Stress fractures are often missed, especially in unusual clinical settings. We report on 2 patients who presented to our orthopedic surgery clinic with incidental findings of asymptomatic proximal fibular tension side stress fractures in severe longstanding varus osteoarthritic knees. Initial plain films demonstrated an expansile deformity of the proximal fibular shaft, and differential diagnosis included a healed or healing fracture versus possible neoplasm. Magnetic resonance imaging with and without gadolinium was utilized to rule out the latter prior to planned total knee arthroplasty.