+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn

+ Translate
+ Recently Requested

The effect of spinal implant rigidity on vertebral bone density. A canine model

The effect of spinal implant rigidity on vertebral bone density. A canine model

Spine 16(6 Suppl): S190-S197

An animal model of anterior and posterior column instability was developed to allow in vivo observation of bone remodeling and arthrodesis following spinal instrumentation. After an initial anterior and posterior destabilizing lesion was created at the L5-L6 vertebral levels in 63 adult beagles, various spinal reconstructive surgical procedures were performed--with or without bilateral posterolateral bone grafting, with or without bilateral oophorectomies, and with or without spinal instrumentation (Harrington distraction, Luque rectangular, Cotrel-Dubousset pedicular, or Steffee pedicular implants). Observation 6 months after surgery revealed a significantly improved probability of achieving a spinal fusion if spinal instrumentation had been used (X2 = 5.84, P = .016). Nondestructive mechanical testing after removal of all metal instrumentation in torsion, axial compression, and flexion revealed that the fusions performed in conjunction with spinal instrumentation were more rigid (P less than .05). Quantitative histomorphometry showed that the volumetric density of bone was significantly lower (ie, device-related osteoporosis occurred) for fused versus unfused spines. In addition, a linear correlation occurred between decreasing volumetric density of bone and increasing rigidity of the spinal implant (r = .778); ie, device-related osteoporosis occurred secondary to Harrington, Cotrel-Dubousset, and Steffee pedicular instrumentation. Oophorectomized dogs became more osteoporotic than their surgically matched controls (posterolateral bone grafting alone, Cotrel-Dubousset pedicular instrumentation, and Steffee pedicular instrumentation); device-related osteoporosis added to the degree of hormonally induced osteoporosis (t = 5.0, P less than .0001). This is the first study to date documenting the occurrence of stress shielding in the spine secondary to spinal instrumentation.

(PDF emailed within 1 workday: $29.90)

Accession: 033784015

Download citation: RISBibTeXText

PMID: 1862413

Related references

The relative importance of vertebral bone density and disc degeneration in spinal flexibility and interbody implant performance. An in vitro study. Spine 21(22): 2558-2569, 1996

Association of prevalent vertebral fractures, bone density, and alendronate treatment with incident vertebral fractures: Effect of number and spinal location of fractures. Bone (New York) 25(5): 613-619, 1999

The effect of vertebral collapse on spinal bone mineral density measurements in osteoporosis. Bone & Mineral 18(3): 267-272, 1992

Effect of spinal osteophytosis on bone mineral density measurements in vertebral osteoporosis. Bmj 307(6897): 172-173, 1993

Comparison of the radiographic vertebral trabecular pattern with the vertebral fracture prevalence and spinal bone density. Osteoporosis International 3(6): 293-299, 1993

Association of prevalent vertebral fractures, bone density, and alendronate treatment with incident vertebral fractures: effect of number and spinal location of fractures. The Fracture Intervention Trial Research Group. Bone 25(5): 613-619, 1999

Spinal implants and radiation therapy: the effect of various configurations of titanium implant systems in a single-level vertebral metastasis model. Journal of Bone and Joint Surgery. American Volume 88(5): 1093-1100, 2006

Spinal bone mineral density measured with quantitative CT: effect of region of interest, vertebral level, and technique. Radiology 175(2): 537-543, 1990

The effect of alendronate (Fosamax) and implant surface on bone integration and remodeling in a canine model. Journal of Biomedical Materials Research 58(6): 645-650, 2001

Method of using spinal fusion device, bone joining implant, and vertebral fusion implant. Official Gazette of the United States Patent & Trademark Office Patents 1279(2), Feb 10, 2004

Effect of Implant Thread Geometry on Secondary Stability, Bone Density, and Bone-to-Implant Contact: A Biomechanical and Histological Analysis. Implant Dentistry 24(4): 384-391, 2015

Effect of enamel matrix derivative on bone formation around intraosseous titanium implant: An experimental study in canine model. Dental Research Journal 9(6): 790-796, 2013

Effect of estrogen and calcitonin on vertebral bone density and vertebral height in osteoporotic women. Osteoporosis International 2(2): 70-73, 1992

Sublesional spinal vertebral bone mineral density correlates with neurological level and body mass index in individuals with chronic complete spinal cord injuries. Spine 35(9): 958-962, 2010