Sternoclavicular Joint Infection Caused by Staphylococcus capitis

Summary

Here, we present a case of a right sternoclavicular joint infection with osteomyelitis due to Staphylococcus capitis. The patient underwent surgical debridement and drainage followed by 10 weeks of antibiotics, resulting in complete symptom resolution and satisfactory wound healing.

Abstract

A 74-year-old female patient presented with "palpitations and chest tightness for half a day." The symptoms developed suddenly while riding an elevator, accompanied by shortness of breath, but without dizziness or chest pain. The patient had a 5-year history of diabetes, managed with metformin. She had undergone a right mastectomy 20 years ago for breast cancer. On admission, her vital signs were stable. Physical examination revealed a tender, swollen mass in the right side of the neck, soft in texture, with purulent drainage. Blood tests showed an elevated C-reactive protein (CRP) level (51.47 mg/L). Imaging studies (computed tomography [CT], ultrasound, magnetic resonance imaging [MRI]) revealed a soft tissue mass in the right clavicular region, with possible osteomyelitis. The patient was diagnosed with a right-sided sternoclavicular joint skin infection complicated by osteomyelitis.

Surgical debridement and drainage were performed, and pathological examination confirmed a Staphylococcus capitis infection. The patient was treated with a 10-week course of antibiotics, initially with intravenous ertapenem, later switched to oral linezolid. Throughout the treatment, no adverse drug reactions were observed. One month later, follow-up observations indicate that the patient's surgical wound is healing well. The patient's symptoms significantly improved, with complete resolution of palpitations, chest tightness, and shortness of breath. The treatment was well-tolerated. This case report aims to raise clinicians' awareness of sternoclavicular joint infections caused by Staphylococcus capitis and to highlight the importance of early diagnosis and individualized treatment strategies.

Introduction

Sternoclavicular joint infection (SCJI) is a rare form of septic arthritis, accounting for less than 1% of all infectious arthritis cases^1,2. Despite its low incidence, SCJI can lead to serious complications such as mediastinitis, chest wall abscess, and pulmonary empyema^2,3,4. Staphylococcus capitis, a coagulase-negative staphylococcus (CoNS) and a common commensal organism of human skin, has been increasingly implicated in catheter-related bloodstream infections, prosthetic joint infections, and wound infec....

Protocol

This surgical procedure has been approved by the hospital's ethics committee and conducted in accordance with the ethical guidelines provided. Informed consent was obtained from all individual participants involved in the study.

1. Initial evaluation and sample collection

1. Comprehensive skin examination
   1. Conduct a thorough inspection of the affected skin area, paying particular attention to the presence of erythema, swelling, tissue necrosis, and purulent exudation.
      ​NOTE: Capture baseline visual documentation (e.g., photographs and lesion dimensions) and record initial clinical manif....

Results

A 74-year-old woman presented with a half-day history of sudden-onset palpitations, chest tightness, and shortness of breath, without dizziness or chest pain. She had a history of type 2 diabetes managed with metformin and prior breast cancer surgery. Physical examination revealed a ~2 cm red-purple, tender mass over the right sternoclavicular joint with localized warmth and purulent discharge. Electrocardiography showed supraventricular tachycardia (>200 beats/min). Imaging studies, including ultrasound and MRI, demo.......

Discussion

Sternoclavicular Joint Infection (SCJI) is a relatively rare joint infection, but its incidence may be higher in certain populations. According to the literature, sternoclavicular joint infection can occur in various clinical contexts, including postoperative infections (such as extension of sternal osteomyelitis to the sternoclavicular joint after cardiac surgery)¹⁷, immunosuppressive states (such as after the use of immune checkpoint inhibitors)¹⁸, and primary bacterial o.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Amies Transport Medium	Thermo Fisher	9805-200	Used for transporting wound exudate samples to the microbiology lab
Bipolar Electrocautery	Valleylab (Medtronic)	1190-0001	Used for excising necrotic or infected tissue during surgery
Crystal Violet (0.5% w/v)	Sigma-Aldrich	C-5810	Staining reagent for Gram staining
Ethanol (70%)	Sigma-Aldrich	E7023	Used for tissue dehydration and fixation in staining protocols
Faropenem (oral)	N/A	N/A	Antibiotic used in the second phase of treatment
Formalin (10%)	Sigma-Aldrich	F-1635	Used for tissue fixation before histopathological analysis
Grocott's Methenamine Silver Stain	Sigma-Aldrich	3953-000-5	Used for fungal identification in tissue samples
Proteinase K	Sigma-Aldrich	25560-039	Used in DNA extraction from tissue samples
Safranin (0.25% w/v)	Sigma-Aldrich	S8884	Counterstain used in Gram staining
T1-weighted MRI Sequence	Siemens Healthineers	NA	Imaging sequence for soft tissue assessment
T2-weighted MRI Sequence	Siemens Healthineers	NA	Imaging sequence for soft tissue and bone evaluation
VITEK System	BioMérieux	4112118	Automated system for bacterial identification