一种平板流动腔重力灌流系统的力学分析

本文分析了一种采用重力灌流的平板流动腔灌流系统，并根据实验结果确定出相应的阻力系数，获得平板流动腔剪应力、雷诺数以及入口长度与流体重力灌流高度的关系。     

Failure of the rabbit tibial growth plate to respond to the long-term application of a capacitively-coupled electrical field

A continuous 5-V peak-to-peak, 60 kHz capacitively-coupled sine wave signal was applied to the proximal tibial growth plate in fifteen 9-week-old male New Zealand white rabbits for 6 weeks. A pair of flexible stainless steel "injectrodes" was held in place medially and laterally on the surface of the proximal hindlimb in each rabbit by means of tape wrappings. The electrodes were connected to a 9-V battery-operated power unit carried in a dorsal pouch in a body vest worn by each rabbit. Control animals wore the identical apparatus, only the power unit was inactive. Small Tantalum markers were inserted into the anteromedial aspect of the proximal tibial metaphysis 1 cm distal to the proximal tibial growth plate in all of the animals, control and experimental, 2 weeks prior to the onset of electrical stimulation. The distance between the proximal lateral tibial spine and the Tantalum marker, between the Tantalum marker and the apex of the distal tibial intercondylar notch, and between the proximal tibial spine and the distal notch was measured from roentgenograms made at the time of bone marker insertion, at the time of electrode application to the limb, and at the end of the stimulation period. Results indicate that there was no significant difference in tibial lengths between the stimulated and control groups. There was significantly less total body weight gain in both the experimental and control animals than that which occurred in paired normal animals during the same period of time. This failure to thrive may be responsible for the resultant lack of longitudinal growth stimulation of the capacitive coupling.(ABSTRACT TRUNCATED AT 250 WORDS)     

老年转子间骨折角型钢板治疗失误和并发症分析

目的分析角型钢板治疗股骨转子间骨折中出现的各种失误和并发症,并提出预防措施。方法1990年10月以来共治疗股骨转子间骨折68例,逐例分析治疗失误的原因。结果术中操作失误致股骨外侧皮质崩裂2例;钢板刀口穿破股骨头进入髋臼1例,术后切口感染1例,共8例出现并发症,发生率14．7％。结论角型钢板治疗股骨转子间骨折效果好,但不应忽视可能发生的各种失误和并发症。     

骨盆前环皮下内固定支架与微创经皮钢板内固定治疗骨盆前环骨折的疗效比较

目的 比较前环皮下内固定支架（INFIX）和微创经皮钢板内固定（MIPPO）治疗骨盆前环骨折的疗效。方法 回顾性分析2016年7月至2020年5月我院收治且符合标准的48例不稳定型骨盆骨折病人的临床资料,其中INFIX组22例,MIPPO组26例。INFIX组,男15例,女7例,年龄为（36.89±11.12）岁（21~58岁）。MIPPO组,男17例,女9例,年龄为（43.70±17.66）岁（21~71岁）。比较两组手术时间、术中出血量、骨折复位质量（Matta标准）、骨折愈合时间、骨折术后功能恢复情况（Majeed评分系统）,并记录并发症。结果 两组均获得随访,随访时间为5~17个月,平均为13个月。INFIX组手术时间[（75.41±15.25） min]低于MIPPO组[（85.62±17.92） min],差异无统计学意义（t=-5.154,P=0.101）;INFIX组术中出血量[（30.27±7.67） mL]明显低于MIPPO组[（111.15±24.30） mL],差异有统计学意义（t=-14.971,P=0.006）;两组负重时间[（16.00±2.06）周vs.（15.94±2.32）周]、Majeed评分[（81.90±7.73）分vs.（83.44±3.54）分]、骨折复位优良率[81.8% vs.84.6%]比较,差异均无统计学意义（P均＞0.05）,但MIPPO组能够达到更好的解剖复位。INFIX组1例病人出现股外侧皮神经损伤,两组病人未出现内固定失败情况。结论 治疗骨盆前环骨折,INFIX具有出血少、手术创伤小等优点,钢板能够达到更好的解剖复位,两组具有相似的术后功能恢复情况。可根据术者经验和病人具体情况选择适宜的固定方式。     

Tension band plates have greater risks of complications in temporary epiphysiodesis

PurposeThis study aimed to compare the efficacy of decreasing leg-length discrepancy (LLD) and postoperative complications between tension band plates (TBP) and percutaneous transphyseal screws (PETS).MethodsThis retrospective study reviewed LLD patients who underwent temporary epiphysiodesis at the distal femur and/or proximal tibia from 2010 to 2017 (minimum two years follow-up). Efficacy of decreasing LLD was assessed one and two years postoperatively. Complications were classified with the modified Clavien-Dindo-Sink complication classification system. Knee deformities were assessed by percentile and zone of mechanical axis across the tibial plateau.ResultsIn total, 53 patients (25 boys, 28 girls) underwent temporary epiphysiodesis (mean age, 11.4 years). The efficacy of decreasing LLD at two years between the TBP (n = 38) and PETS (n = 15) groups was comparable. Seven grade III complications were recorded in six TBP patients and in one PETS patient who underwent revision surgeries for knee deformities and physis impingement. Four grade I and two grade II complications occurred in the TBP group. The mechanical axis of the leg shifted laterally in the PETS group and medially in the TBP groups (+7.1 percentile versus -4.2 percentile; p < 0.05). Shifting of the mechanical axis by two zones was noted medially in four TBP patients and laterally in two PETS patients.ConclusionMore implant-related complications and revision surgeries for angular deformities were associated with TBP. A tendency of varus and valgus deformity after epiphysiodesis using TBP and PETS was observed, respectively. Patients and families should be informed of the risks and regular postoperative follow-up is recommended.Level of evidenceLevel III     

