Sage Publications Ltd Acta Medica Okayama 1179-5476 14 2021 Urinary Retention as the Presenting Clinical Manifestation of Unstable Thoracic Spinal Fracture with Diffuse Idiopathic Skeletal Hyperostosis 1 3 EN Hisashi Hamaguchi Department of Emergency Medicine, Kasaoka Daiichi Hospital Tetsuya Yumoto Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Soichiro Mae Department of Emergency Medicine, Kasaoka Daiichi Hospital Ayumu Takeshita Department of Orthopedic Surgery, Kasaoka Daiichi Hospital Minae Aoyama Department of Orthopedic Surgery, Fukuyama City Hospital Keiya Yamana Department of Orthopedic Surgery, Fukuyama City Hospital Atsunori Nakao Department of Emergency, Critical Care and Disaster Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Patients with diffuse idiopathic skeletal hyperostosis (DISH) are at high risk for unstable vertebral fracture, which can be frequently missed. An 80-year-old man with pre-existing muscle lower limb weakness due to frailty was referred from another hospital, presenting with progressive urinary retention and its related symptoms, which had been treated as a urinary tract infection at previous hospital. One week prior to our visit, he had fallen. On arrival, he appeared lethargic and unable to follow commands. He denied any back pain. Computed tomography identified a T10 fracture and dislocation associated with DISH. Although immediate surgical fixation was performed, the patient did not recover from the neurological deficits. Diagnostic delay of DISH-associated vertebral fracture can occur due to both patients' and clinicians' delayed action. We believe this case report can help clinicians recognize this potentially devastating condition. No potential conflict of interest relevant to this article was reported.