Vol.2, No.5, 328-331 (2013) Case Reports in Clinical Medicine
Septic arthritis in an unusual localization
Lia Marques*, André Simões, Sara Úria
Serviço de Medicina III, Hospital Pulido Valente, Centro Hospitalar Lisboa Norte, Lisboa, Portugal;
*Corresponding Author: marques.lia@gmail.com
Received 5 June 2013; revised 30 June 2013; accepted 5 July 2013
Copyright © 2013 Lia Marques et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Septic arthritis is a rheumatological emergency
due to its potential for rapid articular destruc-
tion and permanent func tional loss. It s incidence
ranges between 4 and 29 cases per 100,000 per-
son-years, and depends on population variables
and preexisting structural joint abnormalities.
Clinical manifestations, severity, treatment and
prognosis depend on the aetiologic agent, pa-
tient basal status and articulation involved. The
sternoclavicular and condrosternal articulations
are rarely affected. A 24 years old man present-
ed with fever and right shoulder pain. Physical
examination revealed swelling, redness, increas-
ed local heat, intense p ain and functional impair-
ment of the patient’s right shoulder. Laboratory
inflammatory markers were elevated. Right ster-
noclavicular articulation ultrasound, right ster-
noclavicular articulation X-ray, and galium bone
scan have shown sternoclavicular arthritis and
medial clavicular osteomyelitis. Blood cultures
identified Staphylococcus aureus methicillin sen-
sitive. The patient completed a six week antibi-
otic regimen and physical rehabilit ation program.
Herein, the authors report a case of sternocla-
vicular septic arthritis complicated with osteo-
myelitis and review aetiology, diagnosis, treat-
ment and prognosis of this rare medical condi-
Keyw ords: Septic Arthritis; Sternocl avicular;
The incidence of septic arthritis ranges widely from 2
to 5/100,000/year in the general population, 28 to
38/100,000/year in patients with rheumatoid arthritis,
and 40 to 68/100,000/year in patients with joint prosthe-
sis [1,2]. The most common route of articular infection is
hematogenous spread during bacteremia [3,4]. Once in
the joint, microorganisms are deposited in the synovial
membrane, causing an acute inflammatory response. In-
flammatory mediators and pressure from large effusions
lead to the destruction of joint cartilage and bone loss
[3,5,6]. The large joints are most commonly affected, and
monoarticular infection is the rule [4,7]. Infections of
axial joints, such as the sternoclavicular usually occur in
patients with a history of intravenous drug abuse, im-
munossuppression, bacteremia or as a complication of a
subclavian vein central venous catheter [3,8].
Gonococcal arthritis is the most common cause of
acute monoarthritis in sexually active young adults [4].
Bacterial causes of septic arthritis include staphylococci
(40%), streptococci (28%), gram-negative bacilli, myco-
bacteria, gram-negative cocci, gram-positive bacilli, and
anaerobes [3,9]. S. aureus is the most common organism
that causes nongonococcal arthritis. Some of the viru-
lence factors of Staphylococcus aureus include collagen-
binding protein, clumping factor A and B, fibronectin-
binding protein A and B, capsular polysaccharide protein
A, toxic shock syndrome toxin-1 and enterotoxins [10].
The classic presentation of non-gonococcal septic ar-
thritis is the acute onset of pain, swelling, and decreased
range of motion in a single joint. Most patients are feb-
rile, but constitutional symptoms such as fever, chills or
rigours have low sensitivities [3,11]. There is often un-
derlying illnesses and predispositions to infections, such
as intravenous drug abuse; presence of prosthetic joints;
neoplasia, renal failure, and rheumatoid arthritis [1,12].
Physical examination reveals the warmth and tenderness
of the affect ed joint, joint effusion, and limited active and
passive range of motion [3].
Arthrocentesis and synovial fluid analysis should be
performed for all patients who present to an inflamed
joint. Synovial fluid should be evaluated for white blood
cells (WBC) count with differential, crystal analysis,
Gram stain, and culture [3,13,14]. For joints that are deeper
and more difficult to aspirate, ultrasound-guided or fluo-
roscopy-guided needle aspiration should be done [4]. In
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L. Marques et al. / Case Reports in Clinical Medicine 2 (2013) 328-331 329
synovial fluid, a WBC count of more than 50,000 per
mm3 and a polymorphonuclear cell count greater than
90% directly correlate with infectious arthritis, but this
overlaps with crystalline disease [3,11,15]. In patients
without previous antibiotic treatment, synovial fluid cul-
tures are positive in 70% to 90% of nongonococcal bac-
terial arthritis [15]. Blood cultu res are positive in 40% to
50% of cases and are the only method of identifying the
pathogen in 10% of cases [3,15-17].
