颈椎人工椎间盘置换或前路融合内固定术后关节突间压力的改变

目的:通过测量颈椎前路融合内固定或人工椎间盘置换术后关节突间压力的变化,探讨两种手术对颈椎手术节段后部结构的力学影响。方法:6具成年男性新鲜尸体颈椎标本(C2～C7)作为测试对象,分为完整颈椎组、人工椎间盘置换组及前路融合内固定组。在完整颈椎测试后,所有标本先后行C4/5节段Prestige-LP人工椎间盘置换和前路C4/5节段植骨融合固定术后进行测试。将预制的压敏片置于C4/5左侧关节突关节内,标本先给予75N跟随载荷,再持续加载纯力偶进行三维运动测试。屈伸和侧屈最大运动载荷为2.0N·m、旋转最大运动载荷为4.0N·m,测量加载后的运动范围和零运动载荷、最大运动载荷时的关节突间压力。结果:与零运动载荷时相比,在运动加载后完整颈椎组和颈椎人工椎间盘置换组在后伸、左侧屈和右旋时均表现出左侧关节突间压力明显增大(P0.05);但前屈、右侧屈和左旋时左侧关节突间压力变化没有差异;颈椎前路融合内固定组各运动加载后关节突间压力与零运动载荷下压力均无显著性差异(P0.05)。在三个测试组间比较,完整颈椎组和人工椎间盘置换组在各运动载荷下的关节突间压力最为接近;颈椎前路融合内固定组虽然在后伸、左侧屈和右旋时关节突间压力都有减小,但与其他两组比较无显著性差异(P0.05)。结论:颈椎人工椎间盘成形术后关节突间压力与正常颈椎相比没有明显改变,可以有效地维持关节突间正常生理压力。     

颈椎术后邻近节段退变研究进展

脊柱融合固定是众多脊柱疾病行之有效的治疗方法,但随着时间的推移,部分患者手术邻近节段逐渐退变并出现症状,从而引发对其发病率、发病机制、影响因素、预防治疗策略等的大量研究.一般认为颈椎前路融合固定较后路融合固定更易引起邻近节段退变,本身已有退变者术后退变发病率更高.颈椎术后邻近节段退变的确切机制还不清楚,但融合内固定、部位脊柱生理曲度异常等引起生物力学应力改变、邻近节段活动度增加、关节面载荷和椎间盘内压力增加在病程发展中起重要作用.影响邻近节段退变的因素还包括融合节段的多少、融合术式和部位、邻近椎间盘状况、术前疾病类型等.尽可能地保留运动节段能减少邻近节段退变的发生率,人工颈椎间盘置换等治疗效果良好.     

人工颈椎间盘置换的研究进展

近些年，颈椎前路减压椎体间植骨融合手术（ACDF）已成为解除颈脊髓和颈神经根受压的主要治疗方式，其手术效果良好。仅在美国每年大约有150000多位病人接受颈前路手术。ACDF术虽然很好地解除脊髓、神经根受压，稳定了病变颈椎，但是邻近节段椎间盘的活动度代偿性增加，退变加速。有研究显示一个节段融合后邻近节段在前屈、后伸以及旋转上活动度增加30％，2个节段融合后会加倍增加邻近节段活动度。ACDF术后邻近节段退变症状发生率每年约2％-3％，这些患者中超过15％的需要接受二次手术。     

Orion钢板固定后对植骨块及小关节突应力影响的实验研究

目的:研究单纯植骨及植骨 Orion钢板内固定后对植骨块及相邻椎节小关节突应力的影响.方法:采用8具男性新鲜颈椎标本,分别行单纯植骨及植骨 Orion钢板内固定后测量植骨块及相邻椎节小关节突应力的变化.结果:单纯植骨时融合节段上小关节突的应力无明显增加,而植骨 Orion钢板内固定后则显著增加.单纯植骨及植骨 Orion钢板内固定后融合节段下小关节突的应力无明显增加.植骨 Orion钢板内固定后植骨块的应力较单纯植骨时变小.结论:植骨 Orion钢板内固定后融合节段上小关节突的应力明显增加,容易造成融合上节段的退变,并且存在一定的应力遮挡,故在治疗单纯颈椎退行性病变的患者时,使用Orion钢板内固定应持谨慎态度.     

