Serum osteocalcin, total and bone-specific alkaline phosphatase following isolated tibial shaft fracture.

We report the changes in osteocalcin concentrations and in total and bone specific alkaline phosphatase activity occurring in the twenty week period following tibial shaft fracture in 20 subjects. Bone formation during the healing process is reflected by progressive increases in the concentration of osteocalcin and bone specific alkaline phosphatase after week 5 and the latter correlated with the height and weight of the subject. In the early post injury period, total alkaline phosphatase activity increased whereas that of the bone isoenzyme initially fell, starting to rise again during the second week. After an immediate post injury rise, osteocalcin concentration also decreased, reaching a nadir by week 5. As only three of our subjects demonstrated delayed union, we have not been able to demonstrate that biochemical monitoring of the healing process can provide an indication of prognosis in tibial shaft fracture.