Four and a half years experience with a vertical flow sterile enclosure

Summary During the use of a vertical flow enclosure of our own design for almost five years, bacteriological studies and the infection rates in different groups of patients have taught us the following:1. In a clean room operating theatre, the use of a respired air exhaust system improves the sterility compared with the use of ordinary masks. In a vertical flow enclosure, the chest, the arms, and the hands of the team are contaminated from respired airborne bacteria if helmets, etc., are not worn.2. In our vertical flow enclosure with almost continuous absolute sterility of the air, the infection rate in primary total hip replacement is very low and less than 1%, including early and late infections. Antibiotics have not been used.In secondary surgery, i.e., total hip replacement in hip joints previously operated upon, the infection rate is markedly higher, probably because of a flare-up of latent infection.Clean room surgery therefore, can only prevent air borne contamination, and no more; but this is very valuable.3. Vertical flow enclosures of the Charnley-Howorth (1975) and Weber et al. (1971) type provide considerable improvement in sterility of the air compared with adaptations of more conventional theatres. We recommend that these facilities be made available for implant surgery. It is also necessary to have a stringent operational policy with cooperation and discipline on the part of all members of the theatre team.

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Résumé Durant l'utilisation, depuis plus de 5 ans, de la serre stérile à flux laminaire vertical que nous avons construite, nous avons pratiqué des études bactériologiques et pu comparer les taux d'infection suivant les groupes de patients.1. Dans une salle d'opération propre, la stérilité est considérablement améliorée par le port de casques possédant un système d'aspiration de l'air expiré, ceci par rapport au port de masques ordinaires. De plus, si l'on ne porte pas le casque dans une serre à flux laminaire vertical, le tronc, les mains et les membres supérieurs de l'équipe chirurgicale sont contaminés par les microbes en suspension dans l'air expiré.2. Dans notre serre où l'air est pratiquement stérile, le taux d'infections précoces et tardives est inférieur à 1% dans les arthroplasties de la hanche, et cela sans utilisation d'antibiotiques.Lors d'interventions dites secondaires, c'est-à-dire dans les cas déjà opérés au préalable, par exemple par ostéotomie, ostéosynthèse, etc., le taux d'infection est plus élevé. On doit probablement en rechercher la cause dans une contamination de la plaie lors de la première intervention, l'infection alors à l'état latent pouvant se réveiller à la faveur d'une nouvelle opération.En opérant dans une serre stérile, on peut donc prévenir la contamination par l'air ambiant, mais pas plus. Cela est cependant déjà très appréciable.3. Comparées aux salles d'opération conventionnelles modernes, les serres stériles à flux laminaire vertical, comme celle de Charnley-Howorth (1975) et Weber-Meierhans (1971), améliorent considérablement la stérilité de l'air. Surtout pour la chirurgie prothétique de la hanche, dont les risques d'infection sont élevés, nous recommandons l'emploi de ce genre d'installation. Mais il est nécessaire que tous les membres de l'équipe chirurgicale adoptent des règles très strictes de discipline.

     

Cosmetic improvement of testicular prostheses for children

A new testicular prosthesis for pediatric use is presented. This differs from the model usually available in that it is pink-pigmented and opaque. Over a period of 2 years and 6 months, 57 testicular prostheses were implanted in 53 boys. Seventeen of these were opaque, pigmented ones, while the others were regular translucent prostheses. No complications occurred with either type. Even when applied in adults, the traditional translucent prosthesis gives the unpleasent impression of hydrocele. In pediatric cases, this unesthetic appearance is enhanced because of the disproportion between the scrotum and the size of the prosthesis. The cosmetic appearances of these scrota have been partially improved by the use of colored, opaque prostheses. Offprint requests to: F. Ferro     

Detachable shape-memory sewing ring for heart valves

The novel sewing ring concept consists of a detachable ring snap connection between valve housing or stent and suture cuff. The suture cuff itself is a memory metal ring of nickel-titanium (NiTi) that is embedded within a textile fabric torus. After a special training program the ring can assume two geometric shapes when alternately cooled and heated. Due to this physical property, the sewing ring can be safely fixed within a groove of the housing or stent by changing between room and physiological temperature. This allows the surgeon first to implant the sewing ring followed by arbitrary positioning and final fixation of the valve by the shape-memory effect. Additional advantages are an increased stiffening of the valve base for minimizing potential leaflet dysfunction, and reduced time and risk of implantation, particularly when a reoperation is necessary.     

Forces and moments on the human leg in the frontal plane during static bipedal stance.

An experimental apparatus was assembled that permitted measurement of the vertical and lateral ground reaction forces as the hip is abducted, resulting in foot separations ranging from 0.25 to 71 cm, with the knee in 0 degree flexion. Twelve healthy volunteers (8 men and 4 women) were tested. The hip joint was located by means of center of rotation measurements on each subject's legs, and the location of the knee joint was determined using anatomical measurements. It was observed that the mediolateral force was nonzero and directed toward the body midline, even when the subject's feet were placed together. With the feet placed at shoulder width, the population mean mediolateral force was 3% of body weight. It was determined that simplifying assumptions based upon either "zero lateral force," or "zero hip moment," produced errors, when compared with our measured values, over various ranges of foot separation, with the zero hip moment assumption providing accuracy over a broader range. The inclination of the tibial plateau, with respect to the long axis of the tibia, that would produce minimal mediolateral shear at the knee is presented. Research and clinical applications of our results and techniques are discussed.     

