Intertrochanteric Femur Fracture Patients Who Receive Metformin With a Placebo

Inclusion Criteria: * Age 60y and older. * Displaced hip fracture (femoral neck, intertrochanteric femur, subtrochanteric femur fracture). * Low energy mechanism of injury (ground level fall, etc). * Operative treatment within 72 hours of injury. * Previously ambulatory. Exclusion Criteria: * History of kidney disease or failure (CKD \> stage 4; eGFR \< 45 mL/min/1.73m2). * History of diabetes mellitus (HbA1c \> 6.5). * Associated lower extremity fracture (ipsilateral or contralateral). * Pathologic fracture. * Presence of infection at the fracture site. * History of metabolic bone disease (Pagets, etc.). * Severe cognitive impairment (Six Item Screener with 3 or more errors). * Stage 5 Parkinson's Disease. * Open fracture. * Risk of developing metformin-associated hypoglycemia (e.g., hepatic impairment (by history or screening laboratory assessment), presence of hypoglycemia at screening, history of adrenal or pituitary insufficiency, alcohol use disorder, subjects unable to maintain normal oral intake). * Severe hepatic impairment (Child-Pugh C). * Expected survival \< 6 months (based on clinical judgement).