AMPLEX Ankle Fusion and Hindfoot

To demonstrate that AMPLEX is non-inferior to autogenous bone graft (ABG) for bone fusion in a population indicated for single, double, or triple hindfoot arthrodesis or ankle arthrodesis surgery with supplemental graft material.


Eligibility Criteria:
Inclusion Criteria:

* Signed written informed consent
* Indicated for ankle or hindfoot arthrodesis and require one of the following arthrodesis procedures:

Tibiotalar (ankle); Talocalcaneal (subtalar); Talonavicular; Calcaneocuboid; Double hindfoot (e.g., talonavicular and talocalcaneal joints); Triple hindfoot (subtalar, talonavicular and calcaneocuboid joints)

* Presents with pain on weight-bearing of at least 40 mm on a 100 mm VAS at the area indicated for arthrodesis
* Presents with at least one comorbid risk factors that warrant the use of supplemental autogenous bone or allograft:

Radiographic evidence of bone defect, deficit, subsidence or subchondral cyst; More than one joint to be fused; Involvement of other adjacent or nonadjacent joints; Large surface area; Intra-articular or extra-articular deformity; Post-traumatic arthritis; Diagnosis of osteoporosis

* The Investigator determines if the joint space(s) can be adequately filled with graft material (AMPLEX or ABG) according to the following parameters:

Single hindfoot joint fusion: up to 5 cm\^3; Double or triple hindfoot fusion: each individual joint up to 5 cm\^3, but overall, not more than 10 cm3 for the full complement of joints; Ankle fusion: up to 10 cm\^3

* Each fused joint can be rigidly stabilized with with at least 1 and no more than 3 screws across the fusion plane. (Supplemental pins and staples may be used, as well as supplemental screws and plates external to the fusion site(s))
* Willing and able to comply with all study requirements including all postoperative clinical and radiographic evaluations
* For women of childbearing potential (not post-menopausal for 12 months or surgically sterile), a urine pregnancy test with a negative result must be obtained at screening and within 24 hours prior to procedure. These trial participants must commit to adequate birth control (e.g., oral contraceptive, two methods of barrier birth control, or abstinence) through the 78 week follow-up

Exclusion Criteria:

* Bone deficit requiring a structural graft
* Charcot foot disease
* Radiographic evidence of open physes
* Prior arthroplasty, arthrodesis, major surgical repair or reconstruction of the index ankle or hindfoot joint(s)
* Requires osteotomy or fusion of the midfoot joints
* BMI greater than 45 kg/m\^2
* Documented medical history of, or radiographic evidence of, a bone disease (e.g. avascular necrosis) or other condition (e.g., osteolysis) that would preclude the subject from receiving screw fixation in the opinion of the surgeon
* Requires intramedullary nail fixation or an external fixator
* Comorbidity that would limit the ability to administer any functional measurements such as FAAM-ADL
* Has at the time of surgery, a systemic infection or local infection at the site of surgery
* Medical condition, serious intercurrent illness, or extenuating circumstance that, in the opinion of the Investigator, would preclude participation in the study or potentially decrease survival or interfere with ambulation or rehabilitation (e.g., history of transient ischemic attack, stroke or liver disease)
* HgbA1c level greater than or equal to 8%
* Known hypersensitivity to any of the components of the product \[e.g. B2A peptide, Hydroxyapatite (HA): beta-tricalcium phosphate (βTCP), ceramic granule\]
* Currently receiving treatment with a drug known to interfere with bone metabolism \[e.g., systemic corticosteroid therapy (topical corticosteroid therapy is permissible), methotrexate\]
* Has previously received treatment with a drug known to interfere with bone metabolism \[e.g., systemic corticosteroid therapy (topical corticosteroid therapy is permissible), methotrexate\] and in the opinion of the investigator could continue to negatively interfere with bone metabolism or bone healing
* History of any severe allergy or anaphylaxis, or a history of hypersensitivity to protein pharmaceuticals \[e.g., monoclonal antibodies or gamma globulins, recombinant Bone Morphogenetic Proteins (BMPs)\]
* Medical condition requiring radiation, chemotherapy or immunosuppression
* Have a prior or active history of malignancy (except for basal cell carcinoma of the skin)
* Has a history of autoimmune disease known to affect bone metabolism. Examples include spondyloarthropathies (e.g., ankylosing spondylitis, Crohn's disease, and ulcerative colitis), Juvenile Arthritis, Grave's disease and Hashimoto's thyroiditis; Rheumatoid Arthritis is allowed
* Have pathological or genetic liver disease or who have clinically significant, elevated baseline liver function enzymes
* Has obvious and/or documented alcohol or illicit drug addictions
* Is a prisoner in a correctional institution/facility
* Actively involved in litigation or workman's compensation
* Has participated in clinical studies evaluating investigational devices, pharmaceuticals or biologics within 6 months of randomization
* Requires chronic therapeutic use of NSAID during the first 6 post-operative weeks (except aspirin up to 325 mg bid for cardiovascular protection and/or DVT prophylaxis)
* Has previously been treated with, or exposed to, therapeutic levels of synthetic or recombinant BMPs
* Requires chronic subcutaneous or intravenous heparin therapies