Inclusion Criteria:  1) Motor complete or incomplete SCI C4 and below {upper motor lesions; AIS grade A-C (wheelchair dependent greater than 75% of the time 2) Duration of SCI between 3-15 years; 3) Males and females (premenopausal) between the ages of 18 and 50 years old (the upper age limit is to reduce the influence of age on the ability of the skeleton to respond to pharmacologic stimulation); 4) aBMD at the distal femur greater than or equal to 0.6 g/cm2 but less than or equal to 1.0 g/cm2; 5) Agreement to use a highly effective contraceptive method for women of reproductive potential.  Exclusion Criteria:  1) Active and/or history of coronary heart disease or stroke; 2) Bone cancer; 3) Long-bone fracture of the leg within the past year; 4) History of prior bone disease [for example Paget's hyperparathyroidism (overproduction of a steroid hormone known as the parathyroid hormone), osteoporosis, etc.]; 5) Postmenopausal women; 6) Men with known low functioning testes before SCI; 7) Medication designed to increase bone density longer than six months after duration of SCI; 8) As determined by study staff review of my medication, glucocorticoid (anti-inflammatory medications) administration longer than three months duration within the last year; 9) Endocrinopathies such as the following: hyperthyroidism (overproduction of a hormone known as thyroxine by the thyroid gland in the neck), Cushing's disease or syndrome (excess production of the steroid hormone cortisol), etc.; 10) Severe underlying chronic disease [for example chronic obstructive pulmonary (lung) disease (COPD, end-stage heart disease, chronic renal (kidney) failure]; 11) Heterotopic ossification (HO- an abnormal growth of bone that can occur after SCI) at the distal femur (the distal femur is the primary outcome variable; HO to any other boney region will not prevent study participation); 12) As determined by study staff review of my medication, prescribed a bisphosphonate for heterotopic ossification (HO), or prescribed any other agent to treat osteoporosis other than calcium and vitamin D; 13) History of chronic alcohol abuse; 14) Diagnosis of hypercalcemia (excess calcium levels in the blood); 15) Diagnosis of hypocalcemia (low calcium levels in the blood). If corrected, subject may still be eligible for study participation); 16) Pregnancy, or plans to become pregnant within 6 months after the end of study treatment; 17) Lactation; 18) Current diagnosis of cancer or history of cancer within the last 5 years; 19) As determined by study staff review of my medication, prescribed moderate or high dose corticosteroids (>40 mg/d prednisone or an equivalent dose of other corticosteroid medication) for longer than one week, not including drug administered to preserve neurological function at the time of acute SCI; 20) As determined by study staff review of my medical records, life expectancy less than 5 years; 21) History of hypersensitivity reaction (including allergic reaction, facial swelling and hives) to any Prolia (denosumab) or Evenity (romosozumab) component; 22) Currently experiencing a weakened immune system or infection; 23) Recent fracture or extensive bone trauma; 24) Osteonecrosis of the jaw (ONJ- deterioration of the jaw bone) or risk for ONJ, such as invasive dental procedures (including tooth extraction, dental implants, oral surgery in the past 6 months), poor oral hygiene, periodontal and/or pre-existing dental disease; 25) Planned invasive dental procedure over the next two years.