X-Ray Goes Knee Deep

 

 

 

An 80-year-old woman complaining of head and right knee pain is brought to your emergency department following a motor vehicle collision. The patient was an unrestrained driver when she possibly hydroplaned and then struck another vehicle. Her medical history is significant for mild hypertension. Surgical history is significant for remote arthroplasty of her right knee. On primary survey, you note an elderly female who is slightly hard of hearing but awake, alert, and oriented. Vital signs are stable. Examination of her right knee shows a healed scar with some mild bruising and no obvious deformity. The patient has reduced range of motion, and palpation of the knee is extremely painful. You obtain a radiograph of the right knee (shown). What is your impression?