Biomechanical and clinical evaluation of the expandable intramedullary fixation device.

The use of an expandable intramedullary device for internal fixation of metacarpal or phalangeal bones is described. The device is applicable to transverse fractures, short oblique fractures, or transverse osteotomies. The device consists of a cylindrical apparatus made of titanium that allows collapse in the circumferential diameter. It is introduced into the medullary canal in its collapsed state, and on release expands to its normal diameter in the canal with the fracture reduced over it. A biomechanical evaluation compared the stability of this device with other commonly employed fixation methods. A retrospective review is presented of the first 43 patients in whom the device was implanted.