Strain energy density used as the biomechanical signal for osteophyte growth in the cervical spine - biomed 2009.
Cervical spondylosis is a degenerative disease of the cervical spine that affects over 50% of the population older than 50 years. Spondylosis is a progressive disease where the intervertebral disc degenerates and bony growths called osteophytes form. Osteophyte growth has been identified by numerous investigators as an example of Wolff's law of bone remodeling acting on the abnormal strain energy density (SED) caused by the degenerating spine. A series of finite element models of the progressively degenerating cervical spine was developed to determine the SED of normal spinal vertebral bodies and the SED of degenerating vertebral bodies. The values of SED of the degenerated vertebral bodies were used to find C and HSED, two constants used in the bone remodeling equation: ?X = C (SED-HSED). ?X is the amount of osteophyte growth normal to the vertebral body surface. A bone remodeling algorithm was developed using this equation and implemented on the FEM of the degenerated spine. C was determined to be 99 mm4/mJ and HSED was found to be 24.8 mJ/mm3. An osteophyte 3.9 mm long was grown on a FEM of a degenerated spine with a disc height loss of 37%.
Wheeldon
John A
JA
Medical College of Wisconsin, Marquette University, and VA Medical Center, Milwaukee, WI.
Yoganandan
Narayan
N
Pintar
Frank A
FA