Suggest Treatment For Persistent Tenderness In The Right Knee And Groin Area Post Injury

A patient complains of persistent tenderness in the right knee and groin area. The tenderness started a few weeks after he injured the big toe of his right foot, which became red, swollen, warm, and painful. He says the toe improved without medical attention. The knee and groin tenderness remain. What could the physician identify as the cause of the patient’s knee and groin pain? What is a possible treatment?