TY - JOUR
T1 - Quantitative study of parathyroid hormone (1-34) and bone morphogenetic protein-2 on spinal fusion outcomes in a rabbit model of lumbar dorsolateral intertransverse process arthrodesis
AU - Lina, Ioan A.
AU - Puvanesarajah, Varun
AU - Liauw, Jason A.
AU - Lo, Sheng Fu L.
AU - Santiago-Dieppa, David R.
AU - Hwang, Lee
AU - Mao, Annie
AU - Bydon, Ali
AU - Wolinsky, Jean Paul
AU - Sciubba, Daniel M.
AU - Gokaslan, Ziya
AU - Holmes, Christina
AU - Witham, Timothy F.
PY - 2014/3/1
Y1 - 2014/3/1
N2 - STUDY DESIGN.: A posterolateral rabbit spinal fusion model was used to evaluate the effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) and teriparatide (PTH [1-34]) used individually and in combination on spinal fusion outcomes. OBJECTIVE.: To test the efficacy of parathyroid hormone on improving spinal fusion outcomes when used with BMP-2. SUMMARY OF BACKGROUND DATA.: Of the more than 250,000 spinal fusion surgical procedures performed each year, 5% to 35% of these will result in pseudarthrosis. Growing controversy on the efficacy and cost of rhBMP-2 for improving spinal fusion outcomes has presented a challenge for clinicians. Research into PTH as an adjunct therapy to rhBMP-2 for spinal fusion has not yet been investigated. METHODS.: Forty-eight male New Zealand white rabbits underwent bilateral posterolateral intertransverse process arthrodesis surgery at the L5-L6 level. Animals were divided into 6 groups. Two groups were treated with autograft alone or autograft and PTH (1-34), whereas the other 4 groups were treated with low-dose rhBMP-2 alone, high-dose rhBMP-2 alone, or either dose combined with PTH (1-34). All animals were euthanized 6 weeks after surgery. The L4-L7 spinal segment was removed and assessed using manual palpation, computed tomography (CT), and biomechanical testing. RESULTS.: CT assessments revealed fusion in 50% of autograft controls, 75% of autograft PTH (1-34) animals, 87.5% in the 2 groups treated with low-dose rhBMP-2, and 100% in the 2 groups treated with high-dose rhBMP-2. CT volumetric analysis demonstrated that all groups treated with biologics had fusion masses that were on average significantly larger than those observed in the control group (P < 0.0001). Biomechanical data demonstrated no statistical difference between controls, PTH (1-34), and low-dose rhBMP-2 in any testing orientation. PTH (1-34) did not increase bending stiffness when used adjunctively with either low-dose or high-dose rhBMP-2. CONCLUSION.: Although intermittent teriparatide administration results in increased fusion mass volume, it does not improve biomechnical stiffness over use of autograft alone. When delivered concurrently with high-and low-dose rhBMP-2, teriparatide provided no statistically significant improvement in biomechanical stiffness.Level of Evidence: N/A
AB - STUDY DESIGN.: A posterolateral rabbit spinal fusion model was used to evaluate the effects of recombinant human bone morphogenetic protein-2 (rhBMP-2) and teriparatide (PTH [1-34]) used individually and in combination on spinal fusion outcomes. OBJECTIVE.: To test the efficacy of parathyroid hormone on improving spinal fusion outcomes when used with BMP-2. SUMMARY OF BACKGROUND DATA.: Of the more than 250,000 spinal fusion surgical procedures performed each year, 5% to 35% of these will result in pseudarthrosis. Growing controversy on the efficacy and cost of rhBMP-2 for improving spinal fusion outcomes has presented a challenge for clinicians. Research into PTH as an adjunct therapy to rhBMP-2 for spinal fusion has not yet been investigated. METHODS.: Forty-eight male New Zealand white rabbits underwent bilateral posterolateral intertransverse process arthrodesis surgery at the L5-L6 level. Animals were divided into 6 groups. Two groups were treated with autograft alone or autograft and PTH (1-34), whereas the other 4 groups were treated with low-dose rhBMP-2 alone, high-dose rhBMP-2 alone, or either dose combined with PTH (1-34). All animals were euthanized 6 weeks after surgery. The L4-L7 spinal segment was removed and assessed using manual palpation, computed tomography (CT), and biomechanical testing. RESULTS.: CT assessments revealed fusion in 50% of autograft controls, 75% of autograft PTH (1-34) animals, 87.5% in the 2 groups treated with low-dose rhBMP-2, and 100% in the 2 groups treated with high-dose rhBMP-2. CT volumetric analysis demonstrated that all groups treated with biologics had fusion masses that were on average significantly larger than those observed in the control group (P < 0.0001). Biomechanical data demonstrated no statistical difference between controls, PTH (1-34), and low-dose rhBMP-2 in any testing orientation. PTH (1-34) did not increase bending stiffness when used adjunctively with either low-dose or high-dose rhBMP-2. CONCLUSION.: Although intermittent teriparatide administration results in increased fusion mass volume, it does not improve biomechnical stiffness over use of autograft alone. When delivered concurrently with high-and low-dose rhBMP-2, teriparatide provided no statistically significant improvement in biomechanical stiffness.Level of Evidence: N/A
KW - 4-point bending stiffness
KW - bone graft substitute
KW - hydroxyapatite
KW - parathyroid hormone
KW - posterolateral spinal fusion
KW - pseudarthrosis
KW - rabbit model
KW - recombinant human bone morphogenetic protein-2
KW - tricalcium phosphate
KW - volumetric analysis
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U2 - 10.1097/BRS.0000000000000169
DO - 10.1097/BRS.0000000000000169
M3 - Article
C2 - 24365898
AN - SCOPUS:84896396958
SN - 0362-2436
VL - 39
SP - 347
EP - 355
JO - Spine
JF - Spine
IS - 5
ER -