人工股骨头置换术中置入不同直径假体球头的有限元分析

目的 :针对老年股骨颈骨折行人工股骨头置换术中,借助三维有限元分析的方法 ,探讨置入不同直径的假体球头后的髋关节生物力学变化,观察对髋关节应力分布变化,以便选择出合适的假体球头尺寸。方法:利用薄层CT资料及人工股骨头假体相关参数建立装配有不同假体球头直径的人工股骨头置换术后髋关节有限元模型(M0:术前模型;M1:球头直径=原股骨头直径;M2:球头直径=原股骨头直径+1 mm;M3:球头直径=原股骨头直径-1 mm;M4:球头直径=原股骨头直径-2 mm),并加载关节合力及相关肌肉的负荷,模拟人缓慢行走时单足站立状态,分析不同直径假体植入后髋臼周围骨质及软骨的应力分布及变化。结果:(1)M1～M4中骨盆均出现了不同程度的应力集中,M3的骨盆Von Mises应力峰值为44.8 MPa,与术前最为接近,增量约13.4%,且M3的骨盆位移在术后4组模型中最小,为1.40 mm;其次是M1,应力峰值为47.3 MPa,增量约19.7%,骨盆位移为1.59 mm。(2)在髋臼区域,M3的Von Mises应力峰值为23.3 MPa,与术前最为接近,增量约6.3%,其次是M1,应力峰值为24.0 MPa,增量约8.1%。(3)髋臼软骨上,M1与M3的应力分布同术前相似,且M3的Von Mises应力峰值为18.5 MPa,与术前最为接近;其次是M1,应力峰值为22.5 MPa。(4)M1～M4均在人工股骨头的外上象限出现不同程度的应力集中,而在其下方表现为应力遮挡;其中M3的Von Mises应力分布较其余模型更为均匀,其峰值70.8 MPa为各组中最低,其次为M1(80.7 MPa)。结论:在行人工股骨头置换术时,建议优先使用比原股骨头直径小1 mm的假体球头,其次是与原股骨头直径相等的假体球头,来获得与置换术前的髋关节最接近的自然力学特性,降低因尺寸差异导致的并发症风险。     

偏心髋臼旋转截骨术的生物力学机制及初步临床疗效

 目的 探讨偏心髋臼旋转截骨术治疗髋关节发育不良的生物力学机制及其初步临床疗效。方法 取6具经福尔马林防腐处理的女性尸体骨盆标本,建立髋关节生物力学模型,在模型上模拟偏心髋臼旋转截骨术。对骨盆缓慢施加连续纵向压力0~500 N,测量术前和术后载荷100、200、300、400、500 N时的股骨头承重区应变值,计算应力值。2007年7月至2014年10月应用偏心髋臼旋转截骨术治疗髋关节发育不良25例（26髋）,男6例,女19例;年龄11~57岁,平均31岁。术后以Harris髋关节评分评价髋关节功能,摄骨盆正位X线片测量头臼指数、中心边缘角（center-edge-angle,CE角）及Sharp角。结果-随着脊柱纵向压力加大,股骨头上的应力值随之增加。偏心髋臼旋转截骨术后应力值在载荷超过300 N后由上升趋势转变为下降趋势,总体呈抛物线状。100~500 N载荷下偏心髋臼旋转截骨术后的应力值与术前差异均无统计学意义。临床随访18例（19髋）,随访率72%。随访时间7~85个月,平均40个月。Harris髋关节评分由术前（64.3±7.2）分提高至末次随访时（85.6±5.3）分;头臼指数平均增加36.5%、CE角平均增加33.1°、Sharp角平均减少12.3°,与术前比较差异均有统计学意义。结论-偏心髋臼旋转截骨术具有较好的矫正髋臼畸形的能力,可增大股骨头的髋臼覆盖面和降低承重区压力。     

Factors Associated With Abnormal Joint Contact Pressure After Periacetabular Osteotomy: A Finite-Element Analysis

