[Evaluation of scintigraphic procedures for clarifying pain conditions in hip joint prostheses]

59 patients with implanted one- or two-sided hip prostheses (n = 74) have been investigated by two different scanning techniques to detect both possible loosening of the prostheses and a possible infection as the cause of the loosening. Of the investigated prostheses 47 were loose; in 45 cases this was evidenced by the bone scan using Tc-99m-DPD, thus showing a sensitivity of 95%. Specificity was 89%. In 21 cases (45%) of loose prostheses an infection could be clinically proven. With the aid of In-111 labeled leukocyte scans, 17 of 21 cases were correctly diagnosed as infected, showing a sensitivity of 91%, while the specificity was 94%. In view of the 93% accuracy, bone scanning can be regarded as the method of choice in detecting loosening of prostheses. The 91% accuracy in proving or ruling out infection by means of the leukocyte scan is high enough to assert correct findings in most cases. The main disadvantage of this method is the very demanding technique for marking of white blood cells.