Stress fractures after surgery for osteosarcoma: scintigraphic assessment

To determine how often stress fractures occur in patients who have undergone surgery for osteosarcoma of a lower limb and to characterize such lesions, 156 bone scans obtained in 43 such patients were reviewed for bone stress. Of 43 patients who had undergone amputation or limb-preserving procedures, 42 (98%) had abnormalities on scintiscans attributable to bone stress; 31 had focal or mixed focal and diffuse lesions. Bones most commonly involved were those of the contralateral leg, pelvis, ipsilateral leg, and arms. Focal and mixed lesions seemed to be associated with increased work load on the limb involved. Findings indicated that the more active the patient, the more severe the bone stress. Because of their distribution, appearance, and intensity of tracer uptake, most stress-related lesions were readily distinguishable from bony metastases on scintiscans. Questionable lesions should be evaluated further with other imaging methods.