The Kager's Fat Pad Sign

A 44-year-old man presented to the Emergency Department (ED) with severe pain in the right ankle. He stated that he had fallen on his right foot from stairs with three to four steps 1 h before he presented. He had no history of any medical illness nor any medications, and had no previous surgery or injuries to the affected ankle. The physical examination did not reveal any swelling or deformity on the dorsum of the foot or anterior of the ankle. Palpation revealed tenderness and swelling in the retrocalcaneal area. Palpable defect was not detected on examination. The Thompson test was negative. Radiographic imaging was performed to assess the patient's osseous and soft tissues. Lateral radiography of the ankle revealed obscured borders of Kager's fat pad (triangle) and distorted Achilles tendon trace (Figure 1). These findings were consistent with an Achilles tendon rupture, and Orthopedic Surgery was consulted. Surgery was recommended to the patient and the patient was admitted to the hospital. A short leg splint was placed on the patient's leg with the ankle in minimal plantar flexion. The next day the patient was treated surgically. The Achilles tendon was sutured end to end, according to the Kessler method. A below-knee plaster cast was used for 4 weeks. The patient then gradually started weight bearing with a crutch, and 8 weeks after the operation he was able to walk on his own.