The Stability of Percutaneous Fixation of Proximal Humeral Fractures

Abstract

The treatment of an unstable proximal humeral fracture is challenging. Although the majority of proximal humeral fractures can be treated successfully with nonoperative treatment, some fractures require operative treatment to achieve outcomes that meet the patient’s expectations. Several techniques and devices have been employed to treat unstable proximal humeral fractures, including the locking plate1,2, intramedullary locking nails3, Kirschner wires4, and screw fixation5. The proximal humeral locking plate has been shown to achieve relatively rigid fracture fixation6,7. However, after the initial enthusiasm for locking plates, several authors recently have raised concerns about these implants8,9. Less-invasive techniques, such as Kirschner wire fixation, may provide adequate stability and require a less-invasive second operation for implant removal. However, this advantage must be balanced with the inferior biomechanical properties of Kirschner wires, with risks that include wire migration and loss of fracture reduction10-12. New fracture-fixation devices have been introduced to minimize the disadvantages of Kirschner wires13, with the goal of redistributing the loads on the wires and transmitting the loads from the insufficient subchondral cancellous bone to the lateral cortex of the proximal part of the humerus. However, the biomechanical properties of these devices recently have been shown to be inferior to locking plates14. The reasons for these differences could be related to several variables, including the Kirschner wire dimensions, the length of the threaded portion of the Kirschner wire, the pin configuration used in the humeral head (including the positioning, spacing, orientation, and number of pins), the system for cortical fixation, or a combination of all of these factors. In 2005, a new device was developed to augment percutaneous wire fixation both by using an external fixator to …