SA Orthopaedic Journal
Print version ISSN 1681-150X
BACKGROUND: C-reactive protein (CRP) is an acute-phase protein secreted by hepatocytes during various types of tissue injury. We tried to determine whether the severity of an open fracture of the tibial diaphysis as classified according to the Gustilo-Anderson system corresponds to the degree and pattern of CRP response after trauma and infection. METHODS: This was a prospective study done over a six-month period on 48 patients with open tibial-diaphyseal fracture. Serial blood samples for CRP testing were taken seven times over a two-week period. The fractures were graded according to the Gustilo-Anderson classification and after surgery wounds were examined regularly for signs of surgical-site infection (SSI). RESULTS: Twenty-nine patients (60.4%) did not develop postoperative SSI and mean CRP levels peaked on different days for the different fracture grades with grade II, IIIa, and IIIb fractures all having mean peak levels of 52.2 mg/l. There was no association between the mean peak CRP levels and the fracture grades (p = 0.5). Those patients who developed postoperative SSI (19; 39.6%) still showed no clear association between mean peak levels and fracture grades (p = 0.48) and CRP levels also peaked on different days with grade IIIc fractures having the highest level at 67.7 mg/l. When fracture grading was excluded from data analysis, mean CRP levels for both groups of patients peaked on the third postoperative day with a higher value of 52.2 mg/l for patients with postoperative SSI compared with 47.7 mg/l for those without postoperative SSI, and the difference was significant (p = 0.015). CRP remained elevated up to the fourteenth postoperative day in patients with postoperative SSI while it showed a decline until it approached the pre-operative level in patients without postoperative SSI. CONCLUSIONS: This study has shown that the severity of an open fracture of the tibial diaphysis as classified according to the Gustilo-Anderson system does not correspond to the degree and pattern of CRP response after trauma and SSI. This is demonstrated by the erratic CRP response in both infected and uninfected open fractures of the tibia when fracture grade was compared with the kinetics of CRP response. The elevated CRP level on the third postoperative day and continued persistence thereafter in patients with SSI is, however, a potential early screening tool for infection before clinical signs of infection appear on the fifth postoperative day.