Proximal humeral fractures treated conservatively settle during fracture healing.

OBJECTIVES

Determine the relative position of the main fractured fragments of proximal humerus fractures treated conservatively to compare displacement at 2 time points: injury (0), and 1 year later (1).

DESIGN

Prospective, comparative cohort study.

SETTING

Level I trauma center.

PATIENTS

Eighty-nine prospectively enrolled adults.

INTERVENTION

Six weeks of sling immobilization and a home-based program rehabilitation protocol started 2 weeks after injury.

MAIN OUTCOME MEASUREMENTS

Standardized radiographs of injured shoulders were obtained in all patients at times 0 and 1. Computed tomography scans were also obtained at these times in 73 cases. Forty-two computer-assisted measurements of displacement were performed at times 0 and 1 and then compared. Factors related to progression of displacement were analyzed.

RESULTS

Ninety percent of fractures were classified into 1 of 4 patterns: posteromedial (varus) impaction (46), lateral (valgus) impaction (13), isolated greater tuberosity (15), and anteromedial impaction (6). Head-shaft displacement increased over time. In posteromedial impaction fractures, average fracture settling included 9 degrees in varus, 7 degrees in retroversion, and 3.2 mm in posterior shortening. In valgus-impacted fractures, a decrease in valgus tilt and a tendency toward a more anterior orientation of the articular surface was observed. Greater tuberosity displacement increased more than 5 mm in less than 20% of cases. Age and initial displacement were related to progression of displacement.

CONCLUSIONS

Proximal humerus fractures treated conservatively settle at the head-shaft junction during healing. Substantial additional displacement of tuberosities was seldom observed.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.