What is a Proximal Humerus Fracture?The humerus is the upper arm bone and it forms two joints —shoulder joint and elbow joint. The proximal humerus is the upper end of the arm bone that forms the shoulder joint. Fractures of the proximal humerus are common in elderly individuals suffering from osteoporosis.
Causes of Proximal Humerus FracturesProximal humerus fractures are caused by traumatic injuries such as a fall on an outstretched hand from a height or motor vehicle accidents. In younger individuals, a severe trauma can cause these fractures.
Types of Proximal Humerus FracturesProximal humerus fractures can be categorized into 4 groups:
- Greater tuberosity fractures: Greater tuberosity is the insertion site for attachment of rotator cuff tendons. Greater tuberosity fractures are less common and are seen in cases of shoulder dislocations and in those with osteoporosis. Greater tuberosity fragment is pulled off when the cuff muscle contracts or the anterior shoulder dislocates. Direct impact to the shoulder causes the tuberosity bone to break into multiple fragments. Partial rotator cuff tears often accompany non-displaced fractures and these fractures can be diagnosed using MRI or diagnostic arthroscopy.
- Lesser tuberosity fractures: These fractures are often caused by posterior shoulder dislocations or traumatic muscle contractions by electrical shock or convulsions. If left untreated, these fractures cause subscapularis muscle (stabilizer and mobilizer muscle) deficiency and require a major muscle transfer procedure.
- Surgical neck fractures: Fractures of the surgical neck are most common in patients with osteoporotic bone. These fractures also damage the axillary nerve that carries sensory information from the shoulder.
- Humeral head fractures: Humeral head fractures very often occur in elderly individuals and chances are more in those with osteoporotic bone. These fractures occur in younger individuals by significant trauma, whereas a mild traumatic injury can cause fracture in elderly individuals with osteoporosis.