Higher suggested cut-off values for periprosthetic joint infection diagnosis were identified among obese patients who underwent revision total knee arthroplasty compared with patients who were not obese, according to study results.
Researchers collected body mass index, serum inflammatory markers and synovial fluid for 102 patients who underwent revision total knee arthroplasty (TKA) and analyzed for the highest area under the curve. Patients were classified as infected or non-infected and obese or non-obese and placed into four groups based on their classifications.
No differences in serum C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) or synovial values were observed between patients who were obese and non-obese, according to the researchers.
When using receiver operating characteristic curves, the researchers found a higher CRP cut-off value for diagnosing periprosthetic joint infection (PJI) in obese patients, as well as a smaller difference in ESR cut-off.
Compared with the traditional value, the suggested cut-off value for CRP performed better in every category among patients who were not obese with equal sensitivity. The suggested cut-off value achieved higher accuracy, specificity and positive predictive value among patients who were obese but demonstrated inferior sensitivity and negative predictive value.
According to the researchers, the suggested cut-off ESR values performed similarly to traditional ESR values, but with slight improvements in specificity.
Disclosure: See the study for a full list of all authors’ relevant financial disclosures.