Treatment of proximal humeral fractures - a review of current concepts enlightened by basic principles.

Fractures of the proximal humerus commonly affect elderly patients. The vast majority of proximal humeral fractures result from low-energy trauma in presence of osteoporosis. Incidence of proximal humeral fractures dramatically increased over the last decades. Recent epidemiological studies expect a rather stagnant incidence. Diversity of fracture types attenuates reliability of available classification systems. Even though, predictive morphologic criteria have been detected enabling a prognostic assessment. A short or absent metaphyseal head extension and disruption of the medial periosteal hinge reliably predict ischemia of the humeral head fragment. Still, humeral head necrosis may be prevented in early reduction and fixation. The range of treatment options consists of non-operative therapy, minimal-invasive osteosynthesis, open reduction and plate fixation, intramedullary nailing and primary arthroplasty. Most proximal humeral fractures in the elderly are stable injuries and can be successfully treated by non-operative means. Operative treatment of displaced, unstable fractures should resort to the least invasive procedure providing adequate reduction and fixation stability. To date, open reduction and locking plate osteosynthesis represents the standard operative procedure in displaced three- and four-part fractures. However, a number of risk factors may promote fixation failure or impair functional outcome, most important low local bone mineral density, residual varus displacement of the humeral head, insufficient restoration of medial calcar support, humeral head ischemia and insufficient fracture reduction. Innovation of fixation techniques (e. g. angular stable locking systems and bone augmentation) will further expand indications for operative fracture treatment. Outcome of hemiarthroplasty is closely related to anatomical tuberosity healing and restoration of rotator cuff function. Reverse shoulder arthroplasty may provide satisfactory shoulder function in geriatric patients, rotator cuff dysfunction or failure of first-line treatment. Choice of treatment should be individualized and base on careful evaluation of patient-specific, fracture-specific and surgeon-specific aspects.