Intakes and major dietary sources of cholesterol and phytosterols in the British diet

Cholesterol intakes in Britain have been re-estimated by analysing Total Diet samples taken in 1991 and from 1993 National Food Survey records. The Total Diet samples contained only 284 mg/day compared with 319 mg/day in 1987 and 337 mg/day in 1981, while the National Food Survey showed intakes had fallen to 238 mg/day from 259 mg/day in 1990 and 405 mg/day in 1970-75. More details of the intakes by adults in 1986/87 are given, and compared with the results from the other methods. Daily intakes of eight phytosterols were also estimated, the main ones being β-sitosterol, campesterol, stigmasterol and 57-stigmastenol whose intakes were 104, 49, 10 and 4 mg/day, respectively, in 1991. These intakes had increased since 1981, reflecting the rising consumption of vegetable oils.     

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.     

膝关节 Q 角变化规律的实验研究

本研究利用精密三维位移测读仪，研究分析了Ｑ角的变化趋势，以及对髌股关节运动的影响。研究结果表明，Ｑ角是一空间夹角，随屈膝角的增大而增大。力线在平面上的投影所呈的平面夹角Ｑｐ也就是通常所指的Ｑ角，在屈膝１５°左右达最大，而在９０°左右达最小。整个屈膝过程中，ＱＰ在５°－１５°之间变化，变化幅度达１０°左右。     

珊瑚型人工髋关节置换术的临床随访及松动原因的分析

自１９８３年至今应用珊瑚型人工髋关节置换术共５４例６０髋。其中人工全髋关节置换术３４例４０髋，人工股骨头置换术２０例２０髋。在５４例６０髋珊瑚型人工髋关节置换术中，有３７髋随访６个月～１３年，平均随访时间约７年，疗效满意率为８５．１％，其中假体松动４例占１４．８％，髋臼松动２例７．４％。假体松动原因是假体与股骨负重界面之间没有达到稳定接触，假体与髓腔形状不相匹配，修整髓腔松质骨时，髓腔扩大器应比假体小一号，避免假体与界面存留缝隙。对于髋臼发育不良的患者应避免髋关节旋转中心向外侧移位，应向内上方加深髋臼以减少水平移位距离，其次髋臼植骨加盖勿在负重区。     

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。     

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.     

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.     

Determination of bone mineral density by dual x-ray absorptiometry in patients with uncemented total hip arthroplasty.

Bone remodeling is an expected sequela with total hip arthroplasty (THA). Although there are several methods of estimating bone response in THA patients from radiographs, there are no accurate and generally accepted methods for quantitative determinations in vivo. In this study, we describe an application of dual x-ray absorptiometry (DXA) for measuring bone mineral content and bone mineral density in the proximal femur following THA. DXA is a noninvasive technique with minimal radiation exposure (< 5 mrem). Various aspects of measurement error (accuracy and reliability) of this application of DXA were determined in a series of studies reported here. Accuracy error (how similar are the measured and actual values) was < 1% determined in bone phantoms of four densities. Precision error (how reproducible are the measurements) was also < 1% at all four densities in the phantoms and was only slightly elevated (0.9-1.5%) in repeated measurements of implanted cadaver femora. Precision error in vivo, determined both from multiple replicates on five patients and from duplicate scans on 30 patients, was further elevated but remained < 5%. Contributions to precision error, rotation of the leg, and interoperator variability were assessed; none was found to elevate precision error appreciably. We suggest that DXA is a feasible method for quantifying bone response following THA, and will allow discrimination of small changes (> 5%) not previously measurable.