Periprosthetic humeral fractures: management and classification.

Six patients (67 to 94 years of age) sustained a periprosthetic humeral fracture at an average of 43 months after shoulder arthroplasty (range 13 to 85 months). These fractures were classified depending on fracture anatomy and implant stability. Type A fractures occur about the tuberosities. Type B fractures occur about the stem and are subclassified by fracture anatomy and implant stability: B1 fractures are spiral fractures with a stable implant, B2 fractures are transverse or short oblique fractures about the tip of the stem with a stable implant, and B3 fractures are those fractures about the stem with an unstable implant. Type C fractures occur well distal to the tip of the stem. Five of the 6 fractures required surgery, 4 with revision to a long-stemmed component. All fractures united with restoration of range of motion and function. Satisfactory results may be anticipated if these fractures are managed in an appropriate fashion.