BackgroundIdentifying factors associated with poor hip contact mechanics after periacetabular osteotomy (PAO) may help surgeons optimize acetabular corrections in individual patients. We performed individual-specific finite-element analyses to identify preoperative morphological and surgical correction factors for abnormal contact pressure (CP) after PAO.MethodsWe performed finite-element analyses before and after PAO with reference to the standing pelvic position on individual-specific 3-dimensional hip models created from computed tomography images of 51 dysplastic hips. Nonlinear contact analyses were performed to calculate the joint CP of the acetabular cartilage during a single-leg stance.ResultsThe maximum CP decreased in 50 hips (98.0%) after PAO compared to preoperative values, and the resulting maximum CP was within the normal range (<4.1 MPa) in 33 hips (64.7%). Multivariate analysis identified the roundness index of the femoral head (P = .002), postoperative anterior center-edge angle (CEA; P = .004), and surgical correction of lateral CEA (Δlateral CEA; P = .003) as independent predictors for abnormal CP after PAO. A preoperative roundness index >54.3°, a postoperative anterior CEA <36.3°, and a Δlateral CEA >27.0° in the standing pelvic position predicted abnormal CP after PAO.ConclusionPAO normalized joint CP in 64.7% of the patients but was less likely to normalize joint CP in patients with aspheric femoral heads. Successful surgical treatment depends on obtaining adequate anterior coverage and avoiding excessive lateral correction, while considering the physiological pelvic tilt in a weight-bearing position.     

髂臼成形骨盆截骨术治疗幼儿发育性髋脱位的疗效

目的探讨髂臼成形(Pemberton)骨盆截骨术治疗幼儿发育性髋脱位(DDH)的疗效。方法对54例DDH患儿采用Pemberton骨盆截骨术治疗。记录临床随访结果和髋关节解剖结构参数。末次随访时,采用Mckay评估标准评价髋关节功能,采用Severin标准评价髋关节形态和复位情况。结果单侧DDH患儿均获得9个月随访;双侧DDH患儿先手术侧获15~18个月随访,后手术侧获9个月随访。术后3个月,患儿股骨、髋臼截骨处均愈合,无重要血管神经损伤、截骨处明显感染等并发症发生。术后6个月、末次随访时髋关节各解剖结构参数均较术前改善明显(P<0.05);与术后6个月相比,末次随访时,骨性髋臼指数(AI)和髋臼深度逐渐增大(P<0.05),中心边缘角(CE角)、髋臼顶宽度和Reimers不稳定指数逐渐减小(P<0.05),髋关节各解剖结构参数已逐步接近同龄正常儿童。末次随访时,单侧DDH患儿患侧的髋臼顶宽度、臼头指数均明显高于健侧(P<0.05),AI、CE角、髋臼深度患侧与健侧比较差异均无统计学意义(P>0.05)。末次随访时,4例髋臼Y形软骨已闭合,其中1例Y形软骨早闭;采用Mckay评估标准评价髋关节功能的优良率为86.67%;采用Severin标准评价髋关节形态和复位情况的优良率为83.33%。结论Pemberton骨盆截骨术可以有效纠正DDH,修复髋关节功能,促进骨骺生长及患儿康复,效果显著。     

电阻片应变法在测量三翼臼固定后骨盆应力变化中的应用

目的应用电阻片应变法测量骨盆髋臼骨缺损模型三翼臼固定后髋臼上方的应力值。方法成年男性尸体骨盆标本4只，无髋关节骨质缺损或畸形。于臼顶处造成节段性骨缺损，缺损面积约为髋臼面积的20％。根据三翼臼扩展角度不同分为0、36、45和60°4个实验组，并设立无缺损、无翼假体骨盆为对照组。在4只骨盆标本上各布置7组电阻应变花，1、2和3号位置为骨盆外侧与臼杯3个翼对应的髋臼上方，4号位置为骨盆外侧髋臼与骶髂关节连线近端，5、6和7号位置于骨盆内侧髋臼与骶髂关节连线由外下向内上方均匀分布。模拟单腿站立时髋关节负重情况，进行150、300、450、600、750和900N分级加载，收集各组各级加载和卸载时应变片应变信息。结果测试点最大等效应力为6．93MPa，最小等效应力为1．08MPa。结论骨盆髋臼骨缺损三翼臼固定后，在宿主骨没有引发高应力区，为翼间移植骨的生长提供了力学环境下的数据。     

