Usefulness of Bridging External Fixation for Prevention a Collapse in the Case of Osteoid Osteoma in the Lunate Case Report

Introduction Osteoid osteoma is an osteogenic benign bone tumor that accounts for approximately 14% of all cases of bone tumors [1]. Normally, the nidus is visualized as a 1-cm or smaller round to oval lesion with a clear boundary on plain radiography and computed tomography (CT), and reactive bone formation accompanies the lesion in many cases [1]. This tumor frequently develops in 10–20-year-old males and its development after 40 years old is rare [1]. The frequent development site is the diaphysis of long bones in the lower limbs such as the femur and tibia [2]. The rate of osteoid osteoma developing in the carpal bones is 0.14%, being rare, and the development in the lunate has been reported to be markedly rare [3]. Case Report The patient was a healthy 28-year-old male, right-handed and a cook. The swelling and pain of the right wrist joint were appeared from more than 1 year and 6 months before visiting our hospital. The wrist joint pain was increased when the wrist joint was extended. The range of motion of the right wrist joint was as follows: Flexion, 5°; extension, 10°; forearm pronation, 80°; and forearm supination, 80°. The grip strength was 6 kg (relative to We report a patient with osteoid osteoma that developed in the lunate. The lunate is a carpal bone receiving axial pressure loads of the wrist joint and collapse of the lunate may occur after resection of the lesion. In this patient, in addition to pain relief of osteoid osteoma, surgical treatment to prevent postoperative collapse of the lunate was performed.