Epidemiology and Classification of Tibial Periprosthetic Fractures Following Total Knee Arthroplasty

Tibial periprosthetic fractures (PPF) following total knee arthroplasty (TKA) are uncommon but clinically important complications with rising incidence parallel to the growing volume of arthroplasty procedures. Although the overall 10-year cumulative rate of PPF after primary TKA is approximately 1.7%, tibial fractures account for a small proportion yet are associated with substantial morbidity, reoperation, and infection risk. These injuries occur more frequently in revision TKA, females, and individuals who have osteoporosis or compromised bone stock. Additional risk factors include nonosteoarthritis indications, higher implant constraint, malalignment, and peri-implant bone loss. Mechanistically, most tibial PPFs result from low-energy trauma, stress insufficiency, and altered postoperative load distribution. Accurate classification is fundamental for management and prognosis. The Felix classification remains the most widely used system, integrating fracture location (Types I-IV) with implant stability (subtypes A-C). Fracture pattern reflects anatomical behavior, whereas component stability serves as the principal determinant of treatment strategy. Stable-implant fractures may be treated with fixation, whereas loose components generally require revision arthroplasty. Emerging decision frameworks, such as the Applied Step Algorithm for Periprosthetic Tibial Fractures, further incorporate bone stock and stability into structured treatment pathways. Understanding epidemiology, fracture patterns, and classification principles is essential to guide surgical planning and improve outcomes in this high-risk patient population.