正常步态下距骨关节面接触特征的有限元分析

[目的]通过有限元法分析正常步态下距骨各关节面软骨应力变化,了解各关节面软骨应力分布的生物力学特征.[方法]利用正常男性的足踝部螺旋 CT 扫描数据,运用三维建模软件,建立足踝部三维几何模型,并对其进行有限元网格划分,分析正常步态下距骨各关节面接触应力及 Von Mises 应力分布.[结果]建立包括骨、软骨、韧带在内的正常人体足踝部三维有限元模型,共21 865 个节点、73 440 个单元,较客观地反映了人体足踝的解剖结构和力学特性.不同位相距骨各关节面接触应力及 Von Mises 应力分布区域和应力值不同.[结论]采用有限元法分析关节软骨应力的生物力学特征是一种可行、有效的方法.     

Chiari骨盆截骨术的生物力学基础及临床应用（附36例报告）

本文报告应用Ｃｈｉａｒｉ骨盆截骨术治疗髋臼发育不良、扁平髋等３６例４１个髋。３２个髋平均随防４年４个月。优良者２７个髋，占８４．３７％。术后Ｘ线片显示，截骨均获骨性愈合，髋臼对头覆盖完全，头臼相称。髋臼发育不良者，ＣＥ角平均增加２０°。作者分析此术式后认为：Ｃｈｉａｒｉ手术能增加髋臼面积，减少股骨头单位压强，截骨内移后能增加肌力臂，减少重力臂，从而减少髋关节的载荷，降低关节内压及髂骨髋内压，有利于缓解“休息痛”。为此提出成人先天性髋臼发育不良、扁平髋、股骨头无菌坏死以及髋的骨关节炎病人适合行此手术。     

Biomechanical evaluation of impaction fractures of the femoral head.

OBJECTIVES: To measure the effect of an impaction fracture of the femoral head on load transmission in the hip joint. DESIGN: We measured the contact areas and pressure between the acetabulum and femoral head of cadaveric pelves in four different conditions: intact, with an operatively created one-square-centimeter defect in the superior femoral head, with a two-square-centimeter defect, and with a four-square-centimeter defect. All defects were uniformly three millimeters deep. SETTING: Hips were loaded in a simulated single-limb stance. Pressure and area measurements were made with Fuji pressure-sensitive film. SPECIMENS: Seven hip joints in seven whole pelves were tested. MAIN OUTCOME MEASUREMENTS: Contact area, load, and mean and maximum pressures were measured. RESULTS: Peripheral loading was seen in the intact acetabulum. This was not disrupted after impaction fractures of any size. A significant increase in mean maximum pressures in the superior acetabulum was seen with two-square-centimeter and four-square-centimeter defects. CONCLUSIONS: In contrast to prior biomechanical studies of acetabular fractures, our investigation revealed that disruption of the peripheral distribution of load does not occur with impaction fractures of the femoral head. Clinical series indicate that impaction injuries to the femoral head are associated with a poor prognosis. Previous biomechanical data on acetabular fracture patterns associated with a poor prognosis have shown increases in mean and peak pressures in the superior acetabulum. This was seen with two-square-centimeter and four-square-centimeter impaction injuries. Other factors, such as wear of the articular cartilage during joint motion or associated microscopic damage to the remainder of the joint surface at the time of injury, may also contribute to the rapid joint deterioration seen in these injuries. Further study is indicated.     

