Reconstruction of the Sternoclavicular Joint After Excessive Medial Clavicle Resection

Medial clavicle excision is a rarely indicated procedure and may be performed in different pathologies affecting the medial clavicle. Excessive medial clavicle resection with an injury to the costoclavicular ligament often leads to poor postoperative results. The exact surgical treatment used in this kind of pathology when conservative treatment is unsuccessful remains unclear. The aim of this Technical Note is to describe our preferred surgical technique to treat this condition.

M edial clavicle excision has been used as surgical treatment in cases of recurrent instability of the sternoclavicular joint (SCJ), posttraumatic arthrosis, osteomyelitis, tumor, as well as nonunion or irreparable comminution of the proximal part of the clavicle. [1][2][3][4] During resection of the medial clavicle, the key principle to obtaining a satisfactory postoperative clinical outcome is to avoid injury to the costoclavicular ligament (CCL). Damage to the CCL can result in SCJ instability and poor clinical results. 1,5,6 The recommended extent of medial clavicular resection in the literature is variable, with one author proposing a resection of 4 cm. 1,[6][7][8][9][10][11] However, cadaveric biomechanical studies have reported that the average distance from the inferior articular surface of the medial clavicle and the most medial clavicular insertion of the CCL is 1.1 cm to 1.26 cm. 12,13 Additionally, a continuity between the capsule of the SCJ and the CCL, which has also been observed in a previous anatomical study by Cave,14 has been found in 3% to 12% of shoulders. 13,15 Authors who reported the absence of free space between the CCL and the inferior part of the SCJ cautioned about the lack of a real safe zone for excision of the CCL and recommended identifying the CCL in all cases before resection was initiated. 12,15 Excessive medial resection of the clavicle can result in a persistently unstable sternoclavicular joint. In such cases that have failed conservative treatment, surgical treatment is indicated. This Technical Note aims to describe our preferred surgical technique to treat this condition.

Surgical Technique Preoperative Patient Positioning
Preoperative intravenous antibiotic is administered before the start of surgery. The surgical procedure is performed with the patient under general anesthesia in a semiseated position with a towel roll placed under the central spine so that the chest and SCJ protrude forward. The sites of iliac graft harvesting and the operative arm are prepped and draped so that the SCJ can be examined dynamically during the procedure.

Iliac Bone Autograft Harvesting
The bony landmarks of the anterior superior iliac spine (ASIS) and the iliac crest are palpated. A horizontal incision is performed from 3 cm posterior to the ASIS and extended posteriorly for 3 to 5 cm along the iliac crest. The incision length depends on the size of the autograft needed, based on the preoperative computed tomography (CT) measurements (Fig 1). The cortico-cancellous bone graft is harvested with the straight osteotome. First, 2 coronal cuts are made through the ilium. Thereafter, a horizontal cut is made, and the iliac crest bone autograft (ICBA) is obtained. The defect in the iliac crest is filled with an absorbable hemostatic gelatin sponge (Spongostan; Ferrosan, Søborg, Denmark) to decrease bone bleeding. In thin patients, a cosmetic deformity may be present after iliac bone harvesting. As such, we propose to secure a small plate on top of the iliac crest over the bone defect to prevent cosmetic deformity (Fig 2, Video 1).

Surgical Approach Over the Clavicle and SCJ
In view of the proximity of critical mediastinal and neurovascular structures, we recommend that a cardiothoracic surgeon is on standby during this relatively risky procedure. The medial end of the clavicle and the SCJ is palpated and an incision line is drawn starting 3 cm lateral to the medial clavicular end and extended over the SCJ (Fig 3, Video 1). After the initial incision, the platysma is identified and preserved for later repair. A careful dissection of the proximal clavicular remnant, the upper part of the first rib and a thorough release of the anterior capsule of the SCJ are performed so that they are easily accessible for later reconstruction. The medial clavicular edge is revitalized with a saw (Fig 4, Video 1). Two high-strength sutures (Ethibond 5; Ethicon, Somerville, NJ) are passed through the first rib under the medial clavicle for final costoclavicular stabilization (Fig 5, Video 1). The posterior SCJ capsule is then slightly released (Fig 6, Video  1). A superior and inferior sternal tunnel of 4 mm diameter are drilled in an oblique direction on the sternum from the anterior cortex towards its right articular surface, while a malleable retractor is placed behind the sternum to prevent iatrogenic injury (Fig 7,  Video 1). 16 Preparation of the Gracilis Allograft Tendon (GAT) and ICBA The 4.0 mm diameter GAT is tagged with a stitch of approximately 2 to 3 cm in length on the free ends with a nonabsorbable suture material (Ethibond 6; Ethicon). The ICBA is shaped with a rongeur such that it nicely fits between the medial end of the clavicle and the sternum, while avoiding overstuffing. A tunnel is drilled horizontally through the ICBA, and the prepared GAT is passed through it (Fig 8, Video 1).

