The Case Files: Foreign Body in Hoffa's Fat Pad

By Osgood, James Gale MD, MBA; Robison, Matthew MD; Siethel, Michelle PA   A 19-year-old woman presents with right knee pain and a laceration after a fall. She states that she was drinking alcohol at a local bar, and fell and cut her knee on broken glass on the bathroom floor. She denies loss of consciousness or other injuries. The patient is able to bear weight, but has increased pain when moving her knee. She denied distal numbness or weakness. The patient also denied other medical problems, and her last tetanus was four years earlier.   Physical exam revealed a stable knee with several lacerations and abrasions with mild tenderness to palpation only near the laceration sites. ROM was mildly limited by pain. The sensation to the distal extremity was intact to light touch, and dorsalis pedis and posterior tibial pulses were 2+. X-rays of the knee were obtained. What is your diagnosis?   The x-ray demonstrates normal bony alignment without cortical disruption. A radiopaque foreign body was seen in Hoffa's fat pad, or the infrapatellar fat pad of the knee joint, which physically separates the antero-inferior synovial membrane of the knee from the patella. It is intraarticular but extrasynovial. Functionally, the infrapatellar fat pad may provide some cushioning to the articulating surfaces of the knee, but it also helps distribute synovial fluid during knee movement.   Orthopedics was consulted given the intraarticular position of the foreign body and a concern for possib...
Source: The Case Files - Category: Emergency Medicine Tags: Blog Posts Source Type: research