Evaluation of a novel silicate substituted hydroxyapatite bone graft substitute in a rabbit posterolateral fusion model.
ABSTRACT Randomized, controlled study in a laboratory setting. Blinded observations/assessment of study outcomes.
The purpose of this study is to determine the performance characteristics of a novel silicate-substituted hydroxyapatite bone graft substitute (BGS), SiCaP EP (Baxter Healthcare/ ApaTech, Elstree, UK), in a stand-alone mode, a stand-alone with bone marrow aspirate (BMA) mode, and an extender mode with iliac crest autograft (ICBG) in a rabbit posterolateral spine fusion model. The investigational BGS is compared to a standard iliac crest autograft (ICBG) control.
The rabbit posterolateral fusion model is an established environment for testing of fusion efficacy. It offers the opportunity to obtain radiographic, histological, and biomechanical data on novel bone graft substitutes.
One hundred and twenty rabbits were entered into the study with 116 used for analysis. Bilateral posterolateral lumbar intertransverse fusions were performed at L5-L6. The lateral two thirds of the transverse processes were decorti cated and covered with graft material in the following five groups: ICBG, SiCaP EP stand-alone, SiCaP EP with BMA (1:0.5 by volume), and SiCaP EP with ICBG (1:3 by volume). Rabbits were necropsied at 4, 8, and 12-week time points and fusion rate, quantity, and quality was evaluated based on manual palpation, mechanical stiffness testing, pqCT, and histological assessment.
SiCaP EP, ICBG+SiCaP EP (3:1), and SiCaP EP+BMA (1:0.5) compare favorably to iliac crest autologous bone by multiple metrics in this rabbit posterolateral fusion model. Fusion efficacy via manual palpation and mechanical stiffness testing metrics indicate that all SiCaP EP groups had similar group-to-group performance, and were not significantly different than the ICBG control at each time period evaluated.
In this commonly used rabbit posterolateral fusion model, SiCaP EP utilized as a stand-alone, as a stand-alone with BMA, and as an autograft (ICBG) extender produces results that are clinically and radiographically similar to ICBG.
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ABSTRACT: This review analyzes the literature of bone grafts and introduces tissue engineering as a strategy in this field of orthopedic surgery. We evaluated articles concerning bone grafts; analyzed characteristics, advantages, and limitations of the grafts; and provided explanations about bone-tissue engineering technologies. Many bone grafting materials are available to enhance bone healing and regeneration, from bone autografts to graft substitutes; they can be used alone or in combination. Autografts are the gold standard for this purpose, since they provide osteogenic cells, osteoinductive growth factors, and an osteoconductive scaffold, all essential for new bone growth. Autografts carry the limitations of morbidity at the harvesting site and limited availability. Allografts and xenografts carry the risk of disease transmission and rejection. Tissue engineering is a new and developing option that had been introduced to reduce limitations of bone grafts and improve the healing processes of the bone fractures and defects. The combined use of scaffolds, healing promoting factors, together with gene therapy, and, more recently, three-dimensional printing of tissue-engineered constructs may open new insights in the near future.Journal of Orthopaedic Surgery and Research 03/2014; 9(1):18. DOI:10.1186/1749-799X-9-18