Although inflammatory markers such as erythrocyte
sedimentation rate (ESR), C-reactive protein (CRP), and
WBC, are usually raised, their sensitivity is low [18,19].
There are no data on imaging studies that are pathogno-
monic for acute septic arthritis. Ultrasonography is more
sensitive for detecting effusions, particularly in difficult
to examine joints, such as acromioclavicular, or sterno-
clavicular [3]. Computed tomography (CT) and magnetic
resonance imaging (MRI) can provide useful images to
delineate the extent of the infection [4,20]. Triple-phase
bone scintigraphy is the preferred modality of investiga-
tion for multiple articular involvement [4].
A clinical suspicion of a joint infection warrants the
immediate initiation of antibiotic therapy [4]. Delays in
treatment increase morbidity and mortality. A consensu al
initial empiric therapy to cover gonoco cci, S. aureus, and
streptococci is ceftriaxone plus vancomycin pending
final culture results [4]. In healthy, young, sexually ac-
tive individuals with community-acquired septic arthritis
and a negative synovial fluid gram-stained smear, ceftri-
axone is a reasonable option to cover N. gonorrhoeae.
Narrow antibiotic coverage is indicated if gram-positive
cocci are found in the synovial fluid, and there is a pri-
mary source of staphylococcal skin infection. Appropri-
ate monotherapy in this case may be a penicillinase-re-
sistant penicillin or vancomycin if methicillin resistance
is likely [4]. During the first few days of management,
immobilization of th e infected join t by external sp linting
and adequate analgesic admin istration ensure patient com-
fort. Physical therapy should be instituted as soon as the
patient can tolerate it because early active range-of-mo-
tion exercises are beneficial for ultimate functional re-
covery [4].
Before antibiotics were available, two-thirds of pa-
tients died from septic arthritis [3]. Current mortality
rates of bacterial arthritis range from 10% to 20%, de-
pending on the presence of comorbid conditions, such as
older age, coexisting renal or cardiac disease, and con-
current immunosuppression [3].
Even with all incremental knowledge of the patho-
genesis of septic arthritis caused by the common organ-
isms, such as Staphylococcus aureus, treatment and out-
come, of septic arthritis, have not improved sub stantially
over the past 30 years [4,21] making it important to no-
tify and discuss clinical cases of septic arthritis, particu-
larly those with special context such as the case pre-
sented here.
A 24 years old male, single, professional volleyball
player, with no previous clinical history was observed at
the emergency room for a 4-days story of fever (axillary
temperature: 39.2˚C) with chills, and a fever free period
of 6 hours after acetaminophen ingestion. He had also a
3-weeks pain lo calized in his right infraclavicular region,
irradiating to the right shoulder, without a previous
trauma. There were no other symptoms associated. He
was monogamist, maintained unprotected sexual inter-
course, and had no risk factors for particular infectious
diseases. One month previous to hospital admission he
had an incise skin wound in the right dorsal region, at the
time without any disinfection. For the right infraclavicu-
lar pain he had already seek medical attention being di-
agnosed tendinitis and prescribed nonsteroidal anti-in-
flammatory drugs and mesotherapy.
Physical examination revealed: dehydration, fever (tym-
panic temperature 39.5˚C), normal blood pressure and
sinus tachycardia (heart rate 110 bpm), swelling, redness,
increased local heat, intense pain and functional impair-
ment (abduction and adution) in his right shoulder. The
investigations yielded the following results: white blood
count, 4480/mm3; neutrophil, 82.4%; Haemoglobin: 14.3
g/dL, platelets: 240,000/mm3. Blood C-reactive protein:
9.5 mg/L; Creatinine 1.2 mg/dL; Urea 23 mg/dL; Chest
X-ray, right shoulder X-ray, clavicle and sternoclavicular
join X-ray, right shoulder ultrasound and right shoulder
computerized tomography (CT) has shown no structural
The patient was admitted to an intern al medicine ward
where investigation for febrile illnesses revealed: viral
serological investigations were negative; transthoracic
echocardiogram without abnormalities or valvular vege-
tations. For the first 48 h ours the patient remained feb rile
and there were worsening inflammatory signs in right
infraclavicular region, he was then admitted with a pre-
sumptive diagnosis of septic arthritis of the right sterno-
clavicular articulation. He was started with IV Ceftri-
axone. At fourth antibiotic treatment day the patient had
sustained apyrexia with reduction of laboratory inflam-
mation markers. Blood cultures yielded Staphylococcus
aureus methicillin sensitive (in five separate blood sam-
ples). Antibiotic regimen was changed to oxacillin ac-
cording to sensibility testing. The patient was submitted
to right clavicular ultrasound that has shown: liquid im-
age in the sternoclavicular articulation measuring 39 ×
24 × 0.5 mm with calcification representing arthritis
(Figure 1). A right sternclavicular articulation X-ray was
performed: inferior medial clavicular erosion (Figure 2).
