Orthopedics

Sternoclavicular Joint Dislocation: Serious concern or not a big deal?

Case

A healthy 8-year-old girl was playing basketball and fell forward onto the anterior aspect of her right shoulder. When she rotates her shoulder in a circular motion, she feels a “popping” sensation in the middle of her chest. Her mother further notes a slight deformity near the center of her chest. She reports no other injuries and is not currently in pain.

Exam

Well-developed young female in no acute distress with full range of motion of her right shoulder. There is a palpable deformity at the right sternoclavicular joint without tenderness. A reproducible pop is evident with circumduction of the right shoulder. Neurovascular exam is normal. Skin is intact.

Clinical image showing a protrusion over the right SCJ. Corresponding AP plain film demonstrating widening of the SCJ

Clinical image showing a protrusion over the right SCJ. Corresponding AP plain film demonstrating widening of the SCJ

Diagnosis

Anterior sternoclavicular joint dislocation

Treatment

Sling for support/comfort, and outpatient orthopedics follow-up.

About Sternoclavicular Joint (SCJ) Dislocations

KaineJ Ortho Figure 3.jpg

The SCJ is the only true articulation of the upper extremity with the axial skeleton. It is a well-supported joint with multiple ligamentous attachments to surrounding structures and thick anterior/posterior sternoclavicular ligaments. Note that the joint closely overlies the vascular and airway structures of the mediastinum.

Injuries to the SCJ are rare, comprising less than 1% of all joint dislocations and only 3% of shoulder girdle injuries. The SCJ can be dislocated anteriorly or posteriorly.  A thorough neurovascular examination of the affected extremity is essential given the clavicle’s proximity to the brachial plexus and important vascular structures. SCJ injuries may include physeal fractures in young patients (the physis doesn’t fuse until the early to middle twenties!). CT is typically favored as the imaging modality of choice over plain radiographs.

Mechanism of injury

  • Direct - force applied to the medial aspect of the clavicle forces it posteriorly (i.e., MVC or when one athlete falls on top of another)
  • Indirect - force applied to the shoulder and is transmitted medially (commonly seen in football pileups or falls on an outstretched arm)
A - A posterior SCJ dislocation caused by a force applied to the posterolateral aspect of the shoulder.  B - An anterior SCJ dislocation caused by a force applied to the anterolateral aspect of the shoulder.

A - A posterior SCJ dislocation caused by a force applied to the posterolateral aspect of the shoulder.

B - An anterior SCJ dislocation caused by a force applied to the anterolateral aspect of the shoulder.

Anterior dislocation

  • The more common type of SCJ dislocation.
  • Largely a cosmetic defect, with minimal functional impairment in mild to moderate cases.
  • Most patients can be treated conservatively with a sling, NSAIDs, and ice. This typically results in a favorable outcome with the joint stabilizing in the subluxed position. Patients can be pain free in as little as 2-3 weeks and have full return to unrestricted activity by 3 months (~80% of patients show no functional impairment).
  • Closed reduction can be attempted. However, re-dislocation rates range from 21% - 100%.
  • Rarely is operative reduction indicated and, when performed, has mediocre outcomes.

Posterior dislocation – an orthopedic emergency

  • Less common than anterior SCJ dislocation.
  • 30% of posterior dislocations are associated with life-threatening complications due to mediastinal injury.
  • Extent of injury is best characterized by CT angiogram.
  • Emergent consultation of orthopedic surgery is recommended.
  • Reduction is best performed by orthopedics in the OR with vascular surgery readily available.
  • However, in the event of a pulseless limb, consider emergent reduction in the ER.
Axial CT image showing retropulsion of the medial aspect of the left clavicle behind the manubrium with potential compromise of the mediastinal structures. The corresponding anatomical diagram highlights the structures at risk.

Axial CT image showing retropulsion of the medial aspect of the left clavicle behind the manubrium with potential compromise of the mediastinal structures. The corresponding anatomical diagram highlights the structures at risk.

The most common reduction technique involves placing towels between the patient’s shoulder blades. Then, traction is applied to the affected arm while holding it in abduction (90 degrees) and extension (15 degrees). An assistant may be required to apply manual pressure to the medial aspect of the clavicle to facilitate reduction of an anterior dislocation. Similarly, an assistant may use a towel clip to percutaneously grasp a posteriorly dislocated clavicle and apply forward traction.

The most common reduction technique involves placing towels between the patient’s shoulder blades. Then, traction is applied to the affected arm while holding it in abduction (90 degrees) and extension (15 degrees). An assistant may be required to apply manual pressure to the medial aspect of the clavicle to facilitate reduction of an anterior dislocation. Similarly, an assistant may use a towel clip to percutaneously grasp a posteriorly dislocated clavicle and apply forward traction.

