Review Question - QID 7477

A 47-year-old man reports a 12-week history of pain and swelling of his right hindfoot and ankle. Examination reveals a significant limp with swelling and tenderness over the distal Achilles tendon. He also has weak plantar flexion strength and squeezing of his calf produces only a small amount of ankle plantar flexion that is much less than his asymptomatic contralateral ankle. He reports suffering an Achilles tendon rupture some years ago that was treated in a cast. A radiograph obtained at that time is shown in Figure 89a. He was sent for physical therapy and did well except for a mild persistent limp. He then returned 1 year later with similar complaints and with a history of a fall 3 months earlier. A current radiograph and MRI scan are shown in Figures 89b and 89c. What is the most likely diagnosis?