Reconstruction of the Medial Clavicle With Iliac Crest Bone Autograft
The ICBA is fixed onto the medial end of the clavicle with a plate (Fig 9, Video 1). Afterward, the GAT, which is passed through the ICBA, is pulled by shuttle sutures through the bone tunnel in the sternal part of the SCJ so that it forms a figure-of-eight configuration.  Patient is placed in a semiseated position. Iliac crest on the right side is seen. After iliac bone graft harvesting, a cosmetic deformity is a possibility. This is especially so in thin patients. To avoid it, we propose to fill the bone defect with an absorbable hemostatic gelatin sponge (Spongostan; Ferrosan, Søborg, Denmark) and additionally, to fix a 1/3 tubular plate on top of the iliac crest over the bone defect to allow the iliac crest to recover its shape. CAUD, caudal. e2734 While the joint is reduced, stabilization of the SCJ is performed by suturing both free ends of the GAT to one another using the high-strength suture (Ethibond 5) (Fig 10). 17 The figure-of-eight reconstruction is chosen because it is the stiffest construct for SCJ instability repair. 18 The final costoclavicular stabilization reconstructing the CCL is performed with the high-strength sutures passing through the first rib. Each strand of the sutures is brought around the opposite sides of the plate, and multiple knots are performed on the superior surface (Fig 11, Video 1). The SCJ can be dynamically tested for stability. During the procedure, the posterior structures should be protected with a Hohmann retractor.

Closure
The surgical field is irrigated with saline solution. Saline solution is allowed to pool inside the surgical field, and the anesthetist performs a Valsalva maneuver for the patient (Fig 12, Video 1). If air bubbles are seen coming up from underneath the clavicle, there has been a perforation of the pleura or lung. Next, the joint capsule and the platysma are reconstructed with Vicryl 2 sutures. Last, the subcutaneous layer and skin are closed in a standard fashion.

Postoperative Protocol
The patient was admitted to the hospital for overnight observance. The operated upper extremity should be in a sling for 6 weeks after operation. Supervised passive range of motion in the scapular plane is permitted. After 6 weeks, the patient begins with a progressive rehabilitation program.

Discussion
Resection of the medial clavicle is an infrequent surgical procedure and, if inadequately performed, results in poor clinical outcomes mandating further management. 1,5,6 If conservative treatment fails, surgical treatment is proposed. However, due to the rarity of this condition, controversy remains regarding the ideal surgical technique that should be used in symptomatic SCJ instability after excessive medical clavicle resection. Some authors have previously described surgical options in cases of nonunion or comminuted fractures of the medial proximal clavicle. Dion et al. 2 proposed to treat a medial clavicular fracture nonunion with medial clavicle excision combined with stabilization of the medial clavicle to the sternum with a figure-of-eight stabilization construct of palmaris longus graft. A similar solution was proposed by Sanchez et al. 19 who described a stabilization of SCJ with a tibial anterior allograft after medial clavicle excision of the medial comminuted clavicle fracture. Although these Fig 7. Patient is placed in a semi-seated position. Right SCJ is seen. Superior and inferior sternal tunnels are drilled in an oblique direction on the sternum from the anterior cortex towards its right articular surface in order to avoid an injury, whereas a malleable retractor is placed behind the sternum for additional protection. SCJ, sternoclavicular joint.    soft-tissue reconstructions could be an option in previously described conditions with a high-risk of osteosynthesis failure, we believe that the procedure we proposed is more beneficial because it includes bony reconstruction in addition to soft tissue reconstruction. By reconstructing the bone, there is better anatomic reconstruction with improved shoulder mechanics and function restoration. In addition, with bony consolidation of the graft to the native clavicle (Fig 13), there is a lower risk of failure of the soft tissue reconstruction.
Thus this technique should be used as the first option in the surgical treatment of a shortened clavicle because of excessive medial clavicle resection.
In cases where reconstruction of the normal clavicular osseous anatomy is unattainable, a salvage procedure such as a complete claviculectomy may be performed to try to ease symptoms. 20 However, this should be achieved as a last possible surgical option, only when all other options are exhausted.
The type of surgical technique we propose in this article should only be used in patients with a low risk of osteosynthesis failure. This includes patients who are compliant to immobilization treatment, have an intact first rib, which is needed to recreate the CCL effect, and do not smoke. Not following these recommendations could lead to failure. 21 To our knowledge, this is the first description in the literature reporting an anatomic   The cosmetic defect after autograft harvesting from the iliac crest can be avoided by filling the defect with an absorbable hemostatic gelatin sponge (Spongostan; Ferrosan, Søborg, Denmark) and securing a 1/3 tubular plate over the iliac crest. Injury of the retro-sternoclavicular joint structures is minimized during drilling of the sternal tunnels by drilling in an oblique direction on the sternum from the anterior cortex toward its articular surface and by placement of a malleable retractor behind the sternum. The autograft is shaped to fit between the medial clavicle edge and the sternum. This should be done appropriately to avoid overstuffing. While the joint is reduced, the stabilization of the sternoclavicular joint is performed by suturing the free ends of the gracilis allograft tendon to one another using a high-strength suture. After the reconstruction is finished, the saline is left inside the surgical field and observed for 10 to 20 seconds. Pneumothorax is excluded by absence of rising air bubbles. Pitfalls Postoperative nonunion or resorption of bone graft can occur that may require revision surgery. reconstruction involving bone and ligamentous restoration of the medial clavicle and SCJ in case of excessive medial clavicle resection. Further long-term studies can be performed to assess whether this surgical reconstruction and stabilization technique adequately restores normal shoulder mechanics and function.

Conclusion
In the setting of persistent sternoclavicular instability after excessive medial clavicle resection, a combination of osseous and soft tissue reconstruction can adequately restore sternoclavicular stability.