Take Home Points

  • Sternoclavicular joint injuries are rare injuries.
  • In younger patients be careful to look for physeal fracture and displacement.
  • Anterior dislocations can be conservatively managed and have favorable outcomes.
  • Posterior dislocations can be life threatening and require emergent orthopedic consultation.

Faculty Reviewer: Jeffrey P. Feden, M.D.

 

References

Morell DJ, Thyagarajan DS. Sternoclavicular joint dislocation and its management: A review of the literature. World J Orthop 2016 April 18; 7(4): 244-250

Jiang W, Gao Sg, Li Ys, Lei Gh. Bipolar dislocation of the clavicle. Indian J Orthop 2012;46:721-4

Roepke, Clare et al. Chest Pain Bounce-Back: Posterior Sternoclavicular Dislocation Annals of Emergency Medicine, Volume 66 , Issue 5 , 559 - 561

Bjoernsen, LP, Ebinger, A. Shoulder and Humerus Injuries. In: Tintinalli’s Emergency Medicine. 8th ed. New York: McGraw-Hill; 2016

Bengtzen, R, Daya, M. Shoulder. In: Rosen's emergency medicine: concepts and clinical practice 9th edition. Philadelphia, PA: Mosby/Elsevier; 2017

Egol, KA, Koval, KJ, Zuckerman, JD. Acromioclavicular and Sternoclavicular Joint injuries. In: Handbook of Fractures. 5th ed. Philadelphia, PA : Wolters Kluver; 2014

Thurston,M, Jones, J, et al. Sternoclavicular joint dislocation [Internet]. [Accessed August 15, 2017]. Available from: https://radiopaedia.org/articles/sternoclavicular-joint-dislocation

Cadogan, M. Sternoclavicular Joint Dislocation [Internet]. 2014. [Accessed on August 15, 2017]. Available from: https://lifeinthefastlane.com/sternoclavicular-joint-dislocation.

Weatherford, B. Sternoclavicular Dislocation [Internet] [Accessed on August 15, 2017]. Available from: http://www.orthobullets.com/trauma/1009/sternoclavicular-dislocation

Tales From the Community: A Bike Wipeout

 

A 35 year old male is biking when he crosses are area of sand on the road. The bike fishtails and he falls onto his left shoulder. He was helmeted and denies head trauma, neck pain, or LOC. The patient is holding his left arm close to his side and across his chest. On physical exam there is a prominent acromion and coracoid anteriorly.

 

What Injury does this mechanism and presentation correlate with?

Posterior Shoulder Dislocation

 

Incidence:

Posterior Shoulder dislocations account for only 2-4% of all shoulder dislocations. Most commonly they are associated with or caused by seizure, electrical shock, FOOSH or a direct blow to the shoulder, as occurred in this patient. Given the atypical presentation, they are missed in up to 50% of cases on initial presentation.

 

Presentation:

On presentation the patient will usually presents with the arm adducted and internally rotated. More so than in an anterior shoulder dislocation, movement, especially abduction or external rotation is very painful. A prominent acromion and coracoid are palpable, with the humeral head displaced posteriorly.

 

Radiographs:

The deformity can be very subtle on the Anterior/Posterior view and most reliably visualized on the Axillary or Transscapular Y views. On the anterior/posterior view classically shows a “light bulb sign”.  This occurs when the humeral head is forced into internal rotation as it dislocates posteriorly, giving it the appearance of a light bulb.

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Another characterstic sign on radiograph after a posterior shoulder dislocation is the “Trough Sign”. This may be present when the dislocation results in a Reverse Hill-Sachs deformity. Radiographs will show a loss of overlap of the humeral head and glenoid fossa.

Screen Shot 2017-08-30 at 6.36.43 PM.png

Reduction:

In general, Traction - CounterTraction is the most efficacious means to reduce this dislocation. In addition to the traction, gentle pressure to the humeral head in the posterior and lateral directions can be helpful to disengage the humeral head from the posterior glenoid. In our case above, gentle pressure to the humeral head quickly disengaged the humerus from the glenoid and under procedural sedation the patients shoulder was reduced on first attempt.


Disposition:

Similar to anterior dislocations after a posterior shoulder dislocation is reduced, the patient is placed in a sling and swath and discharged with orthopedic follow-up and instructions for non-weight bearing and to keep the shoulder in the sling at all times.


Complications:

The “Reverse Hill-Sachs” lesion mentioned above is one of the complications of a posterior shoulder dislocation. This “lesion” is an osteochondral impression fracture in the anteromedial portion of the humeral headand is known by many names: enoche fracture, McLaughin lesion or reverse Hill-Sachs lesion. In posterior dislocations the shoulder rotates internally causing a anteromedial fracture while in an anterior shoulder dislocation which can lead to a Hill-Sachs deformity which is in the posteriorlateral humeral head.

