Use of finite element analysis of a Lenke type 5 adolescent idiopathic scoliosis case to assess possible surgical outcomes

Abstract

Objective: To use the finite element model of a Lenke 5 adolescent idiopathic scoliosis (AIS) patient to simulate four corrections (including anterior and posterior correction); to investigate the corrective effect of different surgical protocols; and to analyze the biomechanical stress and strain of the scoliotic spines. Methods: Four surgical strategies were designed and simulated with the model of scoliosis. All the main steps of each strategy, including derotation and compression, were simulated. The stress variation of the spine and the corrective effect were compared among the protocols for different surgical approaches and fusion levels. Results: With the four different surgical protocols, the coronary lumbar deformity was corrected to 22 , 23 , 26 and 26 , respectively, and a physiological sagittal configuration was maintained; however, higher stress was observed with solutions A1 (screw model implanted in the convex side of T12-L3) and A2 (screw model implanted in the convex side of T11-L4), while solution B2 (the posterior approach: T10-L5, fusion to SV) lost too many lumbar movement segments. A similar apical rotational correction was recorded (41.68 and 37.79 ) for solutions A2 and B1 (the posterior approach: T10-L4, fusion to LEV), which both instrumented the lower end vertebrae. Conclusions: The presented model could be used successfully to simulate correction procedures, including 90 derotation and compression, for the first time. The Lenke 5 AIS in this particular case was more rigid, and solution B1 was considered the ideal choice for treatment of this patient.

Anterior versus posterior approach in Lenke 5C adolescent idiopathic scoliosis: a meta-analysis of fusion segments and radiological outcomes

“…Bennett et al conducted a study with TL/L patients, who were taken posterior spinal fusion with 5 years follow-up, and drew a conclusion that the curve correction of coronal plane and sagittal plane was well maintained [ 39 ]. Furthermore, the finite element analysis was used to estimate possible surgical results of the anterior and posterior approach in Lenke 5 curves, and Zhang et al found that the posterior spinal fusion was regarded as the ideal surgical procedure [ 40 ].…”

Quantification of Pediatric and Adult Cervical Vertebra—Anatomical Characteristics by Age and Gender for Automotive Application

“…The spinal canal radius was smaller in the 60+ age group compared to the 18-29 age group (P < .0001) for both males and females. Zhang et al (2013) showed how anatomical measurements obtained from CT scans can be combined with crash and demographic data and used in statistical models to predict thoracic injury risks. Using averaged logistic regression models, the authors reported that cortical bone density and chest eccentricity were important variables.…”

“…Research on spine modeling is also increasing (Czyż et al 2012;Fice and Cronin 2012;Lalonde et al 2013;Tchako and Sadegh 2009;Zhang et al 2013). Physical and numerical models of occupants have been developed to investigate injury mechanisms.…”

The importance of curve severity, type and instrumentation strategy in the surgical correction of adolescent idiopathic scoliosis: an in silico clinical trial on 64 cases

“…Similar models were used in other studies, which focused on the evaluation of correction targets on the instrumentation strategy 51,52 . Several other papers by various research groups described the simulation of AIS correction in specific patients or in a small set of subjects by means of finite element models [53][54][55][56][57][58] , but to our knowledge no one reported data which can be directly compared with the present ones. The simple beam-based modeling approach is a major limitation of this study, and should be accounted for in light of the need for the full automatization of model generation, execution and postprocessing.…”