Mechanical analysis of the human cadaveric thoracic spine with intact rib cage.
The goal of this study was to characterize the overall in-plane and basic coupled motion of a cadaveric human thoracic spine with intact true ribs. Researchers are becoming increasingly interested in the thoracic spine due to both the high prevalence of injury and pain in the region and also innovative surgical techniques that utilize the rib cage. Computational models can be useful tools to predict loading patterns and understand effects of surgical procedures or medical devices, but they are often limited by insufficient cadaveric input data. In this study, pure moments to ±5 Nm were applied in flexion-extension, lateral bending, and axial rotation to seven human cadaveric thoracic spine specimens (T1-T12) with intact true ribs to determine symmetry of in-plane motion, differences in neutral and elastic zone motion and stiffness, and significance of out-of-plane rotations and translations. Results showed that lateral bending and axial rotation exhibited symmetric motion, neutral and elastic zone motion and stiffness values were significantly different for all modes of bending (p<0.05), and out-of-plane rotations and translations were greater than zero for most rotations and translations. Overall in-plane rotations were 7.7±3.4° in flexion, 9.6±3.7° in extension, 23.3±8.4° in lateral bending, and 26.3±12.2° in axial rotation. Results of this study could provide inputs or validation comparisons for computational models. Future studies should characterize coupled motion patterns and local and regional level biomechanics of cadaveric human thoracic spines with intact true ribs.
University of Kansas, Mechanical Engineering, 1530 W 15th Street, Learned Hall Room 3138, Lawrence, KS 66045, USA. Electronic address: erinmannen@gmail.com.
Erin M
EM
Mannen
Children's Mercy Hospital and Clinics of Kansas City, Orthopaedic Surgery, 2401 Gillham Road, Kansas City MO 64108, USA. Electronic address: jtanderson@cmh.edu.
John T
JT
Anderson
University of Kansas Medical Center, Department of Neurosurgery, 3901 Rainbow Bvld., MS 3021, Kansas City, KS 66160, USA. Electronic address: parnold@kumc.edu.
Paul M
PM
Arnold
University of Kansas, Mechanical Engineering, 1530 W 15th Street, Learned Hall Room 3138, Lawrence, KS 66045, USA. Electronic address: lfriis@ku.edu.
Elizabeth A
EA
Friis
D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D002102:Cadaver; D003198:Computer Simulation; D004548:Elasticity; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D016059:Range of Motion, Articular; D012272:Ribs; D012399:Rotation; D013314:Stress, Mechanical; D013904:Thoracic Vertebrae
Biomechanics; Human cadaver; Range of motion; Rib cage; Thoracic spine