Patterns in the excretion of muscle markers after trauma and orthopedic surgery.

The urinary output of 3-methylhistidine (3-MeHis), creatinine, creatine, and zinc has been followed in 13 patients after accidental injuries and in nine 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 (15). The latter method gave two groups, (I) "very severe," and (II) "severe." The changes in the urine were not related to ISS. The initial output of 3-MeHis and zinc 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 four 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 not clear. The most constant changes after accidental or operative trauma were delayed increased in the excretion of creatine and zinc. These changes, and the abnormality of the 3-MeHis/creatinine ratio, showed that alterations in muscle metabolism could persist for long periods after trauma.