Orion钢板固定后对植骨块及小关节突应力影响的实验研究

目的：研究单纯植骨及植骨 Orion钢板内固定后对植骨块及相邻椎节小关节突应力的影响。方法：采用8具男性新鲜颈椎标本，分别行单纯植骨及植骨 Orion钢板内固定后测量植骨块及相邻椎节小关节突应力的变化。结果：单纯植骨时融合节段上小关节突的应力无明显增加，而植骨 Orion钢板内固定后则显著增加。单纯植骨及植骨 Orion钢板内固定后融合节段下小关节突的应力无明显增加。植骨 Orion钢板内固定后植骨块的应力较单纯植骨时变小。结论：植骨 Orion钢板内固定后融合节段上小关节突的应力明显增加，容易造成融合上节段的退变，并且存在一定的应力遮挡，故在治疗单纯颈椎退行性病变的患者时，使用Orion钢板内固定应持谨慎态度。     

颈椎间盘退变对颈椎生物力学影响的有限元研究

目的建立人体颈椎C4-C5-C6节段颈椎间盘退变三维有限元模型,分析椎间盘退变对颈椎运动节段生物力学的影响。方法通过改变椎间盘材料特性和高度等参数,建立椎间盘轻度退变模型(LD)、中度退变模型(MD)和重度退变模型(SD)。在45 N垂直载荷下,分别对正常、轻、中、重度4种有限元模型进行生物力学测试,比较4种模型之间各项生物力学参数的差异。结果建立了C4-C5-C6节段颈椎间盘逐级退变三维有限元模型。45 N垂直载荷条件下,正常模型(ND)、MD、SD椎间盘轴向位移及向外膨出位移逐渐变小,LD椎间盘轴向位移及膨出位移比ND增大,四组模型纤维环轴向压缩应力逐渐增大,髓核内压力逐渐减小。ND、MD、SD关节突关节接触力逐渐减小,LD关节突关节接触力较ND轻度增大。结论椎间盘轻度退变时,颈椎稳定性下降。中、重度退变时,颈椎稳定性重新获得。从生物力学方面证明退变的椎间盘对维持颈椎的稳定性有一定的代偿作用。     

Orion钢板固定后对植骨块及小关节突应力影响的实验研究

目的:研究单纯植骨及植骨+Orion钢板内固定后对植骨块及相邻椎节小关节突应力的影响。方法:采用8具男性新鲜颈椎标本,分别行单纯植骨及植骨+Orion钢板内固定后测量植骨块及相邻椎节小关节突应力的变化。结果:单纯植骨时融合节段上小关节突的应力无明显增加,而植骨+Orion钢板内固定后则显著增加。单纯植骨及植骨+Orion钢板内固定后融合节段下小关节突的应力无明显增加。植骨+Orion钢板内固定后植骨块的应力较单纯植骨时变小。结论:植骨+Orion钢板内固定后融合节段上小关节突的应力明显增加,容易造成融合上节段的退变,并且存在一定的应力遮挡,故在治疗单纯颈椎退行性病变的患者时,使用Orion钢板内固定应持谨慎态度。     

相邻节段退变对颈椎前路手术后远期疗效的影响

[目的]探讨相邻节段退变对颈椎前路节段性融合手术后远期效果的影响。[方法]对128例颈椎前路手术后患者进行长期有效的随访，通过复查颈椎MRI观察颈椎前路融合术后其相邻节段的退变情况、颈髓受压及变性情况、生理曲度的变化及颈椎稳定程度等，并根据退变情况加以分型，对退变患者保守治疗无效且进行性加重及退变较重且神经受损症状明显患者35例采用颈椎后路单开门椎骨成形手术治疗。[结果]随访1．5年～11年6个月，平均5．6年。颈椎前路减压植骨，融合手术后其相邻节段退变发生率为91．4％，颈椎前路手术后1．5年发现有相邻节段椎间盘信号的异常改变，显示早期退变征象。随访病例中由于相邻节段退变而再次行后路手术的比例约27．3％，这种退变与手术患者的年龄、手术时相邻节段间盘的退变情况、融合节段的长短、颈椎生理曲度的变化、术后的自我保健、工作性质等有直接关系。[结论]相邻节段退变是颈椎前路手术主要的远期并发症，正确的手术方式及术后有效的康复指导可以预防或减缓相邻节段退变的发生。     