A galium bone scan has shown osteomielitis of the me-
Copyright © 2013 SciRes. OPEN ACCESS
L. Marques et al. / Case Reports in Clinical Medicine 2 (2013) 328-331
Figure 1. Right clavicular ultrasound showing liquid image in
the sternoclavicular articulation measuring 39 × 24 × 0.5 mm
with calcification representing arthritis.
Figure 2. A right sternclavicular articulation X-ray with inferior
medial clavicular erosion.
dial half of right clavicle (Figure 3). The patient com-
pleted a 14 days regimen of parenteral antibiotic therapy
with oxacillin 2 gr every 6 hours. Followed by oral flu-
oxacillin for another 6 weeks. One year of intense phy-
sical therapy he came back to his active professional life
as a volleyball player.
Septic arthritis incidence appears to be increasing,
probably due to orthopedic procedures, an aging popula-
tion, and the increased use of immunosupressive therapy
[15]. Even so, the sternoclavicular articulation is rarely
Figure 3. Galium bone scan showing osteomielitis of the medial
half of right clavicle.
affected, with an incidence of 5% [4,22]. A case of septic
arthritis of the right ster oclavicular articulation compli-
cated with osteomyeliltis is reported. There are no clas-
sical risk factors identified for septic arthritis in this pa-
tient, but previous articular damage due to the patient
profession may represent a susceptibility factor. A main
source of hematogenous spread to septic arthritis is skin
lesions, as in this case [3]. The definitive diagnosis of
septic arthritis is established through the isolation of the
bacteria in the articular fluid [4]. In the reported case
arthrocentesis was attempted but wasn’t possible due to
lack of ultrasound window for the exam. Even so, the
clinical setting associated with the positive blood cul-
tures and imagiologic findings are representative of sep-
tic arthritis. Usually plain films are initially normal, but
often show nonspecific changes of inflammatory arthritis,
and may reveal complicating osteomyellitis [4]. When
the identity and the sensitivities of the organism are
known, antibiotic therapy should continue with the most
efficacious agent that has the best safety profile and nar-
rowest spectrum. The parenteral route of antibiotic ad-
ministration is the preferred initial treatment [4]. The
optimal duration of antibiotic treatment has not been pro-
spectively studied. For non-gonococal septic arthritis ther-
apy ranging from 2 weeks to 6 weeks is recommended.
Parenteral antibiotics may be switched to oral antibiotics
after 2 weeks provided that there is clinical improv ement,
inflammatory markers are trending down, and oral anti-
Copyright © 2013 SciRes. OPEN ACCESS
L. Marques et al. / Case Reports in Clinical Medicine 2 (2013) 328-331
Copyright © 2013 SciRes.
biotics are available to which the microorganism is sus-
ceptible [4,17]. Staphylococcal septic arthritis usually
requires 3 to 4 weeks of therapy [6,23]. Due to the pres-
ence of osteomyelitis antibio tic therapy was prolonged to
6 weeks in this patient.
The outcome of treated septic arthritis can be meas-
ured as mortality and functional outcome of the infected
joint. After completing antimicrobial therapy, patients
with S. aureus septic arthritis regain 46% to 50% o f their
baseline joint function [3,16]. Morbidity (e.g., amputa-
tion, arthrodesis, prosthetic surgery, severe functional de-
terioration) occurs in one-third of patients with bacterial
arthritis, usually affecting older patients, those with pre-
existing joint disease, and those with synthetic intraar-
ticular material [3]. This patient had a long term full
functional articular recovery.
This case report highlights that septic arthritis can be
particularly difficult to diagnose and treat if it occurs in
fibrocartilaginou s joints such as the sterno clavicular join t.
It also reinforces the need to consider the diagnosis of
septic arthritis in any patient with acute inflammatory
arthritis, since prompt diagnosis and treatment of infec-
tious arthritis can prevent significant morbidity and mor-
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