Paediatric Sternoclavicular Joint Pseudodislocation Fixation Technique

Abstract

Background:

Posterior sternoclavicular joint (SCJ) injuries in children are rare and frequently misdiagnosed. Due to the anatomy of the immature medial clavicle, many of these injuries are Salter-Harris type I/II physeal fractures rather than true joint dislocations—termed pseudodislocations. These injuries require careful diagnosis and tailored management to ensure safe and functional outcomes.

Indications:

Surgical intervention is indicated in paediatric SCJ pseudodislocations with significant posterior displacement of the medial clavicular fragment, particularly when the posterior metaphysis poses a risk to mediastinal structures or functional deficits persist.

Technique Description:

We describe a paediatric SCJ pseudodislocation fixation technique performed at the Royal Children’s Hospital in Melbourne. The patient is positioned supine with a bolster behind the shoulders. A curvilinear incision is made, and dissection is performed to identify the clavicular diaphysis and sternum. The fracture is reduced under direct vision with a reduction clamp, blunt periosteal elevator, and axial traction. An anterior-inferior drill hole is made in the medial clavicular metaphysis, and 2 anterior drill holes are created in the sternum. Fibertape is passed in a double figure-of-8 configuration through the posterior clavicle, disc, and posterior sternal cortex, before being tied anteriorly over the sternum and clavicle. This anterior-directed force resists further posterior subluxation. The capsule and strap muscles are repaired to restore soft tissue support.

Results:

In our internal audit of 30 paediatric posterior SCJ pseudodislocations treated operatively over a decade, this technique consistently resulted in anatomical reduction, full range of motion, and return to sports. Complication rates were low. Computed tomography confirmed the reduction, and rehabilitation was tailored to the biology of physeal injuries, allowing an earlier return to activity compared with soft-tissue dislocations.

Discussion/Conclusion:

Posterior SCJ pseudodislocations can be safely and effectively managed with this transosseous fibertape fixation technique. Restoration of anterior stability using a double figure-of-8 construct provides strong mechanical support while preserving anatomy. Accurate diagnosis, surgical planning, and soft tissue repair are essential. This technique facilitates a reliable return to sports and function, with minimal complications.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

This video describes a paediatric sternoclavicular joint (SCJ) pseudodislocation fixation technique used at The Royal Children’s Hospital in Melbourne.

Background

The SCJ is a diarthrodial saddle joint that forms the only articulation between the axial and appendicular skeleton. It has the least amount of bony congruity in the body. There is an intra-articular disc that displays stability across different movement planes, comprising both static and dynamic structures.^3,6 The medial clavicle physis appears between the ages of 12 and 19 years and fuses between 22 and 25 years. Around 80% of growth occurs from this area. ¹¹ This has been described in the radiology and computed tomography (CT) literature.^9,10

True SCJ dislocations have an incidence of 0.26/million. ⁸ Posterior SCJ dislocations comprise up to a quarter of cases. ⁷ In children, Salter-Harris (SH) type I and II fractures, the aptly named pseudodislocations, are more common than true dislocations. ⁵

Direct force causes 10% to 25% of posterior dislocations. ¹ Around one-third of dislocations are diagnosed once chronic, which may be due to initial misdiagnosis. ¹³ Patients present with limited abduction while supporting the arm and protracting their scapula. The neck is often flexed forward, tilted ipsilaterally, and rotated away from the ipsilateral side. Be aware of potential venous congestion and associated injuries. Compression of the superior mediastinum may cause associated symptoms. The literature appreciates fatalities, but fortunately, these are rare.^2,4 There is, however, controversy as to whether fixation of posterior SCJ dislocations is necessary. No comparative studies are looking at nonoperative versus operative treatment, and, as the biology is different from that of a true dislocation, some postulate that posteriorly displaced SH type I and II fractures may heal and remodel. There remains the need for further work to explore this in more detail. We believe the indications for surgery include significant posterior displacement of the lateral fragment, particularly if it encroaches on superior mediastinal contents, such as the brachiocephalic vein.

Indications

We present the case of a 14-year-old male patient who was playing Australian Rules Football and sustained a collision with another player. He presented with significant pain and deformity in the right SCJ region with a normal neurovascular examination and no dysphagia. A CT scan of the right clavicle and SCJ was conducted, demonstrating a posterior subluxated SCJ pseudodislocation.

