Inclusion Criteria:  Skeletally mature, ages 18-70 (inclusive) Diagnosis of isolated closed extra-articular fractures of the humeral shaft deemed appropriate for closed treatment by immobilization and a sling by the treating physician Approached for consent within two weeks of injury Available for follow up at this treatment facility for at least six months  Exclusion Criteria:  Humeral shaft fractures that extend into the articular surface. Pathologic fractures. Additional long bone injuries or fractures of upper or lower extremity that would compromise outcome assessments of single fracture protein levels. Previous retained hardware in humerus from other injuries. Soft tissue injury compromising selected treatment method. Any injury that involved a trauma activation with entry of more than two AIS codes. Fractures with vascular injury. Pregnant women, potentially pregnant, or lactating women Immunocompromised based on the medical record and patient reported use of pharmacological medications that would lead to immunocompromise. (i.e., Anti-TNF therapies, or associated therapies for treatment of various rheumatological conditions.) Unable to comply with postoperative rehabilitation protocols or instructions (i.e., head injury or cognitively impaired). Known metabolic bone disease. Severe problems with maintaining follow-up (e.g., patients who are prisoners or homeless at the time of injury or who are intellectually challenged without adequate family support).