A Comparative Evaluation of Commercially Available Cell-Based Allografts in a Rat Spinal Fusion Model

Abstract

Background: To evaluate the comparative abilities of commercially available, viable, cellular bone allografts to promote posterolateral spinal fusion. Methods: Human allografts containing live cells were implanted in the athymic rat model of posterolateral spine fusion. Three commercially available allogeneic cellular bone matrices (Trinity Evolution, Trinity ELITE and Osteocel Plus) were compared with syngeneic iliac crest bone as the control. All spines underwent radiographs, manual palpation, and micro-computed tomography (CT) analysis after excision at 6 weeks. Histological sections of randomly selected spines were subjected to semiquantitative histopathological scoring for bone formation. Results: By manual palpation, posterolateral fusion was detected in 40% (6/15) of spines implanted with syngeneic bone, whereas spines implanted with Trinity Evolution and Trinity ELITE allografts yielded 71% (10/14) and 77% (10/13) fusion, respectively. Only 7% (1/14) of spines implanted with Osteocel Plus allografts were judged fused by manual palpation (statistically significantly less than ELITE, P , .0007, and Evolution, P , .0013). The mineralized cancellous bone component of the allografts confounded radiographic analysis, but Trinity Evolution (0.452 6 0.064) and Trinity ELITE (0.536 6 0.109) allografts produced statistically significantly higher bone fusion mass volumes measured by quantitative micro-CT than did syngeneic bone (0.292 6 0.109, P , .0001 for ELITE and P , .003 for Evolution) and Osteocel Plus (0.258 6 0.103, P , .0001). Semiquantitative histopathological scores supported these findings because the total bone and bone marrow scores reflected significantly better new bone and marrow formation in the Trinity groups than in the Osteocel Plus group. Conclusions: The Trinity Evolution and Trinity ELITE cellular bone allografts were more effective at creating posterolateral fusion than either the Osteocel Plus allografts or syngeneic bone in this animal model. Clinical Relevance: The superior fusion rate of Trinity cellular bone allografts may lead to better clinical outcome of spinal fusion surgeries.

Comparative Evaluation of Mineralized Bone Allografts for Spinal Fusion Surgery

“…For example, Russell et al [35] found large variations in fusion rates (0-100%) for seven commercially-available DBM products using a rat postero-lateral spinal fusion model, with two products yielding a 0% fusion rate by manual palpation and lack of evidence of bone bridging by micro-computed tomography. Similarly, Johnstone et al [36], using the same postero-lateral spinal fusion model, reported fusion rates of 7%, 71% and 77% for three commercially-available CBM allograft products. These findings suggest that more highly manipulated bone allografts exhibit greater variability in clinical performance than minimally manipulated mineralized structural bone allografts [37].…”

Investigating the efficacy of allograft cellular bone matrix for spinal fusion: a systematic review of the literature

“…The second study compared Trinity Evolution, Trinity ELITE, Osteocel Plus, and syngeneic ICBG. 14 By manual palpation over the grafted area, Trinity Evolution and Trinity ELITE allografts demonstrated the highest fusion rates, at 71% (10/14) and 77% (10/13), respectively. Osteocel Plus showed a significantly lower fusion rate than both Trinity products at 7% (1/14).…”

“…All human clinical studies and animal research in which ACBMs were used as bone substitutes or BGEs and where clinical and/or radiological outcome data were provided were included. The final 18 selected articles for the systematic review included 5 publications pertaining to animal research, [11][12][13][14][15] 5 publications pertaining to ACBM use in cervical spine surgery in human subjects, [16][17][18][19][20] and 8 publications pertaining to ACBM use in lumbar spine surgery in human subjects. [21][22][23][24][25][26][27][28] Tables 2 and 3 detail the study characteristics, patient profiles, and study outcomes for ACBM use in human clinical studies in cervical spine and lumbar spine surgery, respectively.…”

Radiographic Fusion Outcomes for Trinity Cellular Based Allograft versus Local Bone in Posterolateral Lumbar Fusion

“…Trinity Elite, developed by Orthofix Medical Inc, is one such cellular-based autograft (CBA) consisting of viable cancellous bone with demineralized cortical bone and osteogenic cells. Trinity in patients undergoing foot and ankle arthrodesis with comorbidities provide comparable or greater fusion rates than autograft, 7 , 8 and both animal model 6 , 9 and limited clinical studies have shown that it can be safely used for fusions involving the cervical 10 , 11 and lumbar 12 13 14 spine. However, limited evidence exists directly comparing fusion rates with Trinity with other bone graft alternatives.…”