This study intends to determine the best surgical treatment for humeral shaft fractures. One third of the patients will be treated with open reduction and internal fixation with plate; one third, with bridge plate technique and the remaining third with locked intramedullary nail.

Humerus diaphyseal fractures are amongst the most common of the appendicular skeleton. Despite the fact that the conservative treatment is still the gold standard for the majority of these fractures, this method was not proven to be superior when compared to the surgical treatment. Surgical options for the treatment of humeral shaft fractures range from open reduction and internal fixation with plate to minimally invasive methods (bridge plate and intramedullary nail) and the best method has yet to be determined. The goal of this study is to determine the best surgical option for the treatment of humeral shaft fractures. For this, will be recruited 105 patients with humeral shaft fractures, wich will be allocated, randomly, in 3 distinct groups. Each patient will be submitted to one of three possible methods of humerus osteosynthesis: open reduction and internal fixation with plate (ORIF), closed reduction and fixation with bridge plate or closed reduction and fixation with intramedullary nail. All data will be paired according to the age, gender, fracture classification, patient comorbidities and smoking habit. The Pearson's chi-square" test will be used to analyze the results of the three groups regarding categorical variables, and Student t-test (parametric) will be used to compare groups with respect to the numerical variables. The investigators expect to conclude that the methods of minimally invasive osteosynthesis of humeral shaft fractures have similar or better functional and radiographic outcomes, compared to the method of open reduction and internal fixation with a plate, with lesser risk of complications and an earlier return to activities.

Inclusion Criteria:

• Complete fracture with angulation greater than 20 degrees, rotation greater than 30 degrees and/or shortening greater than 3 cm.
• Fractures located from 4 cm distal to the surgical neck to 2 cm proximal to the end of the medullary canal.

Exclusion Criteria:

• fractures older than 3 weeks
• pathologic fractures
• fractures with extension to elbow or shoulder joint
• patients with ipsilateral upper extremity fracture or injury
• fractures with associated neurologic injury
• patients with previous pathology of the shoulder, arm or elbow that cause pain or range of motion limitation
• patients who do not agree with the terms of the study