Inferior shoulder dislocation combined with a 4-part fracture of the proximal humerus: two case reports and literature review

The glenohumeral joint is the most mobile and unstable joint in the human body: Shoulder dislocation accounts for 45% of all large joints dislocation.^2,13 Inferior shoulder dislocation (ISD), also known as “luxatio Erecta” (LE), is the least common type of glenohumeral dislocation accounting for only 0.5% in this location.^2,4,6,13

LE of the shoulder in an unusual traumatic entity that often occurs after a high-energy trauma or a fall from height, with a clear male predominance.^6,13 It may be associated with fracture of the coracoid, clavicle, acromion, scapula, greater tuberosity, and rotator cuff tears.^2,6,13

To the best of our knowledge, there has not been any report of ISD combined with ipsilateral four-part proximal humerus fracture.

Case report 1

A fifty-seven-year-old female was involved in a car accident as a pedestrian after a double-impact collision with a vehicle on the right shoulder and knee. The patient could not recall the exact mechanism of injury because of retrograde amnesia. She was transported to the emergency department of our institution, where physical examination revealed a deformity of the right upper limb: the right humerus was hyper-abducted and externally rotated with an inability to bring the arm back to the body. Active shoulder motion was impossible and attempts to passive movement caused severe pain. She did not have any signs of vascular or neurologic involvement: the patient had no paresthesia nor numbness; the brachial and radial pulses were palpable.

Radiological investigations including plain radiographs and computed tomography scan demonstrated inferior dislocation of the right shoulder combined with a four-part fracture of the proximal humerus (Fig. 1).

Figure 1.

Prereduction radiographs (A) and computed tomography scan (B) showing inferior dislocation of the right shoulder combined with a four-part fracture.

Under general anesthesia, the reduction maneuver includes gentle traction followed by pushing the humeral head from the axilla back to the glenoid fossa. Postreduction radiographs and scanner showed successful reduction of the dislocation with a displaced 4-part fracture of the proximal humerus (Fig. 2). A neurological reassessment after reduction was performed and did not reveal any abnormalities.

Figure 2.

Postreduction radiographs (A) and computed tomography scan (B) showed successful reduction of the dislocation with a displaced 4-part fracture of the proximal humerus.

The next step in management was an open reduction and internal fixation performed through a deltopectoral approach. It included an osteosynthesis with a proximal humeral internal locking system plate combined with bone allograft.

Postoperative radiographs showed a congruent reduction with a satisfactory position of the hardware (Fig. 3).

Figure 3.

Anteroposterior and lateral radiograph of the right shoulder: at the immediate postoperative period (A, B), and at 1-year follow-up (C, D).

On the last follow-up at 1 year postoperatively, the right shoulder was pain-free with an active flexion of 120°. Plain radiographs showed a healed fracture without any signs of implant failure or necrosis of the humeral head. However, it shows a clear double contour of the humeral head leaving the joint congruent, this, however, was asymptomatic (Fig. 3).

Case report 2

A seventy-two-year-old female presented to the emergency department after a fall from height for left hip and right shoulder pain with complete functional impairment. Her medical history was significant for left total hip arthroplasty.

Plain radiographs revealed a dislocated left hip arthroplasty as well as an inferior right shoulder dislocation combined with a four-part fracture of the proximal humerus (Fig. 4A).

Figure 4.

(A) Prereduction radiographs showing inferior dislocation with 4-part fracture of the right proximal humerus, (B, C) post reduction radiograph and computed tomography scan showing the four-part fracture of the proximal humerus along with the detached humeral head in the axila (yellow arrow).

On the same day of the injury, the patient underwent, under general anesthesia, a closed reduction for her left hip and right shoulder. A gentle traction-counter traction technique was performed to reduce the right shoulder dislocation.

Postreduction radiographs revealed a well-reduced left hip arthroplasty. However, on right shoulder radiographs and computed tomography scan the greater tuberosity and the humeral shaft were facing toward the glenoid fossa without hyper-abduction of the arm, but the humeral head was trapped in the axilla (Fig. 4B and C).

We decided to manage the patient prosthetically. The patient underwent a right shoulder hemiarthroplasty through a deltopectoral approach with reinsertion of the tuberosities.

Postoperative radiographs were satisfactory (Fig. 5A), and the postoperative course was uneventful. A shoulder immobilizer was applied for six weeks. The patient underwent passive then active rehabilitation.

Figure 5.

Anteroposterior radiograph of the right shoulder: at the immediate postoperative period (A), and at 30-month follow-up showing malunion of the greater tuberosity (B).