颈椎前路钛网钢板内固定及自体髂骨植骨在不同颈椎节段中的生物力学研究

目的 采用颈椎前路钛网钢板及自体髂骨植骨对不同颈椎节段进行内固定，分析其生物力学改变。方法 取自愿捐赠的6具新鲜尸体C3～7标本，C5、C5.6及C4～6椎体次全切除后，分别行髂骨植骨和钛网前路钢板内固定术，测量各节段的前屈、后伸、左、右侧弯及左、右旋转运动变化，以完整标本作为对照组。结果 自体髂骨的植入使失稳颈椎的稳定性提高，其侧弯、屈伸运动度减少，与对照组比较，差异有统计学意义（P〈0．05），但抗旋转运动减少不明显（P〉0．05）。不同颈椎节段开槽减压椎间撑开钛网前路钢板内固定状态下，手术节段的即刻稳定性比对照组及撑开植骨状态增加（P〈0．05）。结论 颈椎前路椎体次全切除之后，植骨仅能部分改善其稳定性，但应用颈椎前路钛网钢板内固定可明显增强颈椎的稳定性，也较完整颈椎运动功能单位稳定。     

颈椎融合内固定对相邻节段椎间盘及椎间关节压力影响的生物力学研究

目的 探讨颈椎间植骨内固定相邻节段退变的生物力学机制.方法 5具成人尸体颈椎(C2-T1)标本用于试验.固定T1,施加作用力于C2,测量A、B、C、D各组在前屈、后伸2种状态下相邻节段(C3-4C6-7)椎间盘、椎间关节应力.结果 各组相邻节段椎间盘、椎间关节应力随固定强度增加而增加.即D组＞C组＞B组＞A组,其中C、D两组与A组相比应力增加明显,差异有显著性意义(P＜0.05),且C3-4间隙C组与B组、D组与C组相比差异均有显著性意义(P＜0.05).结论 颈椎间植骨内固定后增加相邻节段椎间盘、椎间关节应力;相邻上节段的影响较下节段大;固定强度越大影响越大.     

Pressure garments for use in the treatment of hypertrophic scars--a review of the problems associated with their use

Pressure garments have been the mainstay of hypertrophic scar treatment since the 1970s. However, there are many problems associated with their use. This is the first in a series of papers on pressure garments that will review the literature published to date on the origins of pressure garments for hypertrophic scar treatment and the problems associated with current pressure garment use.     

Validation of the Pliance X System in measuring interface pressure generated by pressure garment

Introduction

Pressure monitoring is crucial for effective pressure therapy. Precise and reliable interface pressure measurement system, however, remains unavailable in current practice.

Methodology

This is a validation study on the application of a recently developed device, the Pliance X System, for static interface pressure measurement. Sensor properties were evaluated through series of laboratory tests in the first phase of the study. Phase II was a clinical study using the Pliance X system to differentiate the loading generated on the patients’ scars through additional inserts and pressure garment.

Results

Results showed high test–retest and inter-rater reliability (ICC ≥ 0.995) with good linearity (adjusted R-square = 0.997) by measuring standard weights. The maximum deviation between the measurement generated by the sensor and the sphygmomanometer cuff was ±1.451 mmHg. Results in the clinical trial revealed its discriminant ability in distinguishing different levels of pressure loading on patients with scars (p < 0.01).

Conclusion

The commercially available pressure measurement system was found to be a reliable tool for measurement of low interface pressure under static condition.     

