Role of disc area and trabecular bone density on lumbar spinal column fracture risk curves under vertical impact. J Biomech 2018 Apr 27;72:90-98
Date
03/22/2018Pubmed ID
29559244DOI
10.1016/j.jbiomech.2018.02.030Scopus ID
2-s2.0-85044157269 (requires institutional sign-in at Scopus site) 21 CitationsAbstract
UNLABELLED: While studies have been conducted using human cadaver lumbar spines to understand injury biomechanics in terms of stability/energy to fracture, and physiological responses under pure-moment/follower loads, data are sparse for inferior-to-superior impacts. Injuries occur under this mode from underbody blasts.
OBJECTIVES: determine role of age, disc area, and trabecular bone density on tolerances/risk curves under vertical loading from a controlled group of specimens. T12-S1 columns were obtained, pretest X-rays and CTs taken, load cells attached to both ends, impacts applied at S1-end using custom vertical accelerator device, and posttest X-ray, CT, and dissections done. BMD of L2-L4 vertebrae were obtained from QCT. Survival analysis-based Human Injury Probability Curves (HIPCs) were derived using proximal and distal forces. Age, area, and BMD were covariates. Forces were considered uncensored, representing the load carrying capacity. The Akaike Information Criterion was used to determine optimal distributions. The mean forces, ±95% confidence intervals, and Normalized Confidence Interval Size (NCIS) were computed. The Lognormal distribution was the optimal function for both forces. Age, area, and BMD were not significant (p > 0.05) covariates for distal forces, while only BMD was significant for proximal forces. The NCIS was the lowest for force-BMD covariate HIPC. The HIPCs for both genders at 35 and 45 years were based on population BMDs. These HIPCs serve as human tolerance criteria for automotive, military, and other applications. In this controlled group of samples, BMD is a better predictor-covariate that characterizes lumbar column injury under inferior-to-superior impacts.
Author List
Yoganandan N, Moore J, Pintar FA, Banerjee A, DeVogel N, Zhang JAuthors
Anjishnu Banerjee PhD Associate Professor in the Data Science Institute department at Medical College of WisconsinFrank A. Pintar PhD Chair, Professor in the Biomedical Engineering department at Medical College of Wisconsin
Narayan Yoganandan PhD Professor in the Neurosurgery department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdultAged
Bone Density
Cadaver
Cancellous Bone
Humans
Lumbar Vertebrae
Male
Middle Aged
Probability
Radiography
Risk
Spinal Fractures
Stress, Mechanical
Survival Analysis