Risk Factors for Distal Femoral Periprosthetic Fractures After Total Knee Arthroplasty: A Systematic Review of Patient and Implant Variables

INTRODUCTION: The number of total knee arthroplasty procedures performed continues to rise annually. As projections show a continued increase in these surgeries, it is important to identify patients at risk for certain complications. Distal femur periprosthetic fractures around total knee arthroplasty can pose significant morbidity on patients, while also imparting significant burden on the health system. This systematic review aims to identify the patients and implant characteristics that are at increased risk of distal femur periprosthetic fractures. METHODS: Three common literature databases were searched for "distal femur periprosthetic fracture". The resulting studies were screened for relevance, inclusion, and exclusion criteria. followed by an in depth review of various patient and implant characteristics. RESULTS: Thirteen studies were included in this systematic review. Despite some variation across the studies the most common population for distal femur periprosthetic fractures was females, over the age of 70, with an ASA of III. These most occurred in a low energy trauma or fall from standing. Additionally, when compared to native distal femur fractures there is evidence that periprosthetic fracture patients are older, have a higher BMI, more commonly osteopenic or osteoporotic, and less commonly sustaining these injuries as part of a polytrauma. CONCLUSION: As we continue to perform increasing numbers of total knee arthroplasty, identifying patients at risk for periprosthetic fractures aids in patient counseling and preventative care. This can allow for patients to optimize modifiable risk factors before and after undergoing total knee arthroplasty in an effort to avoid sustaining periprosthetic distal femur fractures.