Atypical femur fractures in a patient with pycnodysostosis: a case report.

Pycnodysostosis is a rare autosomal recessive disease due to a mutation in the gene for the enzyme Cathepsin K. It is characterized by short stature, craniofacial dysmorphias, osteosclerosis, and brittle bones. There are only a few reports in the literature describing surgical interventions for long bone fractures in pycnodysostosis patients, most of which describe intramedullary nail treatment of isolated long bone fractures. We describe a case in which a pregnant female with pycnodysostosis presented with a shaft fracture of the left femur following minor trauma and a history of increasing thigh pain. Radiographs obtained in the emergency room also revealed an impending subtrochanteric fracture of the contralateral side. The acute left femoral shaft fracture was treated with an adolescent-sized intramedullary nail; it was decided to defer surgery on the contralateral side until after pregnancy. Three months later, the patient had the contralateral femur prophylactically fixated with a plate and screws. One year after the index surgery, both methods demonstrated satisfactory healing both clinically and radiographically. Although we recommend use of an intramedullary nail for long bone fractures in patients with pycnodysostosis, a plate can be utilized if health conditions or skeletal morphology precludes use of a nail.

Determination of ²²6Ra, ²²8Ra and ²¹°Pb in NORM products from oil and gas exploration: problems in activity underestimation due to the presence of metals and self-absorption of photons.

Typical calibration of solid environmental samples for the determination of (226)Ra, (228)Ra and (210)Pb entails the use of standard reference materials which have a very similar matrix. However, TENORM samples from the oil and gas exploration contain unusually high amounts of calcium, strontium and barium which can severely attenuate the photons of (210)Pb and (226)Ra with their characteristic 46.1 keV and 186.2 keV gamma-rays, respectively and to some extent (228)Ra with the characteristic gamma-rays of 911.2 keV and 969.0 keV. We used neutron activation analysis to evaluate the content of TENORM for calcium, barium and strontium and then used a software program SELABS to determine the self-absorption. Our results confirm that even in Petrie containers with small dimensions the (210)Pb can be underestimated by almost by a factor of four while (226)Ra can be underestimated by 5%. The (228)Ra activities are virtually unaffected due to the higher energy gamma-rays. However, the implications for TENORM studies that employ large Marinelli containers having sample sizes between 0.25 and 1.0 L may be severely compromised by the presence of high Z elements in elevated concentrations. The usual spectral interferences on (226)Ra, (228)Ra and (210)Pb coming from other radionuclides in the (234)U, (235)U and (238)U decay chains are virtually nonexistent due the very high activity levels of (226)Ra, (228)Ra and (210)Pb in the tens of thousands of Bq/kg.