膝关节内侧固定平台单髁假体放置位置优化的有限元分析

目的探讨股骨组件及胫骨组件冠状面位置变化对股骨及胫骨生物力学的影响。方法取1名汉族男性志愿者的左侧膝关节CT及MRI图像,建立正常膝关节三维有限元模型(finite elemental model,FEM)。设计股骨组件及胫骨组件内翻6°、内翻3°、0°、外翻3°、外翻6°,组合成25个膝内侧单髁置换FEM。沿股骨机械轴加载1000 N载荷,观察von Mises云图应力分布,测量外侧间室载荷比例,测量胫骨组件下方松质骨及内侧皮质骨、聚乙烯衬垫上表面、外侧间室股骨软骨高接触应力值。将与中立位(胫骨及股骨假体内外翻0°、胫骨假体后倾5°)比较有统计学意义的指标通过散点图标识,找出点项目密集区和稀疏区,比较两区有统计学意义的项目数量,确定股骨组件、胫骨组件优化位置。结果股骨组件0°位放置时,胫骨从内翻6°至外翻6°各组合的胫骨组件下方松质骨高接触应力差异无统计学意义;胫骨组件0°位放置时,股骨组件内翻6°、外翻6°组件下方松质骨高接触应力值与中立位比较增加(9.21±3.38)MPa和(9.08±4.13)MPa(P<0.05)。股骨、胫骨组件从内翻6°至外翻6°变化时,胫骨下方内侧皮质骨高接触应力值逐渐下降(P<0.05)。股骨组件0°位放置时,胫骨组件从内翻6°至外翻6°各组合聚乙烯衬垫上表面高接触应力值的差异无统计学意义;胫骨组件0°位放置时,股骨组件内翻6°、外翻6°组与中立位组比较分别增加(2.88±2.53)MPa和(3.47±2.86)MPa(P<0.05);股骨及胫骨组件从内翻6°至外翻6°变化时,外侧间室载荷比例及外侧间室股骨软骨高应力值逐渐下降(P<0.05)。稀疏区(股骨或胫骨从内翻3°至外翻3°的所有组合的集合)有统计学意义的指标比例(2.8%,1/36)明显小于密集区(去除稀疏区以外的所有组合的集合)的比例(57.8%,37/64),差异有统计学意义(χ^2=29.61,P<0.001)。结论在下肢力线正常、关节线不变的条件下,膝关节内侧固定平台单髁假体放置位置为股骨组件、胫骨组件内翻、外翻角度不宜超过3°。     

Changes in chondrolabral mechanics,coverage, and congruency following peri‐acetabular osteotomy for treatment of acetabular retroversion: A patient‐specific finite element study

Using a validated finite element (FE) protocol, we quantified cartilage and labrum mechanics, congruency, and femoral coverage in five male patients before and after they were treated for acetabular retroversion with peri‐acetabular osteotomy (PAO). Three‐dimensional models of bone, cartilage, and labrum were generated from computed tomography (CT) arthrography images, acquired before and after PAO. Walking, stair‐ascent, stair‐descent, and rising from a chair were simulated. Cartilage and labrum contact stress, contact area, and femoral coverage were calculated overall and regionally. Mean congruency (average of local congruency values for FE nodes in contact) and peak congruency (most incongruent node in contact) were calculated overall and regionally. Load supported by the labrum was represented as a raw change in the ratio of the applied force transferred through the labrum and percent change following surgery (calculated overall only). Considering all activities, following PAO, mean acetabular cartilage contact stress increased medially, superiorly, and posteriorly; peak stress increased medially and posteriorly. Peak labrum stresses decreased overall and superiorly. Acetabular contact area decreased overall and laterally, and increased medially. Labral contact area decreased overall, but not regionally. Load to the labrum decreased. Femoral head coverage increased overall, anterolaterally, and posterolaterally, but decreased anteromedially. Mean congruency indicated the hip became less congruent overall, anteriorly, and posteriorly; peak congruency indicated a less congruent joint posteriorly. Clinical relevance: Medialization of contact and reductions in labral loading following PAO may prevent osteoarthritis, but this procedure increases cartilage stresses, decreases contact area, and makes the hip less congruent, which may overload cartilage. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2567–2576, 2017.