Surgical reconstructive procedures for treatment of ischial,sacral and trochanteric pressure ulcers

Background

Pressure ulcers are frequent complications for long term hospitalized bed-ridden patients which are not able to move or move very little. In fact, the lesion forms in a skin and muscle region which undergoes a constant pressure between an underlying bone protrusion and a support structure such as a bed or a wheelchair. Initially only the outer layers are involved but in time, the ulcer can spread to the deeper structures and reach the bone.

Patients and methods

In our work we described the anatomical areas that are most often subject to developing a pressure ulcer and we considered the surgical treatment and reconstructive procedures which are applied using a logical and rigorous sequence.

Results

We considered 4 clinical cases (2 ischiatic sores, 1 sacral sore and 1 gluteal-trochanteric sore) which demonstrate the surgical treatment and the reconstructive pro-cedures.

Conclusions

It is crucial to cover the defects with a thick flap to give more support and protection to the areas which undergo pressure and to lower the incidence of recurrences.     

Reproducibility of repeated measurements with the Kikuhime pressure sensor under pressure garments in burn scar treatment

This study investigated the reproducibility of repeated measurements with the Kikuhime pressure sensor under two different types of pressure garments used in the treatment and prevention of scars after burns. Also efficiency of garments was assessed in clinical circumstances by assessing pressure loss and residual pressure after 1 month. Intra- and inter-observer reproducibility and repeated measurements with 1-month time lapse were examined on 55 sites in 26 subjects by means of intra-class correlation coefficients and standard error of measurements. Results showed good to excellent ICC and low SEMs in the two conditions. There was a significant difference in pressure after 1 month between elastic tricot and weft knit garments, although evolution of pressure loss after 1 month was similar. Concerning different locations, there was a significant difference in pressure loss after 1 month between gloves and sleeves with the largest pressure loss for sleeves. Considering these results we concluded that the Kikuhime pressure sensor provides valid and reliable information and can be used in comparative clinical trials to evaluate pressure garments used in burn scar treatment. Secondly, elastic tricot garments in our study tended to have higher clinical pressures but both types of garments had similar pressure loss over time.     

Intra- and interrater agreement of pressure pain thresholds in children with orthopedic disorders

Purpose  

Pressure algometry is widely used to obtain measures of mechanical pain sensitivity in adults, both in experimental and clinical pain conditions. Only very few studies describe the use of pressure algometry in children. The purpose of this study was to produce reference values of pressure pain thresholds and to determine the intra- and interrater agreement, in order to introduce pressure algometry as a standardized method for the assessment of pain thresholds in children with orthopedic disorders.     

Designing pressure garments capable of exerting specific pressures on limbs

Pressure garments have been used prophylactically and to treat hypertrophic scars, resulting from serious burns, since the early 1970s. They are custom-made from elastic fabrics by commercial producers and hospital staff. However, no clear scientifically established method has ever been published for their design and manufacture. Previous work [2] identified the most commonly used fabrics and construction methods for the production of pressure garments by hospital staff in UK burn units. These methods were evaluated by measuring pressures delivered to both cylinder models and to human limbs using I-scan pressure sensors. A new calibration method was developed for the I-scan system to enable measurement of low interface pressures to an accuracy of +/-2.5 mmHg. The effects of cylinder/limb circumference and pressure garment design on the pressures exerted were established. These measurements confirm the limitations of current pressure garment construction methods used in UK hospitals. A new method for designing pressure garments that will exert specific known pressures is proposed and evaluated for human thighs. Evaluation of the proposed design method is ongoing for other body parts.     

Surgical Management of Solitary Metastatic Melanoma

Background: Pressure ulcers are a frequent complication of bed rest. The development of an efficient and low cost pressure relieving system for the prevention of bed-sores would be of considerable hospital health and economic interest. Our study was designed to determine the effectiveness in pressure-sore prevention of an interface pressure-decreasing mattress, the Kliniplot® mattress, used in our institution since 1978.

