Introduction
There has traditionally been a high threshold before undertaking any surgical procedure around the sternoclavicular joint (SCJ). This has been, in part, due to its midline location, its high dependence on static and dynamic soft tissue stabilizers, and the retrosternal structures that lie behind it. As a result, conditions such as intra-articular loose bodies, primary and posttraumatic osteoarthritis, and intra-articular disk tears, which would routinely be successfully treated by surgical intervention in other joints, are managed by ongoing nonoperative measures.
More recently a combination of a better understanding of the surgical anatomy of the SCJ, improved diagnostic imaging, and an evolution in arthroscopic techniques has led to the development of arthroscopic SCJ surgery. This has enabled physicians to safely undertake arthroscopic surgical procedures for certain SCJ intra-articular conditions with minimal surgical risk and postoperative morbidity.
Surgical indications
Arthroscopic SCJ surgery enables the surgeon to address certain purely intra-articular conditions and requires the surrounding joint capsule to be intact. Arthroscopic procedures are generally undertaken only for atraumatic disorders but may be indicated for certain traumatic injuries (posttraumatic loose bodies, acute disk tears) once any acute capsular damage has recovered.
Diagnostic arthroscopy
For certain atypical monoarticular inflammatory conditions and occult infections, a fluid aspirate and synovial tissue samples can be obtained for diagnostic purposes.
Therapeutic arthroscopy
A therapeutic SCJ arthroscopy can be undertaken to excise symptomatic loose bodies, which are usually posttraumatic in origin ( Fig. 28.1 ). Joint arthroscopy also remains a treatment option for septic arthritis where the joint can be thoroughly irrigated and an extensive soft tissue debridement undertaken. This can be sequentially repeated if required.
Primary sternoclavicular joint osteoarthritis
Open excision arthroplasty, in the form of excision of the medial end of the clavicle, has been shown to be a successful treatment for symptomatic SCJ osteoarthritis. Arthroscopic intra-articular excision arthroplasty of the SCJ has demonstrated similar results. An arthroscopic SCJ excision may be indicated in patients with symptomatic primary or posttraumatic osteoarthritis who have not responded to adequate conservative management, including an intra-articular cortisone injection. Diagnostic imaging in the form of either magnetic resonance imaging (MRI), computed tomography, or digital tomography is required before considering surgery ( Fig. 28.2 ). ,
Relative contraindications are previous open SCJ surgery (i.e., revision cases), extensive infection (i.e., extra-articular extension into the mediastinum), and instability. This includes patients with large anterior or posterior osteophytes, where the capsule has been stretched out and where there may already be an element of secondary atraumatic instability. There is a possibility that, following arthroscopic excision of the medial end of the clavicle, the joint may become unstable. In these patients an open excision arthroplasty, which can incorporate a capsular plication, may be indicated (see Chapter 27 ).
Intra-articular disk tears
An arthroscopic excision of a torn intra-articular disk may be indicated in patients with a symptomatic disk tear. Symptoms may include pain, clicking, locking, or a feeling of jumping/pseudosubluxation. Disk tears can occur acutely in younger patients as the result of a traumatic shearing injury or as an acute-on-chronic or chronic tear in older patients. Disk tears can be only accurately diagnosed on an MRI scan ( Fig. 28.3 ).
Relative contraindications to an arthroscopic SCJ disk excision are previous open surgery (i.e., revision cases), infection, and instability. Surgery following an acute injury should be delayed for 4 to 6 weeks to allow for any capsular injury to heal.
Sternoclavicular joint arthroscopy
Surgical technique: Initial setup
Positioning and equipment
SCJ arthroscopy is performed with the patient under general anesthesia and positioned supine. The patient’s head is positioned in extension in a head ring with a sandbag positioned between the scapulae to retract and open up the SCJs anteriorly. The operating surgeon stands on the operative side of the patient facing toward the head, where the operating stack (i.e., arthroscopic monitor) is positioned. A 30- or 70-degree, 2.7-mm arthroscope with a 30-mm trocar is used for visualization. A mini-probe, mini-shaver, and mini-bur along with other small instruments are used. A bipolar radiofrequency probe is used for tissue ablation and coagulation.
Portal placement
The main factors to consider when determining the most appropriate and safest positions for portal placement are (1) the anatomy of the anterior SCJ ligament (see Chapter 25 ), (2) the area of bony congruence of the joint in the coronal plane, and (3) the angle of inclination in the axial plane.
Two portals are required to undertake any therapeutic arthroscopic procedure. The first portal established is the inferior portal. This portal is positioned at the inferior edge of the joint, just below the inferior edge of the anterior SC ligament, and enters into the inferior congruent part of the joint. The second (i.e., superior) portal is established at the level of the superior point of the medial clavicle, above the superior edge of the anterior SC ligament ( Fig. 28.4 ).
The plane of the SCJ is not perpendicular to the mediastinum. A computed tomography scan study found that the medial end of the clavicle had a variable angle of inclination but that the angle of inclination of the manubrium was consistent at 30 degrees to the axial plane ( Fig. 28.5 ).
Diagnostic sternoclavicular joint arthroscopy
The bony landmarks of the medial end of the clavicle and the manubrium are drawn out. An 18-gauge spinal needle is inserted into the inferior part of the SCJ at an inclination of 30 degrees to the vertical ( Fig. 28.6 ). Normal saline solution is then injected to distend the joint. Approximately 10 mL of fluid should be easily injected with a “flashback” when removing the syringe. This helps to confirm correct placement.
Related posts:
Tumors and Related Conditions
Throwing athletes
Epidemiology, evaluation, and nonoperative management of acromioclavicular joint disorders
Anterior instability: Arthroscopic surgery and outcomes
Multidirectional instability—open inferior capsular shift
Evaluation of rotator cuff pathology: History, examination, and imaging
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
