Spontaneous Reduction of Posterior Shoulder Dislocation Due to Electrical Injury and the Conservative Management of Associated Complications

Abstract

Posterior shoulder dislocation is a rare and often missed injury, usually due to seizures, electrical shocks, or high-impact trauma. A 32-year-old man with a history of diabetes presented to the emergency department following an electric shock that threw him to the ground. He complained of right shoulder pain with limitation of movement. The initial radiographs of both shoulders did not show fracture or dislocation of either shoulder joint, and the condition was managed with an arm sling. A subsequent CT scan confirmed an irregular depression with sclerosis in the subchondral bone in the anterosuperior part of the humeral head, associated with a spontaneous reduction during the course of the electrical injury. He was managed conservatively, and the one-year follow-up showed excellent clinical results. Most shoulder injuries can be treated satisfactorily without surgery, provided there is no significant instability. This case report emphasizes the successful non-surgical treatment of this very rare posterior shoulder dislocation and highlights that careful rehabilitation, along with conservative management, is effective in ensuring significant recovery. This is further supported by evidence seen in the benefits of non-surgical procedures in similar cases.

Keywords: complication; conservative approach; electrical injury; posterior dislocation of the shoulder; shoulder.

Figure 1. The initial X-ray of the shoulder reveals a depression in the humeral head without any evidence of dislocation or fracture.

No associated cortical disruption or malalignment is noted. Therefore, this would indicate an impaction injury at the bone, which may be clinically relevant in shoulder instability.

Figure 2. The CT scan of the shoulder shows an irregular depression to the subchondral bone of the anterosuperior humeral head, with the glenohumeral articulation remaining intact.

These findings indicate an impaction injury, which might be significant for shoulder stability and clinical management.

Figure 3. MRI of the shoulder reveals a large glenohumeral joint effusion suggesting spontaneous reduction following a posterior shoulder dislocation during an electrical event.

The findings would support a diagnosis of spontaneous reduction of a posterior shoulder dislocation, most likely secondary to an electrical event. There is no associated evidence of a rotator cuff tear or significant labral injury. Features of occult instability of electrically induced shoulder dislocations are shown.

Figure 4. MRI of the shoulder reveals an incomplete inferoanterior to posterior labral tear and reverse Hill-Sachs deformity associated with a previous posterior shoulder dislocation.

These findings suggest residual structural changes following posterior instability that may imply implications for shoulder function and future dislocation risk.