Patterns in the Excretion of Muscle Markers after Trauma and Orthopedic Surgery

Abstract

The urinary output of 3-methylhistidine (3MeHis), creatinine, creatine and Zn was followed in 13 patients after accidental injuries and in 9 patients undergoing elective orthopedic operations. The accidental injuries were classified by their Injury Severity Score (ISS) and according to the amount of muscle damage by the method of Grant and Reeve. The latter method gave 2 groups, (I) very severe and (II) severe. The changes in the urine were not related to ISS. The initial output of 3-MeHis and Zn was greater in Group I than in Group II or in patients after total hip replacement, in whom muscle damage was least. The pattern of excretion of the excess 3-MeHis in Group I and after hip replacement suggested that it was derived from the breakdown of muscle injured in the accident or operation. Only in Group II and after total knee replacement were there additional changes which could be attributed to a generalized increase in muscle breakdown, said to be typical of the post-traumatic flow phase, e.g., the simultaneous increase in the output of all 4 muscle markers, to a peak about 6 days after the injury. In these patients the relative importance of muscle at the injury site and elsewhere is unclear. The most constant changes after accidental or operative trauma were delayed increases in the excretion of creatine and Zn. These changes and the abnormality of the 3-MeHis/creatinine ratio showed that alterations in muscle metabolism could persist for long periods after trauma.