     

骨盆Salter截骨治疗发育性髋关节脱位术后渐发脱位的原因分析

目的探讨骨盆Salter截骨治疗发育性髋关节脱位术后渐发脱位的原因。方法采用骨盆Salter截骨治疗63例儿童发育性髋关节脱位。7例术后发生渐发脱位,分析其发生原因。结果患儿均获得随访,时间12~89个月。术后发生渐发脱位7例中,3例因术后关节囊松弛,不能有效维持关节稳定性,通过佩带髋外展支具后髋关节恢复稳定;2例因术中骨盆截骨旋转角度过大,髋臼后方包容欠佳,术后髋臼软骨发育不良,再次行骨盆Pemberton截骨关节囊紧缩修复矫正;2例因术前合并多关节松弛症,关节稳定性相对较差,术后并发Perthes病行髋臼周围截骨手术矫正治疗。结论儿童发育性髋关节脱位术后渐发脱位与患者自身合并疾病、髋关节病变程度、手术操作等因素均有密切关系,准确的术前评估、适合的手术方式、精确的手术操作、术后早期干预治疗是防治术后渐发脱位的有效方法。     

髋臼发育不良的光弹性生物力学研究

目的 从生物力学角度探讨髋臼发育不良继发骨关节炎的发病机理,为髋臼旋转截骨术提供依据。方法 用环氧树脂制作骨盆、股骨模型,其中包括４个不同Ｓｈａｒｐ角、３个不同软骨厚度及３个颈干角模型,采用二维光弹性方法进行生物力学分析。结果 随着Ｓｈａｒｐ角的增大,髋关节的合力增大,生物应力向髋臼外侧缘移动;关节软骨缺损一半时,髋关节合力未见明显变化,当关节软骨不存在时,生物应力为正常时的２．５倍;随着颈干角的增大,生物应力集中的位置没有变化,但生物应力及合力随之增大。结论 髋臼发育不良因生物力学因素可继发骨关节炎,髋臼旋转截骨术是对其有效的治疗方法。     

人体骨盆生物力学三维光弹性的实验研究

目的 研究人体正常骨盆和髋臼发育不良骨盆的生物力学特征。方法 依据光弹性力学原理,应用光敏材料E－51环氧树脂制作人体骨盆三维光弹模型共4套,模型加载,应力冻结,测量分析骨盆的应力分布及形态改变。结果 人体双腿站立时,正常及髋臼发育不良骨盆环的应用力集中在I7、I8、S4、A1、A2等处;髋臼发育不良时髋臼内壁应力异常集中于髋臼上缘,A1：A4＝6：1。负重后正常骨盆髋臼外口呈“椭圆形”改变。结论 人体骨盆应力分布复杂;人体双腿站立负重时髋臼可发生形态改变;髋臼发育不良时髋臼应力分布不均导致髋关节骨关节炎的发生。     

Application of three-dimensional computerised tomography reconstruction and image processing technology in individual operation design of developmental dysplasia of the hip patients

Purpose

Acetabular coverage deficiency displays individual difference among patients with developmental dysplasia of the hip (DDH). Therefore, the correct direction and degree of the acetabular fragment is patient-specific during Bernese periacetabular osteotomy (PAO). This paper introduces a feasible method using 3D computed tomography (CT) and computer image processing technology for customised surgical planning.

Methods

CT data of 96 hips in 60 DDH patients (male 15, female 45; average age/range 30?±?8/14–49 years) and 53 normal hips (male 13, female 37; average age/range 52?±?13/16–69 years) were reconstructed using commercially available software Mimics and Imageware. Geometric parameters of each hip were measured in relation to the anterior pelvic plane after correcting for pelvic tilt and rotation. Deficiency types and degrees of acetabular dysplasia in patients with DDH were determined by comparison with normal hips, and improvement in femoral-head coverage was analysed again after virtual PAO. A customised surgery programme for each DDH patient was designed and provided the reference for the actual operation.

