Vertebral crush fracture syndrome and reflex sympathetic dystrophy.

The association of reflex sympathetic dystrophy in one or more extremities with vertebral crush fracture syndrome is reported in six cases. In two of them the reflex sympathetic dystrophy preceded the vertebral crush fractures. The 99mTc-methylene diphosphonate scintigraphy results of the skeletons of 42 consecutive patients suffering from vertebral collapse and of 30 matched controls without osteoporosis have been evaluated by three independent observers for abnormal uptakes in the extremities. An abnormal radioactive bone tracer uptake in the extremities has been observed in 15 osteoporotics (36%) and 8 controls (29%). In most cases, osteoporotics and controls, the abnormal uptake was of the zonal type in a localized area, probably reflecting bone remodeling due to localized degenerative changes. An abnormal uptake of the segmental type involving multiple joints and even multiple extremities, as seen in reflex sympathetic dystrophy, was observed in 7 patients of the osteoporotic group (17%) and in none of the control group (P less than 0.05). The patients with an abnormal segmental uptake were younger and had a significantly higher mean 24 h calcium:creatinine ratio as well as a higher urinary hydroxyproline excretion. These observations and results suggest that in some cases of idiopathic osteoporosis there might be a relation between reflex sympathetic dystrophy and vertebral crush fracture syndrome, the vertebral crush fracture syndrome being the axial type of reflex sympathetic dystrophy.