Purpose: Currently, there is little information available on the management and outcome of intra-operative periprosthetic humeral fractures during shoulder arthroplasty. The purpose of this study was to report on the incidence, management, and outcome of intra-operative periprosthetic humeral fractures.

Method: Between 1980 and 2002, forty-six intra-operative periprosthetic humeral fractures occurred during shoulder arthroplasty at our institution. Thirty-six fractures occurred during primary total shoulder arthroplasty, five during primary hemiarthroplasty and four during revision shoulder arthroplasty. Twenty-one fractures involved the greater tuberosity, 16 the humeral shaft, 6 were metaphyseal and 2 fractures involved the greater tuberosity and extended to the humeral shaft. All patients were followed for a minimum of two years (mean, 7.5 years). At final follow-up, the Simple Shoulder Test (SST) and ASES scores were calculated and preoperative, postoperative, and most recent radiographs were examined for fracture healing and implant integrity.

Results: The incidence of intra-operative humerus fractures at our institution was 1.5%. All fractures healed at mean of 13 weeks (range, 6 to 56 weeks). At a mean final follow-up of 90 months (range, 25 to 194 months), the mean forward elevation was 108° and the mean external rotation was 39°. The mean SST was 6 and the mean ASES score was 61. Four patients underwent revision shoulder surgery, two for shoulder instability, one for a massive rotator cuff tear, and one for another periprosthetic humerus fracture that occurred after a fall. Complications included transient nerve injuries in six patients and four fractures displaced postoperatively which were then managed nonoperatively to healing.

Conclusion: The data from this study suggest that although intra-operative fractures have a high rate of healing, there was a significant rate of associated complications including transient nerve injuries and fracture displacement. Patients with intra-operative fractures also appear to have less forward elevation at final follow-up when compared to patients who have not sustained an intra-operative humeral fracture.