Serum CK-MB is useful in diagnosis of acute myocardial infarction after total hip arthroplasty.

Skeletal muscle trauma and myocardial infarction both increase the serum values of the creatine kinase isoenzyme MB (CK-MB) which may render the diagnosis of perioperative myocardial infarction in major orthopaedic surgery more difficult. The significance of postoperative changes in CK-MB was studied in 30 patients subjected to total hip replacement (THR), and the results were compared to CK-MB in 30 nonsurgical patients with acute myocardial infarction (AMI). AMI patients had significantly higher serum CK-MB values at 24 h than THR patients. However, the highest value after THR exceeded the lowest value in AMI. The results suggest that skeletal muscle release of CK-MB after THR is slight. CK-MB thus also seems useful in the diagnosis of AMI in postoperative patients.