Introduction: Routinely used inflammatory markers such as ESR and CRP are suggested to suspect post-operative infection at an early stage. Therefore their normal trend after arthroplasty surgeries need to be known and their variation from that trend need to be understood.
Methods: A prospective observational study was conducted. 75 patients  undergoing THR or HRA surgeries of hip or TKR surgeries fulfilling the inclusion and exclusion criteria were considered for the study. Blood samples were collected preoperatively and postoperatively on day 1, 3, 5, 7 and 15 after surgery and sent to measure ESR and CRP values. Surgical site was assessed for presence of any discharge, which was sent for culture. Presence of any growth after 48 hours of incubation was diagnosed as infection.
Result: Values of both ESR and CRP raised after surgery. ESR reached its peak value on POD 5 while CRP reached its peak value on POD 3. Both ESR and CRP declined thereafter. On correlating these trends with infected cases, we reported a statistically significant correlation of CRP with infection on POD 15. However, ESR values did not show any significant correlation with infection in starting 15 days post-operatively.
Conclusion: There is a significant variation in levels of ESR and CRP after arthroplasty surgeries of lower limb. In infected cases, there is a deviation from this normal trend, that can be used to suspect post-operative infection. However, none of these parameters can be used to suspect it in starting 7 days after surgery.