Each year, as more than 500,000 spinal fusions are performed in the United States, surgeons are faced with uncertainty over which bone graft extenders are most effective in supporting the healing process. While the gold standard is harvesting the patient's own bone, surgeons are reluctant to perform this procedure due to the chronic pain and potential infection associated with it. A variety of synthetic calcium-based bone graft substitutes have been developed to overcome these problems but are reported to present additional challenges, including variable and unpredictable rates of resorption, potential adverse effects on normal bone remodeling, and brittleness (1).
To address these challenges, ISTO Technologies developed InQu, a novel bone graft extender. A combination of hyaluronic acid and poly(lactide-co-glycolide) (PLGA), InQu provides a unique microenvironment that is conducive to bone formation. The structural component of InQu, PLGA, creates an osteoconductive surface well recognized to support bone growth as it undergoes resorption at the site of implantation (2,3). This unique biomaterial offers optimized handling during surgery, unobscured radiographic monitoring of bone healing, and predictable results. Unlike the ceramic bone graft substitutes, which are slowly replaced during osteoclastic remodeling, InQu Bone Graft Extender has been found to support the normal process of endochondral bone formation (8).
While hyaluronic acid is present in InQu to optimize the product's handling and absorbency, hyaluronic acid by itself (a natural component of tissue central to regeneration and repair) is reported to mediate cellular migration and attachment (4-7).
When mixed with autologous bone, InQu has been shown to be equivalent to iliac crest bone graft, the gold standard, in producing a solid arthrodesis in posterolateral spinal fusion.(8)
InQu was granted FDA clearance in 2007, both as an Extender and a Substitute and is currently available for use.
For more information about InQu's mechanism of action and available product configurations, please click here to visit the InQu Product page.
1. Buchholz RW. Nonallograft osteoconductive bone graft substitutes. Clin Orthop Rel Res 2002; 395:44-52.