Teaching Case

We present a case series of three patients who were admitted to our Emergency Department for shoulder pain and the arm fixed in an abducted position:

• Case 1. A 101-year-old woman with osteoporosis presented after a fall with her right arm abducted; the humeral head was palpable in the axilla.
• Case 2. A 63-year-old woman woke up with her right arm abducted without history of trauma.
• Case 3. A 90-year-old woman presented with both arms elevated after falling down the stairs.

All three patients underwent plain X-rays of the shoulder in standard projections:

• Case 1. The radiograph showed inferior-medial displacement of the proximal epiphysis of the right humeral head with respect to the glenoid fossa with the humeral shaft parallel to the spine of the scapula, as well as a fracture of the inferior glenoid edge, known as Bony Bankart Lesion (Figure 1).
• Case 2. The radiograph demonstrated inferior dislocation of the right humeral head with respect to the glenoid fossa, without fractures (Figure 2).
• Case 3. X-rays showed displacement of both humeral heads inferiorly in relation to the glenoid fossa; both humeral shafts were parallel to the scapular spines (Figure 3).

Closed reduction with the traction-countertraction method was performed in all three patients. Repeated X-rays showed successful reduction (Figures 4, 5, 6a, 6b) and an associated wedge-shaped defect in the posterolateral aspect of the humeral head, known as Hill-Sachs fracture (Figure 6a).

Background

Inferior shoulder dislocation (ISD) is a rare event, accounting for 0.5% of all shoulder dislocations [1]. It typically occurs after trauma, with falls being the most common cause, but spontaneous cases during sleep are reported [2].

The pathological mechanism involves either indirect leverage on the abducted humeral head across the acromion by a hyperabduction force, which results in tearing the middle and the inferior glenohumeral ligaments (IGHL) and the rotator cuff, or, less commonly, a direct axial loading on a fully abducted arm which drives the humeral head through the IGHL [3].

Clinical Perspective

Clinical presentation is typical with the arm fixed in an abducted position, the elbow flexed, and the hand lying either on the head of the patient or behind it. On physical examination, the humeral head may be palpable in the axillary fossa [3].

Imaging Perspective

Plain X-rays of the shoulder in standard projections show the humeral head displaced below and medially to the glenoid fossa, without contact with the glenoid rim, and the humeral shaft lying parallel to the scapular spine. This distinctive presentation allows differential diagnosis with anterior and antero-inferior dislocation, where the humeral shaft is parallel to the chest wall [4].

ISD is frequently associated with musculoskeletal injuries. Proximal humerus and scapular fractures are reported in 39% and 8% of patients, respectively, with greater tuberosity, Hill-Sachs and bony Bankart lesions being the most common [5]. Rotator cuff, labral and IGHL tears may be detected with magnetic resonance imaging [6].

Outcome

Closed reduction is performed in the ED after adequate sedation and analgesia. The most used traction-countertraction method consists in upward in-line traction on the extended arm, while countertraction is provided by a folded sheet on top of the shoulder in the opposite direction [7]. Afterwards, X-rays are performed to confirm successful reduction and detect any iatrogenic fracture. A repeated clinical examination must rule out the presence of associated neurovascular compromise, which is less common than musculoskeletal injuries and, in most cases, resolves after reduction [5].

When closed reduction is successful and no associated lesion is detected, the patients can be dismissed with a shoulder immobilizer, analgesia, and orthopaedic referral. Immobilization is maintained for 2–3 weeks followed by rehabilitation [8]. Surgery is required for irreducible dislocation, internal fracture fixation, capsule-labral and rotator cuff repair. Both non-operative and surgical treatments have good long-term results [8].

Take Home Message

Luxatio Erecta Humeri is an uncommon form of shoulder dislocation. Prompt clinical evaluation and radiological confirmation of diagnosis are essential for successful urgent reduction.

Written informed patient consent for publication has been obtained.