[Role of densitometry and scintigraphy in post-traumatic algodystrophy of the arms. Initial diagnosis and monitoring during treatment with carbocalcitonin].

In 24 patients affected with post-traumatic reflex sympathetic dystrophy syndrome (RSDS) with upper limb involvement following humeral fractures, bone mineral density (BMD, mg/cm2) was measured by means of dual-photon absorptiometry in the distal radius of both the affected and the normal contralateral limbs. Subsequently, all patients underwent dynamic and static scintigraphic exams after i.v. injection of 99mTc-MDP (20 mCi), with gamma camera collimator centered in both limbs. BMD values were significantly lower in the affected sides than in the normal contralateral ones. Time-activity curves with MDP showed increased flow in the involved limbs. Significant increase in blood pool and in bone uptake was also observed. After carbocalcitonin treatment (80 U/q.d. i.m. in 12 cases and 40 U/q.d. i.m. in the other 12 cases for a month) all the patients presented improved clinical symptoms and significant increase in BMD, that was restored to normal values in 7 of the patients who had a longer treatment (40 U/q.d. i.m. for 2 months). Both local blood flow and bone uptake in the affected side significantly decreased after carbocalcitonin therapy while bone avidity index increased in those patients in whom this parameter had been measured. Our results confirm the usefulness of radioisotopic procedures in post-traumatic RSDS for both diagnosis (by demonstrating increased local blood flow and early bone demineralization) and monitoring response to treatment with carbocalcitonin, which seems to play an important role in this condition.