In most cases simple falling onto the extended arm results in a fracture of the humeral head associated with rupturing of the anterior or posterior shoulder joint capsule depending on the direction of dislocation. As already described in Chap. 1 over 90 % of proximal humeral fractures occur in patients with age >60 years.

Especially in this elderly population even low impact trauma can result in multi part fractures along with fracture dislocation due to general disorders such as osteoporosis, diabetes mellitus, or neoplasia compromising bone mineral density and quality respectively. Another factor considered as predisposition of multi part and even fracture dislocation are degenerative changes of the rotator cuff tendons as well as atrophy of the shoulder girdle muscles.

Fracture dislocation of the proximal humerus can also evolve from epileptic seizures, in up to 60 % following posterior luxation of the shoulder joint presenting a characteristic impression among the humeral bearing area and the minor tuberosity, which can be fractured or dislocated [11].

After initial clinical examination of the patient including an exact documentation of nerval and pulse status, radiographs in at least two planes (true a-p, axillary view) should be performed. In case of clinically suspected vascular lesions a CT scan including CT angiography administering iv iodinated contrast agent of the shoulder should be performed to detect bony as well as vascular pathologies. If furthermore nerval lesions are suspected even additional imaging in terms of e.g. magnetic resonance imaging might be considered. In any case of suspected nerval injury an electrophysiologic exam is to be performed to assess nerval lesions accurately.

The incidence of collateral nerve lesions reaches from 30 to 40 % in fracture dislocation of the humeral head [9]. In particular, most commonly the axillary nerve is affected, in rather rare cases the suprascapularis nerve, the musculocutaneus nerve and the radial nerve as well.

Depending on the two different pathophysiological types of fracture dislocation, the position and displacement of the humeral head in refer to the humeral stem is of particular importance regarding prognosis and outcome.

In general any dislocation of the shoulder joint should immediately be reduced. In case of a gleno-humeral dislocation also if associated with a fracture of the greater tuberosity closed reduction presents usually the adequate type of initial treatment followed by X-ray or CT in order to verify the reduction’s result as well as to complete the diagnostics regarding adequate fracture classification. Dislocated fractures of the greater tuberosity present shearing fractures of the supraspinatus as well as of the infraspinatus muscle tendon and displace corresponding to the traction direction of the inserting muscle in cranial and dorsal direction resulting in an abduction and external rotation blockade. In patients older than 60 years about 30 % of all traumatic shoulder dislocations are associated with fractures or infraction of the greater tuberosity [10]. Regarding treatment already shearing fractures of the supraspinatus muscle tendon with a dislocation of less than 5 mm should be treated surgically since the fragments lying on the top of the cartilage of the humeral calotte will not consolidate and thus can result in a loss of function of the supraspinatus muscle [12]. However, in case of younger patients already a dislocation distance of 3 mm should be considered as indication for surgical refixation. In conclusion typical indications for surgery are greater tuberosity fractures with a dislocation >3 mm as well as shearing fractures of the supra- and infraspinatus muscle tendons. Most commonly these fractures are treated by osteosynthesis using 2 screws with the option of additionally using cerclages in case of osteoporotic bone in older patients and presence of several fragments. According to Resch percutaneous transfixation using two cannulated small fragment screws can be performed as well after reduction of the fragments.

In dislocation fractures associated with subcapital fractures and isolated fragments of the calotte close reduction is not possible. In these cases the so-called “head-fragment” needs to be repositioned out of an anterior luxation pouch by surgery in term of open reduction.