Results

We produced a 3D pelvic model using image processing software, doing precise measurement and with close approximation to the actual PAO. Lateral centre-edge angle (LCEA), anterior centre-edge angle (ACEA), acetabular anteversion angle (AAVA), anterior acetabular sector angle (AASA) and posterior acetabular sector angle (PASA) of normal hips in the control group were 35.128?±?6.337, 57.052?±?6.853, 19.215?±?5.504, 61.537?±?7.291 and 99.434?±?8.372°, respectively. Angles of hips with DDH before surgery were 11.46?±?11.19, 35.79?±?13.75, 22.77?±?6.13, 43.58?±?9.15 and 88.46?±?8.24, which were corrected to 33.81?±?2.36, 55.38?±?2.09, 20.16?±?2.18, 58.29?±?7.60, and 4.71?±?7.75°, respectively, after surgery. After virtual Bernese PAO, LCEA, ACEA, AAVA, AASA and PASA were corrected significantly (p?<?0.01). There was no statistically significant differences between LCEA, ACEA and AAVA after virtual Bernese PAO and normal hips (p?=?0.06, p?=?0.23, p?=?0.06°, respectively). AASA improved significantly (p?=?0.002) post-operatively at the cost of reducing posterior coverage represented by PASA, which is significantly smaller than in normal and pre-operative hips of DDH patients (p?<?0.01).

Conclusions

The geometric feature of the pelvis for patients with DDH can be assessed comprehensively by using 3D-CT reconstruction and image processing technology. Based on this method, surgeons can design individualised treatment scheme and improve the effect of PAO.

     

In vitro contact stress distribution on the femoral condyles

Contact stress distributions were measured across the tibiofemoral joints of 11 fresh-frozen normal cadaver specimens. Local stress magnitudes were sensed by arrays of miniature piezoresistive transducers inset superficially in the cartilage of the femoral condyles. Knee joints were tested at 0, 10, 20, and 30 degrees of flexion and later retested at 0 degrees following medial and dual meniscectomies. For the intact joint, both the spatial mean and peak local contact stresses rose approximately linearly with the joint resultant, reaching levels of 2.6 and 8.0 MPa, respectively, at 3 kN of applied loading. Flexion angle variations in the range studied failed to cause significant changes in the major contact parameters. Although meniscectomies involved contact area reductions and consequent stress increases, such effects were more moderate than results previously seen for static loading of the tibial plateau.     

Comparative study of the intrinsic mechanical properties of the human acetabular and femoral head cartilage

Biphasic creep indentation methodology and an automated indentation apparatus were used to measure the aggregate modulus, Poisson's ratio, permeability, thickness, creep and recovery equilibrium times, and percentage of recovery of normal articular cartilage in 10 human hip joints. These properties were mapped regionally to examine the mechanical factors involved in the development of site-specific degenerative lesions in the acetabulum and femoral head. The results indicate that there are significant differences between these properties regionally in the acetabulum and femoral head and between the two anatomical structures. Specifically, it was found that cartilage in the superomedial aspect of the femoral head has a 41% larger aggregate modulus than its anatomically corresponding articulating surface in the acetabulum. In addition, the supermedial aspect of the femoral head has the greates aggregate modulus (1.816 MPa) within the hip joint. During sitting, the inferior portion of the femoral head is in contact with the anterior acetabulum, and the anterior acetabulum has a 53% greater aggregate modulus than the inferior femoral head. This area below the fovea on the femoral head has the least aggregate modulus (0.814 MPa) within the hip joint. These mismatches in the compressive modulus of opposing articulating surfaces may contribute to degeneration of cartilage in the superomedial acetabulum and the inferior femoral head. Our findings support the clinical observation that these areas are frequent sites of early degeneration.     