This coronal CT shows superior and posterior displacement of the right clavicle. This is confirmed on the axial sequences.

Technique Description

The patient is positioned supine with a bolster behind their shoulder blades. Bony anatomy is marked with an indelible marker. We also suggest marking the clavicle line, as skin contours can be deceptive. The intended curvilinear incision is then marked. The patient is prepared with an alcoholic chlorhexidine surgical solution, and sterile drapes are placed. The curvilinear incision is made with dissection through fat and fascia. We recommend dissection of the lateral aspect of the wound to identify the diaphysis of the clavicle. The SCJ can be palpated.

This should be opened at the sternum/disc interface. The sternum and its overlying periosteum are also dissected to allow clear visualization of the bone. Of note, care should be taken around the epiphysis, which is all cartilaginous, and dissection in this region should not be conducted using electrocautery.

Dissection occurs between the clavicle and its periosteum to create a protective envelope. It is important to perform this dissection to avoid avulsion of the underlying vasculature or scar. We recommend using a blunt periosteal elevator, such as a Howarth periosteal elevator or mini-Cobb, while using a bone clamp to provide a small amount of anterior axial traction on the clavicle. This provides stability to the clavicle during the dissection. Once the medial clavicle metaphysis is liberated, the bone clamp is then used to gently tease reduction of the clavicle metaphysis. This can be aided with axial traction of the ipsilateral arm. Once the medial clavicle is delivered, the congruency of the metaphysis to the epiphysis is restored. The relationship of the metaphysis, epiphysis, disc, and sternum can also be appreciated.

Additionally, visualizing the metaphysis from the contralateral cranial angle clearly shows that this is a pseudodislocation caused by a fractured bone rather than joint cartilage.

This diagram depicts the SCJ pseudodislocation with the sternum, first rib, metaphysis, epiphysis, disc, and fracture present. We suggest making a 2.5-mm drill hole on the anterior-inferior aspect of the clavicle metaphysis in a posterior-inferior direction, using a blunt mini-Hohmann retractor on the posterior cortex to prevent iatrogenic injury to soft tissue structures. Two further 2.5-mm drill holes are made from the anterior aspect of the sternum into the base of the SCJ, around 2 mm anterior to its posterior margin. Again, a blunt mini-Hohmann retractor can be used to protect the surrounding structures. Two-mm Fibertape (Arthrex) is passed through the initial drill hole. This is then passed behind the clavicle metaphysis, through the posterior aspect of the epiphysis, disc, and then through the posterior aspect of the sternal drill holes. This allows the clavicle to be pulled from a posterior-to-anterior position, thus providing a hammock to resist posterior subluxation. We feel that this anterior-directed force is important to maintain normal joint congruency. The limbs of the fibertape are then retrieved through the anterior aspect of the sternum. A second 2.5-mm drill hole is made on the anterior aspect of the clavicle metaphysis. One limb of the fibertape is then passed through this, and the fibertape is then secured with a surgeon’s knot on the anterior aspect, thus creating a double-figure-of-8 configuration.

In this video, you can see the anterior-inferior sited clavicle drill hole being made. The 2 SCJ drill holes are then made, 1 inferior and 1 superior. A nitinol loop is used to pass the fibertape through the initial clavicle metaphysis drill hole. The fibertape is then passed beneath the clavicle and then through the posterior aspect of the epiphysis and disc using a size 2 Mayo needle. As both of these structures are cartilaginous, the needle will pass without significant resistance. As mentioned previously, it is important to ensure the fibertape is posterior to the clavicle to allow an anterior force to be created. It must also pass through the posterior aspect of the epiphysis for the same reason. The fibertape is then passed through the posterior aspect of the sternal drill hole through the inferior drill hole and out through the sternum. The second limb of the fibertape is then passed, ensuring the figure-of-8 configuration is present at the posterior aspect of the fixation. The 2 limbs are now free on the anterior aspect of the sternum, and the second drill hole through the clavicle metaphysis is now made. This is at a more anterior site on the clavicle. A passing stitch can be used to pull one of the limbs of the fibertape through, again, in a figure-of-8 configuration, before a surgeon’s knot is placed on the anterior aspect of the clavicle fixation. This creates a very strong construct with the anatomy restored.

