Background: The purpose of the present study was to determine whether there
was a difference between septic arthritis (SA) combined with osteomyelitis
and SA alone with regard to clinical and laboratory findings, such as symp
toms on admission, age, sex, joint involvement and isolated micro-organisms
, and a relationship between age and joint involvement in SA. In addition,
we also aimed to determine the prognostic factors in SA.
Methods: The clinical and laboratory findings of 40 patients who were diagn
osed with SA in our hospital were reviewed retrospectively. The diagnosis o
f SA was made according to the following criteria: immediate joint fluid as
piration (culture and Gram's stain positive, leukocyte count markedly eleva
ted and glucose level low), blood culture positive and positive cultures fr
om other possible sites of infection.
Results: Of the 40 patients, 22 were boys, 18 were girls and the male to fe
male ratio was 1.2/1. Patient ages ranged from 6 months to 14 years (mean (
+/- SD) 8.44+/-4.18 years). The most observed symptoms were fever (52.5%),
arthralgia (50%) and joint swelling (45%). Thirty-four (85%) patients had o
nly one joint and six patients (15%) had more than one joint involved. In t
otal, arthritis was diagnosed in 49 joints. The joints diagnosed as having
arthritis were the following: knee (n=18), hip (n=12), ankle (n=12), elbow
(n=3), shoulder (n=2), wrist (n=1) and interphalangeal joint (n=1). Of the
40 patients, 21 (52.5%) had SA alone and 19 (47.5%) had arthritis together
with osteomyelitis. While arthritis was diagnosed in 27 joints in the group
of patients with SA, it was diagnosed in 22 joints in the group of patient
s with SA combined with osteomyelitis; in the latter, an increase was not o
bserved in the number of joints involved. Joint fluid culture was positive
in 22 (55%) patients; the growth of Staphylococcus aureus was observed in 2
0 cases and Pseudomonas aeruginosa and Staphylococcus epidermidis were isol
ated in each patient. In contrast, in one patient, arthritis occured during
meningococcal meningitis (in this patient, Gram-negative diplococci was is
olated from a cerebrospinal fluid culture). Patients with SA combined with
osteomyelitis and those with SA alone were compared for symptoms on admissi
on, the history of trauma and antibiotic use, sex, age, fever, joint involv
ement, anemia, leukocytosis and micro-organisms isolated from joint fluid a
nd blood; there were no significant differences for these parameters betwee
n the two groups (P >0.05). In addition, we found that there was no relatio
nship between age and joint involvement in SA and there was no effect of mi
cro-organisms on mortality. Three of 40 patients died; the mortality rate w
as 7.3%. Of the three patients who died, two had SA alone and one had SA co
mbined with osteomyelitis. The primary disease was sepsis in these three pa
tients; S. aureus was cultured from blood in two patients and Gram-positive
cocci was observed following examination of the joint fluid in the other p
atient.
Conclusions: We would like to emphasize that SA is mono-articular, frequent
ly localized in the knee, hip and ankle in 85% of patients, joint fluid cul
ture was positive in 55% of patients, bacteria was isolated from one or mor
e cultures of blood, joint fluid, pus or bone in 70% of patients and the mo
st common isolated micro-organism was S. aureus. In addition, it must be po
inted out that children younger than 2 years of age with fever, a positive
trauma history and/or abnormal joint findings should be carefully examined
for SA because the rate of SA was lower (7.5%) than expected in this age gr
oup. We also found that the mortality of SA was not influenced by age, join
t involvement and bacterial agents, and there was no significant difference
in symptoms on admission, the history of trauma and antibiotic use, sex, a
ge, fever, joint involvement, anemia, leukocytosis and micro-organisms isol
ated from joint fluid and blood between patients with SA combined with oste
omyelitis and SA alone (P >0.05).