髋臼后壁重建模型的建立及其生物力学分析

目的 :在尸体上模拟髋臼后壁缺损的模型,评价不同后壁重建方法对髋臼与股骨头接触特性的影响。方法:获取6具成人尸体的骨盆股骨标本,采用随机数字表法分为A组和B组。均采用后壁截骨法建立髋臼后壁60°弧1/2缺损的模型;两侧缺损区分别选用不同的重建方法。其中,A组凿取髂前上棘后方的自体髂骨以制作解剖性自体髂骨;B组于髂后上棘前方凿取髂骨块。将髋关节置于直立位、屈曲位及后伸位,从10~250 N分级加载,使载荷直接作用于髋臼后壁上。采用压敏片检测不同状态下形变位移、载荷、头臼接触面积及接触应力。结果:在不同的髋关节状态下,A组在一定载荷下的形变位移略大于B组,但差异无统计学意义(P0.05)。与完整髋臼相比,后壁重建使头臼接触面积有所减少;在250 N载荷下,A组(解剖重建组)头臼接触面积与B组(普通重建组)比较的差异无统计学意义(P0.05);其平均接触应力小于B组(P0.05),说明A组应力集中小于B组。结论:后壁截骨法建立的尸体髋臼后壁缺损模型可有效模拟临床实际;解剖重建使后壁头臼接触面积及应力分布恢复比较理想,接近正常髋关节,避免了局部应力集中。     

Three-Dimensional Evaluation of Innominate Bone Rotation in Female Patients with Developmental Dysplasia of the Hip

BackgroundPatients with developmental dysplasia of the hip (DDH) are known to have abnormal pelvic morphologies; however, rotation of innominate bone features remains unclear. Thus, we investigated innominate bone rotation in patients with DDH by measuring the associated angles and distances using three-dimensional (3D) computed tomography.MethodsWe defined four straight lines in pelvic 3D models: from the anterior superior iliac spine to the posterior superior iliac spine, from the anterior inferior iliac spine to the posterior inferior iliac spine, from the pubic tubercle to the ischial spine, and from the pubic tubercle to the ischial tuberosity. Similarly, we measured the angles formed by these lines using the vertical axis of the anterior pelvic plane on the horizontal plane and the horizontal axis on the sagittal plane. Additionally, we measured the distances between the femoral head centers and the acetabular centers in the coronal plane.ResultsThe difference in internal rotation angle between the superior and inferior parts of the iliac bone was significantly lower, by approximately 1.7°, in the DDH group than in the control group (p = 0.007); the difference between the inferior and superior parts of the ischiopubic bone was significantly higher, by approximately 1.5°, in the DDH group (p < 0.001). In the sagittal plane, the sum of the superior aspect of the iliac bone and the inferior aspect of the ischium was significantly lower in the DDH group (p = 0.001) than in the control group. The distances between the femoral heads and the acetabula were significantly greater in the DDH group than in the control group (p = 0.03, p < 0.01, respectively).ConclusionsPatients with DDH had a more internally rotated ilium and ischiopubic bone than normal individuals; however, it should be emphasized that internal rotation was reduced near the acetabulum, and the acetabulum was shifted laterally. Similarly, it was shown that patients with DDH had different rotations of the ilium and ischiopubic bone in the sagittal plane.     

Triple pelvic osteotomy: Report of our mid-term results and review of literature

A wide variety of pelvic osteotomies have been developed for the treatment of developmental dysplasia of the hip (DDH). In the present paper, we present a detailed review of previous studies of triple osteotomy as an alternative treatment for DDH. We also report our experience treating 6 adult cases of DDH by triple osteotomy in order to highlight the various aspects of this procedure.The mean age of our patients was 31.2 years with a mean follow-up period of 6 years. We assessed range of motion, center-edge angle, acetabular index angle, Sharp angle, acetabulum head index, head lateralization index, Japanese Orthopedic Association score, Harris hip score, patient satisfaction, and the difference between lower limb lengths before and after the procedure. At final follow-up, clinical scores were significantly improved and radiographic parameters also showed good correction of acetabulum.