残根残冠修复的临床应用研究

目的 探讨残根残冠修复的临床效果。方法 对285例321颗前后牙残根残冠经过完善的根管治疗后进行铸造桩核全冠修复，并进行2年至6年的临床观察。结果 285例321颗患牙修复后成功310颗，失败11颗，成功率96．6％。结论 残根残冠经过完善的根管治疗后铸造桩核全冠修复是其目前得以保留并发挥功能的理想方法。     

自体心包瓣“内皮化”的实验研究

目的 探讨有利于自体心包瓣内皮化的处理方法。方法 将体外培养小牛主动脉内皮细胞接种于不同方法处理的自体牛心包表面。采用＾３Ｈ－ＴｄＲ摄取量测定、扫描电镜及放射免疫法观察不同处理方法对接种后内皮细胞生长、前列环素（ＰＧＩ２）合成量和细胞内ｃＡＭＰ含量的影响。结果 三种不同浓度戊二醛短时间（１０ｍｉｎ）处理的心包表面内皮细胞均可生长,其中以体积分数为０．２％戊二种不同浓度戊二醛短时间（１０ｍｉｎ）处理     

强直性脊柱炎髋关节软组织的扫描电镜和X线能谱观察及其临床意义

目的：采用扫描电镜—Ｘ线能谱联机观察强直性脊柱炎（ＡＳ）髋关节囊和滑膜组织的病理变化，用以指导临床治疗。方法：对６例年青ＡＳ病人的髋关节囊和滑膜组织进行固定、干燥、喷金行扫描电镜观察，并用２例老年股骨头坏死髋关节炎的同名组织作对照。对扫描图象中的组织进行Ｘ线能谱扫描以确定是否存在钙颗粒。结果：ＡＳ组的关节囊和滑膜组织中胶原排列紊乱，其间有钙颗粒沉积。而对照组同名组织仅见胶原排列紊乱，Ｘ线能谱显示无钙峰出现。结论：青年ＡＳ病人髋关节囊和滑膜组织均有成骨现象发生，而老年股骨头坏死髋关节炎同名组织无成骨现象。这种软组织病理变化是影响ＡＳ髋关节功能的主要原因。其关节清理术需将关节囊和滑膜全部切除。     

Do the hamstrings and adductors contribute to excessive internal rotation of the hip in persons with cerebral palsy?

Children with cerebral palsy frequently walk with excessive internal rotation of the hip. Spastic medial hamstrings or adductors are presumed to contribute to the excessive internal rotation in some patients; however, the capacity of these muscles to produce internal rotation during walking in individuals with cerebral palsy has not been adequately investigated. The purpose of this study was to determine the hip rotation moment arms of the medial hamstrings and adductors in persons who walk with a crouched, internally-rotated gait. Highly accurate computer models of three subjects with cerebral palsy were created from magnetic resonance images. These subject-specific models were used in conjunction with joint kinematics obtained from gait analysis to calculate the rotational moment arms of the muscles at body positions corresponding to each subject’s internally-rotated gait. Analysis of the models revealed that the medial hamstrings, adductor brevis, and gracilis had negligible or external rotation moment arms throughout the gait cycle in all three subjects. The adductor longus had an internal rotation moment arm in two of the subjects, but the moment arm was small (<4 mm) in each case. These findings indicate that neither the medial hamstrings nor the adductor brevis, adductor longus, or gracilis are likely to be important contributors to excessive internal rotation of the hip. This suggests that these muscles should not be lengthened to treat excessive internal rotation of the hip and that other factors are more likely to cause internally-rotated gait in these patients.     

股骨颈骨折人工股骨头置换术后下肢不等长的预防处理（附6例报告）

目的探讨股骨颈骨折人工股骨头置换术后下肢不等长的预防方法。方法选择6例单纯股骨颈骨折人工股骨头置换作为研究对象。通过术前术中双侧髂前上棘及髌骨上缘反复测量验证，骨盆标准X线正位片股骨头模板运用确定股骨颈截骨平面及股骨距保留长度。术中软组织松解及假体试模反复运用验证，有效保持术后双下肢基本等长，避免下肢不等长引起跛行。结果术前6例患肢短缩2．0～4．7cm不等。术后测量4例双下肢等长，1例患肢短缩0．3cm，1例患肢延长0．2cm，无跛行。结论通过术前测量评估，骨盆X线正位片上模板运用设定股骨颈截骨平面及股骨距保留长度，术中适当软组织松解及假体试模运用，双下肢髂前上棘与髌骨上缘长度再次测量印证，可有效保持术后双下肢基本等长，避免下肢不等长引起跛行。     

Acetabular ossicles: normal variant or disease entity?

Ossicles located in the acetabular fossa may confuse diagnostic and therapeutic work-up. An accessory ossification centre may persist unfused as an os acetabuli centrale which is surrounded by intact hyaline cartilage representing an anatomic variant. Bone islands located in the pillars of the acetabulum can project into the acetabular fossa simulating acetabular ossicles. Osteochondrosis dissecans, posttraumatic articular bodies, degenerative disease and other rare lesions may be responsible for clinical symptoms and are of similar appearance than anatomic variants. Plain film radiography, X-ray tomography, CT and MRI are used to categorize these lesions. MRI is very valuable to assess cartilage integrity in a noninvasive way, but arthro-CT or arthro-MRI have to be used in unclear cases. Therefore the purpose of this presentation is to discuss the appearance, the possible etiology and the differential diagnosis of acetabular ossicles and how they can be evaluated to avoid an unnecessary arthrotomy. Received: 22 December 1998; Revised: 28 May 1999; Accepted: 8 July 1999