This article presents a case of anterior bilateral sternoclavicular joint dislocation associated with an open-book pelvic fracture, a case not previously reported in the literature. This is a rare case, as no literature search revealed any in which the trauma mechanism involved a vehicle being run over, where the vehicle's wheel passed over the sternum, displacing it posteriorly, resulting in bilateral anterior dislocation of the sternoclavicular joints. Furthermore, the same wheel that caused the posterior dislocation of the sternum, passing over the pubic symphysis, caused an open-book fracture.

Keywords: Luxation, sternal-clavicular joint. pubic symphysis disjunction

This is a rare case,¹ not only due to the causative mechanism, which will be described later, but also due to the association of bilateral dislocation of the sternoclavicular joints with disjunction of the pubic symphysis.

Literature review

Sternoclavicular joint (SJJ) dislocation refers to the complete rupture of all sternoclavicular and costoclavicular ligaments, with complete loss of joint relationship. Anterior dislocation is more common than posterior dislocation, which is associated with greater morbidity due to underlying mediastinal and vascular structures, which may be compromised. In cases of anterior dislocation, it usually occurs from a single, well-defined trauma, most commonly a motor vehicle accident or a contact sport, such as rugby or American football.

The force is typically indirect at the shoulder; most commonly, it arises from an anterolateral force vector directed at the shoulder. In this type of anterior dislocation, the force is typically directed anterolaterally to the shoulder, pushing the shoulder backward and forcing the clavicle anteriorly on its medial side.

Traumatic bilateral dislocation of the sternoclavicular joint is a very rare injury, as 95% are unilateral;² they can be symmetrical, when the clavicles deviate in the same direction, as in the case in question, or they can be asymmetrical, when one side deviates anteriorly and the other posteriorly.^3,4 As highlighted previously, posterior dislocation, which is rarer, is potentially fatal due to the possibility of concomitant injuries to thoracic structures, such as the trachea, esophagus or large vessels.

Acute surgical intervention is necessary to reduce and repair injured structures. Although the mechanism of action is due, as already reported, where the force is typically directed anterolaterally to the shoulder, pushing the shoulder backward and forcing the clavicle anteriorly on its medial side. It may, however, atypically, be the result of direct trauma to the chest, as described by Mohammed, displacing the sternum in a posterior direction, allowing the clavicles to be maintained in their original positions and, thus, dislocating anteriorly, as in the case under discussion here.

In the engraving provided alongside, we demonstrate, using arrows, the direction of the force applied to the sternum bone.

In the engraving provided alongside,⁵ we demonstrate, in cross-sectional view, the position of the Clavicle, when dislocated anteriorly from the Sternum bone (circled in blue).

Anatomy

The Sternoclavicular Joint - shown in the figure alongside, identified by the black arrow.⁶ It presents two involved articular surfaces,⁷ which are the slightly concave articular surface of the sternal end of the clavicle. The clavicular notch of the manubrium of the sternum and the superomedial part of the first costal cartilage.

The bones are joined by a fibrous capsule that surrounds the entire joint, reinforced in front and behind by the Anterior and Posterior Sternoclavicular Ligaments.

In addition to the capsular ligaments, a strong extracapsular costoclavicular ligament contributes to the stability of the joint. Attached to the superior aspect of the first costal cartilage, it runs to the inferior aspect of the sternal end of the clavicle.

In the case presented, which was examined by the author of this text, the etiology was blunt trauma to the presternal region, a motor vehicle tire that passed over the sternum and across the central region of the abdomen, beyond the pubic symphysis.⁸

As a result of the trauma, bilateral symmetrical anterior dislocation of the sternoclavicular joints, fracture of several costal arches, bilateral lung injuries, liver injury and disjunction of the pubic symphysis were identified, which, classified by the Marvin Tile classification, was of the type of horizontal instability of the pelvis, with relevant retroperitoneal bleeding.

In the engraving provided alongside, one can see the medial ends of both clavicles (identified by the green arrows and circled in green) dislocated in an anterior position in relation to the sternoclavicular joint.

In the engraving provided alongside, you can see the ends of the bones that make up the pubic symphysis (identified by the green circles), with a diastasis greater than 2.5 cm.

The case under discussion presents a rare mechanism in the genesis of symmetrical bilateral anterior dislocation of the sternoclavicular joint. The deforming force was exerted directly on the sternum, pushing it posteriorly. This resulted in anterior dislocation of the clavicles at the sternoclavicular joint, in addition to an open-book fracture of the pubic symphysis.

This type of mechanism of action is extremely rare,⁹ as was found by the literature review. As is the association with pelvic fracture. In order for the force exerted to push back the sternum bone to be sufficient to cause dislocations, other segments of the rib cage were damaged, with fractures of numerous costal arches, which allowed the displacement of this bone in a posterior direction.

The area of action of the trauma mechanism ranged from the presternal region, extending throughout the abdomen, ending in the pelvic region, confirming the literature, from which it is extracted: “The majority of pelvic fractures result from high-energy injuries, most commonly caused by traffic accidents (including being run over) or falls from a certain height.¹⁰ Being associated with significant retroperitoneal bleeding.

The objective of this case presentation was to demonstrate the rarity of the mechanism of action that causes stenoclavicular joint dislocations, their rare association with open-book fractures with pubic symphysis disjunction; the finding that high-intensity trauma is necessary for the genesis of such injuries; that other associated injuries are always present; and that mortality in most cases occurs both from bone injuries, which cause intense bleeding, and from associated visceral injuries.

None.

The authors declare there is no conflict of interest.

1. Mohammed K Albarrag. Bilateral asymmetrical traumatic sternoclavicular joint dislocations. Sultan Qaboos Univ Med J. 2012;12(4):512–516.
2. Renfree KJ, Wright TW. Anatomy and biomechanics of the acromioclavicular and sternoclavicular joints. Clin Sports Med. 2003;22(2):219–237.
3. Bahk MS, Kuhn JE, Galatz LM, et al. Acromioclavicular and sternoclavicular injuries and clavicular, glenoid, and scapular fractures. J Bone Joint Surg Am. 2009;91(10):2492–2510.
4. Nettles JL, Linscheid R. Sternoclavicular dislocations. J Trauma. 1968;8(2):158–164.
5. https://maurogracitelli.com/blog/luxacao-esternoclavicular
6. https://ortopediaeombro.com.br/luxacao-sternoclavicular/#:~:text=a%20luxa%C3%A7%C3%A3o%20esternoclavicular%3F- A%20luxa%C3%A7%C3%A3o%20esternoclavicular%20%C3%A9%20a%20perda%20do%20contato%20normal%20entre,3%25%20das%20luxa%C3%A7%C3%B5es%20do%20ombro.
7. Shoulder Generalities. Systems. 2024.
8. Euler de Carvalho G, João Wagner JP, Alex Fabiano DP. Tertiary Injury Care Hip and Pelvic Trauma. 2007. p. 136–147.
9. Groh GI, Wirth MA. Management of traumatic sternoclavicular joint injuries. J Am Acad Orthop Surg. 2011;19(1):1–7.
10. Danielle Campagne, Diane M. Birnbaumer. Overview of Fractures. MSD manual professional version. 2025.