The patient was a 27-year-old man who sprained his right thumb while playing softball, resulting in tenderness and swelling around the interphalangeal (IP) joint. He was a software engineer, and his dominant hand was the right hand. Physical examination revealed complete loss of active extension and also that passive extension and active flexion of the IP joint were full. The IP joint was stable against radial and ulnar stress. The images of plain radiography and computed tomography showed an avulsion fracture of one-third to half of its articular surface at the base of the distal phalanx (Figure 1). Using the hook plate technique, open reduction was performed under general anesthesia 19 days after the injury (Figure 2). An incision was made along the crease on the dorsal side of the IP joint. The fracture was reduced and fixed using a hook plate adapted from a 1.5 mm micro module (KLS Martin, Germany, Figure 3(a)). One of the holes was cut, and one-third of its circumference was removed. The ends of the crescent arc were bent approximately 100  by pliers to form two sharp pointed hooks (Figure 3(b)). Two small longitudinal incisions were made at the EPL. The hook plate was slid under the nail matrix, the hooks were inserted through the slips, and the bone fragment was gripped. The screw was inserted into the plate hole to add compression to the fragment. The articular congruency and stability of the fragment in the direction of passive flexion were checked, and the wound was closed.
The splint was maintained for 1 week before motion of the IP joint was allowed, and the patient returned to work 1 day after surgery. Bone union was achieved and the plate was removed 3 months after the procedure (Figure 4). At the last follow-up of 6 months after surgery, the active range of motion at the IP joint was 80 degrees of flexion and 8 degrees of extension. The range of motion on the contralateral side was 85 degrees of flexion and 10 degrees of extension (Figures 5(a) and 5(b)). The patient had a transverse line nail deformity (Figure 6) that gradually improved. According to Crawford's evaluation criteria, the result was excellent. The patient experienced no injury-related difficulties both at work and while playing softball.