Relationship of C-reactive protein, erythrocyte sedimentation rate and knee skin temperature after total knee arthroplasty - prospective study

Knee osteoarthritis is a common cause of severe pain and functional limitation. Total knee arthroplasty is an effective procedure to relieve pain, restore knee function, and improve quality of life for patients with end stage knee arthritis. The aim of this study was to investigate the inflammatory process in patients with primary knee osteoarthritis before surgery and in subsequent periods following total knee arthroplasty.A prospective study of 14 patients undergoing primary total knee replacements was conducted from October 2014 to May 2015 in our institution. The patients were evaluated by monitoring serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), knee skin temperature, and clinical status. Measurements were carried out preoperatively and postoperatively on day 2 and 2nd week, 6th week , 14th week and 24th week during follow-up review. The CRP was elevated on the 2nd postoperative day but fell to preoperative values at two weeks postoperatively. CRP returned to within the normal range by six weeks postoperatively. In addition, the postoperative ESR showed a slow rise with a maximum level at two weeks after surgery and returned to the within normal range at 14 weeks postoperatively. The difference in skin temperature between operated and contralateral knees had a mean value of 3.9C at two weeks. The mean value decreased to 3.4C at six weeks, 2.3C at 14 weeks, and 1.0C at 24 weeks. The difference in skin temperature decreased gradually and eventually there was no statistically significant difference at 24 weeks after surgery. A sustained elevation in serum CRP, ESR, and skin temperature must raise the concern of early complication and may suggest the development of postoperative complication such as haematoma and or infection.