Ortho Hors D'oeuvres (Answer):

To review, this is a 50 year-old female with previous similar injuries and normal neurovascular examination presenting with right shoulder pain status post a fall.

Questions and Answers:

1) What is the injury?

As you can see in the above image, this patient has suffered an inferior and (corroborated in the lateral film) anterior dislocation of the humeral head (blue arrow) in respect to the glenoid (yellow arrow). There is also a significantly displaced fracture of the greater tuberosity that can be visualized lateral to the lateral aspect of the humerus. G

Shoulder x-rays performed with suspicion of dislocation should always include 3 views: AP or PA, lateral, and axillary. Anterior dislocations can often be seen on isolated PA or AP views. Posterior dislocations, however, can masquerade as normal on PA or AP views and can usually be readily identified in lateral x-rays.

One sign of a posterior dislocation on x-ray is the "lightbulb sign" or "ice cream cone sign," in which the head of the humerus rotates posteriorly and the normal contours of the humeral head are lost.

2) Did you need to perform the x-ray to appropriately treat this injury?

Unless the patient is a frequent dislocator and the injury is atraumatic, x-rays should be obtained in order to rule out associated fractures, as you can see in this case. ED physicians miss 14.4% of fracture-dislocations in patients with diagnosed dislocation. These injuries are orthopedic emergencies, as disruption of the capsular attachments causes devascularisation of the humeral head.

In this case the identified fracture (the greater tuberosity) is not technically an intra-articular fracture and does not count as a fracture-dislocation.These fractures are very common, occuring with

6.2% of all anteriorly dislocated shoulders. They are often caused by a shearing force against a glenoid rim and are likely a completed form of a Hill-Sachs lesion which is discussed below.

Two other bony injuries that are associated with shoulder dislocations and are not considered orthopedic emergencies are the Hill-Sachs deformity and the Bankart lesion.

As you can see here, superio-lateral aspect of the humerus articulates with the inferior border of the glenoid in a typical anterior-inferior shoulder dislocation. When axial traction is applied to these dislocations the provider is attempting to 'disengage' this articulation.

Here we have someone with a previous Hill-Sachs deformity, likely from previous dislocations, form an articulation with the inferior aspect of the glenoid. In the process of the initial dislocation or possibly the relocation, that notch in the humerus has chipped off the edge of the inferior glenoid, forming the bankart lesion. As you can imagine, these deformities contribute greatly to an increasingly unstable shoulder and more future dislocations.

3) What is the appropriate emergent management for this injury?

If the identified fracture is intra-articular or contributing to distal instability, this is considered an orthopedic emergency and likely requires intra-operative fixation. If the identified fracture is not intra-articular and cortical only, reduction of the shoulder can be attempted as usual. Greater tuberosity fractures can make complete reduction more difficult, so formal recommendations are 1-2 attempts in the emergency department prior to calling orthopedics for assistance.

The patient should be pre-treated with pain medications and intra-articular lidocaine or bupivacaine should be considered, as it has been demonstrated to decrease complication rates from 13.3% to 0.67% while decreasing overall length of stay from ~180 minutes to ~80 minutes.

This patient was successfully reduced in the emergency department and an axillary views was obtained, demonstrating adequate reduction. The greater tuberosity fracture, previously grossly laterally translated, is now minimally displaced.

If the patient has been appropriately reduced and has a Hill-Sachs or Bankart lesion, they should follow-up with orthopedics in 1-2 weeks in order to discuss nonemergent surgery. Greater tuberosity fractures, especially those with displacement greater than 5mm, can be associated with significantly poor functional outcome. These patients should follow-up within 3-5 days, as operative management is often recommended.

References:

Dimakopoulos P et al. Anterior traumatic shoulder dislocation associated with displaced greater tuberosity fracture: the necessity of operative treatment. J Orthop Trauma. 2007 Feb;21(2):104-12.

Fitch RW, Kuhn JE. Intraarticular lidocaine versus intravenous procedural sedation with narcotics and benzodiazepines for reduction of the dislocated shoulder: a systematic review. Acad Emerg Med. 2008 Aug;15(8):703-8.

Hendey GW. Managing Anterior Shoulder Dislocation. Ann Em Med. 2015. Aug 12 2015. Epublication.

Mimura T et al. Closed reduction for traumatic posterior dislocation of the shoulder using the 'lever principle': two case reports and a review of the literature.

Robinson CM, Khan LAK, Akhtar MA. Treatment of anterior fracture-dislocations of the proximal humerus by open reduction and internal fixation. JBJS April 2006 88-B. 502-508.

Robinson CM, Akhtar A, Mitchell M, Beavis C. Complex posterior fracture-dislocation of the shoulder. Epidemiology, injury patterns, and results of operative treatment. JBJS Am 2007 Jul;89(7):1454-66.

Thanks to Erin Sullivan for radiographic images!