Methods: In a prospective randomised controlled 7-month clinical trial we compared the Kliniplot® mattress with our standard hospital mattress in 1729 patients admitted to medical and surgical departments (neurology, cardiology, oncology-haematology, neurosurgery, thoracic surgery and orthopaedic surgery). Two groups (Klinipot^® mattress and standard hospital mattress) were monitored for the prevention of pressure sores. The patients were evaluated on a daily basis from their admission until the eventual occurrence of a bed-sore. Patients’ characteristics and pressure-sore risk factors were similar at the baseline in both groups. Patients presenting with a pressure sore at the time of admission were excluded.

Results: Forty-two of the 1729 patients (2.4%) who entered the study developed at least one pressure sore. Twenty-one of the 657 patients (3.2%) nursed on the Kliniplot® mattress, and 21 of the 1072 patients (1.9%) on the standard mattress developed bed-sores (p = 0.154). The median time for the occurrence of pressure sores was 31 days (range 687) with the Kliniplot® mattress and 18 days (range 2 to 38) with the standard mattress (p < 0.001). The risk categories for developing bed-sores using the modified Ek’s scale were no different at the baseline between both groups (p = 0.764). The severity of the pressure sores was no different between both groups (p = 0.918).

Conclusions: Our results show that the occurrence of pressure sores is not reduced but is delayed when patients are nursed on a Kliniplot^® pressure-decreasing mattress.     

Comprehensive management of pressure ulcers in spinal cord injury: Current concepts and future trends

Abstract

Pressure ulcers in spinal cord injury represent a challenging problem for patients, their caregivers, and their physicians. They often lead to recurrent hospitalizations, multiple surgeries, and potentially devastating complications. They present a significant cost to the healthcare system, they require a multidisciplinary team approach to manage well, and outcomes directly depend on patients' education, prevention, and compliance with conservative and surgical protocols. With so many factors involved in the successful treatment of pressure ulcers, an update on their comprehensive management in spinal cord injury is warranted. Current concepts of local wound care, surgical options, as well as future trends from the latest wound healing research are reviewed to aid medical professionals in treating patients with this difficult problem.     

正常足与外翻足的足底压力研究

目的　对正常足与外翻足的足底压力进行测量。方法　运用自行研制的足底生物力学测试系统对30 名健康人60 足,45 例外翻患者89 足进行了行走时足底压力的测试。结果　重度外翻组31 足和正常组相比,第一跖骨头下压力明显减低( P< 0.001),第二跖骨头下压力明显增加(P< 0 .05),第三、五跖骨头下压力有增高的趋势。结论　正常人前足第一跖骨头下压力最高,并向外侧递减。重度外翻足前足第一跖骨头下压力明显减低,第二跖骨头下压力明显增高     

Pressure garment design tool to monitor exerted pressures

Pressure garments are used in the treatment of hypertrophic scarring following serious burns. The use of pressure garments is believed to hasten the maturation process, reduce pruritus associated with immature hypertrophic scars and prevent the formation of contractures over flexor joints. Pressure garments are normally made to measure for individual patients from elastic fabrics and are worn continuously for up to 2 years or until scar maturation. There are 2 methods of constructing pressure garments. The most common method, called the Reduction Factor method, involves reducing the patient's circumferential measurements by a certain percentage. The second method uses the Laplace Law to calculate the dimensions of pressure garments based on the circumferential measurements of the patient and the tension profile of the fabric. The Laplace Law method is complicated to utilise manually and no design tool is currently available to aid this process. This paper presents the development and suggested use of 2 new pressure garment design tools that will aid pressure garment design using the Reduction Factor and Laplace Law methods. Both tools calculate the pressure garment dimensions and the mean pressure that will be exerted around the body at each measurement point. Monitoring the pressures exerted by pressure garments and noting the clinical outcome would enable clinicians to build an understanding of the implications of particular pressures on scar outcome, maturation times and patient compliance rates. Once the optimum pressure for particular treatments is known, the Laplace Law method described in this paper can be used to deliver those average pressures to all patients. This paper also presents the results of a small scale audit of measurements taken for the fabrication of pressure garments in two UK hospitals. This audit highlights the wide range of pressures that are exerted using the Reduction Factor method and that manual pattern ‘smoothing’ can dramatically change the actual Reduction Factors used.