Risedronate Reduces the Risk of First Vertebral Fracture in Osteoporotic Women

Risedronate treatment reduces the risk of vertebral fracture in women with existing vertebral fractures, but its efficacy in prevention of the first vertebral fracture in women with osteoporosis but without vertebral fractures has not been determined. We examined the risk of first vertebral fracture in postmenopausal women who were enrolled in four placebo-controlled clinical trials of risedronate and who had low lumbar spine bone mineral density (BMD) (mean T-score =–3.3) and no vertebral fractures at baseline. Subjects received risedronate 5 mg (n= 328) or placebo (n= 312) daily for up to 3 years; all subjects were given calcium (1000 mg daily), as well as vitamin D supplementation (up to 500 IU daily) if baseline serum 25-hydroxyvitamin D levels were low. The incidence of first vertebral fracture was 9.4% in the women treated with placebo and 2.6% in those treated with risedronate 5 mg (risk reduction of 75%, 95% confidence interval 37% to 90%; P= 0.002). The number of patients who would need to be treated to prevent one new vertebral fracture is 15. When subjects were stratified by age, similar significant reductions were observed in patients with a mean age of 64 years (risk reduction of 70%, 95% CI 8% to 90%; P= 0.030) and in those with a mean age of 76 years (risk reduction of 80%, 95% CI 7% to 96%; P= 0.024). Risedronate treatment therefore significantly reduces the risk of first vertebral fracture in postmenopausal women with osteoporosis, with a similar magnitude of effect early and late after the menopause. Received: 12 September 2001 / Accepted: 11 December 2001     

Vertical interpositional augmentation genioplasty with porous polyethylene

Recent advances in the field of biomatrix porous implant technology has stirred the interest of the oral and maxillofacial surgical community. One such material (Medpor), is a biocompatible, large-pore, high-density polyethylene implant which has proven both experimentally and clinically to fulfil the criterion for maxillofacial reconstructive and aesthetic surgical grafting.     

血管内支架成形术治疗症状性椎动脉起始部狭窄的疗效分析

目的研究血管内支架成形术治疗症状性椎动脉起始部狭窄的安全性及有效性。方法对16例症状性椎动脉起始部狭窄的患者行支架成形术治疗。16例患者均成功植入球囊扩张支架。结果术后11例患者恢复正常管径;5例患者狭窄程度明显改善,残余狭窄均小于20%。无1例发生严重并发症。在6个月的临床随访中,16例患者均无脑缺血发作及再狭窄发生。结论血管内支架成形术是治疗症状性椎动脉起始部狭窄的安全、有效方法,其长期疗效还需进一步随访研究。     

Three-dimensional spinal curvature in idiopathic scoliosis

Scoliosis is usually considered as a deformity of the spine in the frontal plane, without reference to curvatures in other planes. In this study, the three-dimensional shape of the spine of 104 patients with untreated idiopathic scoliosis (5-55 degrees Cobb) was studied by means of stereo radiographs to determine relationships between curvature of the spine in the frontal plane view, in the lateral view, and in the intermediate views. There was a weak but statistically significant correlation (r = 0.2) relating greater scoliosis with lesser kyphosis or greater lordosis. In the thoracic region, the sagittal plane spinal curvature was less than that measured in a population without scoliosis (mean difference, 7.72 +/- 9.9 degrees). Seventy-four of 76 scolioses in the upper region of the spine with lateral curvature greater than 5 degrees Cobb were kyphotic. Sixty-four of 84 curves greater than 5 degrees Cobb in the lower region were lordotic. Measuring curvatures in the plane of symmetry of the rotated apical vertebra altered these ratios to 69 of 76 kyphotic in the upper region and 68 of 84 lordotic in the lower region. The plane of maximum curvature of sections of the spine with scoliosis was not related to the plane of symmetry of the rotated apical vertebra, for in kyphotic regions of the spine the rotations of these two planes were in opposite directions. In all cases, the magnitudes of the rotations were quite different, i.e., by a factor of -0.22 for curves in thoracic region and by a factor of 0.24 for curves in the lumbar region. This implies that mechanical measures to correct this spinal deformity or to prevent progression should apply different rotations to the apex from those applied to the curve as a whole and, in opposite senses, in curves in kyphotic regions. There was no evidence of an abnormality of sagittal curvature of a magnitude to implicate it in the etiology or in the treatment.     

Vertebral body replacement system Synex in unstable burst fractures of the thoracic and lumbar spine

A prospective longitudinal study was performed to evaluate the vertebral body replacement system Synex associated with posterior fixation in unstable burst fractures of the lumbar and thoracic spine. Within 24 months, we treated 28 patients (average age, 41 years; range, 22–64 years; 14 women, 14 men) with acute unstable burst fractures without osteoporosis of the thoracolumbar region (n=16) and the thoracic (n=3) as well as the lumbar (n=9) spine in two stages (primary dorsal transpedicular stabilization and secondary vertebral body replacement). The complications were analyzed and the postoperative follow-up result was evaluated regarding stability, bone fusion, correction loss, pain and neurological status. One patient showed a transient irritation of the lumbosacral plexus and one patient had a superficial wound infection (complication rate, 7.1%). At the follow-up examination (mean follow-up, 13 months) only in two cases a minimal loss of correction (<5°) was measured. Radiologically, 27 patients showed secure bone fusions and all patients had stability of the osteosynthesis. Most of the patients stated no or just slight pain at follow-up. Only two patients with pain to a medium degree had to take painkillers. The vertebral body replacement system Synex seems to be a good alternative for vertebral body replacement in unstable burst fractures of the thoracic and lumbar spine since at present follow-up it shows a high rate of bone fusion and minimal loss of correction.     

