PYOGENIC ABSCESSES OF THE PSOAS MUSCLE

Thirteen cases of pyogenic abscess of the psoas muscle were reviewed r etrospectively. The abscess was primary in five cases (38.5 %) and sec ondary in eight (61.5 %). Fever (n = 12), low back pain (n = 7), and h ip flexion with a psoas sign (n = 8) were the main clinical manifestat ions. Ultrasonography was done in all 12 patients and computed tomogra phy in ten. Cultures of pus specimens were performed in 11 patients an d yielded Staphylococcus aureus in eight, Escherichia coli in two, and Proteus mirabilis in one. All patients were given antimicrobials. The abscess was drained surgically in seven patients and percutaneously i n six. The short-term outcome was favorable in every case. An unusual characteristic of our series was the large proportion of patients with abscesses secondary to renal or osteoarticular infections. Nonsurgica l treatment was effective in five of six patients.