Recurring Peri-Prosthetic Fracture of the Femur Ultimately Managed by Custom-Made Distal Femoral Mega-Prosthesis – A Case Report and Literature Review

Patients with peri-prosthetic fractures of the knee comprise a specific cohort demanding a specific set of orthopedic considerations. These fractures are difficult to manage, and essential orthopedic considerations must include patient factors such as age, co-morbid medical conditions, and overall bone quality. Further fracture considerations go beyond fracture displacement, and if present whether a reduction can be achieved, but must also specifically incorporate unique aspects such as prosthetic alignment, the degree of prosthetic fixation, whether there is a prosthetic stem, distal bone stock, and the extensor mechanism. For ease of understanding peri-prosthetic knee fractures are divided into femoral, tibial, and patellar sub-types, each of which has its own specific epidemiology, classification system, and set of well-defined surgical nuances. Of these three major types peri-prosthetic fractures of the femur are the most common surgical subtype encountered. We present a 65-year old male patient who presented to our unit with a neglected right-sided recurrent peri-prosthetic fracture of his femur, post having undergone multiple surgical interventions at another hospital. Our clinical assessment and X-ray investigation of his right knee revealed what we considered to be profound. With complete loss of distal femoral bone stock, gross malunion, and the complex mass of broken hardware noted, our only option was to remove the distal femur and prosthesis and replace these with a custom-made distal femoral mega-prosthesis. Our case report illustrates an extreme example of a peri-prosthetic fracture of the femur, and we compliment this with a review of the topic in general. It is hoped that our case report and review will assist orthopedic surgeons who perform total knee replacement surgery and will, at some point, need to manage this specific complication.