Reviewed by: Dr Kristina McAteer

Clinical Image 23: The Painful Limp

Case

A nine year old male with no past medical history presents to the emergency department accompanied by his mother, describing a two day history of acute on chronic right hip pain. The patient states that while bathing two days ago, he slipped on a bar of soap onto his right side. Subsequent to the fall, the patient has been having difficulty walking secondary to right hip pain, and the mother reports that the patient has developed a noticeable right sided limp. Additionally, the mother states that the patient has had occasional right hip pain for the past year. He has been able to participate in all school physical activities, albeit with some difficulty. 

Figure 1: Anteroposterior pelvic radiograph

Figure 1: Anteroposterior pelvic radiograph

What's the diagnosis?

Aneurysmal Bone Cyst

Aneurysmal bone cysts (ABCs) are benign bone lesions that predominantly develop in the pediatric population and form to create blood-filled cavities lined with fibroblasts, giant cells and trabecular bone (Figure 1). They are commonly found in the first two decades of life, and can present in any skeletal location, although there is a propensity for their development in the metaphysis of long bones. Their origin is thought to arise as either a primary neoplasm from a gain-of-function translocation causing rapid growth and expansion of lesions, or secondarily from other benign bone tumors [i].

Evaluation

ABCs universally present with pain and swelling at the affected site. Plain film radiography is obtained to identify the localized destruction and dilation of affected bone. Plain films characteristically demonstrate a radiolucent lesion surrounded by a thin layer of bony cortex (Figure 2); because plain films do not fully demonstrate the extent of invasion into nearby structures, or tissue characteristics and adjacent edema, cross-sectional imaging is also obtained [i].

Figure 2: Re-demonstration of the anteroposterior pelvic radiograph in Figure 1, highlighting the radiolucent cystic lesion surrounded by a thin layer of bony cortex

Figure 2: Re-demonstration of the anteroposterior pelvic radiograph in Figure 1, highlighting the radiolucent cystic lesion surrounded by a thin layer of bony cortex

Computed tomography is less frequently used as an imaging adjunct in the pediatric population due to radiation exposure; however when compared to magnetic resonance imaging (MRI), it is better able to evaluate cortical changes and diagnose pathologic fractures [ii].

Combined with plain radiography, MRI provides the highest positive predictive value and interobserver agreement in diagnosing ABCs [iii]. Features characteristically apparent on MRI include trabecular loculations, adjacent soft tissue edema, and fluid-fluid levels comprised of cellular blood products layering under serous components (Figure 3).  However, fluid-fluid levels may also be present in malignant neoplasms, namely telangiectatic osteosarcomas, thereby necessitating a histologic analysis to achieve a definitive diagnosis [iv].

Figure 3: T2-weighted magnetic resonance, axial cross-sectional image of the pelvis demonstrating an expansile mass containing trabecular loculations and fluid-fluid levels

Figure 3: T2-weighted magnetic resonance, axial cross-sectional image of the pelvis demonstrating an expansile mass containing trabecular loculations and fluid-fluid levels

Management

The standard treatment of ABCs is surgical: curettage with or without bone grafting depending on the size and position of the resulting void. Adjuvant therapies developed to decrease recurrence include augmentation of curettage with a high speed burr, argon beam coagulation, addition of phenol, cryosurgery, cementing, radiotherapy, arterial embolization and sclerotherapy.  An emerging technique is “curopsy,” a less aggressive surgical technique involving percutaneous biopsy to obtain lining for diagnostic evaluation that by itself is hypothesized to disrupt the internal lesion architecture and induce healing [i]. Curopsy may be combined with an experimental treatment, instillation of doxycycline, which has anti-neoplastic properties and has been shown to further reduce recurrence [v].

Case Outcome

The patient was admitted for interventional radiology guided percutaneous biopsy of the lesion, with instillation of intra-lesional doxycycline. The biopsy specimen was reviewed by pathology, and deemed insufficient for definitive diagnosis although aneurysmal bone cyst was suspected. Post-procedure, the patient was monitored with no complications, and discharged with pain control and follow-up.  

Resident Reviewer: Dr. Ross
Faculty Reviewer: Dr. Tubbs

References

[i] Park HY, Yang SK, Sheppard WL, et al. Current management of aneurysmal bone cysts. Curr Rev Musculoskelt Med. 2016;9:435-44.

[ii] Wyers MR. Evaluation of pediatric bone lesions. Pediatr Radiol. 2010;40:468-73.

[iii] Mahnken AH, Nolte-Ernsting CCA, Wildberger JE, et al. Aneurysmal bone cyst: value of MR imaging and conventional radiography. Eur Radiol. 2003;13:1118–24.

[iv] Biermann JS. Common benign lesions of bone in children and adolescents. J Pediatr Orthop. 2002;22:268-73.

[v] Shiels WE 2nd, Beebe AC, Mayerson JL. Percutaneous Doxycycline Treatment of Juxtaphyseal Aneurysmal Bone Cysts. J Pediatr Orthop. 2016;36(2):205-12.