Assessment of the restriction of arm elevation after intramedullary fixation for proximal humeral fractures.

Background: Nail protrusion is suspected as a reason for the restriction of arm elevation after antegrade nailing of proximal humeral fractures, although assessment of the restriction of the glenohumeral joint during arm elevation has been insufficient.

Methods: In this retrospective study, 30 shoulders with proximal humeral fractures in 29 cases were treated with Polarus short nails (Acumed, Beaverton, OR, USA). At a mean final follow-up of 14 months, clinical outcomes, bony union, alignment including retroversion of the head and entry points of the nails were evaluated. The ability of a subject to achieve maximum elevation above the zero position was also evaluated.

Results: Constant and Japanese Shoulder Association scores were a mean (SD) of 54 (12) and 71 (8.9) points, respectively. Even though all cases achieved bony union without mal-alignment of the head and greater tuberosity height or protrusion of the nail at its entry point, only six subjects could achieve maximum elevation above the zero position.

Conclusions: Based on these findings, treatment of proximal humeral fractures with an antegrade humeral nail inserted from the top of the humeral head results in restricted arm elevation, even in patients without nail protrusion or fragment malalignment.