title: Pathologic fractures in a patient with renal osteodystrophy. Failure of early detection on bone scans.
abstract: A case of false-negative Tc-99m MDP bone scintigrams, taken at one and two weeks for pathologic fractures in a patient with metabolic bone disease and a super-scan appearance, is described. The patient had renal osteodystrophy, and postparathyroidectomy hypocalcemia. Postoperative seizures caused multiple pathologic fractures. Initial scans were negative for focal tracer localization in the presence of a continued super-scan appearance. After months of calcium and vitamin D replacement therapy, fracture sites became positive on Tc-99m MDP imaging. The observations in this case lend credence to the hypothesis of Tc-99m MDP binding by immature collagen in the production of a super scan in metabolic bone disease, as well as that of Tc-99m MDP chemisorption to calcium hydroxyapatite crystal in fracture healing. In addition, aluminum toxicity, common in chronic renal osteodystrophy, may have played a role in the delayed fracture healing.
mesh_terms: D000328:Adult; D012080:Chronic Kidney Disease-Mineral and Bone Disorder / Q000150:complications*; D003951:Diagnostic Errors; D005598:Fractures, Spontaneous / Q000150:complications* / Q000000981:diagnostic imaging; D006801:Humans; D006996:Hypocalcemia / Q000150:complications; D008297:Male; D010280:Parathyroid Glands / Q000601:surgery; D011183:Postoperative Complications; D011877:Radionuclide Imaging; D012640:Seizures / Q000150:complications; D013669:Technetium Tc 99m Medronate
chemical_list: D013669:Technetium Tc 99m Medronate