Fractures of the lesser tuberosity of the humerus.

Background: Fractures of the lesser tuberosity are rare injuries, and little is known of their epidemiology. Operative treatment is generally recommended for displaced fractures; however, the outcome of this method of treatment has not previously been studied. The aims of our study were to determine the approximate incidence of lesser tuberosity fractures, as well as the functional outcome following operative treatment in a consecutive series of patients.

Methods: Over an eight-year period, we studied the demographic details of a consecutive series of twenty-two adult patients who had a fracture of the lesser tuberosity. We used age and sex-specific local census data to estimate the annual incidence of this injury in our local population. Seventeen of the original cohort of twenty-two patients, who were medically fit and had a displaced (two-part) fracture, were treated with open reduction and internal fixation of the fracture. We assessed the outcome using the Short Form-36 (SF-36) general health measure, the Constant score, and the Disabilities of the Arm, Shoulder and Hand (DASH) score.

Results: The estimated annual incidence of these fractures was low at 0.46 per 100,000 population per year during the study period. There were fifteen men and seven women, with a median age of forty-three years. There was an even distribution of fractures across the age cohorts, and most fractures were sustained from a high-energy transfer mechanism. The median Constant score was 95 points at two years, and the median DASH score was 12 points at two years after the injury. Most patients regained nearly normal range of motion in the affected shoulder by three months. One patient had development of posttraumatic shoulder stiffness, which responded to arthroscopic release. All patients who were in regular employment prior to the injury returned to their jobs within six months. There were no significant differences between each component of the SF-36 at two years compared with age and sex-matched controls.

Conclusions: A lesser tuberosity fracture, without an associated humeral head or greater tuberosity fracture, is a rare injury. Open reduction and internal fixation provides excellent restoration of function and range of shoulder movement, with a low risk of complications.