We then repair the capsule and the medial strap muscles. We use a 1.3-mm Fibertak DX anchor (Arthrex) to repair the strap muscles, restoring the normal contours of the neck musculature. This is important to allow normal facial gesticulation and to provide an anterior-directed force on the clavicle. The wound is then closed with Vicryl and Monocryl.

Postoperative axial sequences on the right show anatomical reduction of the SCJ as compared with the preoperative CT scan on the left. This is also visible on the coronal sequences, again, postoperative on the right and preoperative on the left.

There are potential complications that can be avoided. In the preoperative phase, we recommend CT angiography to assess the great vessels and identify potential pseudodislocations. In the operative phase, it is important to ensure adequate setup, with a bolster behind the shoulders, to present the SCJ adequately. In our local series of 30 posterior SCJ dislocations treated in our institution over the past decade, we have not required cardiothoracic surgeons. We recommend using a curvilinear incision and dissecting from known structures toward unknown areas. Therefore, during deep dissection, we advocate identifying the clavicle diaphysis and working toward the metaphysis and the fracture zone. Careful dissection is paramount—including using blunt scissors to identify the SCJ next and avoiding the use of electrocautery near the SCJ to avoid inadvertently burning the epiphysis. Ensure adequate exposure and control of the clavicle. It is also important to plan the metaphyseal tunnels as close to the fracture as possible to reduce the working length of the figure-of-8 construct. The initial tunnel must also be placed more posteriorly in the sagittal plane to achieve an anteriorly directed support for the clavicle. Drilling with protection to avoid plunging is also important. We suggest using tape rather than suture, as the larger surface area may reduce the risk of cutout through drill holes or material breakage. The fibertape knot should be placed on the inferior aspect of the clavicle between the clavicle and the first rib, with the strap muscles repaired above this layer. This helps to avoid the knot stack from being prominent or irritable.

Our postoperative management protocol includes a CT scan to confirm reduction before discharge. Patients are placed in a broad-arm sling for 4 weeks, with pendular movements allowed for the first 2 weeks until wound review. Patients can then perform active-assisted range of motion to shoulder height from weeks 2 to 4. They progress to the above-shoulder height range from 4 to 6 weeks, with no heavy lifting until 3 months.

Results

We believe in an individualized goal-oriented approach to rehabilitation and expected milestones. In our experience, most patients have a comfortable pain-free range of movement by 6 weeks postoperatively and are therefore allowed to participate in noncontact sports such as swimming, cycling, and running at that stage. We predict that sufficient bony union has occurred by the 3-month stage to allow return to contact sports. Of note, rehabilitation strategies for true dislocations versus physeal injuries may differ due to underlying biology. With true dislocations, this relies on soft tissue joint stabilizers to heal before returning to sports. In physeal fractures, bone healing is the primary factor, and children may return to sports sooner.

In our internal audit of 30 consecutive posterior SCJ pseudodislocation cases, all cases with open reduction had low complication rates, a full range of motion, and returned to sports. Of the 23 open reduction cases, 2 had complications. One patient had a redislocation when an older technique was used. A second patient had a tunnel cut out, with suture material used rather than the tape used in the current technique. Regarding follow-up, of the 23 open reduction cases, one patient was lost to follow-up because they moved out of the area. The remaining 22 cases had a full range of motion and had returned to competitive sports at a mean follow-up of 12 months.

Discussion/Conclusion

This meta-analysis ¹² included 972 articles, of which 79 were case reports or series, totaling 140 cases. The demographics match our own patients. The pseudodislocation rate was similar to ours. There was a large heterogeneity in treatment methods—including closed reduction and open reduction techniques. Of the open reduction techniques, there were low treatment complication rates, but the use of metal in fixation was linked with case fatalities.

Future areas of research should focus on understanding the indications for fixation of posterior SCJ pseudodislocations, the role of magnetic resonance imaging scans in the preoperative period to reduce radiation exposure and differentiate a true dislocation from a pseudodislocation, the role of closed reductions compared with open reduction and stabilization, and the longer-term effects of stabilization on the medial clavicle growth plate.

CT has implications for intraoperative findings. Physeal injuries may be easily missed; thus, careful dissection and identification of the epiphysis is crucial. The transosseous suture technique with suture tape, using our double-8 technique, is safe and yields excellent outcomes. Strategies to obtain an anteriorly directed force with fixation strategies are important to prevent posterior subluxation. Return to contact sports is consistently achievable in our experience.