Intraoperative bone scintigraphy in orthopaedic surgery

A sterilisable radiation probe of small dimensions was designed to locate the lesions at orthopaedic surgical sites according to the procedure of intraoperative bone scintigraphy. The probe has a collimated opening 2 mm in diameter. It is connected to a portable radioactivity counter which converts the disintegration rates detected at surgical sites into an acoustic signal that increases steeply with increasing disintegration rate. The acoustic signal enables the surgeons and isotope specialists to readily monitor radioactivity in the region of interest without attention being distracted from the surgical site. Dimethylaminodiphosphonate (designated SF44) was the osteotropic radiopharmaceutical chosen for carrying out intraoperative bone scintigraphy, since the available data show that this chemical increases the pathological: normal bone uptake ratio of the lesion by 25% compared to the usual diphosphonates. Forty-seven orthopaedic interventions were carried out according to the intraoperative bone scintigraphy procedure. They showed that this procedure facilitated the rapid location of the lesion, the objective termination of the operation, less frequently the reduction in dimension of the excised areas, and rarely the simplification of the surgical technique. Practice of intraoperative bone scintigraphy requires proper training and caution.