In twenty of twenty-four children whose legs were lengthened by closed osteoclasis of the tibia followed by slow distraction (Anderson's method) blood pressure increased by more than twenty millimeters of mercury during the lengthening period.
In seven dogs the tibia was similarly distracted and an increase in blood pressure occurred. This increase in blood pressure was shown to be a reflex response to tension developed in the sciatic nerve in the upper part of the thigh. It is possible that the reported blood-pressure elevation in human patients who undergo leglenthening is due to the same cause.