Background:Implantation of joint prosthesis, either in the knee or in the hip, may cause some problems such as an infection, so that a timely treatment is essential. In this respect, discovering a marker detecting the incidence of an infection is one of the requirements of arthroplasty. The present study was conducted to determine variations of two markers in arthroplasty and infection incidence in Iranian patients.Materials and Methods:This prospective study was carried out in Isfahan’s educational treatment centers from 2009 to 2011 on patients undergoing total knee arthroplasty (TKA) and total hip arthroplasty (THA) surgical operations. The erythrocyte sedimentation rate (ESR) was measured by Sed rate device (Lena) and C-reactive protein (CRP) by autoanalyzer device (Erba) with the unit of ng/dL. The patients underwent ESR and CRP tests the day before operation, the day of operation, and 1, 2, 5, and 15 days and 1, 3, 6, and 12 months after operation.Results:Mean ESR increased during the first 5 days then decreased gradually lasting for 3 months. After 1 year it increased to a level higher than before the operation. The variations in ESR values were 19.1 ± 12.9 before the operation and 21.14 ± 10.8 after 1 year with significant difference (P < 0.001). The level of CRP had an upward trend from the first day after operation and reached its maximum on the second day, then had a downward trend up to 1 month after the operation; however, it did not reach its preoperative level during 1 year.Conclusion:ESR and CRP and their variations can be suitable factors to detect probable infections in patients undergoing TKA and THA operations.