Various techniques have been described for the treatment of SCJ dislocations. In cases of acute traumatic dislocations, an initial trial of conservative management following successful reduction may be considered. Nevertheless, the rate of re-dislocation, particularly in ventral dislocations, remains relatively high [16, 17]. Despite this, many patients still achieve satisfactory and largely pain-free shoulder function. In cases of persistent symptoms — whether following acute trauma or due to chronic instability associated with hyperlaxity — surgical stabilization is indicated.

For both anterior and posterior dislocations, a variety of surgical methods have been reported, including stabilization using suture anchors, plating systems, and graft augmentation [18,19,20]. In recent years, figure-of-8 reconstruction using a hamstring graft has emerged as a preferred technique for SCJ stabilization. Favorable mid- and long-term outcomes, including 5- and 10-year follow-up results, have been demonstrated by Lacheta and Hinz et al. [9, 10] These studies showed that sternoclavicular SCJ reconstruction using a figure-of-8 hamstring tendon autograft led to significant improvements in shoulder function, pain reduction, high patient satisfaction, and a 90% construct survivorship at midterm (5-year) follow-up [10].

At minimum 10-year follow-up, these positive outcomes were maintained, with excellent function, low pain levels, and a 100% return-to-sport rate, although a 36% rate of recurrent subjective instability was noted [9]. Despite these promising results, there are some drawbacks to stabilization using a hamstring graft. Two clavicular and two sternal drill holes are required to tension the graft across the SCJ in a Fig. 8 configuration. These drill holes are typically created with a minimum of 4 mm diameter [10, 21, 22]. A study by Qui et al. demonstrated that the mean thickness in the coronal plane at the sternal end of the clavicle is 20.8 ± 6.0 mm, meaning that approximately 38% of the sternal clavicular thickness in the coronal plane is perforated by the drill holes, with some variation depending on the patient [23]. The study by Petri et al. 2016 evaluated clinical outcomes after SCJ reconstruction using hamstring tendon autografts in 21 patients with SCJ instability, demonstrating significant improvements in function and pain scores, high patient satisfaction, and no intraoperative or postoperative complications. Although good clinical outcomes were achieved in three patients, insufficient clavicular bone stock necessitated a modification from the standard figure-of-8 technique to a single drill hole with a loop reconstruction [24]. This finding indicates that insufficient clavicular bone stock is not uncommon, a limitation that would be obsolete with the technique demonstrated within the underlying article, as smaller clavicular drill holes are required only for the wire. In our cadaver study, the flaps were elevated on only three sides and remained attached near the SCJ. Additionally, the sternal and clavicular drill holes could be significantly reduced to 1.6 mm, which may help minimize the potential risk of fracture. Furthermore, it is possible to create two unicortical drill holes in the sternum that meet intraosseously, thereby minimizing the risk of injury to retrosternal structures [15]. A study by Tytherleigh-Strong et al. investigated a surgical approach for first-time traumatic anterior SCJ dislocations, involving direct repair of the anterior capsule augmented with an internal brace wire. Although no additional biological augmentation was performed, the technique aimed to restore stability in the acute setting by reinforcing the native anterior capsule. The reported outcomes were excellent, with no recurrent instability and a mean QuickDASH score of 2.3 at a median follow-up of 28 months [12]. Similar to their technique, we would also repair the capsule in the acute setting, followed by additional synthetic augmentation using the FiberWire and biological augmentation using the flap; in chronic cases with a torn and scarred capsule, the flap likewise offers the possibility of locally available biological augmentation. Another advantage of our technique is that the periosteal flaps, in contrast to tendon grafts, are highly vascularized and therefore provide superior healing potential. Furthermore, stabilization with a periosteal flap is much less prominent compared to the conventional figure-of-8 hamstring graft, which adds another benefit to our approach. Biomechanical testing showed that the CPF can withstand tensile forces on its own; however, as outlined in the surgical technique, primary stability is provided by the FiberWire fixation, while the locally available flap may support healing.

A limitation of our CPF technique could be, that not enough periosteal tissue is present at the clavicle or the sternum. In rare cases of particularly posterior dislocations, the authors observed within the surgery of clinical cases, that the periosteum may be sheared off together with the joint capsule. In those cases, the SPF could be an alternative.

Another advantage of our technique is that no hamstring graft harvesting from the knee is necessary. This avoids potential complications such as failed harvesting with premature tendon rupture or sensory deficits caused by injury to the infrapatellar branches of the saphenous nerve.

As early as 2006, Almazán et al. demonstrated that complications related to hamstring graft harvesting occur in 8.3% of cases. Furthermore, various studies have reported sensory deficits due to injury of the infrapatellar branches of the saphenous nerve in up to 88% of cases [25,26,27].

With our surgical technique, utilizing mobilization and fixation of a CPF or SPF, these potential complications can be avoided. While autografts may offer advantages in terms of biological incorporation and clinical outcomes compared to allografts, they are associated with the above-mentioned complications; therefore, alternative approaches such as locally available periosteal flaps warrant further investigations as potential biological augmentation [28].

This study has several limitations that should be considered when interpreting the results. First, the sample size was small, which is inherent to cadaveric feasibility investigations and limits the generalizability of the findings. Second, the body donors had a relatively advanced mean age, which represents a limitation, as patients with SCJ injuries are typically younger; however, it also demonstrates that the flaps can be mobilized even in older individuals despite age-related changes in the periosteum, including reduced thickness, cellularity, and regenerative capacity [29, 30].

Furthermore, biomechanical testing was only performed on the CPFs and was limited to the structural properties of the harvested flap tissue itself. The complete reconstruction construct, including the flap in combination with the figure-of-8 FiberWire augmentation, was not subject to construct-level biomechanical testing. Therefore, conclusions regarding the overall mechanical stability of the final reconstruction cannot yet be drawn.

Finally, this investigation represents a purely cadaveric anatomic feasibility study. Although cadaveric experiments allow standardized assessment of anatomy and tissue handling, they cannot reproduce biological healing, remodeling, or clinical outcomes.

Clinical studies are needed to validate this technique in both acute and chronic SCJ dislocations in the future.