Periprosthetic fractures of the knee.

Periprosthetic fractures around total knee arthroplasty are an increasingly common and complex problem driven by rising arthroplasty volumes, aging populations, and longer implant survivorship. Successful management requires integration of trauma principles with arthroplasty-specific considerations, particularly implant stability, bone stock, and patient frailty. Implant stability and bone quality are the primary determinants of treatment strategy, outweighing fracture morphology alone. Classification systems are useful frameworks but must be interpreted in the context of component fixation and host factors. Fixation using locked plating, retrograde intramedullary nailing, or combined constructs is appropriate for stable implants with adequate bone stock and achieves high union rates, while preserving bone and future revision options, particularly important in younger or active patients. Revision arthroplasty with stemmed components, cones or sleeves, and appropriate constraint is indicated for loose components or compromised bone stock, offering durable reconstruction but with complication profiles similar to complex revision total knee arthroplasty. Distal femoral replacement serves as an effective salvage option for fractures that cannot be fixed or in frail, low-demand patients, enabling immediate weight-bearing but at the cost of higher complication and re-revision rates. Overall, outcomes depend not only on fracture union but also on restoration of alignment, extensor mechanism function, and early mobilization. High complication rates reflect the combined burden of fragility fracture biology and revision arthroplasty complexity, underscoring the need for individualized, patient-centered decision-making.