We encountered a patient with a soft tissue defect after forearm open fracture accompanied by distal radio-ulnar joint instability, in whom the wound was closed with a free groin flap and the postoperative course could be followed for 4 years. The patient was a 72-year-old female who fell, causing open fracture of the left forearm. An emergency operation was performed, but skin defects appeared. The second surgery ( re-osteosynthesis of the ulna, repair of the triangular fibrocartilage complex, and free groin flap ) was performed 14 days after the first surgery at our hospital. The flap was engrafted without problems and bone union was achieved. As of 4 years after surgery, it does not interfere with her daily life, and the flap has maintained a favorable condition. This case required functional evaluation of the wrist joint for a prolonged period because distal radio-ulnar joint instability was treated, which allowed us to follow-up the free groin flap for 4 years. Based on this long-term follow-up, we consider the free groin flap to be a useful reconstruction method for skin soft tissue defects of the forearm.
