A 35-year-old male presented to fast track complaining of bilateral severe shoulder pain for one-day duration. He reports waking up like that, and not being able to move his shoulders much due to the pain.
He denied any recent falls, injuries, or direct trauma to his shoulders. He also denied any fever, rashes, skin changes, headaches, numbness or weakness. No further findings found upon review of systems. Past medical history revealed a history of epilepsy. Otherwise, he’s not on any medications and denies any known allergies.
Physical examination showed slim male, with flattened anterior shoulders and normal inspection of the skin overlying his shoulders. He had internally rotated upper extremities, flexed elbows, and arms held in adduction. Upon attempts on any passive or active test of the range of motion, he experienced reluctance and pain on external rotation or abduction of his shoulders. Bilateral Shoulder X-rays were obtained.
This patient had bilateral posterior shoulder dislocation, with associated fractures.
- Posterior shoulder dislocations make up 2-4% of shoulder dislocations.
- May go undiagnosed and often missed on physical exam and imaging
- Epileptic seizures or electrical shocks, sports injuries are the most common causes.
- Subtle signs on AP X-Ray include:
- Light Bulb Sign: Fixed internal rotation of the humeral head, makes the greater tuberosity anterior, giving a symmetrical appearance of the humeral head, that looks like a light bulb.
- Empty Glenoid Sign: Humeral Head and Glenoid fossa widened articular space
- Trough Sign: Vertical Line on AP, can indicate compression fracture of the humeral head medially.
- In suspected Posterior Shoulder Dislocations, you should always get multiple views, including Anterior-Posterior (AP), scapular (Y), and Axillary Views.
- Subtle signs on AP X-Ray include:
- Rounded posterior shoulder.
- Prominent coracoid and acromion.
- Palpable posterior humeral head.
- Flattened anterior shoulder contour.
- Neurovascular injuries
- Rotator cuff tears
- Osteonecrosis of the humeral head
- Recurrent posterior shoulder instability or re-dislocation
- Joint stiffness and post-traumatic osteoarthritis
- You need to evaluate each case separately. The cases like this patient, with associated fractures, can complicate your management, and hence consulting orthopedic services would be advised, as surgical interventions should be evaluated.
- If closed reduction fails, usually open reduction is pondered by subspecialty, especially in cases with extensive damage to the humeral head.
- In cases with no associated fractures, the approach is the reduction of the dislocation. Most of them would require procedural sedation and analgesia.
- Consider discussing options of procedural sedation and analgesia, with or without intraarticular blocks with your attending, for better and successful procedures, and minimal pain for your patient. The most convenient procedure options should also be discussed with patients, and consent should be taken.
- Patients would require pre and post-reduction neurovascular examination and X-rays.
- Make sure your patient is examined again after the procedure, assessing the stability of the joint for regained full range of motion.
- Shoulder immobilization and follow up care plans with orthopedics services should be arranged.
- Don’t forget, patients with known epilepsy, non-adherence or uncontrolled seizures have to be evaluated as well, and referred to appropriate neurology evaluation.
- Bilateral shoulder dislocations are rare and of these, bilateral posterior shoulder dislocations are more prevalent than bilateral anterior shoulder dislocations.
- Bilateral fracture-dislocation is even rarer, with a few cases reported in the literature.
- In the rare case of an asymmetrical bilateral dislocation, attention may be distracted to the more evident lesion, which is the anterior dislocation. This may lead to delayed diagnosis, especially in an unconscious patient in a post-ictal state.
- In the present case, open reduction and internal fixation was performed.
References and Further Reading
- Roberts & Hedges Clinical Procedures in Emergency Medicine (6th ed) 2014. Philadelphia. Elsevier Saunders Inc. – Chapter 49
- Tintinalli’s Emergency Medicine: A Comprehensive Study Guide (7th ed) 2011. New York. McGraw Hill Companies Inc. – Chapter 268
- Rosen’s Emergency Medicine: Concepts and Clinical Practice (8th ed) 2014. Philadelphia. Elsevier Saunders Inc. – Chapter 53
- Wikem – Posterior Shoulder dislocation: https://www.wikem.org/wiki/Posterior_shoulder_dislocation
- Canadiem – Posterior Shoulder Dislocation: Radiographic Evidence : https://canadiem.org/posterior-shoulder-dislocation-radiographic-evidence/
- Meena S, Saini P, Singh V, Kumar R, Trikha V. Bilateral anterior shoulder dislocation. J Nat Sci Biol Med. 2013;4(2):499–501. doi:10.4103/0976-9668.117003S – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3783813/
- Sharma A, Jindal S, Narula MS, Garg S, Sethi A. Bilateral Asymmetrical Fracture Dislocation of Shoulder with Rare Combination of Injuries after Epileptic Seizure: A Case Report. Malays Orthop J. 2017;11(1):74–76. doi:10.5704/MOJ.1703.011 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5393121/
Credit and acknowledgment for Dr. Eelaf Elhassan for sharing the case.