2nd order laboratory parameters – depending on the results of the history, physical examination and obligatory laboratory parameters – for differential diagnostic clarification.
- Small blood count [septic arthritis (inflammatory joint disease)/osteomyelitis (bone marrow inflammation): leukocytes ↑]
- Inflammatory parameters – CRP (C-reactive protein) [septic arthritides/osteomyelitis: CRP ↑]Note: Inflammatory parameters may not be elevated or only slightly elevated in an infant even in the presence of massive joint empyema (pus accumulation).
- Urine status – in arthritis (joint inflammation) with renal involvement, proteinuria (excessive excretion of protein in the urine), hematuria (blood in the urine), if necessary.
- Alkaline phosphatase – suspected bone changes such as bone metastases, Paget’s disease.
- If necessary, rheumatism diagnostics (see at the corresponding clinical picture).
- If necessary, Lyme disease diagnostics (see at the disease picture of the same name).
- Hip joint puncture – if inflammatory (possibly rheumatic) and tumorous processes are suspected, as well as with detectable joint effusion and elevated inflammatory parameters, the puncture must be performed immediately
Notice:
- In febrile children (body temperature > 38 °C) with elevated CRP and leukocytosis (increase in the number of white blood cells) and the suspicion of a septic event, immediate further X-ray diagnosis and hip puncture are required.
- Low-grade PPI (periprosthetic infection, PPI) is not detectable by any laboratory analysis!
