Iliac Crest Bone Graft for Minimally Invasive Transforaminal Lumbar Interbody Fusion

Study design: Preclinical ovine model. Objective: To assess the in vivo efficacy and safety of the P-15 L bone graft substitute and compare its performance to autologous iliac crest bone graft (ICBG) for lumbar interbody fusion indications. Methods: Thirty skeletally mature sheep underwent lumbar interbody fusion surgery. Half of the sheep received autologous ICBG and the other half the peptide enhanced bone graft substitute (P-15 L). Following termination at 1, 3, and 6 months after surgery, the operated segments were analyzed using micro computed tomography (µCT), histology, and destructive mechanical testing. Additional systemic health monitoring was performed for the P-15 L group. Results: One month after surgery, there was only minor evidence of bone remodeling and residual graft material could be clearly observed within the cage. There was active bone remodeling between 1 and 3 months after surgery. At 3 months after surgery significantly denser and stiffer bone was found in the P-15 L group, whereas at 6 months, P-15 L and ICBG gave similar fusion results. The P-15 L bone graft substitute did not have any adverse effects on systemic health. Conclusions: The drug device combination P-15 L was demonstrated to be effective and save for lumbar interbody fusion as evidenced by this ovine model. Compared to autologous ICBG, P-15 L seems to expedite bone formation and remodeling but in the longer-term fusion results were similar.

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Microcomputed tomographic, biomechanical and histological analyses of lumbar interbody fusion with iliac crest bone graft in a pig model

Acta Veterinaria Brno ◽

10.2754/avb202190010069 ◽

2021 ◽

Vol 90 (1) ◽

pp. 69-75

Author(s):

Milan Krtička ◽

Vladimír Nekuda ◽

Daniel Ira ◽

Radek Sedláček ◽

Tomáš Suchý ◽

...

Keyword(s):

Bone Graft ◽

Interbody Fusion ◽

Iliac Crest ◽

Biomechanical Analysis ◽

Iliac Crest Bone Graft ◽

Testing System ◽

Lumbar Interbody Fusion ◽

Micro Ct ◽

Histological Assessment ◽

Load Limit

The main goal of this study was to assess the progress of vertebral stability after lumbar interbody fusion related to microcomputed tomography (micro CT), biomechanical analysis, and histological assessment towards spine fusion. Twelve male pigs were used; each underwent L2-3 discectomy and implantation of an iliac crest bone graft in two groups; six spines were harvested eight weeks (A1) and six spines 16 weeks (A2) after surgery (7 native spines for biomechanical analysis). The CT was performed by GE phoenix datos|x 2.0 with a sample drift correction. The samples were divided according to fusion quality. Biomechanical evaluation was carried out on the MTS Mini Bionix testing system. In the nondestructive mode, three cycles of pure bending moments were applied (5 Nm load limit) at a rate of 20 °/min in flexion (+40 °) and extension (-40 °). Two representative histological sections from four samples were obtained (A1, n = 2; A2, n = 2); areas of mature bone were quantified. In micro CT, better results were achieved in group A2 (not significant). Eight weeks after the operation, flexural stiffness decreased to 48% of its initial value for native cadavers (P < 0.05); after 16 weeks it was comparable to native cadavers, demonstrating the suitability of the implanted graft (P < 0.05). The newly formed bone tissue occupied an average area of 94.205 mm2 (A1) and 26.240 mm2 (A2). It was confirmed that micro CT, biomechanical analysis, and histological assessment are technically feasible and suitable for the evaluation of results of other methods of large bone defect treatment.

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