计算机导航对人工髋关节股骨柄假体置入的精确性验证

Objective To evaluate the accuracy of surgical navigation for localization and orientation of the femoral stem component in total hip arthroplasty, nethods In the hypothesized space, 3-D images of femoral stem were reconstructed. The coronal, sagittal and horizontal axes and scale divisions were established to calculate the displacement and rotation of the stem. Matching between the stem and its 3-D images was performed while the stem was moved in various distances and angles on the digital motion-platform. Then the actual change in the position of the implant and the caleulative data obtained from the navigation system were compared to evaluate the accuracy. Results The mean difference in displacement between the measurements and the actual changes was (1.01 ±0.47) mm, and the mean difference in the measured and actual angles was 1.09°±0.62°. The duplicate test found no significant difference (t = 0.238, P > 0.05). Conclusion Precise placement of the stem in the desired location and orientation can be achieved by the navigation system in the total hip arthroplasty.     

Gait biomechanics and the evolution of total joint replacement

The history and evolution of total knee and total hip replacement has been influenced substantially by the knowledge obtained from gait analysis studies. Many of the mechanical problems associated with these devices have been analyzed and evaluated in terms of the mechanics of walking. The magnitude and pattern of the forces at the hip and knee joints derived from gait analysis studies have provided valuable input into the design criteria of both total hip and total knee replacements. Information generated from the gait analysis of patients with total joint replacements has provided objective criteria for assessing functional recovery following this procedure. In addition to providing a basis for design evaluation, the key to the analysis of function following joint replacement is the ability to identify functional adaptations specific to design features. Gait analysis provides a unique opportunity to obtain objective information that cannot be obtained through other clinical means and provides a means for evaluating current designs and future design modifications.     

吸入一氧化氮对心瓣膜置换术后肺动脉高压患者血流动力学的影响

目的：观察吸入一氧化氮（ＮＯ）对心瓣膜置换术后肺动脉高压患者血流动力学的影响。方法：选择９例心瓣膜置换术后伴肺动脉高压的病人，吸入ＮＯ０．００３％，观察三个时象点：吸入ＮＯ前；开始吸入ＮＯ后１５分钟；停止吸入ＮＯ后１５分钟。结果：吸入ＮＯ能显著降低肺动脉压和肺循环阻力指数（Ｐ＜０．０１），停止吸入ＮＯ１５分钟后，肺动脉压和肺循环阻力指数恢复到原有水平。在整个观察过程中，心率、平均动脉压、中心静脉压、肺动脉楔压、体循环阻力指数和心脏指数均无显著变化（Ｐ＞０．０５）。结论：吸入ＮＯ具有选择性肺血管扩张作用，是治疗心瓣膜置换术后肺动脉高压的较理想药物。     

连续性肾脏替代治疗在慢性肾衰竭并发急性心肌梗死中的应用

目的:总结日间连续性肾脏替代治疗(CRRT)救治慢性肾衰竭并发急性心肌梗死的经验.方法:对9例慢性肾衰竭常规透析时发生急性心肌梗死的患者改行CRRT,观察临床效果,监测血生化、肾功能.结果:所有患者经CRRT治疗,心前区疼痛、胸闷、憋气均有不同程度缓解,7例患者度过急性期,平均治疗时间90～146 h,转为常规血透,目前仍存活;2例患者因并发症死亡.结论:CRRT操作简便,对血流动力学影响小,日间CRRT同样能有效救治病人,使其度过急性期,降低急性心肌梗死的病死率.     

Analgesic nephropathy in Hungary: the HANS study.

BACKGROUND: The diagnosis of analgesic nephropathy has improved significantly with modern imaging techniques. We reviewed a large portion of the Hungarian dialysis population to obtain additional insight into the problem. METHODS: Twenty-two participating dialysis units enrolled 1400 patients on renal replacement therapy between 1 January 1995 and 1 January 1998. Patients with no known aetiology (n = 284) were interviewed and studied with renal imaging. We assessed the presence of decreased renal mass combined with either bumpy contours, papillary calcification, or both. The subjects studied were interrogated extensively. RESULTS: Our survey suggested analgesic nephropathy in 47 of 1400 patients (3.3%), 3-fold higher than the EDTA database estimate for Hungary. The analgesics most commonly abused were phenacetin-containing mixtures. The driving symptoms were mainly headache and joint pain. Cardiovascular complications were more common than in the rest of the dialysis population, independent of smoking and lipid values (P<0.01). CONCLUSIONS: Phenacetin should be banned. Our study results support the need for longitudinal cohort and case-control studies in Hungary.     

