Iliopsoas AbscessesJeremy Lynch

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Case66 year old female former secretary

6 month history of increasing right loin and hip pain

Recently saw an orthopaedic surgeon who ascribed the hip symptoms to age

For past 2 days: Severe exacerbation of pain Fever Nausea

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ExaminationPyrexial

Tachycardic

BP: 100/72

Swelling, and tenderness localized at the right side at the back of waist

Most comfortable with right hip in flexion

Extension especially painful

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InvestigationsRaised WCCs, CRP, mild anaemia

CXR/AXR: nil of note

Ultrasound pelvis/abdomen: nil of note

CT shows: hypodense lesion causing enlargement of the psoas muscle

Diagnosis of psoas abscess made

Treated with CT guided drainage

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DefinitionCollection of pus in the iliopsoas compartment

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Psoas Major

Iliacus

Aetiology1. Primary: haematogenous spread of bacteria

from distant source

2. Secondary: inflammatory/infectious process nearby

Growing in frequency with growing use of CT scanning

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Primary Causes

Risk Factors

Diabetes mellitus

AIDS

Renal Failure

Immunosuppression

IV drug abuse

Older patients

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Haematogenous spread of bacteria

Secondary Causes

System Cause

Gastrointestinal Crohns, Diverticulitis, Appendicitis, Colorectal Cancer

Genitourinary UTI, Cancer, Extracorporeal Shock Wave Lithotrypsy

Muskuloskeletal Verterbral osteomyelitis, Septic arthritis, Infected sacroilitis

Vascular Infected AAA, Femoral catheterization

Miscellaneous Endocarditis, IUD

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Inflammatory/infectious process

Epidemiology

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Clinical Features

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Examination

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Investigations

Bloods CRP/ESR FBC Cultures

Radiological Plain films Ultrasound CT/MRI

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Management Antibiotics

CT Drainage 1984 first attempted Wael, 2008: 41 adults Problem of recurrence:

15% in Wael study

Surgical Drainage: Significant morbidity

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MessageDiagnosis is difficult and often delayed

Diagnosed more frequently now due to CT

Dangerous if untreated

Thorough clinical examination can suggest

Repeated imaging often needed to confirm

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ReferencesMallick, Thoufeeq, Rajendran. Iliopsoas

Abscesses. Postgrad Med J. 2004. 80:459-462

M. Cantasdemir, B. Kara, D. Cebi, N. D. Selcuk and F. Numan. Psoas abscess rarely requires surgical intervention. The American Journal of Surgery. 2003. 58:811

Ricci, M.A., Rose, F.B., Meyer, K.K. Pyogenic psoas abscess: Worldwide variations in etiology. World Journal of Surgery. 1986. 10:834

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