STUDY OBJECTIVES:

To demonstrate equivalent clinical and radiologic outcomes as "gold standard" (Autologous Bone Graft) in a representative clinical model (hindfoot fusions)

STUDY HYPOTHESIS:

Augment® Injectable is an equivalent bone grafting substitute to autologous bone graft in applications as shown by superiority analysis for safety and non-inferiority analysis for effectiveness

STUDY RATIONALE:

To evaluate a fully synthetic bone graft material to facilitate fusion in conditions or injuries requiring bone graft in a representative clinical fusion model and thus the opportunity to provide equivalent union rates as Autologous Bone Graft without necessitating an additional invasive procedure to harvest the graft

STUDY DESIGN:

Prospective, randomized, controlled, non-inferiority, multi-center trial

NUMBER OF STUDY CENTERS:

25

NUMBER OF SUBJECTS:

299 Subjects (see "Study Population"). The subject population included subjects enrolled in 3 separate Clinical Trials. (BMTI-2006-01, BMTI-2009-01, and BMTI-2010-01)

STUDY POPULATION:

Male and female subjects 18 years of age or older requiring a hindfoot fusion procedure involving a bone grafting procedure.

TREATMENT GROUPS:

Group I: Standard Rigid Fixation + Autologous Bone Graft Group II: Standard Rigid Fixation + Augment® Injectable Bone Graft

Subjects will be randomized in a 2:1 ratio (Augment® Injectable:Autologous Bone Graft).

ROUTE OF ADMINISTRATION:

Investigational device is manually implanted inside and around the fusion space to ensure Augment® Injectable Bone Graft (beta-TCP/bovine collagen matrix +rhPDGF-BB) or autologous bone graft is contained within the joint space

STUDY DURATION:

Twenty-four month follow-up post-surgery

KEY INCLUSION CRITERIA:

• at least 18 years old and considered skeletally mature

• diagnosed with degenerative joint disease (DJD) affecting the hindfoot due to a congenital or acquired deformity, osteoarthritis, rheumatoid arthritis, post- traumatic arthritis or ankylosing spondylitis of the ankle, subtalar, calcaneocuboid, and/or talonavicular joints

• requires one of the following hindfoot fusion proceduress with supplemental bone graft/substitute: ankle fusion (tibiotalar), subtalar fusion (talocalcaneal), calcaneocuboid fusion, talonavicular fusion, triple arthrodesis (subtalar, talonavicular and calcaneocuboid joints) OR double fusions (any combination of any two of the following: subtalar, talonavicular and calcaneocuboid joints)

• fusion site able to be rigidly stabilized with no more than 3 screws across the fusion site

  • supplemental pins or staples allowed
  • supplemental screws external to the fusion site(s) allowed

• signed informed consent document, independent, ambulatory, and can comply with all post-operative evaluations and visits

KEY EXCLUSION CRITERIA:

• undergone previous fusion surgery at the proposed location, i.e., revision of a failed fusion

• more than one previous procedure at the involved joints

• retained hardware spanning the joint(s) intended for fusion

• procedure anticipated to require plate fixation (including claw plates), IM nails or more than 3 screws to achieve rigid fixation based on pre-op planning

• procedure expected to require more than 9cc of graft material based on pre-op planning

• procedure expected to require structural bone graft, allograft, bone graft substitute, platelet rich plasma (PRP) or bone marrow aspirate

• procedure expected to require a pantalar fusion, i.e., fusion of ankle plus all hindfoot joints (talonavicular, subtalar, and calcaneocuboid) or an ankle fusion in combination with any hindfoot fusion

• radiographic evidence of bone cysts, segmental defects or growth plate fracture near the fusion site that could negatively impact the proposed fusion procedure

• tested positive or been treated for a malignancy in the past or is suspected of having a malignancy or currently undergoing radio- or chemotherapy treatment for a malignancy anywhere in the body, whether adjacent to or distant from the proposed surgical site

• pre-existing sensory impairment, e.g., diabetics with baseline sensory impairment, which limits ability to perform objective functional measurements and may be at risk for complications

  - diabetics not sensitive to the 5.07 monofilament (Semmes-Weinstein) are to be excluded

• metabolic disorder known to adversely affect the skeleton other than primary osteoporosis or diabetes, e.g., renal osteodystrophy or hypercalcemia

• use of chronic medications known to affect the skeleton, e.g., glucocorticoid usage > 10mg/day

• pre-fracture neuromuscular or musculoskeletal deficiency which limits the ability to perform objective functional measurements

• physically or mentally compromised, e.g., current treatment for a psychiatric disorder, senile dementia, Alzheimer's disease, etc., to the extent that the Investigator judges the subject to be unable or unlikely to remain compliant

• allergic to yeast-derived products or bovine collagen or other bovine-sourced products

• received an investigational therapy within 30 days of proposed surgery or during the follow-up phase of the study

• is a prisoner, known or suspected transient or a history of drug/alcohol abuse within the 12 months prior to screening

• pregnant or intending to become pregnant within 12 months of the study procedure

• morbidly obese defined as BMI > 45 kg/m2

• currently has an acute infection at the surgical site