Evaluation of Trinity Evolution in Patients Undergoing Foot and Ankle Fusion

Symptomatic arthritic conditions of the foot and ankle including osteoarthritis,
post-traumatic arthritis, inflammatory arthropathies and others can be painful and disabling
conditions that lead to a reduced quality of life. Major symptoms include pain, stiffness,
swelling, and difficulty walking. Many patients may be initially treatable with
non-invasive measures such as analgesics, ankle-foot orthosis, physical therapy and
medications such as steroids; however, over time, surgery becomes necessary to improve
quality of life and maintain function. Arthrodesis is a well-known procedure that can reduce
pain and result in a foot/ankle that can withstand an active lifestyle.

Bone graft is used to stimulate new bone formation at the operative site by providing
osteogenic cells with osteoinductive factors with an osteoconductive matrix. Although
autologous bone is often used as the structural graft material for fusion procedures, donor
site morbidity (e.g., pain, infection, and fracture), limited supply, and inconsistent
osteogenic activity continue to be associated problems. The quality of an autograft is
dependent upon the age and medical condition of the patient, as well as the number of viable
mesenchymal and osteoprogenitor stem cells that are present in the specimen. This tissue is
harvested during the surgical procedure; the process can prolong morbidity at the harvest
site. The ideal bone graft would offer osteogenic cells, osteoinductive factors, and an
osteoconductive matrix with a consistent supply of viable mesenchymal stem cells (MSCs) and
osteoprogenitor cells (OPCs)—but without the morbidity of autograft.

Due to the limitations associated with autograft, researchers are pursuing the use of
bone-graft substitutes to promote arthrodesis. Bone-graft substitutes now being used by
surgeons include ceramic synthetics, bone morphogenic proteins (BMPs), demineralized bone
matrices (DBMs) and other allografts; these may be used alone or in combination. Allografts
available as substitutes for autograft offer some of the benefits of autograft without its
limitations—but do not contain viable MSCs and OPCs.

Trinity Evolution is an allogeneic cancellous bone matrix containing demineralized cortical
bone (DCB) as well as viable osteoprogenitor and mesenchymal stem cells. Adult mesenchymal
stem cells and osteoprogenitor cells, such as those in Trinity Evolution, are the precursor
cells that differentiate into osteoblasts—the cells responsible for bone growth and repair.

Trinity Evolution provides the required osteoconduction, osteogenesis, and osteoinductivity
necessary for successful bone grafting. It offers viable osteoprogenitor and mesenchymal
stem cells and demineralized cortical bone—all in a single product. Data from preclinical
studies with Trinity Evolution have demonstrated in-vitro and in-vivo safety and
effectiveness. Trinity Evolution is a "minimally manipulated" tissue that is considered an
allograft, and as such, is labeled for bone repair for all orthopedic and podiatric
indications where autograft is used. In this study, Trinity Evolution will be used as a
substitute for autograft and/or standard allograft in the following arthrodesis procedures:
tibiotalar, subtalar, calcaneocuboid, talonavicular, double fusions (i.e. calcaneocuboid and
talonavicular), and triple fusions (i.e. subtalar, calcaneocuboid, and talonavicular).