Periprosthetic Humeral Fractures in Shoulder Arthroplasty

» The reported combined rates of intraoperative and postoperative periprosthetic humeral fractures range widely, from 1.2% to 19.4%.» The risk factors for an intraoperative humeral fracture and literature-reported strength of association include a press-fit humeral component (relative risk [RR], 2.9), revision arthroplasty (RR, 2.8), history of instability (odds ratio [OR], 2.65), female sex (OR, 4.19), and posttraumatic arthritis (RR, 1.9). The risk factors for a postoperative humeral fracture include osteonecrosis and increased medical comorbidity index (OR, 1.27).» Intraoperative fractures, in order of decreasing frequency, most often occur during implant removal in cases of revision arthroplasty (up to 81%), during reaming or broaching of the humerus (up to 31%), during trial or implant insertion (up to 18% to 19%), or because of excessive humeral torque or forceful retractor placement during exposure or reduction (up to 13% to 15%). Postoperative fractures typically occur from a fall onto the outstretched extremity or through an area of osteolysis.» The treatment of intraoperative or postoperative fractures is based on fracture location, prosthesis type and stability, rotator cuff status, and available bone stock.» Nonoperative treatment for periprosthetic humeral fractures appears to have high failure rates. When treating a periprosthetic humeral fracture operatively, surgical techniques for tuberosity fractures include suture repair, cerclage wiring, or revision to reverse components. For humeral shaft fractures, techniques include revision to a long-stem component, cerclage wiring, plate-and-screw fixation, and use of a strut allograft. For extensive humeral bone loss, techniques include component-allograft composites or humeral endoprostheses. All techniques have the goals of permitting early range of motion and preserving function.