Functional Disability Associated With Proximal Clavicle Resection and Pectoralis Flap Transposition for Sternoclavicular Joint Infections

Sternoclavicular joint infections (SCJI) are rare yet serious infections associated with chronic disease states, including diabetes, chronic immunosuppression, rheumatoid arthritis, HIV, and end-stage renal disease.¹ Though comprising only 1% of all bone and joint infections, the incidence of SCJI is growing with increased rates of intravenous drug abuse (IVDA).² Treatment for such infections can range from conservative therapy with intravenous antibiotics to more invasive treatment, including incision and drainage and proximal clavicle and sternoclavicular joint (SCJ) resection with or without pectoralis muscle transposition. Though there have been successful cases of treatment with joint aspiration and intravenous antibiotics reported, studies have shown an 83% failure rate among patients treated with conservative medical management only vs a 100% cure rate in patients who underwent SCJ resection with subsequent transposition of the pectoralis muscle to cover the defect. Thus, surgical management remains the optimal treatment of choice.^3-5 Whereas smaller defects can be closed primarily by approximating the edges of the sternocleidomastoid with surrounding tissue, the majority of SCJ resections are subcutaneous and create a large defect, necessitating the use of a pectoralis flap.

Anatomically, the SCJ comprises part of the shoulder girdle, alongside the proximal clavicle and the acromion of the scapula. The shoulder girdle is responsible for maintaining strength in the upper extremities. Furthermore, the sternocleidomastoid muscle attaches to the posterior edge of the of the inner 1/3 of the clavicle, whereas the pectoralis major attaches to the anterior edge. Resection of the proximal 1/3 of the clavicle lateral to the costoclavicular joint may result in deficits in arm elevation and shoulder protraction, potentially leading to long-term shoulder disability.^6-8

Diagnosis of SCJI is usually clinical based on symptoms, including fever, joint swelling, and immobility of the septic joint; however, the nonspecific symptomatology, rarity of cases, and insidious onset of symptoms often lead to late diagnoses that are delayed on average up to 2 weeks after symptom onset.^7,8 The close proximity of the SCJ to the subclavian vessels, phrenic nerve, and underlying pleural space increase the risk for seeding of the infection to these structures, resulting in mediastinitis and sepsis. The spread of SCJI to the mediastinum qualifies as a surgical emergency.

Uncomplicated cases of SCJI can be managed medically with antibiotics, whereas complicated cases involving spreading of the infection pose a risk to shoulder joint functionality. Timely surgical management of complicated SCJI has been associated with preserved physical function of the shoulder joint, further warranting early diagnosis and treatment. The long-term sequelae of surgical management of SCJI on shoulder joint function remains unclear due to a paucity of research addressing the topic, with some studies showing minimal impact on shoulder joint function with surgical resection of the SCJ, associated ribs, and pectoralis flap closure.^5,8

Here, we report on the long-term physical functionality and shoulder joint dysfunction of 15 SCJI patients managed surgically with proximal clavicle resection and pectoralis flap coverage.

In this prospective study, 15 consecutive cases of sternoclavicular joint infections were treated with proximal clavicle resection and pectoralis muscle flap coverage. Patients were followed 8 to 19 months after initial treatment.

Operative Technique

All diagnoses of SCJI were confirmed with computed tomography imaging. Initial debridement was performed by a single thoracic surgeon, which involved resection of the SCJ along with the hemimanubrium, the clavicle lateral to the inflammatory mass (typically medial third of the clavicle), and medial aspect of the first rib, if involved. Temporary closure was then achieved with a wound vacuum-assisted closure device (Kinetic Concepts, Inc). Subsequent debridement was performed as required if the margins of the debridement did not appear healthy. In most cases, 1 subsequent debridement followed by immediate pectoralis flap closure was performed by a single plastic surgeon. The ipsilateral pectoralis muscle was mobilized off its medial attachments to the sternum and superior attachments to the clavicle (Figure 1). The plane deep to the pectoralis was mobilized as far lateral as the underlying pectoralis minor muscle (Figure 2). The plane superficial to the pectoralis fascia was developed but to a lesser extent to allow advancement of the pectoralis muscle into the defect. The pectoralis muscle was secured to the sternocleidomastoid muscle with interrupted sutures in an imbricating fashion to obliterate the dead space (Figure 3), and 2 drains, 1 deep and 1 superficial to the flap, were placed.

The average length of follow-up was 12 months. None of the patients received postoperative physical therapy. To evaluate functional disability postoperatively, the Shoulder Disability Questionnaire (SDQ), a 16-question patient-reported questionnaire (van der Heijen et al, Appendix 1)⁹ was used. This questionnaire was chosen based on its simplicity (patients who were lost to follow-up could still answer the survey over the phone) and ability to provide a functional assessment of activities of daily living. Shoulder disability score was calculated based on patient responses. Score was assessed on a 100-point scale. Data were analyzed in SPSS (IBM Corp, version 26). Consent for the study was obtained by phone. This study was approved by the University of Louisville IRB (IRB #20.0692).

