Considering the high-rate of air entrapment as seen in elective total hip arthroplasty directly postoperatively and still at discharge, the suspicion of infection with gas-producing bacteria may only be raised in case of radiological air entrapment in combination with severe pain, local signs of infection and deteriorating patients’ condition, whilst high CRP- as well as reduced haemoglobin-levels are rather the consequence of surgery than an indication of underlying necrotising fasciitis. Here, CRP is linked to infection.