脊椎错位引起的代偿及其临床意义

脊柱的平衡在发生病理性变化时会打破，但人体有保持自我平衡的能力，脊柱必会发生一系列代偿性变化来重新建立平衡，这就是人体平衡系统作用的结果。当脊椎发生错位，即推拿医生最关心的脊椎错位时，脊柱内部将会发生怎样的代偿性变化及具有什么样的临床意义，下文将给予阐述。     

微小假体鼻根局部隆鼻术

目的:扩大隆鼻手术的适用范围。方法:针对一组21例单纯鼻根部低平、鼻根最低点位置偏下的就医者,置入微小假体进行隆鼻。结果:19例求医者经过一期手术均取得了满意的效果;2例就医者出现假体下移,经再次剥离腔隙,术后胶布固定3天后恢复良好,形成了良好的鼻根黄金窝和鼻整体美观效果。结论:微小假体鼻根局部隆鼻术对单纯鼻根部低平者,通过置入微小假体,提高骨性部分,尤其是鼻根部的高度,可以获得更好的鼻外形效果。     

经皮椎体成形术治疗胸腰椎椎体转移癌的疗效观察

目的：观察经皮椎体成形术治疗胸腰椎椎体转移癌的效果。方法：对25例胸腰椎椎体转移癌患者的37个椎体在C型臂X线透视下经皮椎体穿刺并注入骨水泥成形，术后按疼痛缓解程度6级评定法及简明健康状况调查表（SF-36）对治疗后患者生活质量进行评估。结果：所有患者术后均未发生感染、脊髓压迫和肺栓塞等并发症。24例患者术后2～72h内疼痛得到不同程度缓解，1例多发脊柱严重破坏者术后疼痛无缓解，术后1周疼痛缓解优良率为72．0％。术后随访3～27个月，平均7个月，根据SF-36评分，患者总体生活质量评分由术前的平均232分提高到末次随访时的平均349分。结论：经皮椎体成形术治疗胸腰椎椎体转移癌安全可行，具有良好的止痛效果．能够有效改善患者的生活质量。     

Vascular Centerline Extraction in 3D MR Angiograms for Phase Contrast MRI Blood Flow Measurement

The accuracy of 2D phase contrast (PC) magnetic resonance angiography (MRA) depends on the alignment between the vessels and the imaging plane. PC MRA imaging of blood flow is challenging when the flow in several vessels is to be evaluated with one acquisition. For this purpose, semi-automatic determination of the plane most perpendicular to several vessels is proposed based on centerlines extracted from 3D MRA. Arterial centerlines are extracted from 3D MRA based on iterative estimation-prediction, multi-scale analysis of image moments, and a second-order shape model. The optimal plane is determined by minimizing misalignment between its normal vector and the centerlines’ tangent vectors. The method was evaluated on a phantom and on 35 patients, by seeking the optimal plane for cerebral blood flow quantification simultaneously in internal carotids and vertebral arteries. In the phantom, difference of orientation and of height between known and calculated planes was 1.2° and 2.5 mm, respectively. In the patients, all but one centerline were correctly extracted and the misalignment of the plane was within 12° per artery. Semi-automatic centerline extraction simplifies and automates determination of the plane orthogonal to one vessel, thereby permitting automatic simultaneous minimization of the misalignment with several vessels in PC MRA.     

Comparative genomic hybridization (CGH) of augmentation cystoplasties

OBJECTIVE: Tumors arising within augmentation cystoplasties are aggressive, have poor prognosis and the majority are not detected at follow-up cystoscopy. Genetic changes in tumors precede morphological abnormalities. Therefore, the aim of this study was to investigate whether genetic abnormalities detected by comparative genomic hybridization (CGH) could be used to identify those patients with augmentation cystoplasties at increased risk of tumorigenesis. METHODS: Bladder biopsy samples were obtained from 16 augmentation cystoplasty patients both distant from and near to the enterovesical anastomosis. CGH was used to detect genetic abnormalities in DNA extracted from the biopsies, archival specimens of two augmentation cystoplasties and two de novo bladder adenocarcinomas. RESULTS: A greater number of amplifications on 2p, 3q, 8q, 9p, 17p, 18pq and 20pq, were observed in bladder biopsies obtained near to the enterovesical anastomosis compared to those taken distant to the suture line. CGH of archival augmentation cystoplasty tumor DNA indicated abnormalities at several loci with amplifications at 2q, 5q, 10p and 21pq, while deletions occurred at 5p and 16p. CONCLUSIONS: The results of this study suggest that the urothelium adjacent to the bladder and/or bowel anastomosis in augmentation cystoplasties is genetically unstable. Furthermore, longitudinal studies are required to establish whether or not patients exhibiting genetic instability following augmentation cystoplasty are at greater risk of developing tumors than those with genetically stable epithelia.