The demographic data are reported in Table 1. This study identified 15 patients undergoing proximal clavicle resection with pectoralis flap coverage. The average age was 50 years (range, 23-73 years), 7 were male, and nearly half (7/15) were IVDA or tobacco users. MRSA represented most infections, and IVDA represented the most common etiology for SCJI in this cohort. Of these patients, 3 were lost to follow-up, 1 was excluded due to subsequent shoulder surgery for a problem unrelated to their SCJI, and another was excluded due to inability to participate due to neurologic deficits from a stroke. An additional patient whose initial infection was associated with IVDA had recurrence of their infection within 30 days of the original operation. The final analysis included 10 patients. Despite a wide range of etiologies and patient comorbidities, the long-term shoulder disability was minimal (mean score of 6 ± 9). When the SCJI was attributed to IVDA, however, the long-term shoulder disability was significantly higher (mean score of 33 ± 16, P < .05).

Though rare, infections of the SCJ are serious and often difficult to diagnose. Delayed diagnosis due to nonspecific symptoms can allow for seeding of the infection to nearby structures in the mediastinum, posing a risk for sepsis and prompting emergent surgical management. Resection of the proximal clavicle and pectoralis muscle flap transposition is the preferred surgical approach for complications of SCJI and has been generally observed to result in minimal long-term shoulder disability.

The clavicle, together with the scapula, forms the shoulder girdle by adjoining the manubrium of the sternum to the acromion of the scapula and is the only articulation between the upper extremity and the axial skeleton. It also serves as an insertion site for cervical and thoracic musculature, including the sternocleidomastoid muscle (SCM) and the pectoralis major, protecting the subclavian and axillary vessels as well as the brachial plexus. The clavicle participates in transmitting the force of the trapezius to the scapula via the coracoclavicular ligament.⁵ Given the role of the shoulder girdle in maintaining strength in the upper extremities, partial resection of the proximal clavicle, particularly lateral to the costoclavicular ligament, was believed to lead to deficits in shoulder function and upper body strength. As such, all SCJI should involve thorough examination of the shoulder girdle.^5-7 Overall, this study found that long-term shoulder disability was minimal.

Pectoralis flaps can pose a risk for postoperative morbidity and mortality, including recurrence of infection, requiring additional debridement or revision.¹⁰ In this study, the surgery was well tolerated by the patients, with only 1 patient experiencing recurrence of their infection, most likely due to ongoing IVDA.

Though shoulder disability was low overall, IVDA experienced significantly higher shoulder disability than non-IVDA (33/100 mean score in IVDA vs overall). The score for IVDA was higher despite full resolution of symptoms postoperatively. This could be due, in part, to the well-documented chronic pain and opioid-induced hyperalgesia among persons with chronic opioid use.^11,12

IVDA is a well-known risk factor for SCJI.^13,14 In this study, nearly half (7/15) were IVDA, correlating with the high prevalence of opioid dependence particularly within the Midwest and Southern regions of the United States.¹⁵ Of the patients lost to follow-up in this study, 2 of 3 were IVDA. The elevated risk among IVDA patients for developing SCJI coupled with the possibility of missed or delayed diagnoses highlight the need for close meaningful follow-up and maintaining a high clinical suspicion in this vulnerable patient population.

Comorbid conditions, including end-stage renal disease, in patients undergoing clavicle resections and pectoralis flaps have been shown to correlate with postoperative morbidity and mortality.¹⁶ This study demonstrated similar comorbid conditions as those most reported, with 2 patients having diabetes and 3 being immunocompromised. Notably, nearly half of this study’s patients were tobacco users, but tobacco use did not correlate with shoulder disability long-term or resolution of symptoms.

Most patients in our study were infected with staphylococcus aureus (6/15 MRSA vs 3/15 MSSA), which is consistent with reports that staphylococcus aureus is the leading source of infection in most cases of SCJI.¹⁷ The remaining 5 patients with non–MRSA or MSSA infections did not demonstrate higher incidence of shoulder joint disability or delayed symptom resolution.

This study had several limitations, including a small patient population (N = 15). This is due, in part, to the relatively rare incidence of these infections. These results were also limited by the subjective nature of patient-centered outcomes from a self-report survey. Furthermore, the study did not compare shoulder joint disability in patients with SCJI managed nonoperatively. Finally, the high prevalence of IVDA in this study could be associated with Louisville’s regional position as an area heavily affected by the opioid epidemic. Thus, the results might not be generalizable to other areas.

Affiliations: ¹School of Medicine, University of Louisville, Louisville, KY; ²Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Kentucky, Lexington, KY; ³Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Louisville, Louisville, KY

Correspondence: Rachel H Safeek, MD, MPH; rachel.safeek@gmail.com

Ethics: Consent for the study was obtained by phone. This study was approved by the University of Louisville IRB (IRB #20.0692).

Disclosures: The authors disclose no financial or other conflicts of interest.