Anticoagulant-induced hemarthrosis presenting as anterior shoulder dislocation

This is a case of nontraumatic shoulder pain initially diagnosed on x-ray as an anterior dislocation. The patient was on anticoagulants and, in actuality, had severe hemarthrosis that caused the subluxation. Attempts to reduce the dislocation in this situation might have resulted in worsening of the intra-articular bleed. There has been only 1 similar reported case in the European Journal of Emergency Medicine in 2013 of a 53-year-old woman who was thought to have a nontraumatic anterior shoulder dislocation, and attempts were unsuccessful at reduction. Definitive therapy involved hemarthrosis aspiration. Others have reported spontaneous hemarthrosis due to anticoagulants; however, only 1 has reported an initial mistaken joint dislocation diagnosis. Nontraumatic hemarthrosis do occur in patients on anticoagulant therapy, and it is important to recognize that this can be misdiagnosed as a joint dislocation requiring reduction. In a patient who is on anticoagulants presenting with nontraumatic joint pain and anterior shoulder or possibly other dislocations on plain radiographs, it is pertinent to consider hemarthrosis.