Scar Cellulitis

Did you know... because I didn't

read on to find out more.

65yo patient presented to ED with increasing erythema and warmth to the skin surrounding a lateral hip scar for THR 1 year ago. At the time of the THR he had had a post op collection and washout. But had no problems since. 

In ED he was well, afebrile.

Cellulitic area was about 15x10 with no fluctuance. 

EDUS revealed hypoechoic areas in the soft tissue suggestive of a collection. But there was no hip effusion anteriorly.

We got a formal US:

hypoechoic collection surrounded by echogenic fat

So, the interesting thing about this is that once you have a THR, you no longer have a capsule. So any joint effusion spreads out and collects posterior and lateral to the hip joint like in this patient. 

He was admitted under ortho and is having a washout and removal of prosthesis today.

So beware upper thigh and buttock cellulitis in the patient with a THR.