Femoral anteversion is correlated with acetabular version and coverage in Asian women with anterior and global deficient subgroups of hip dysplasia: a CT study

Objective

Morphological correlation between the acetabulum and femur at the hip joint is still controversial. We tested the hypothesis that femoral anteversion correlates with acetabular version and coverage in patients with developmental dysplasia of the hip (DDH).

Materials and methods

Using pelvic computed tomography (CT) images of 79 hips in 49 Asian women with DDH and 49 normal hips, we measured femoral anteversion, the axial and vertical acetabular version and the acetabular sector angle (ASA) to demarcate femoral head coverage. Depending on the location of the acetabular bone defect, dysplastic hips were divided into three subgroups: the anterior, global and posterior deficiency groups. We performed a comparative analysis between dysplastic and normal hips using the Wilcoxon rank sum test, and a relative analysis between femoral anteversion and acetabular measurements in dysplastic hips using Pearson’s correlation coefficient.

Results

The amount of femoral anteversion in dysplastic hips was greater and more variable than in normal hips (p?p?=?0.0277 respectively). Femoral anteversion in dysplastic hips correlated significantly with acetabular anteversion in the groups with anterior and global deficiency subgroups (p?p?Conclusions Our results showed significantly greater and more variable femoral anteversion in DDH, and a significant correlation between femoral anteversion and acetabular version and coverage in DDH with anterior and global acetabular bone deficiency.     

Radiographic measurements of dysplastic adult hips

 Hip dysplasia is a not uncommon feature in adults and can vary from subtle acetabular dysplasia to complex sequelae of developmental dysplasia of the hip. This review article describes the most useful radiographic measurements used to evaluate the adult hip. The frontal projection of the pelvis permits measurement of the center-edge angle (CE angle) and ”horizontal toit externe” angle (HTE angle), both of which assess the superior coverage of the acetabulum. The femoral neck-shaft angle (NSA) is also measured on this view. The false profile radiograph of the pelvis is described. It allows measurement of the vertical-center-anterior angle (VCA angle), which determines the anterior acetabular coverage and detects early degenerative hip joint disease. When surgery is contemplated, computed tomography (CT) is useful to better determine the anterior acetabular coverage by use of the anterior acetabular sector angle (AASA), and the posterior acetabular coverage by use of the posterior acetabular sector angle (PASA). CT also permits measurement of femoral anteversion. These measurements are particularly useful in the evaluation of acetabular dysplasia and for the preoperative assessment of the dysplastic hip.     

正常成人髋臼断面角的CT测量

目的通过ＣＴ测量,建立国内成人髋臼断面角的正常值标准。方法对１２０例因腹部或盆腔病变行ＣＴ检查而无髋部症状的病人加扫双侧髋关节。从中挑选Ｘ线和ＣＴ表现正常的１００例作为统计对象。结果成年男性被研究者髋臼前断面角（ＡＡＳＡ）的范围为５９．００°～８３．００°,平均值为７２．５６°,标准差为５．６１°;髋臼后断面角（ＰＡＳＡ）的范围为８４．００°～１１６．００°,平均值为１００．６２°,标准差为５．７６°。成年女性研究者ＡＡＳＡ的范围为５３．００°～９２．００°,平均值为７０．４５°,标准差为７．７９°;ＰＡＳＡ范围８７．００°～１２０．００°,平均值为１０３．６６°,标准差为７．２２°。结论国内正常成年男性ＡＡＳＡ正常值范围为６１．５６°～８３．５６°,ＰＡＳＡ为８９．３３°～１１１．９１°,成年女性ＡＡＳＡ为５５．１８°～８５．７２°,ＰＡＳＡ为８９．５１°～１１７．８１°     

Computed tomography measurements of the acetabulum in adult dysplastic hips: which level is appropriate?

A study has been performed to evaluate whether one or several levels are needed with computed tomography (CT) study to provide sufficient information regarding anteversion and acetabular support to the femoral head. A total of 23 hips in 14 adults with uni- or bilateral congenital hip dysplasia (center-edge angle less than 20°) were assessed by obtaining 5-mm contiguous CT slices and performing acetabular measurements at four levels. Both anterior and posterior acetabular supports as quantified by the anterior and posterior acetabular sector angles were significantly lower than normal at all levels. The sector angles increased in the proximal cuts, whereas the acetabular anteversion increased caudally. Because no important additional information was gained by measuring at different levels, we conclude that CT study at one level is sufficient for acetabular measurements and suggest that the slice through the center of the femoral head is the most appropriate one.     

