可吸收球囊椎体成形术治疗胸腰椎爆裂骨折的实验研究

[目的]探讨结合短节段椎弓根螺钉系统撑开复位内固定的可吸收球囊椎体成形术治疗胸腰椎爆裂骨折的生物力学性能变化。[方法]采集6具新鲜固定湿润成人尸体胸腰椎标本，制成T11-L1，L2～4、L1～3节段标本10个，用自由落体撞击试验造成中间椎体爆裂型骨折，行APF椎弓根螺钉撑开复位，经椎弓根于伤椎椎体内置入可吸收高分子材料-DL-乳酸与ε-己内酯（70：30）的共聚物（PDLLA-CL）制作的可吸收球囊，注入自固化磷酸钙骨水泥行可吸收球囊椎体成形术。分别于骨折前、骨折撑开复位椎体成形术后，用万能材料试验机测定中间椎体在前屈、后伸、侧屈状态下应力-应变、轴向刚度变化及扭转应力下刚度的变化。[结果]伤椎经可吸收球囊椎体成形术治疗后，抗压强度均有所增加，前屈为8％，后伸15％，侧屈9．8％，其中以后伸时增加显著（P〈0．05）。治疗后的轴向刚度普遍得到提高，与骨折前相比，前屈增加11％，后伸增加8％，侧屈增加3％。治疗后椎体在扭转应力下刚度小于骨折前，但两者差异不明显（P〉0．05）。[结论]（1）结合短节段椎弓根螺钉系统撑开复位内固定的可吸收球囊椎体成形术，有助于伤椎的重建，术后脊柱的生物力学特性接近骨折前水平；（2）可吸收球囊椎体成形术治疗胸腰椎爆裂骨折，在避免骨水泥渗漏可能导致的潜在危险之前提下，从本质上恢复胸腰椎爆裂型骨折伤椎椎体结构的完整性，恢复其高度，从而恢复和维持脊柱的生理弧度，防止继发性脊柱后凸畸形变引起的迟发性腰背痛及脊髓、神经损伤，以从根本上解决单纯用经椎弓根内固定器治疗胸腰椎爆裂型骨折遗留的并发症，为临床治疗胸腰椎爆裂骨折提供了一个新的方法。     

Catastrophic failure of modular Zirconia—Ceramic femoral head components after total hip arthroplasty

Catastrophic failure of two zirconia—ceramic modular femoral heads occurred, despite the theoretical improved toughness of zirconia—ceramic relative to alumina—ceramic. This experience led the authors to return to cobalt—chromium as the metal of choice for articulation against polyethylene in total hip arthroplasty.     

胸腰椎爆裂骨折椎管内骨片侵入倾向与对策

根据98例中获得随访的39例的X线、CT和MRI(24例)影像学资料,分析胸腰椎爆裂骨折椎管内骨片侵入倾向及对策。将爆裂骨折侵入椎管分为四类八型,宜采用Harrington器械钢丝或椎弓根螺钉钢板轴向撑开系统,使骨折复位,椎管容积恢复,毋需行后路椎管减压。本组取得良好效果。仅对骨片游离型需要切开椎管直接摘除骨片。     

加压滑动鹅头钉治疗股骨转子间骨折的临床与实验研究

探讨加压滑动鹅头钉在治疗股骨转子间骨折中的作用。临床应用４５例。男３４例，女１１例。平均年龄６１岁。稳定型１３例，不稳定型３２例。经临床应用和生物力学实验测定，结果表明：（１）对不稳定型转子间骨折，恢复小转子区内后侧皮质骨的连续性在骨折的稳定中具有重要作用。（２）内后侧骨折块解剖复位，加压螺丝钉固定或大转子骨折端加压螺丝钉固定能显著增强加压滑动鹅头钉的固定作用，明显提高不稳定型转子间骨折的术后稳定性。（３）该装置设计合理，性能坚固，对转子间骨折具有很强的固定作用，能有效地达到早期下床和避免长期卧床的目的，是目前临床最理想的内固定装置。     

Polylactic acid (PLA) root replica in ridge maintenance after loss of a vertically fractured incisor

Abstract A periodontally affected tooth was prepared for a special treatment: Calcium hydroxide was introduced into the apical half of the root canal whereas its cervical part was filled with glass ionomer cement. The tooth was shortened subgingivally. After 6 weeks of epithelization over the residual root a palatal full-thickness flap was mobilized. The root was carefully extracted and chairside copy-milled from the biodegradable polylactic acid (PLA) material. The PLA-replica was implanted immediately into the socket and the flap was sutured. Aim of the treatment was to prevent the ridge collapse of the extraction area. Ridge height could be preserved during the 21 months of observation. With time the radiographic density of the cancellous bone increased in the implanted area, indicating that a PLA-replica is replaced by host's bone tissue.     

