Study To Assess FRacTure Healing with SclerosTin Antibody - HipSTARTT-Hip

- Males and females, age 55 to 95 years - fresh unilateral low energy intertrochanteric or femoral neck fracture as the primary injury, confirmed by X-ray and in the opinion of the treating surgeon amenable to repair by internal fixation - internal fixation of the fracture with devices approved by local regulatory agency, performed no later than 7 days after injury for intertrochanteric or undisplaced femoral neck fractures and no later than 2 days after injury for displaced femoral neck fractures -- intertrochanteric fracture: sliding hip screw or IM nail -- femoral neck fracture: sliding hip screw or at least 3 cancellous screws

- severe symptomatic osteoarthritis of the lower extremity - inability to independently rise from armchair or walk 200 meters before hip fracture - presence of concomitant injuries such as rib fractures, wrist fractures, or acute symptomatic vertebral fractures which severely impair the ability to rise from a chair - associated extremity injuries including ipsilateral or contralateral fractures of the foot, tibia or fibula, wrist, humerus, femoral shaft, femoral head or hip dislocation, that may delay weight-bearing beyond one week after surgery - head-injury, as defined by Glasgow Coma Scale < 13 prior to randomization - use of bone grafts or bone substitutes at the time of fracture fixation - major polytrauma or significant axial trauma, with Injury Severity Score > 16 - pathological fracture or history of metabolic or bone disease (except osteoporosis) that may interfere with the interpretation of the results, such as Paget’s disease, rheumatoid arthritis, osteomalacia, osteopetrosis, ankylosing spondylitis, Cushing’s disease, hyperprolactinemia - history of symptomatic spinal stenosis that has not been surgically corrected. If surgically corrected, the subject must be asymptomatic to be eligible for the study. - history of facial nerve paralysis - malignancy (except fully resected cutaneous basal cell or squamous cell carcinoma, cervical carcinoma in situ) within the last 5 years - history of solid organ or bone marrow transplants - evidence of elevated transaminases (≥ 2.0 x upper limits of normal) or significantly impaired renal function (creatinine clearance of ≤ 30 mL/min) - evidence of current hypercalcemia or hypocalcemia (outside of 1.1 x the normal range) - bone morphogenic proteins (BMP)-2 or BMP-7 at the time of definitive fracture fixation