Incomplete Periprosthetic Atypical Femoral Fracture With Concomitant Hip and Knee Arthroplasties: A Case Report.

The incomplete PAFF was contributed by both decreased bone turnover from bisphosphonate use and increased mechanical stress at the lateral femoral cortex. Her previous left bipolar hemiarthroplasty and subsequent Total Knee Arthroplasty shifted the mechanical alignment medially, hence increasing tensile stress.