髋臼发育不良患者髋臼周围截骨术前的三维CT测量

目的 使用三维CT测量无晚期骨关节炎的髋臼发育不良患者的髋臼,并分析覆盖缺损类型和程度.资料与方法 30例患者共46个髋关节于髋臼周围截骨术前行X线片和三维CT扫描,分别测量外侧中心边缘角、臼顶倾斜角和前方中心边缘角,及三维CT上的髋臼前倾角、髋臼前角、髋臼后角.应用Harris评分对患者进行临床评估.结果 三维CT和X线片测得的外侧中心边缘角、臼顶倾斜角和前方中心边缘角差异无统计学意义(P＞0.05).根据髋臼覆盖缺损部位分为外侧缺损(7个髋)、外侧+前方缺损(12个髋)、外侧+后方缺损(9个髋)和完全缺损(18个髋)04组前方中心边缘角、髋臼前倾角、髋臼前角和髋臼后角差异有统计学意义(P＜0.01),而外侧中心边缘角、臼顶倾斜角、髋臼覆盖率及Harris评分差异无统计学意义(P＞0.05).结论 三维CT能更直接显示和精确测量不同类型的髋臼发育不良改变.     

Patterns of femoral head migration in osteoarthritis of the hip: a reappraisal with CT and pathologic correlation

Although medial, superior, and axial patterns of migration of the femoral head in osteoarthritis of the hip have been well described, it is not clear what anatomic and biomechanical factors determine the direction of migration. The authors studied 22 patients with bilateral (11 patients) or unilateral (11 patients) osteoarthritis by means of conventional radiography and computed tomography (CT) to define any relationships between migration in the coronal plane and that in the transverse plane and to determine whether femoral anteversion, acetabular anteversion, femoral neck-shaft angle, or acetabular inclination were related to particular migration patterns. Anterior migration was evident in 14 of the 19 hips with a superior migration pattern, whereas posterior migration was present in five of the seven hips with a medial migration pattern. In the remainder of cases, no migration in the transverse plane was present. Femoral anteversion as determined with CT, femoral neck-shaft angle, angle of acetabular inclination, and acetabular anteversion angle in this relatively small sample were all found to be within normal limits and appeared to have no influence on the occurrence of a specific pattern of femoral head migration.     

人工关节置换治疗晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形

目的 探讨晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形患者采用普通假体髋关节置换的手术方法及临床疗效.方法 本组男9例,女6例;年龄30～42岁,平均37岁.前倾角40°～50°,术前Harris评分(59±8)分,术中通过将股骨假体缩小前倾角20°～30°,同时将髋臼杯前倾角增大10°～15°,使其基本恢复正常对合关系,防止关节前脱位.术后定期影像学检查和临床疗效Harris髋评分.结果 术后15例患者均获得随访2.5～3.7年(平均2.9年),关节假体稳定性良好,关节活动度基本正常.术后2年Harris评分为(88±6)分,与术前相比,疗效显著(P<0.01).结论 晚期股骨头缺血性坏死合并严重股骨颈前倾角畸形患者手术中通过对普通的股骨假体及髋臼杯安放的角度的联合调整,使关节置换术后人工假体与髋臼的对合基本恢复正常,疗效显著,同时避免了使用小柄股骨假体、转子下截骨或使用特殊前倾角股骨假体等治疗方法.     

Degeneration in dysplastic hips

Background Hip dysplasia is considered pre-osteoarthritic, causing degeneration in young individuals. Objective To determine the pattern of degenerative change in moderate to severely dysplastic hips in young patients. Design and patients One hundred and ninety-three consecutively-referred younger patients with hip pain believed to be caused by hip dysplasia constituted the study cohort. The average age was 35.5 years (range, 15–61 years). They were examined by close-cut transverse pelvic and knee computed tomography and antero-posterior radiographs (CT). We identified 197 hips with moderate to severe dysplasia, and 78 hips with normal morphology in the study cohort, whilst 111 hip joints were borderline dysplastic according to preset definitions. Comparative analyses of anatomy and distribution of degeneration between dysplastic and normal hips in the study cohort were performed. Results In dysplastic hips the anterior acetabular sector angle was significantly and inversely associated to femoral anteversion (p<0.001). The center-edge (CE) angle, the acetabular angle (AA), and the acetabular depth ratio (ADR) were significantly interrelated (p<0.001; correlation coefficients ranging from −0.8 to 0.7). Fifty-one hips were subluxated (24R/27L). There were no cases of complete dislocation. The formation of subchondral cysts or osteophytes in dysplastic hips was significantly associated with reduced minimum joint space width (p ranging from 0.005 to 0.02). However, in 67 hips with acetabular cysts, only 6 hips had minimum joint space widths =2.0 mm (8.9%) in the coronal plane. In 96 cases with acetabular cysts found in the sagittal plane, 43 cases had minimum joint space widths =2.0 mm (44.7%). Bony rim detachment at the site of labral insertion was recorded in 30 hips. Twenty-three of these were dysplastic (p=0.01). Conclusions Degeneration was most often found in the anterolateral part of the dysplastic hip joints. Most cysts were located above the transition zone between the bony and the fibrocartilaginous acetabulum, and we found a significantly- increased number of cases with avulsed bony fragments at the antero-lateral labral insertion in dysplastic hips compared to normal hips. It seems likely that the early degenerative process in dysplastic hips originates at the watershed zone between the acetabular labrum and the acetabular cartilage in response to subluxation and femoroacetabular impingement.     

