European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
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Psoas muscle (PM) function with regard to the lumbar spine (LS) is disputed. Electromyographic studies attribute to the PM a possible role as stabilizer. Anatomical textbooks describe the PM as an LS flexor, but not a stabilizer. ⋯ Conversely, any increase of lordosis of the strip brought about by vertical downward pushing of its top, will be stabilized by tightening the pulling string in the same specific direction. As this direction corresponded with the psoas orientation, the experiments show that the PM probably functions as a stabilizer of the lordotic LS in an upright stance by adapting the state of contraction of each of its fascicles to the momentary degree of lordosis imposed by factors outside the LS, such as general posture, general muscle activity and weight bearing. The presence of multiple PM fascicles, all of about equal length, and attaching to all LS levels, facilitates this function.
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Although reinfusion of salvaged shed blood has become popular in major orthopaedic procedures, this blood saving technique is still controversial. In an effort to assess the functional and metabolic status of shed blood erythrocytes and the impact of postoperative shed blood reinfusion on allogenic blood requirements and patient's blood parameters, analyses of perioperative blood samples were performed in 28 consecutive orthopaedic patients undergoing spinal fusion, in which postoperative shed blood was collected and reinfused with the ConstaVac CBC II device. In comparison with a previous series of 31 patients, this procedure reduced allogenic blood requirements by almost 30% (P < 0.05), without any increase in postoperative complications. ⋯ Serum levels of some enzymes increased at the end of surgery and remained elevated at postoperative day 2 (CK) or 7 (GOT, LDH), with a higher increase if postoperative autotransfusion was used as a blood saving method. Therefore, caution should be taken when these serum enzyme levels are used for diagnosis. In conclusion, salvaged shed blood in orthopaedic procedures of the spine seems to be an excellent source of red cells which are not significantly damaged, keeping a normal functional and metabolic status, and reduces allogenic blood requirements without significant side effects.
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Neck sprain is a general term denoting a soft tissue injury of the neck, which seldom causes major disability but is considered a modern epidemic. The purpose of the present study was to determine the prevalence of sprain of the neck injury due to motor vehicle accidents (MVAs) in both drivers and passengers. In addition, the degree of seat belt wearing in both driver and passenger was analysed. ⋯ The results of this population-based study revealed a sharp increase in neck sprain from 1989 through 1995, whereas a more or less stable pattern was found for seat belt use. The sharp increase was found to be attributable to outpatients. Finally, we found a driver predominance as well as a female predominance; groups at risk were the 20- to 24-year-olds for drivers and 15- to 19-year-olds for passengers.
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Screw augmentation with calcium apatite cement (CAC) was used in seven patients with a progressive osteoporotic spinal deformity. Thirty-nine spinal segments (64 screws) were augmented: 15 anteriorly (three patients) and 24 posteriorly (five patients). Dorsally, hemilaminectomy was performed at the level of all augmented screws to rule out CAC leakage. ⋯ Pedicle wall damage was present at two levels, while at two other levels no wall damage was found during visualization. No CAC-related complications were observed perioperatively. No implant migration was observed, and fusion was observed in all cases at follow-up examination performed at a mean of 32 months after surgery.
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Loosening of the screws is a problem in instrumentation with pedicle screws. Coating with hydroxyapatite improves the holding characteristics for metal implants, but the possible effects on the anchorage of pedicle screws have not been described. In this study, seven patients were operated on with spinal instrumentation using four stainless steel pedicle screws. ⋯ Hydroxyapatite coating was shown to have improved the purchase of pedicle screws very effectively. By using fully coated screws, as in the present study, extraction was extremely difficult compared to extraction of conventional stainless steel screws, which were regularly loose. By reducing the area of the screws that is coated, it may be possible to achieve an enhanced purchase while extraction will be easier when compared to fully coated screws.