Intrathoracic Fracture-dislocation of the Humeral Head: A Case Report and Review of the Literature

Introduction: Intrathoracic displacement of a humeral head fracture is extremely rare. Only slightly more than 30 cases have been reported in this regard. Since few cases have been reported, there is no consensus on how to treat this injury. The etiology, injury mechanism, related lesions, and treatment of the injury are diverse. Case Presentation: A 73-year-old female presented with multiple fractures of the left ribs, bilateral lung contusions, extensive emphysema of the anterior and posterior chest wall, massive left hemopneumothorax, fracture-dislocation of the proximal humerus, and intrathoracic displacement of the humeral head. The patient was sent to the operating room for emergency thoracotomy surgery. The head of the humerus was confirmed to be completely removed from the thoracic cavity during the operation. After discussion with the orthopedic surgeon, the humeral head was discarded considering avascular necrosis; moreover, open reduction and internal fixation were not performed. The orthopedic surgery team performed reverse shoulder arthroplasty three weeks later. During follow-up, the patient's shoulder was free from pain, and its range of movement included 110 degrees flexion, 70 degrees abduction, 35 degrees external rotation, and 50 degrees internal rotation. Conclusion: Intrathoracic displacement of the humeral head due to proximal humeral fracture is a very rare and serious trauma that requires multidisciplinary treatment. Considering the extremely high risk of humeral head necrosis, actively removing broken bone fragments of the humeral head in the early stage is recommended, and we advocate for shoulder arthroplasty for elderly patients. Detailed preoperative evaluations and individualized operation plans should be made to achieve the best effect.