Summary

Proximal humerus fractures are a common type of fracture often seen in older patients with osteoporotic bones. These fractures are usually caused by low-energy falls. Diagnosis is made with orthogonal radiographs of the shoulder. Treatment with sling immobilization is indicated for minimally displaced fractures with surgical fixation versus arthroplasty indicated in more complex and displaced fractures.

Epidemiology

Proximal humerus fractures are a common type of fracture, accounting for 4-6% of all fractures. They are the third most common non-vertebral fracture pattern seen in the elderly (>65 years old), and two-part surgical neck fractures are the most common. They occur more frequently in females (2:1 ratio) and increasing age is associated with more complex fracture types.

Etiology

Proximal humerus fractures are often caused by low-energy falls in elderly patients with osteoporotic bone, or high-energy trauma in young individuals. Concomitant soft tissue and neurovascular injuries may also occur. The vascularity of the articular segment is more likely to be preserved if ≥ 8mm of calcar is attached to the articular segment. Predictors of humeral head ischemia include disrupted medial hinge, increasing fracture complexity, displacement >10mm and angulation >45°. However, predictors of humeral head ischemia do not necessarily predict subsequent avascular necrosis. Risk factors include osteoporosis, diabetes, epilepsy, and female gender.

Anatomy

The proximal humerus is comprised of several important structures, including the anatomic neck, surgical neck, greater and lesser tuberosities, and articular surface. The pectoralis major muscle displaces the shaft anteriorly and medially, while the supraspinatus, infraspinatus, and teres minor externally rotate the greater tuberosity, and the subscapularis internally rotates the articular segment or lesser tuberosity. The coracohumeral ligament attaches to the coracoid and greater tuberosity, while the SGHL, MGHL, and IGHL are important restraints that provide stability to the joint. The anterior humeral circumflex artery and the posterior humeral circumflex artery are the main blood supply to the area.

Epidemiology

Proximal humerus fractures are a common type of fracture, accounting for 4-6% of all fractures. They are the third most common non-vertebral fracture pattern seen in the elderly (>65 years old), and two-part surgical neck fractures are the most common. They occur more frequently in females (2:1 ratio) and increasing age is associated with more complex fracture types.

Diagnosis

Diagnosis is typically made with orthogonal radiographs of the shoulder. Other imaging modalities, such as CT and MRI scans, may be useful in identifying comminution or concomitant rotator cuff injury, but are not necessary for diagnosis. A complete trauma series is recommended, including AP (Grashey), scapular Y, and axillary views. Findings include combined cortical thickness, pseudosubluxation, and a larger coracohumeral interval. Classification of proximal humerus fractures is based on fracture location, status of the surgical neck, and presence/absence of dislocation.

Treatment

Treatment options for proximal humerus fractures include nonoperative approaches, such as sling immobilization followed by progressive rehabilitation, and operative approaches, such as percutaneous pinning, open reduction internal fixation (ORIF), hemiarthroplasty, and reverse total shoulder arthroplasty (RTSA). The choice of treatment depends on several factors including age, fracture type, fracture displacement, bone quality, dominance, general medical condition, and concurrent injuries. Complications include screw cut-out, avascular necrosis, nerve injury, malunion, nonunion, adhesive capsulitis, posttraumatic arthritis, and infection.