全髋关节置换术髋臼旋转中心的回顾性研究

[目的]通过手术前后对髋臼旋转中心的X线测量，探讨髋臼旋转中心的变化对髋关节平衡稳定性的影响。[方法]追溯调查近年本院收治120例155髋，均为首次行全髋关节置换术患者，对比术前术后双髋关节正位X线片，比较术后髋臼假体的旋转中心（HJC1）与解剖髋臼旋转中心（HJC0）的符合率。[结果]旋转中心恢复者98髋（63．23％）（A组），未恢复者57髋（36．77％）（B组）；A、B两组中因人工髋关节松动、脱位、髋部痛等行髋关节假体翻修术分别为6髋（6．12％）、17髋（29．82％）。[结论]髋臼旋转中心的恢复对人工髋关节置换术后的关节稳定性有直接影响。     

髋关节中心性骨折脱位的外科治疗

目的探讨髋关节中心性骨折脱位的诊断、分类及外科治疗的特点。方法采用回顾性研究方法对髋关节中心性骨折脱位的外科治疗病例进行总结分析。结果 8例髋关节中心性骨折脱位均为臼底部骨折并股骨头中心型脱位突入盆腔,其中仅累及臼底部骨折3例,臼底部骨折合并髋臼前柱骨折2例,臼底部骨折合并髋臼前柱骨折及前壁骨折3例。8例均采用术前下肢股骨牵引使脱位的股骨头复位及改良扩大的髂股入路进行髋臼底骨折的切开复位钢板螺丝钉内固定术,其中2例臼底破损严重的病例采用取带缝匠肌髂骨骨瓣植骨重建术。髋臼骨折复位按Matta标准,术后解剖复位4例,满意复位4例,无不满意复位。结论髋关节中心性骨折脱位为髋臼较少见的严重损伤。对中心性脱位的股骨头宜采用三向分力的股骨牵引进行复位,因髋臼底位置深在手术复位较困难,故采取髂股手术入路,直视下可显露髋臼底骨折处。采用重建钢板进行骨折固定可确保髋臼内壁的光滑,髋臼底破损严重病例采用带肌蒂髂骨骨瓣植骨可起到重建臼底及加速骨折愈合的目的 。     

髋关节发育不良人工全髋关节置换术中髋臼中心重建

目的探讨髋关节发育不良(developmental dysplasia of hip,DDH)的人工全髋关节置换(total hiparthroplasty,THA)术中髋臼中心重建方法及疗效。方法 2004年1月-2010年1月,对29例(32髋)DDH患者行THA。男6例(6髋),女23例(26髋);年龄45～67岁,平均50.6岁。左侧22髋,右侧10髋。DDH按照Crowe分型标准:Ⅰ型12髋,Ⅱ型20髋。患者双下肢不等长,相差1.9～4.4 cm。髋关节Harris评分为(50.7±8.6)分。结果术后患者切口均Ⅰ期愈合;1例1髋发生髋关节后脱位。29例均获随访,随访时间2年～4年6个月,平均2.3年。术后下肢延长0.5～5.8 cm,平均2.5 cm。术后1年髋关节Harris评分为(87.7±5.9)分,与术前比较差异有统计学意义(t=21.77,P=0.00)。X线片检查示,术后1例1髋髋臼杯假体松动,1例1髋髋臼杯假体外移且外展角过大;其余患者随访期间无髋臼杯及股骨假体松动和下沉。术后1年髋臼中心水平位置、髋臼中心与泪滴连线垂直距离、髋臼垂直外展角、股骨偏心距均较术前显著改善,差异均有统计学意义(P<0.05)。结论对DDH行THA时重建髋臼中心能有效延长患者肢体,提高关节功能,降低关节置换失败率。     

髋关节旋转中心测量方法的研究进展

<正>髋关节旋转中心(hip joint center,HJC)的精确定位对人工全髋关节置换术(total hip arthroplasty,THA)的术前规划和术后评估具有重要意义。THA需要重建HJC以维持髋关节的机械平衡和压力分布[1]。手术重建后臼杯的偏移会对假体的存活率和髋关节活动功能产生负面影响[2-3]。目前,HJC的准确定位被认为是实现髋关节术中臼杯置入和生物力学再复制的基础,逐渐引起了人们的重视[4-5]。本文就文献中报道的HJC测量方法作一综述,以期对髋关节置换术前规划和术后评估提供参考,提高THA的有效性。     