The association between caudal block and urethroplasty complications of distal tubularized incised plate repair: experience from a South China National Children’s Medical Center

BackgroundThe effect of caudal block (CB) on the incidence of urethroplasty complications in hypospadias repair remains controversial. The evidence is conflicting, and some confounding bias issues need to be addressed. We sought to study a more homogenous group of distal hypospadias patients undergoing primary tubularized incised plate (TIP) repair by a senior pediatric urology surgeon in the past 2 years to examine the relationship between urethroplasty complications and the use of CB.MethodsWe reviewed our database to identify consecutive patients who had undergone hypospadias repairs by a senior director surgeon at our Center between January 2018 and November 2020. To be eligible to participate in the study, patients had to meet the following inclusion criteria: (I) have distal hypospadias; (II) have undergone a primary TIP repair; and (III) have attended follow-up appointments for a minimum period of 6 months. The primary outcome was the development of urethroplasty complications during the follow-up period. The principal variable of interest was whether or not CB was used perioperatively. The patients were categorized into a CB group (general anesthesia combined with CB) or a control group (general anesthesia only). Other potential risk factors were analyzed, including patient age at operation, patient weight, glans width, and the length of the urethral plate defect.ResultsThirty (12.2%) of the distal patients developed postoperative surgical complications. The postoperative surgical complication rates were similar between the different anesthesia groups. Weight, the length of the urethral plate length, and glans width did not contribute to the risk. Age was the only independent risk factor for postoperative surgical complications, and the complication rates increased in older patients.ConclusionsOur data from consecutive TIP repairs in distal hypospadias patients indicated no association between the use of CB anesthesia and the postoperative urethroplasty complication rate. Patients who were older in age when they underwent surgery had a higher risk of complications.     

游离肱三头肌入路微型锁定板治疗移位型儿童肱骨髁上骨折

目的探讨游离肱三头肌入路微型锁定板治疗移位型儿童肱骨髁上骨折的疗效。方法 34例手法复位失败的移位型儿童髁上骨折均行游离肱三头肌微型锁定板固定术。术中采用长约6cm肘后正中切口途径,沿筋膜下两侧游离,内侧从肱三头肌与肱二头肌间隙进入,并显露尺神经加以保护,外侧从肱三头肌与肱桡肌间隙进入,紧贴肱骨骨膜剥离,游离肱三头肌,直视下牵引将骨折解剖复位,2块微型锁定金属接骨板于肱骨髁后内外侧固定牢靠。术后屈肘90°三角巾制动,2周行主动和被动肘关节屈伸功能锻炼。结果术后1~4天X线显示所有骨折复位满意。随访6~18个月(平均11.5个月),所有骨折均达到骨性愈合,无血管神经损伤,肘关节功能及外观满意,无严重并发症发生。结论移位型儿童髁上骨折行游离肱三头肌微型锁定板固定术后无需石膏外固定,并发症少,是目前治疗移位型儿童髁上骨折的安全有效的方法。     

Biomechanical activity of the growth plate

Summary The authors analyze at several levels the biomechanical activity of the epiphyseal plate.From a histologic point of view, they show the role played by the different cell layers in growth.The rapid growth of long bones is well known in animals, not entirely in human beings. The factors involved in mechanical regulation of the epiphyseal plate are analyzed according to distraction and compression stresses. Other factors have also been reported (periosteum and muscle).Analysis of the literature reveals that biomechanical activity and the factors managing growth are not well known yet.A combined effort should be made to obtain better understanding of the surgical procedures carried out in pediatric orthopedics.

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Comportement biomécanique du cartilage de croissance. Incidences cliniques

Résumé Les auteurs analysent le comportement biomécanique du cartilage de croissance à plusieurs niveaux.Sur le plan histologique ils montrent le rôle joué dans la croissance par les différentes couches cellulaires.La vitesse de croissance des os longs est bien connue chez les animaux et difficile à apprécier chez l'homme. Les facteurs intervenant dans la régulation mécanique du cartilage sont analysés en fonction des contraintes en compression et en détraction. Les autres facteurs (périoste et muscle) sont rapportés.L'analyse de la littérature montre combien le comportement mécanique et les facteurs régissant la croissance sont mal connus et mériteraient un effort de recherche conjugué pour mieux comprendre la portée des gestes chirurgicaux en orthopédie infantile.

     

改良股骨近端锁定钢板治疗老年A2型股骨转子间骨折的疗效分析

目的分析改良股骨近端锁定钢板治疗老年A2型股骨转子间骨折的疗效。方法 2012年2月~2013年7月间收治76例股骨转子间骨折患者,符合研究入选标准40例,随机分成两组,研究组和对照组,研究组给予改良股骨近端锁定钢板内固定治疗,对照组给予普通股骨近端锁定钢板内固定治疗。以Harris髋关节评分标准评价疗效及对疗效进行统计学分析。结果 40例患者均获随访,平均10.5月(5~18月),研究组Haris评分(89±7.24)分,对照组Haris评分(76±6.84)分,=5.837,0.01。结论对于老年A2型股骨转子间骨折,改良股骨近端锁定钢板与普通股骨近端锁定钢板相比,能够有效增加固定的可靠性,降低并发症的发生率,疗效满意。