Hip fracture incidence in the canton of Vaud,Switzerland, 1986–1991

The objective of this study was to estimate the incidence of hip fracture in the canton of Vaud, Switzerland (total population 584 000), for the period 1986–1991 using routine hospital discharge data collected by the Cantonal Service of Statistical Research and Information (SCRIS). For the survey period, the estimated average annual crude incidence rate of hip fractures was 167 per 100 000 persons aged 20 or older (241 for women and 84 for men). For the population aged 50 years or older, the crude incidence rate was 388 per 100 000 persons (546 for women and 185 for men). The average annual age-specific rates rose exponentially by successive 5-year age groups. The median age of patients at the time of the fracture was 82 years in women and 74 years in men. There was no significant difference between the total number of cervical and trochanteric fractures. Between the ages of 20 and 84 years, the cumulative risk for a woman to be admitted to hospital with a hip fracture was twice that of a man (15.8% vs 7.8%). From 1986 to 1991, the age- and sex-adjusted incidence, like the ratio of cervical to trochanteric fractures, did not show any significant trend, although it was consistent with an increase in men (p=0.09). However, the annual number of fractures rose from 644 to 776, particularly among very aged men. The mean length of stay in the acute care hospital fell from 38 days in 1986 to 25 days in 1991. Finally, the comparison of these results with those obtained in 1986 for the same population from more exhaustive sources has confirmed the provision of a consistent, although overestimated, assessment of hip fracture incidence by means of these routine hospital statistics in the canton of Vaud, Switzerland.     

Differences in hip axis and femoral neck length in premenopausal women of Polynesian, Asian and European origin

There are substantial inter-racial differences in hip fracture incidence. Studies in several different ethnic groups have suggested that differences in the length of the femoral neck may contribute to these. The present study assesses femoral neck and hip axis lengths in three ethnic groups in which it has not been documented previously (Chinese, Indians and Polynesians) and compares these values with those in Europeans. Lengths were measured from dual-energy X-ray absorptiometry scans of the proximal femur in normal premenopausal women (n=225). The Polynesian (1.65 m) and European (1.64 m) women were significantly taller than the two Asian groups (mean height in each, 1.58 m). There were also differences in mean body weight, the Polynesians being the heaviest (76 kg) and the Chinese the lightest (53 kg). Femoral neck lengths were (mean + SD) Chinese 61.5+4.4 mm, Indian 61.5+5.1 mm, Polynesian 68.2+4.3 mm and Europeans 66.0+4.8 mm. Hip axis lengths were Chinese 98.0+5.6 mm, Indian 94.5+5.2 mm, Polynesian 106.4 ± 5.3 mm and European 102.3+5.3 mm. Each of the other groups were significantly different from the Europeans for both variables and, in general, this remained so after height adjustment. These data suggest that shorter femoral necks are common to the major Asian racial groups. However, in contrast to all other ethnic groups studied, Polynesians have longer femoral necks than Europeans and their low incidence of hip fracture is not explicable, therefore, in terms of their femoral neck length. This suggests that either higher bone density or other more subtle differences in proximal femoral geometry must account for the low hip fracture incidence in Polynesians.     

Short-term lack of cerebral perfusion with good outcome. Advantages of early intracranial pressure monitoring

A 21-year-old man was injured by a tailboard of a truck. He suffered a severe head injury with bilateral depressed skull fractures necessitating surgical decompression. On admission to the hospital the patient showed bending to pain stimuli (Glasgow Coma Score 5). Anisocoria was noticed from the beginning. Initial intracranial pressure (ICP), measured 3 hours after injury, was 30 mm Hg, and the cerebral perfusion pressure (CPP) was 70 mm Hg. During surgical elevation of the skull fracture on the right side an unexplainable rise of ICP to values of 100 mm Hg occurred, which corresponded to the mean arterial blood pressure (MAP). At the same time both pupils were dilated and fixed indicating a lack of cerebral perfusion. Due to immediate trephination of the opposite side, the ICP was lowered to values below 20 mm Hg, and sufficient cerebral perfusion (above 50 mm Hg) was regained. The patient showed a good recovery and was transferred to a rehabilitation center 5 weeks after injury.This case report emphasizes the importance of early and continuous intracranial pressure monitoring for adequate therapy in neurosurgical emergencies.     

尺骨鹰嘴骨折皮质骨加压螺钉固定的实验研究及临床应用

比较尺骨鹰嘴骨折加压螺钉与常用的4种内固定的强度,为临床选择内固定方法提供实验依据。用22具新鲜尸体肘关节做成横型、斜形和粉碎形鹰嘴骨折模型。用5种内固定后置于MD—10E万能电子力学试验机上,测定骨折处的位移与压力的关系;结果:钢丝内固定强度最小,钩钢板最大。髓内加压螺钉固定欠可靠。横形骨折皮质骨加压螺钉与张力带钢丝比较,统计学上无显著差异(P〉0.05),斜形骨折皮质骨加压螺丝钉强于张力带钢丝(P〈0.01)。粉碎形骨折使用钩钢板尤佳(P〈0.01)。临床应用24例中,22例平均随访14个月。骨折全部愈合,优良率达90.91％;认为皮质骨加压螺丝钉治疗横、斜形尺骨鹰嘴骨折,创伤小,操作简便,固定确切,是一种安全可靠的方法。     

24例骨折术后深部感染的原因及对策

目的 探讨骨折术后深部感染的原因、预防和治疗方法。方法 对骨折术后深部感染病灶行扩创后置管闭合灌洗。结果 24例经清创闭合灌洗平均27．5d后，感染均得以控制，效果满意。结论 骨折手术后深部感染原因是多方面的，宜积极预防，早期发现，及时扩创闭合灌洗，遗留肢体功能障碍者留待后期治疗。