全髋关节置换术中采用直接前方入路放置髋臼假体疗效观察

目的通过测量髋臼假体的外展角与前倾角,探讨全髋关节置换术(THA)中采用直接前方入路(DAA)放置髋臼假体的准确性。方法选取2015年7月至2016年1月收治的THA中采用DAA放置髋臼假体的患者81例(100髋),手术均由同一名具有高级职称的医师完成,术中使用可透光手术床,结合透视与髋臼假体导向器放置髋臼假体。术后骨盆正位X线影像测量髋臼假体的外展角与前倾角,并与Lewinneck安全区(外展角30°~50°,前倾角5°~25°)进行比较,评估THA中采用DAA放置髋臼假体的准确性。结果患者术后髋臼假体的外展角为(39.00°±4.47°),前倾角为(14.29°±5.50°);91.0%(91/100)患者术后髋臼假体的外展角与前倾角均在Lewinneck安全区内;所有患者术后10个月均未见脱位。结论 THA中采用DAA放置髋臼假体安全有效,可准确地将假体放置在安全区内。     

Rotational profile of the lower extremity in achondroplasia: computed tomographic examination of 25 patients

Purpose To evaluate lower-extremity rotational abnormalities in subjects with achondroplasia using computed tomography (CT) scans.Materials and methods CT scans were performed in 25 subjects with achondroplasia (13 skeletally immature, mean age 8.7 years; 12 skeletally mature, mean age 17.6 years). In a total of 50 bilateral limbs, CT images were used to measure the angles of acetabular anteversion, femoral anteversion, and tibial external torion. Measurement was performed by three examiners and then repeated by one examiner. Inter- and intraobserver agreements were analyzed, and results were compared with previously reported normal values.Results Mean values for skeletally immature and skeletally mature subjects were 13.6±7.5° and 21.5±6.4° respectively for acetabular anteversion, 27.1±20.8° and 30.5±20.1° for femoral torsion, and 21.6±10.6° and 22.5±10.8° for tibial torsion. Intra- and interobserver agreements were good to excellent. Acetabular anteversion and femoral anteversion in skeletally mature subjects were greater than normal values in previous studies. Both skeletally immature and mature subjects with achondroplasia had decreased tibial torsion compared to normal skeletally immature and mature subjects.Conclusion Lower-extremity rotational abnormalities in subjects with achondroplasia include decreased tibial external torsion in both skeletally immature and mature subjects, as well as increased femoral and acetabular anteversion in skeletally mature subjects.     

Three-dimensional computed tomography analysis of non-osteoarthritic adult acetabular dysplasia

OBJECTIVE: Little data exists on the original morphology of acetabular dysplasia obtained from patients without radiographic advanced osteoarthritic changes. The aim of this study was to investigate the distribution and degree of acetabular dysplasia in a large number of patients showing no advanced degenerative changes using three-dimensional computed tomography (3DCT). MATERIALS AND METHODS: Eighty-four dysplastic hips in 55 consecutive patients were studied. All 84 hips were in pre- or early osteoarthritis without radiographic evidence of joint space narrowing, formation of osteophytes or cysts, or deformity of femoral heads. The mean age at the time of CT scan was 35 years (range 15-64 years). 3D images were reconstructed and analyzed using recent computer imaging software (INTAGE Realia and Volume Player). Deficiency types and degrees of acetabular dysplasia were precisely evaluated using these computer software. RESULTS: The average Harris hip score at CT scans was 82 points. Twenty-two hips (26%) were classified as anterior deficiency, 17 hips (20%) as posterior deficiency, and 45 hips (54%) as lateral deficiency. No significant difference was found in the Harris hip score among these groups. The analysis of various measurements indicated wide variations. There was a significant correlation between the Harris hip score and the acetabular coverage (p < 0.001). CONCLUSION: Our results indicated wide variety of deficiency type and degree of acetabular dysplasia. Hips with greater acetabular coverage tended to have a higher Harris hip score.     