高位全髋关节置换治疗CroweⅡ和Ⅲ型成人髋臼发育不良

[目的]观察全髋关节置换术(total hip arthroplasty, THA)中髋臼高位放置治疗CroweⅡ型、Ⅲ型髋关节发育不良(developmental dysplasia of the hips, DDH)的临床疗效。[方法]回顾性分析2014年2月~2016年10月本院收治的行THA治疗的21例(28髋) CroweⅡ型和Ⅲ型DDH患者(高位放置组),以同期19例(26髋)接受THA治疗的CroweⅠ型DDH患者为对照(解剖位放置组)。采用Trendelenburg征和Harris髋关节评分评价临床效果,拍摄双髋关节正侧位X线片,测量髋关节旋转中心距泪滴的垂直距离和水平距离、下肢长度差异。[结果]高位放置组手术时间和术中出血量均低于解剖位放置组,差异有统计学意义(P<0.05)。术后2年时,CroweⅠ型、CroweⅡ型和CroweⅢ型DDH患者Harris评分的差异无统计学意义(P>0.05)。术后所有患者步态良好,无跛行发生,Trendelanburg征均为阴性。所有患者X线片均未见放射性透亮线和假体下沉,高位放置组和解剖位放置组双下肢长度差值比较差异无统计学意义。CroweⅡ型和Ⅲ型患者髋关节旋转中心距泪滴的垂直距离均高于CroweⅠ型患者(P<0.05),而组间水平距离的比较差异无统计学意义(P>0.05)。[结论] THA术中髋臼高位放置治疗CroweⅡ型、Ⅲ型DDH的效果较好,未来需要扩大样本量,并进行长期随访,以证实本研究结论。     

全髋关节置换术治疗成人高位髋关节发育不良

目的探讨人工全髋关节置换术(THA)治疗成人高位髋关节发育不良(DDH)的临床疗效。方法对17例成人高位DDH患者行人工全髋关节置换术。以改良Harris评分和影像学检查评价术后疗效。结果 17例患者得到平均5年随访。患肢缩短畸形基本得到矫正,Harris评分术前平均(38.00±6.47)分,术后平均(89.60±7.61)分,P<0.05。结论 THA治疗成人高位DDH,能够有效解除患者疼痛、改善功能、提高生活质量,是安全、有效的手术方法。     

成人髋关节发育不良髋臼和Harris窝解剖特征及在全髋置换术中旋转中心重建的意义

目的 观察成人髋关节发育不良(DDH)终末期骨关节炎髋臼和Harris窝的解剖学特征,探讨复原Harris窝和确定髋臼中心的方法,以准确安装髋臼假体,恢复髋关节旋转中心。方法自2005年3月至2011年2月,对42例(48髋)成人髋关节发育不良终末期骨关节炎施行人工全髋置换术(THA),其中男6例6髋,女36例42髋。年龄27~62岁(平均45岁);术前拍摄标准骨盆平片确定Crowe分型,其中CroweⅠ型6髋,Ⅱ型11髋,Ⅲ型20髋,Ⅳ型11髋。采用后外侧入路显露髋臼,观察髋臼和Harris窝的解剖学特征,清除覆盖于Harris窝表面的骨赘,复原出Harris窝和髋臼切迹,并以此为标志确定髋臼中心,磨削髋臼,安装髋臼假体。术后拍摄骨盆平片测量髋关节旋转中心的垂直距离和水平距离,评价旋转中心恢复效果。结果 48例成人DDH髋臼呈浅杯形、浅盘形、贝壳形、三角形四种基本病理类型,Harris窝根据骨赘覆盖程度不同呈现出裂隙状、三角状、封闭状、浅平状四种病理类型;根据复原Harris窝及髋臼切迹,确定髋臼中心并安装髋臼假体,手术前后骨盆前后X线片对比髋关节旋转中心:髋关节旋转中心垂直距离术前(37.8±5.2)mm,术后(13.7±2.4)mm,差异有统计学意义(P<0.05)。髋关节旋转中心水平距离术前(41.6±6.3)mm,术后(24.4±4.7)mm,差异有统计学意义(P<0.05)。结论 在成人DDH终末期骨关节炎髋臼和Harris窝因脱位程度和骨赘增生程度不同呈现出不同的病理类型,清除覆盖于Harris窝表面的骨赘可以复原出Harris窝和髋臼切迹,以复原后的Harris窝和髋臼切迹为标志确定髋臼中心,安装髋臼假体,可以准确地恢复髋关节旋转中心。     

3D打印辅助重建重度骨缺损翻修患者髋臼旋转中心的疗效

目的 探讨应用个体化3D打印钛合金臼杯重建重度骨缺损髋臼旋转中心病例的早期临床效果.方法 选取2017年1月至2018年12月安徽医科大学附属宿州医院收治的应用个体化3D打印钛合金臼杯重建重度骨缺损髋臼旋转中心的10例患者.其中男4例,女6例;年龄36～67岁,平均(54.71±10.23)岁.术前Paprosky髋臼...     

