1. The four patients who underwent orthopaedic procedures were in negative nitrogen balance well below the dietary levels recommended by Rhoads, while the two patients who maintained a high nitrogen and caloric intake per kilogram of body weight were either in positive nitrogen balance or showed transient and minimal nitrogen deficits. It is of interest to note that, with the exception of F. G. (Fig. 2), all the patients showed fluctuations in weight and nitrogen balance that fairly well paralleled their dietary intake.
2. There was no correlation between the nitrogen deficits and the urinary excretion of 17-hydroxycorticosteroids.
3. It therefore appears from these studies that factors other than trauma to bone and adrenal overactivity are of major importance in governing the patient metabolic response. The factors which must be considered are: nutritional intake, fever, immobilization, and the preoperative nutritional status of the patient.