Magnetic resonance imaging (MRI) is an indispensable tool for musculoskeletal imaging. The presence of metal, however, raises concerns. The potential risks are loosening and migration of the implant, heating of the metal with surrounding tissue, causing thermal damage, and artifactual distortion which compromise the diagnostic value of the procedure. The aim of this study was to test experimentally the nature and extent of the first two of these effects in orthopedic implants. The degree of ferromagnetism was evaluated by deflection studies at the portals of a 0.25 Tesla permanent magnet and 1.0 Tesla clinical MRI scanner. None of the orthopedic implants exhibited any attraction. External fixator clamps, however, showed significant ferromagnetism. The heating of implants by ''worst-case'' scenario imaging sequences was insignificant. Many contemporary nonferromagnetic orthopedic implants can be imaged safely. It is prudent, however, to perform ex vivo deflection studies on a duplicate implant to confirm MR compatibility. With external fixator devices exhibiting strong ferromagnetism, MRI should be avoided. With expanding indications for MRI, orthopedic implants are unlikely to limit the potential of this powerful tool. ß

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Aneurysmal bone cysts are benign, locally aggressive osteolytic neoplasms that usually affect individuals in their second decade. Majority of aneurysmal bone cysts occur in metaphysis of long bones and vertebra. Clavicle is an uncommon location and only few cases have been reported in literature. We present a case of 17 year old male who presented with gradually progressive painful swelling in left shoulder region. Xray and CT scan showed expansile osteolytic swelling. Excision of the lesion with subtotal claviculectomy was done. On follow up, patient was able to perform his daily activities without any restriction and no recurrence was noted on ten year follow up.

There is little data regarding Vitamin D deficiency in Greece. Also conflicting are the data regarding the bone turnover during the acute hip fracture interval and the situation is even more complex considering the recently developed bone turnover markers (BTMs). The aim of this study was to evaluate the parameters of bone mineral homeostasis of women with fragility hip fracture using the recently developed BTMs of carboxy-terminal collagen crosslinks (CTx) and the procollagen type 1 aminoterminal propeptide (PINP) and to determinate vitamin D (25-OHD) levels of elderly Greek women with acute hip fracture. 38 self-sufficient, community-living Greek women with acute hip fracture were included. A similar number of age-and sex-matched controls with no clinically evident fractures were included in the study meeting the same inclusion and exclusion criteria. To exclude the effect of trauma blood samples were drawn within 24 hours from the fracture. Hip fracture group had significantly lower serum 25-OHD levels and significantly higher intact parathormone (PTH) levels compared to the control group but no correlation between PTH and 25-OHD was found in both groups. CTx was significantly correlated with PINP in the total group and in both groups separately but there was no statistical difference of their levels between the two groups. There was high prevalence of severe Vitamin D deficiency within the postmenopausal Greek women with acute hip fracture and the fracture did not influence the above mentioned BTMs. The processes of bone resorption and bone production are in balance during the first 24 hours after the fracture.