Radiograph demonstrating classic tuberculous arthritis

findings of Phemister’s triad: 1. Peripheral erosions. 2.

Juxta-articular osteoporosis. 3. Joint space loss.

The Rarely Hot Knee Dr S Arun-Castro MBBS PgDip PH

Clinical Fellow in Emergency Medicine, Newham University Hospital

Discussion:

Tuberculosis masquerades.

Experience tells us that tuberculosis is an

uncommon cause of knee mono-arthritis.

Epidemiology teaches us that whilst 47% of

disease is extra-pulmonary, only 2.5% is at

bony sites including the knee. [2]

If you see a hot knee, would you consider TB?

Abstract:

A 45 year old man with no rheumatological

history re-attended A&E with a swollen knee.

He had been discharged from Orthopaedics in

the previous month with the same problem

with a normal full blood count and joint

aspirate. His CRP was 120 and he was

discharged with anti-inflammatories.

Examination revealed a stiff, swollen, warm

knee with a temperature of 38.2C. Radiography

demonstrated Phemister’s triad.[1] Bloods

were unremarkable except for a still elevated

CRP.

As the 4 hour breech loomed closer, attention

turned to the previous joint aspirate. After 4

weeks, Acid Fast Bacilli had been detected,

making the diagnosis.

Words: 146 References: 1. Watts, R. Clunie, G. Hall,F. Marshall,T (2009). Oxford Desk Reference: Rheumatology. Oxford: Oxford University Press. 472. 2. Public Health England. (2013). Tuberculosis case reports by site of disease, UK, 2012. Enhanced Tuberculosis Surveillance (ETS). http://www.hpa.org.uk/webc/HPAwebFile/HPAweb_C/1317139694870#