STUDY DESIGN: The sheep anterior lumbar spinal fusion model was used to study the efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2)-collagen composite in comparison with autograft to enhance spinal interbody fusion. Comparisons were drawn from temporal radiographic and end-point biomechanical and histologic data. OBJECTIVE: To analyze histologically the ability of rhBMP-2 to achieve complete arthrodesis between vertebral bodies. SUMMARY OF BACKGROUND DATA: Studies using rhBMP for enhancement of anterior interbody fusion have used numerous endpoints. However, systematic histologic evaluation of the fusion has not been conducted. METHODS: Twelve sheep underwent single-level anterior lumbar interbody fusion performed with a cylindrical fenestrated titanium interbody fusion device (INTER FIX, Medtronic Sofamor Danek, Inc., Memphis, TN). The device was filled either with rhBMP-2-collagen (n = 6) or autogenous iliac crest bone graft (n = 6). Radiologic evaluation was carried out at 2-month intervals, and all sheep were killed 6 months after surgery. Nondestructive biomechanical testing for stiffness to flexion, extension, and lateral bending moments, un-decalcified histology, and qualitative and quantitative histologic evaluation were performed. RESULTS: Radiographs revealed a bony bridge anterior to the cage in five of six rhBMP-2-treated animals, whereas it was present only in one of five in the autogenous bone graft group. Segments treated with rhBMP-2 were 20% stiffer in flexion than autograft-treated segments at 6 months. Six of six in the rhBMP-2 group and two of six in the autograft group showed complete fusion. There was a significantly higher rate of bony continuity observed at the fenestrations of the rhBMP-2 group. Three times more number of cage fenestrations in the rhBMP-2 group demonstrated "all-bone" when compared with the autograft group (P < 0.001). Further, the scar tissue in and around the autograft-treated cages was 16-fold more (P < 0.01) than that seen for rhBMP-2-treated cages. CONCLUSIONS: The study demonstrates that rhBMP-2 can lead to earlier radiologic fusion and a more consistent increased stiffness of the segments when compared with autograft in sheep anterior lumbar interbody fusion. Furthermore, a three times higher histologic fusion rate is attainable with significantly reduced fibrous tissue around the implant when rhBMP-2 is used.
STUDY DESIGN: The sheep anterior lumbar spinal fusion model was used to study the efficacy of recombinant humanbone morphogenetic protein-2 (rhBMP-2)-collagen composite in comparison with autograft to enhance spinal interbody fusion. Comparisons were drawn from temporal radiographic and end-point biomechanical and histologic data. OBJECTIVE: To analyze histologically the ability of rhBMP-2 to achieve complete arthrodesis between vertebral bodies. SUMMARY OF BACKGROUND DATA: Studies using rhBMP for enhancement of anterior interbody fusion have used numerous endpoints. However, systematic histologic evaluation of the fusion has not been conducted. METHODS: Twelve sheep underwent single-level anterior lumbar interbody fusion performed with a cylindrical fenestrated titanium interbody fusion device (INTER FIX, Medtronic Sofamor Danek, Inc., Memphis, TN). The device was filled either with rhBMP-2-collagen (n = 6) or autogenous iliac crest bone graft (n = 6). Radiologic evaluation was carried out at 2-month intervals, and all sheep were killed 6 months after surgery. Nondestructive biomechanical testing for stiffness to flexion, extension, and lateral bending moments, un-decalcified histology, and qualitative and quantitative histologic evaluation were performed. RESULTS: Radiographs revealed a bony bridge anterior to the cage in five of six rhBMP-2-treated animals, whereas it was present only in one of five in the autogenous bone graft group. Segments treated with rhBMP-2 were 20% stiffer in flexion than autograft-treated segments at 6 months. Six of six in the rhBMP-2 group and two of six in the autograft group showed complete fusion. There was a significantly higher rate of bony continuity observed at the fenestrations of the rhBMP-2 group. Three times more number of cage fenestrations in the rhBMP-2 group demonstrated "all-bone" when compared with the autograft group (P < 0.001). Further, the scar tissue in and around the autograft-treated cages was 16-fold more (P < 0.01) than that seen for rhBMP-2-treated cages. CONCLUSIONS: The study demonstrates that rhBMP-2 can lead to earlier radiologic fusion and a more consistent increased stiffness of the segments when compared with autograft in sheep anterior lumbar interbody fusion. Furthermore, a three times higher histologic fusion rate is attainable with significantly reduced fibrous tissue around the implant when rhBMP-2 is used.
Authors: Blake P Sherman; Emily M Lindley; A Simon Turner; Howard B Seim; James Benedict; Evalina L Burger; Vikas V Patel Journal: Eur Spine J Date: 2010-08-09 Impact factor: 3.134
Authors: Hsin Chuan Pan; Soonchul Lee; Kang Ting; Jia Shen; Chenchao Wang; Alan Nguyen; Emily A Berthiaume; Janette N Zara; A Simon Turner; Howard B Seim; Jin Hee Kwak; Xinli Zhang; Chia Soo Journal: Am J Pathol Date: 2017-05-11 Impact factor: 4.307
Authors: Emily M Lindley; Cameron Barton; Thomas Blount; Evalina L Burger; Christopher M J Cain; Howard B Seim; A Simon Turner; Vikas V Patel Journal: Eur Spine J Date: 2016-05-10 Impact factor: 3.134
Authors: Ronald K Siu; Steven S Lu; Weiming Li; Julie Whang; Gabriel McNeill; Xinli Zhang; Benjamin M Wu; A Simon Turner; Howard B Seim; Paul Hoang; Jeffrey C Wang; Arthur A Gertzman; Kang Ting; Chia Soo Journal: Tissue Eng Part A Date: 2011-02-08 Impact factor: 3.845