人工全膝关节置换术治疗膝关节骨关节炎

[目的]评价人工膝关节置换术治疗骨关节炎的临床疗效。[方法]本院自1994年10月～2003年10月采用人工全膝关节置换术治疗膝关节骨关节炎81例（95膝），男10例，女71例；平均年龄65．5岁（50—82岁）；左膝35例，右膝26例，双侧同时置换17例；保留后交叉韧带假体18膝，后方稳定性假体62膝，活动衬垫15膝。[结果]本组平均随访42个月（14—108个月），应用HSS膝关节评分系统进行分析，优：80膝（84．21％），良：10膝（10．53％），可：3膝（3．16％），差：2膝（2．10％）。优良率94．74％。[结论]作者认为人工全膝关节置换术能有效的缓解膝关节骨关节炎的疼痛，改善膝关节功能。正确的选择假体、精细的手术操作和严格的术后康复是保证手术效果的关键。     

采用羟基磷灰石涂层股骨柄假体行全髋置换术的早期疗效

目的总结采用羟基磷灰石(HA)涂层股骨柄假体行全髋关节置换术的早期疗效。方法2000年2月～2003年10月,采用钛合金HA涂层股骨柄假体行无骨水泥全髋关节置换术65例(70髋)。术前诊断:股骨颈骨折30例,骨关节炎15例,股骨头缺血性坏死9例,人工股骨头术后松动8例,类风湿性髋关节炎2例,髋关节融合1例。分别于术后1周、3个月、6个月,以后每年一次行髋关节功能和X线片检查,其中44例接受双能X线骨密度仪(DEXA)的骨密度(BMD)检查。结果术后X线片提示股骨柄假体的初始固定均符合优良标准。随访2～5.5年,平均3年。髋关节功能从术前Harris平均评分32分(25～52分)恢复至最后随访时的平均96分(85～100分),至今无一髋表现股区痛或需行翻修手术。术后1年内的X线片测量显示:<1.5mm下沉者7髋,其余均无假体下沉。至今无一例显示股骨近端或髓内骨溶解,也无一例显示假体松动。DEXA检查显示BMD在术后下降,然后迅速恢复,3～6个月后可达到正常或接近正常水平,其中Ⅱ、Ⅵ区的BMD增加速度最快,有时甚至高于对照侧。按Engh标准评定,全部患者均获骨性固定。结论近段HA涂层能增强股骨柄假体的初始固定,促进早期骨长入和骨性生物学固定,阻止聚乙烯磨屑的髓内移行和骨溶解,故用于无骨水泥全髋置换术的早期疗效满意。     

Nasal nicotine spray: a rapid nicotine delivery system

Plasma nicotine concentrations following administration by two types of nasal nicotine spray were compared in ten subjects. Absorption was particularly rapid during the first 2.5 min, the average rise in blood nicotine concentrations during this time being 8.6 ng/ml for the two products, followed by a small further rise to an average peak increase of 10.5 ng/ml 5 min after the dose of 2 mg nicotine base (mean 27.8 micrograms/kg). Despite a four-fold Cmax variation between subjects, the levels of individual subjects were fairly consistent across the two products. There were no significant differences between the two products in blood nicotine concentrations or cardiovascular responses, and the correlation between the AUCs from the two products was 0.68 (P = 0.01). Eight subjects reported subjective feelings of light-headedness or slight dizziness, which are not typical after slower absorption from nicotine gum or skin patches. Blood nicotine levels within the smoking range were soon built up with repeated doses, even in the subject with the least efficient nasal absorption. In a second study of ad libitum use under clinical conditions both products appeared sufficiently acceptable for therapeutic use as an aid to smoking cessation. There was no tendency to escalate to excessive use over 4 weeks, and blood nicotine concentrations in nine subjects averaged only 44% of their prior smoking levels. Only one subject had levels equivalent to prior smoking and possible reasons why this was not more common are discussed.     

ARTHROSCOPIC REMOVAL OF ACRYLIC CEMENT FROM UNREDUCED HIP PROSTHESIS

A case is reported in which entrapped polymethylmethacrylate following traumatic dislocation of a total hip replacement prevented complete reduction. A combined arthroscopic and fluoroscopic technique was used to remove the entrapped polymethylmethacrylate. Manipulation of the total hip prosthesis was done after removal of polymethylmethacrylate to minimize mechanical abrasion. This technique allows direct visual assessment of the articulating surfaces as well as the mechanical stability of the prosthesis. The morbidity related to the procedure is minimal and a short rehabilitation period is the major advantage.     

Contact finite element stress analysis of porous ingrowth acetabular cup implantation, ingrowth, and loosening

Two-dimensional linear and contact finite element analyses were conducted of total hip arthroplasty using metal-backed, porous ingrowth acetabular components. The stress transmission characteristics from the component to the surrounding bone were given special attention. Resultant loads of 20 and 40 degrees medial of vertical were studied, and the influence of adding a metal flange to the rim of the cup was evaluated. The results indicated that when a conventional metal-backed component (without a flange) is initially implanted and subjected to normal loading, these components may experience distraction between the component and the surrounding bone at inferior sites. Compressive stresses in the superior dome cancellous bone, however, will be substantial. If complete porous ingrowth is achieved, the superior dome compressive stresses will be reduced and substantial shear stresses created. In addition, high local bone stresses were found at the component rim. If bone ingrowth is achieved only in specific locations, stress transmission will be dictated by those locations and may differ markedly from the case of complete bone ingrowth. In the event that no porous ingrowth is achieved and a fibrous layer forms around the component, the interface stresses will be similar to those calculated for the natural hip. The addition of a flange to the rim of the cup will reduce the magnitude of the radial stresses transmitted to the cancellous bone superiorly and medially by directly transferring some of the load to the lateral wall of the pelvis. The flange will also help to relieve the high local stresses that are found at the component rim.