髋臼旋转截骨术时髋臼后上方植骨前后髋关节生物力学的改变及其对比

目的探讨在偏心性髋臼旋转截骨术时于髋臼后上缘旋出部分上方进行植骨并检测植骨前、后髋关节生物力学的变化,为临床进行该类手术时髋臼后上方是否需要植骨提供必要的理论依据。方法将7具人体防腐骨盆标本建立成髋关节发育不良模型,测定每具标本模型髋关节所受应力的初始应变值仅,在每具标本的同一侧做偏心性髋臼旋转截骨术,再测定应变值β,然后,于旋转截骨后的髋臼后上缘旋出部分上方加骨块进行植骨,再测定应变值β’。应用配对资料的t检验比较植骨前后髋关节间应力的改变程度在不同压力负荷时有无差别。结果植骨前后组的对比中,当压力负荷为100N时,t=0．254,P〉0．05;200N时,t=-0．542,P〉0．05,可以认为植骨前后两组问数值差异无统计学意义;但植骨组多数标本的绝对数值要优于非植骨组。结论髋臼旋转截骨后,在髋臼旋出部分后上方进行植骨,能使股骨头所受的应力更趋于合理分布,而且,待植骨块与宿主骨完全愈合后,能较好地增加髋臼后上方骨的储备量。     

髋臼原位重建及高髋关节中心技术治疗Crowe Ⅱ、Ⅲ型发育性髋关节发育不良的对比研究

目的 比较全髋关节置换术（total hip arthroplasty, THA）中行髋臼原位重建及高髋关节中心技术治疗Crowe Ⅱ、Ⅲ型发育性髋关节发育不良（developmental dysplasia of the hip, DDH）的临床疗效。方法 对2012年8月至2015年12月于我科行THA治疗Crowe Ⅱ、Ⅲ型DDH合并髋关节骨性关节炎（Tonnis Ⅲ期）的37例病例进行回顾性分析,根据髋臼重建方式分组：其中髋臼原位重建组17例,高髋关节中心重建组20例。比较两组病人的手术时间、手术出血量、Harris评分、影像学假体松动率。结果 37例病人平均随访41个月（25~63个月）。髋臼原位重建组的手术时间和手术出血量分别为（119±16） min、（413±36） ml,高髋关节中心重建组的手术时间和手术出血量分别为（92±21） min、（389±44） ml,两组间比较,差异均有统计学意义（t=29.561,P=0.021;t=0.682,P=0.231）。两组术后的Harris评分均较术前显著提高,但两组间术前及末次随访的Harris评分比较,差异均无统计学意义（P均＞0.05）。髋臼原位重建组中有2例少量植骨吸收,两组随访未见影像学假体松动。结论 高髋关节中心技术的手术时间较髋臼原位重建更短,两种技术治疗Crowe Ⅱ、Ⅲ型DDH的中期临床疗效较好,均可显著恢复病人的髋关节功能。     

The high hip center

Revision of a failed acetabular component presents many challenges to the arthroplasty surgeon. The goal in most cases should be to reconstruct the acetabulum by positioning the hip center as close as possible to the anatomic hip center. However, severe acetabular bone stock deficiency and distorted acetabular anatomy often preclude placement of the acetabular component at the true anatomic hip center. In these cases, many options exist for reconstruction of the acetabulum, including placement of the cup superiorly at a high hip center. Although biomechanical studies have shown that superolateral placement of the hip center may lead to increased moments and forces across the hip (leading to potentially higher rates of loosening), superior only displacement of the hip center does not seem to adversely affect the forces about the hip. Proximal placement of the hip center facilitates contact between intact, viable host bone and the acetabular implant, thereby reducing the need for structural bone grafts, and increasing the chances for stable bony ingrowth. With proper patient selection and meticulous surgical technique, the high hip center can be a useful technique for reconstruction of the deficient acetabulum in the patient with a loose acetabular component after total hip arthroplasty.     

The prevalence of shunt-treated hydrocephalus: a mathematical model

Background

The aim of the study was to create a mathematical model that reproduces the prevalence of shunt-treated hydrocephalus in the United States over the years and predicts trends in the near future.