At the last follow-up of 30 months, the right shoulder was pain free. The patient was able to undertake all his daily activity using her shoulder satisfactorily. The active range of motion of the right shoulder was 130° of flexion, 100° of abduction, and 30° of external rotation. For internal rotation, the right hand was as high as L3. Last follow-up radiographs were satisfactory but demonstrate asymptomatic malunion of the greater tuberosity (Fig. 5B).

Discussion

The most common associated fractures with shoulder dislocation are Hill Sachs impaction lesions followed by a greater tuberosity fracture and a humeral neck fracture.⁹ According to the literature, their rate ranges from 30 to 55% of all shoulder dislocations.⁹ Four or three-part fractures combined with shoulder dislocation are much less frequent.⁷

ISD are often associated with soft tissues injuries and fractures. The most common associated injuries are neurologic involving the brachial plexus^4,15 or the axillary nerve.^3,13 In 2017, Nambiar and col reported, in a systematic review of 199 inferior shoulder dislocation, 29% of neurologic complications, 8% of proximal humerus fractures among which 77% involved the greater tuberosity, 16% of rotator cuff injury.⁸

LE of the shoulder is usually managed by close reduction followed by shoulder immobilization for 3 to 4 weeks.¹⁵ It may fail in case of buttonholing of the humeral head in a torn inferior capsule.²

Regardless of the direction, the combination of a complex proximal humerus fracture with shoulder dislocation makes close reduction very challenging and not safe enough to be attempted in the emergency department.^9,12 Open reduction should be considered given that the common reduction techniques may induce major displacement of the fracture and consequently increase the risk of humeral head necrosis.² Regarding the management of shoulder fracture-dislocation, closed reduction under sedation is only safe for anterior dislocation combined with a greater tuberosity fracture. Whenever the surgical or the anatomical neck is involved, closed reduction attempts are not recommended because of the high risk of iatrogenic fracture and further displacement of the initial fracture.^14,16

In 2004, Tomocovcík reported an inferior shoulder dislocation combined with a humeral neck fracture. In that report, the surgeon did not perform the usual traction-counter traction method to reduce the humeral head because the long lever of the humeral shaft could not be effective since it was discontinuous at the level of the surgical neck fracture. The performing physician used his fist to directly push back the humeral head to the glenoid fossa. Despite this gentle reduction technique, the dislocation was reduced however the fracture had displaced afterward and required additional surgery to obtain satisfactory reduction.¹²

The management of ISD may require internal fixation of the greater tuberosity, rotator cuff repair, or capsular repair. According to Fery, immobilization of the arm in the adduction position, to prevent recurrence, put the patient at high risk of greater tuberosity nonunion.³

After close reduction of an inferior shoulder dislocation, the long-term prognosis is usually good; however, some complication might occur such as humeral head necrosis, instability, or stiffness.^5,8,10

In the current paper, we are reporting two unusual cases of four-part proximal humerus fracture combined with inferior shoulder dislocation.

There was one case report of a humeral neck fracture in 2004,¹² and one case of humeral head split in a series of 16 inferior shoulder dislocation in 2010.⁵

In the first case, we managed to reduce the dislocation by performing gentle manipulation of the humeral head from the axillary to the glenoid fossa with a counter-support on the superior aspect of the shoulder. We chose to perform an open reduction with internal fixation for several reasons: the major valgus deformity of the proximal humerus with a subluxation of the glenohumeral joint, the important displacement of the tuberosities, the good bone density of the patient, the size of the cephalic fragment, the relatively young age of the patient with high functional demands. This was associated with multiple risk factors for avascular necrosis of the humeral head such as the complex nature of the fracture and the number of fragments, the lack of medial hinge, the combination with a dislocation, the open reduction which required disimpaction of the cephalic fragment.^1,7,11 This risk encouraged us to use the deltopectoral approach to get prepared for an eventual arthroplasty through the same approach in case of reduction failure.

Regarding the second case, closed reduction caused a major disimpaction of the cephalic fragment which required a prosthetic management. We opted for a hemiarthroplasty despite the advanced age of the patient because the rotator cuff was intact.

Conclusion

The combination of inferior shoulder dislocation to a complex fracture of the proximal humerus is extremely rare in daily practice. Closed reduction is very delicate and can be difficult to achieve with common reduction techniques.

This entity put the patient at a very high risk of avascular necrosis of the humeral head. The latter should be informed of the potential complications of this injury, especially when open reduction is considered.

Disclaimers

Funding: No funding was disclosed by the authors.

Conflicts of interest: The authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.