Extremity and eye lens dosimetry for medical staff performing vertebroplasty and kyphoplasty procedures.

Measurements of doses to hands, legs and eyes are reported for operators in four different hospitals performing vertebroplasty or kyphoplasty. The results confirm that occupational doses can be high for interventional spine procedures. Extremity and eye lens doses were measured with thermoluminescent dosimeters positioned on the ring fingers, wrists, legs and near the eyes of interventional radiologists and neurosurgeons, over a period of 15 months. Doses were generally larger on the left side for all positions monitored. The median dose to the left finger was 225 µSv per procedure, although a maximum of 7.3 mSv was found. The median dose to the right finger was 118 µSv, but with an even higher maximum of 7.7 mSv. A median left eye dose of 34 µSv (maximum 836 µSv) was found, while the legs received the lowest doses with a median of 13 µSv (maximum 332 µSv) to the left leg. Annual dose to the hand assessed by the cumulated doses almost reached the annual dose limit of 500 mSv, while annual dose to the eyes exceeded the eye lens dose limit of 20 mSv yr(-1). Different x-ray systems and radiation protection measures were tested, like the use of lead gloves and glasses, tweezers, cement delivery systems and a magnetic navigation system. These measurements showed that doses can be significantly reduced. The use of lead glasses is strongly recommended for protection of the eyes.

A custom-made guide for femoral component positioning in hip resurfacing arthroplasty: development and validation study.

In the field of hip resurfacing arthroplasty, accurate femoral component placement is important to achieving a positive outcome and implant survival in both the short and long term. In this study, femoral component placement was defined preoperatively using virtual computed tomography-based surgical simulation of a classical posterior surgical approach. Custom-made surgical drill guides were produced to reproduce the surgical plan in the operating room. We first developed a custom-made guide for guide-wire placement to position the femoral resurfacing component. Then, to assess the accuracy in vivo, the custom-made guide was evaluated in five patients with normal anatomy. The first hypothesis of this patient study was that the use of custom-made neck guides would allow for an average accuracy within the range of ± 4° for the drill path and ± 4 mm for the entry point of the guide-wire. A second hypothesis was that three-dimensional preoperative planning would enable the prediction of an implant size differing by a maximum of one size from the size eventually implanted. The presented hip resurfacing guide performed well in terms of fit, stability and accuracy. The in vivo accuracy study revealed an accuracy of 4.05 ± 1.84° for the drill path and 2.73 ± 1.97 mm for the entry point of the guide-wire. The predicted component sizes and the implanted component sizes differed maximally by one size, confirming our hypothesis. We conclude that these preliminary data are promising, but require further validation in a full clinical setting in larger patient groups.

Central neurocytoma presenting with intraventricular hemorrhage: case report and review of literature.

We report a case of a 25 year old man presenting with acute headache, vomiting and nuchal rigidity. Computed Tomography (CT) scan and MRI without contrast showed a right ventricular hemorrhage surrounding a mass lesion. The tumor and hematoma were completely removed by neurosurgical transcortical-transventricular approach. Anatomopathological analysis revealed a central neurocytoma. Central neurocytoma seldom present with hemorrhage. We review 16 cases of neurocytoma with hemorrhage. It is important to recognize central neurocytoma as a cause of intraventricular hemorrhage, especially in adolescents and young adults. Outcome is often favorable when the tumor is completely removed. In some patients the clinical course is more aggressive and additional treatment such as radiotherapy, radiosurgery or chemotherapy is needed.

Failure of a modified posterior lumbar interbody fusion technique to produce adequate pain relief in isthmic spondylolytic grade 1 spondylolisthesis patients. A prospective study of 20 patients.

A modified posterior lumber interbody fusion procedure is described: this technique basically uses only two tricortical bone grafts and does not produce a distraction at the interspace while inserting the bone grafts. Twenty patients with intractable back and leg pain due to an isthmic spondylolysis and a grade 1 spondylolisthesis were operated using this technique and a prospective study with a mean follow-up of 41 months was conducted to evaluate the results. The final evaluation involved a questionnaire, a clinical examination, and a lumbar spine radiographic series. Fourty-five percent of the patients had good or excellent results whereas 55% had fair or poor results. The possible reasons for these unfavorable results are discussed.