Methods

A structured search was performed of the English language literature for case series reporting rates of shunt insertion and revision, shunt removal, and patient mortality. A meta-analytic model was constructed to pool data from multiple studies and to calculate these rates at various time intervals. Separate Markov models were used to predict numbers of shunts at any one time for children (<17 years old) and adults. The models analyze the number of shunts inserted every year since 1955 and follow the likely fates of those patients as time passes.

Results

Prevalence rates predicted by the model agree closely with those reported in the literature. However, the model's structure creates considerable variability around point estimates.

Conclusions

The model gives a comprehensive view of the prevalence of shunt-treated hydrocephalus in both children and adults from 1955 to the present. This model may prove useful in predicting resource use and needs for patients with hydrocephalus.     

Primary hip arthroplasty through a limited posterior trochanteric osteotomy

This study evaluates primary hip replacement performed using a modified posterior approach through a limited posterior trochanteric osteotomy bone block that includes the insertions of the posterior capsule and short external rotators--as this may enhance secure reattachment of the posterior soft-tissue envelope and protect against postoperative instability. Sixty-eight consecutive primary hip replacements performed through a posterior trochanteric osteotomy were prospectively followed. Two were lost to follow-up before a minimum of 2 years after the arthroplasty; the remaining 66 hips were followed for a mean of 10 years (range: 2 to 15). The median Harris hip score improved from 43 to 84 points (p < 0.0001). Radiographic union of the osteotomy was confirmed in 64 hips (94%). Two episodes of early dislocation occurred 5 days and 8 months postoperatively; both were successfully managed nonoperatively without continuing instability. There were no cases of late instability. Posterior approach to the hip joint through a posterior trochanteric osteotomy is associated with high union rates and a low rate of late instability after hip replacement.     

The simulation of continuous arteriovenous hemodialysis with a mathematical model

We have developed a mathematical model that predicts the performance of continuous arteriovenous hemodialysis. Given patient (plasma protein concentration, hematocrit, mean arterial pressure, central venous pressure) and circuit (flow resistance, membrane hydraulic permeability, dialyzer mass transfer coefficient, ultrafiltrate column height, dialysate flow rate) characteristics as inputs, predictions of hydraulic and oncotic pressure distribution, filtration rate, blood flow, total, diffusive, and convective urea clearances are provided. The model was tested by perfusing a circuit with bovine blood under conditions of pure ultrafiltration, zero net ultrafiltration and dialysis, or combined ultrafiltration and dialysis (countercurrent dialysate flow at rates of 10, 20, and 30 ml/min). In order to permit computation, membrane hydraulic permeability and flow resistances were measured. Dialyzer mass transfer coefficient for urea could not be measured directly and so was determined by fitting model predictions to measured urea clearances. For all conditions of operation, a urea mass transfer coefficient of 0.014 cm/min successfully simulated the data. Predictions of blood flow, filtrate generation rate, and circuit pressure distribution were accurate. At lower dialysate flow rates, urea clearance approximated the sum of dialysate flow and filtration rate. At higher dialysate flows, however, departure from this ideal blood-dialysate equilibrium was observed. Model predictions regarding the relative contributions of diffusion and convection to urea clearance were explored. Under conditions of nearly perfect equilibration of urea between blood and dialysate at the blood inlet, the model predicts that the diffusive clearance of urea will increase with increasing rate of filtration and may exceed the rate of dialysate inflow.     

The influence of the centre of rotation on implant survival using a modular stem hip prosthesis

The restoration of the hip centre of rotation in an anatomical position is considered to be relevant for total hip prosthesis survival. When the cup is implanted with a high centre of rotation, the lever arm of the abductor muscles is decreased, causing higher joint-reaction forces. Modular stems with varying lengths and geometries can be used to balance soft tissues, and ceramic bearing surfaces can be used to reduce the wear rate. Forty-four hip replacements performed with a high hip centre of rotation were matched with 44 performed with an anatomical centre of rotation. In all cases the preoperative diagnosis was dysplasia of the hip (DDH) and cementless modular neck prostheses with ceramic bearing surfaces were used. At nine years follow-up the mean Harris hip and WOMAC scores were not statistically different. All stems and cups were stable; the femoral offset was no different between the two groups (p = 0.4) as leg-length discrepancy (p = 0.25).     

