Medial thigh abscess mimicking septic arthritis of the knee: a report of two cases.

Background: Septic arthritis of the knee joint requires prompt diagnosis and treatment for optimal outcomes. Pyomyositis with abscess formation is uncommon but may present with similar symptoms in the vicinity of a joint.

Objective: This report describes two cases of medial thigh abscess initially diagnosed and treated as septic arthritis, and highlights the need to make an accurate diagnosis.