Hamatolunate impingement, a differential diagnosis of ulnar-sided wrist pain.

Ulnar-sided wrist pain (USWP) is a diagnostic challenge. Although most of the etiologies are associated with the triangular fibrocartilage complex, the distal radioulnar joint, ulnocarpal impingement, or extensor carpi ulnaris (ECU) tendinopathy, other differential diagnoses should be suggested during propaedeutics. Carpal anatomical variations, specifically the hamatolunate joint, may be responsible for USWP. The purpose of this case report is to highlight the diagnostic approach to USWP and discuss an infrequent differential diagnosis and its surgical management. We present a 44-year-old male patient, a waiter, with USWP and work difficulties. After careful clinical investigation and radiologic studies (magnetic resonance imaging and dynamic fluoroscopy), it was observed the hamatolunate joint impingement. The patient underwent arthroscopy with inspection of the midcarpal joint through the midcarpal radial portal, revealing joint degradation of both articular surfaces. The proximal pole of the hamate was removed. The patient evolved well and returned to work two months later. Function and pain scores were satisfactory at the one-year follow-up.