PERIPROSTHETIC FRACTURES AFTER JOINT REPLACEMENT: A UNIFIED CLASSIFICATION SYSTEM

Periprosthetic fracture associated with joint replacement is a common reason for revision arthroplasty and is increasing. Establishing universal principles of management is essential for good outcomes and a classification system that not only classifies, but offers these principles, is critical to achieve this. The Vancouver Classification System (VCS) for periprosthetic fractures involving total hip arthroplasty is validated across North America and Europe. It does not, however, consider other periprosthetic fractures in different joints. The Unified Classification System (UCS) was developed to incorporate the classification and treatment principles of all periprosthetic fractures in any anatomic location. The system is based on the simple mnemonic “ABCDEF” which corresponds to fractures characterized by the following anatomic descriptors: 1) apophyseal; 2) bed of the implant; 3) clear of the implant; 4) dividing the bone between two arthroplasties; 5) each of two bones supporting one arthroplasty; 6) facing and articulating with an implant. Initial validation for the UCS shows substantial and near-perfect inter and intra-observer agreement. Given this performance, it has the potential to evolve into the gold standard classification system for periprosthetic fractures in any joint that they occur.