The effects of local insulin application to lumbar spinal fusions in a rat model

Abstract Background context The rates of pseudoarthrosis after a single-level spinal fusion have been reported up to 35%, and the agents that increase the rate of fusion have an important role in decreasing pseudoarthrosis after spinal fusion. Previous studies have analyzed the effects of local insu...

Full description

Saved in:
Bibliographic Details
Published in:The spine journal 2013, Vol.13 (1), p.22-31
Main Authors: Koerner, John D., MD, Yalamanchili, Praveen, MD, Munoz, William, MD, Uko, Linda, MS, Chaudhary, Saad B., MD, Lin, Sheldon S., MD, Vives, Michael J., MD
Format: Article
Language:English
Subjects:
Animals
Bone Transplantation - adverse effects
Delayed-Action Preparations
Disease Models, Animal
Fusion
Growth factors
Hypoglycemic Agents - pharmacology
Insulin
Insulin - pharmacology
Intercellular Signaling Peptides and Proteins - metabolism
Intervertebral Disc Degeneration - diagnostic imaging
Intervertebral Disc Degeneration - surgery
Intervertebral Disc Displacement - diagnostic imaging
Intervertebral Disc Displacement - surgery
Lumbar
Lumbar Vertebrae - diagnostic imaging
Lumbar Vertebrae - metabolism
Lumbar Vertebrae - surgery
Male
Orthopedics
Postoperative Complications - diagnostic imaging
Postoperative Complications - drug therapy
Postoperative Complications - prevention & control
Pseudarthrosis - diagnostic imaging
Pseudarthrosis - drug therapy
Pseudarthrosis - prevention & control
Rats
Rats, Sprague-Dawley
Spinal Fusion - adverse effects
Transplantation, Autologous
X-Ray Microtomography
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Background context The rates of pseudoarthrosis after a single-level spinal fusion have been reported up to 35%, and the agents that increase the rate of fusion have an important role in decreasing pseudoarthrosis after spinal fusion. Previous studies have analyzed the effects of local insulin application to an autograft in a rat segmental defect model. Defects treated with a time-released insulin implant had significantly more new bone formation and greater quality of bone compared with controls based on histology and histomorphometry. A time-released insulin implant may have similar effects when applied in a lumbar spinal fusion model. Purpose This study analyzes the effects of a local time-released insulin implant applied to the fusion bed in a rat posterolateral lumbar spinal fusion model. Our hypothesis was twofold: first, a time-released insulin implant applied to the autograft bed in a rat posterolateral lumbar fusion will increase the rate of successful fusion and second, will alter the local environment of the fusion site by increasing the levels of local growth factors. Study design Animal model (Institutional Animal Care and Use Committee approved) using 40 adult male Sprague-Dawley rats. Methods Forty skeletally mature Sprague-Dawley rats weighing approximately 500 g each underwent posterolateral intertransverse lumbar fusions with iliac crest autograft from L4 to L5 using a Wiltse-type approach. After exposure of the transverse processes and high-speed burr decortication, a Linplant (Linshin Canada, Inc., ON, Canada) consisting of 95% microrecrystalized palmitic acid and 5% bovine insulin (experimental group) or a sham implant consisting of only palmitic acid (control group) was implanted on the fusion bed with iliac crest autograft. As per the manufacturer, the Linplant has a release rate of 2 U/day for a minimum of 40 days. The transverse processes and autograft beds of 10 animals from the experimental and 10 from the control group were harvested at Day 4 and analyzed for growth factors. The remaining 20 spines were harvested at 8 weeks and underwent a radiographic examination, manual palpation, and microcomputed tomographic (micro-CT) examination. Results One of the 8-week control animals died on postoperative Day 1, likely due to anesthesia. In the groups sacrificed at Day 4, there was a significant increase in insulinlike growth factor-I (IGF-I) in the insulin treatment group compared with the controls (0.185 vs. 0.129; p=.001).
ISSN:1529-9430
1878-1632
DOI:10.1016/j.spinee.2012.11.030