are simulated for a single patient. Firstly, a pre-operative patient flexibility assessment, the fulcrum bending radiograph, is simulated to assess the model's ability to represent spine flexibility. Secondly, intra-operative forces during single rod anterior correction are simulated. Clinically, the patient had an initial Cobb angle of 44 degrees, which reduced to 26 degrees during fulcrum bending. Surgically, the coronal deformity corrected to 14 degrees. The simulated initial Cobb angle was 40 degrees, which reduced to 23 degrees following the fulcrum bending load case. The simulated surgical procedure corrected the coronal deformity to 14 degrees. The computed results for the patient-specific FEM are within the accepted clinical Cobb measuring error of 5 degrees, suggested that this modeling methodology is capable of capturing the biomechanical behaviour of a scoliotic human spine during anterior corrective surgery.

Patient‐specific computational biomechanics for simulating adolescent scoliosis surgery: Predicted vs clinical correction for a preliminary series of six patients

“…In previous studies we have described the patient-specific modelling methodology for a single scoliosis patient undergoing a pre-operative flexibility test [31], and shown good agreement between predicted and clinical correction for a single patient undergoing anterior scoliosis surgery [30], but this study extends the previous work to compare predicted and actual surgical correction for a group of six AIS patients.…”

“…Our work in this field to date has developed a patient-specific modelling methodology in which model anatomy is derived from pre-operative low-dose-computed tomography (CT) scans. This methodology was recently applied to simulate anterior surgical correction for a single patient, finding that the predicted post-operative surgical correction agreed with the clinical value [30]. However, it is not clear from a single patient what the relative importance of patient-specific anatomy and patient-specific tissue properties is in correctly predicting surgical correction.…”

“…Our method for deriving patient-specific FE models from low-dose CT scan data has been previously described [30,31]. CT is not normally performed clinically, however Kamimura et al [32] showed that pre-operative CT allowed safer screw sizing and positioning for thoracoscopic (keyhole) anterior surgery approaches.…”

Corrective force analysis for scoliosis from implant rod deformation

“…However, the corrective forces acting at each screw were difficult to measure since the rotating device is attached only to the implant rod. The magnitude of forces occurring at each screw is also important because overloading due to the rod rotation maneuver might occur (Little and Adam, 2010).…”

1,3‐ and 1,2‐Carbo‐Migration of 2‐Vinylbicyclo[2.2.2]octenols: Facile and Concise Synthesis of Bicyclo[4.2.2]/[3.2.2] Skeleton by Two/One‐Carbon Ring Expansion

“…Our method for deriving patient‐specific FE models from low‐dose CT scan data has been previously described 30, 31. CT is not normally performed clinically, however Kamimura et al 32 showed that pre‐operative CT allowed safer screw sizing and positioning for thoracoscopic (keyhole) anterior surgery approaches.…”