The spread of caudal analgesia in children: a mathematical model

A mathematical model correlating the spread of analgesia to the dose of local anaesthetic and to age or body weight was found analysing the data of 763 caudal blocks in children from age one day to twelve years. Two graphs have been plotted: (1) spread of analgesia, dose, age and (2) spread of analgesia, dose, weight. Both age and weight can be used as predictors to determine the desired level of analgesia, but weight is more useful in very young patients while age is a better guide in older children.     

The decline of hip fracture incidence rates over a 10-year period: A single centre experience

AimsAccurate epidemiological hip fracture data is essential for healthcare planning and targeted prevention strategies. Limited reports of hip fracture incidence rates in the Republic of Ireland (ROI) exist. The aim is to calculate the current age- and gender-specific incidence of hip fractures in a level 1 Trauma Centre in the ROI, and the difference in these rates over a 10 year period.Materials and methodsThis was a retrospective, population-based, observational study. The local Hospital In-Patient Enquiry (HIPE) database was used to generate data for analysis; capturing all patients admitted for hip fracture in three time periods over 10 years. Patients < 55 years old, pathological fractures, and periprosthetic fractures were excluded. Age- and gender-specific incidence rate was calculated using HIPE and national census data.ResultsAbsolute number of hip fractures rose by 8.5% between 2008/09 (n = 800) and 2018/19 (n = 868) time periods. Cervical hip fractures dominated in all 3 time periods. The average age of patients remained at 80 years but length of stay for patients was reduced by 16% 5 years later and by 21% 10 years later from the initial study point. Both the entire and susceptible (> 55 years) population numbers increased by 13% and 30%, respectively, yet overall hip fracture incidence rate declined 10 years on. Hip fracture incidence rate in the entire population fell by 3.23 per 100,000 population, and by 65.11 per 100,000 population in the susceptible population. The majority of both male and female age groups exhibited declining annual incidence rates over the 10 year study period.ConclusionResults are consistent with the global experience of declining overall incidence rate of hip fractures, despite rising susceptible population numbers. This report adds to the sparse hip fracture incidence data available in the ROI which can be applied in future healthcare planning strategies.     

Permissive hypercapnia and gas exchange in lungs with high Qs/Qt: a mathematical model

Low volume ventilation with permissive hypercapnia is becoming widely used in the treatment of acute respiratory distress syndrome. A mathematical model was developed to examine the effects of hypoventilation on pulmonary gas exchange in lungs with a range of shunt fractions. Hypoventilation did not worsen gas exchange, provided the inspired oxygen concentration was high enough to maintain PAO2 at an adequate level. In lungs with a high shunt fraction, some improvement in gas exchange may result, but these effects are small. A rightwards shift of the oxygen-haemoglobin dissociation curve induced by hypercapnia, is likely to be beneficial rather than detrimental in patients with acute respiratory distress syndrome. This analysis was limited to the direct effects of hypoventilation in lungs with constant shunt fractions, and did not encompass a number of possible secondary effects such as changes in cardiac output with PaCO2, changes in shunt fraction associated with a reduction in mean airway pressure and possible direct effects of hypercapnia on the pulmonary vasculature or airways.      

The incidence of avascular necrosis following a cohort of treated developmental dysplasia of the hip in a single tertiary centre

PurposeAvascular necrosis (AVN) may occur following treatment for developmental dysplasia of the hip (DDH). The primary aim of this study was to identify the incidence of AVN in a cohort of patients treated for DDH. Secondary aims were to classify AVN using available classification systems, analyze the correlation between the systems and investigate their relationship with the age at diagnosis of DDH.MethodsAn 11-year retrospective study was carried out at a single tertiary centre, using data from the clinical portal (patient records database) and IMPAX (system used to store plain radiographic images). Clinical details (patient demographics and outcomes) and plain radiographic images were used to identify cases of DDH and categorize cases of AVN using available classification systems: Tonnis and Kuhlmann, Kalamchi and McEwen, Bucholz and Ogden and Salter. Severin was used to assess final clinical outcome.ResultsIn total, 405 (522 hips) cases of DDH were identified, of which 213 resolved without treatment, 93 were treated conservatively and 99 surgically. Only treated cases were included in the analysis (n = 192). AVN (45/99; 45.5%) was found to occur only postoperatively. A positive correlation was present between age at presentation and severity of AVN as classified according to Salter’s criteria (chi-squared p value < 0.01).ConclusionAVN incidence was 23.4% (45/192) and only occurred in surgically treated patients. Older age at diagnosis was associated with a higher incidence of AVN, as defined according to Salter’s criteria. The classification systems appeared to show no correlation amongst each other (p-value < 0.01).Level of evidence:III - Retrospective cohort study