成人髋关节撞击综合征患者股骨前倾角的CT影像学研究

目的通过CT测量股骨前倾角对髋关节撞击综合征(FAI)病例组和正常对照组进行对比分析,探讨股骨前倾角在FAI不同亚型患者中的临床意义。方法搜集经手术证实的58例髋关节撞击综合征患者,测量其股骨前倾角,并与正常成人对照组比较分析。结果无论是病例组还是对照组,股骨前倾角在性别上均具有统计学差异(P<0.02),而在左髋和右髋上无统计学意义。股骨前倾角在FAI不同亚型和正常对照组的平均值分别为(18.90±6.17)°、(28.60±6.28)°、(22.88±8.83)°、(21.81±5.50)°,除混合型FAI组与正常组的股骨前倾角无统计学差异,其余各两组间均具有统计学差异。结论CT扫描是FAI患者术前测量股骨前倾角的主要手段。FAI不同亚型的股骨前倾角之间存在一定的差异性,股骨前倾角过大或过小对FAI的发病机制及治疗起重要作用。     

成人髋臼结构不良CT应用价值

目的　探讨CT对成人髋臼结构不良的诊断价值。方法　对 2 8例髋臼结构不良患者的 5 6个髋关节CT资料进行回顾性分析。结果　成人髋臼结构不良的CT影像中 ,75 .0 %髋臼表现有前部发育不良 ,而髋臼前后部均发育不良 ( 14 .4% )和臼窝形态异常 ( 14 .9% )者少见 ,5 7.1%髋臼顶部有发育不良。此外 ,CT发现继发性骨关节病和股骨头缺血坏死分别为 91.1%和 16 .1% ,均高于平片所见。结论　CT有助于全面了解髋臼发育状况及其与股骨头相互适应情况 ;确定髋臼结构不良的基本类型 ;早期发现继发性骨关节病和股骨头缺血坏死及评估髋关节病变的严重程度。     

发育性髋关节脱位髋臼前倾角的CT研究

目的:研究发育性髋关节脱位髋臼前倾角的变化,为手术选择和判断预后提供依据。方法:选择手术前发育性髋关节脱位DunnⅠ型28髋,DunnⅡ型19髋,DunnⅢ型22髋。选取手术后为优的17髋。正常髋关节12髋。采用多层螺旋CT扫描,然后行髋臼三维重建,测量通过两侧Y形软骨中心O点的横断面测量髋臼前倾角。结果:髋臼前倾角度数正常组<术后相似文献   

正常成人髋关节间隙与髋臼角相关性研究

目的 通过CT测量髋关节,探讨正常成人髋臼前唇连线头距、骨关节间隙与髋臼角的相关性.方法 对216例因盆腹部病变行CT检查而无髋部症状患者的髋关节进行数据重建、测量,从中挑选X线和CT表现正常的400例髋关节作为统计对象,测量髋臼前唇连线关距、髋关节前、后间隙及LCE角、髋臼角、股骨头覆盖率、臼顶切线角.结果 髋臼前唇连线头距与LCE角、股骨头覆盖率呈正相关,与髋臼角负相关;髋关节前间隙与LCE角、股骨头覆盖率呈负相关,与髋臼角不相关;髋关节后间隙与CE角呈负相关,与髋臼角、股骨头覆盖率不相关.根据臼顶切线角的不同,将髋臼分为三种类型,髋臼前唇连线头距及髋关节前后间隙三型之间存在显著性差异,Ⅰ型、Ⅱ型均与Ⅲ型有显著性差异,而Ⅰ型与Ⅱ型之间没有显著性差异.结论 CT测量的正常成人髋关节间隙指标与X线测量的髋臼角等指标之间有一定的相关性,二者结合对髋关节的评价更为准确.     

Pelvic inclination and spatial orientation of the acetabulum. A radiographic, computed tomographic and clinical investigation

In a study of 40 young adults the pelvic inclination measured by a specially constructed inclinometer was found to be the same in the supine and standing positions when related to the horizontal and frontal planes, respectively. Consequently supine CT measurements of the hip are also representative of corresponding standing angles. The variations of the acetabular anterversion and the sector angles on CT of the hips in 5 adult corpses were measured by angulating the gantry in increments of 5 degrees to +/- 20 degrees. An approximate linear relationship was found for all parameters, the acetabular anteversion varied 0.5 degree with 1 degree pelvic rotation, and the sector angles 0.7 degree. A theoretic mathematical model for the variation of the acetabular anteversion outside the measured range employing a sine curve is introduced.     

Femoral anteversion in infants: a method using ultrasound

Objective To design a reproducible method to measure femoral anteversion in children under 1 year old.Design and patients We conducted a prospective, observational study to determine intra- and inter-observer reproducibility of the sonographic measurement of femoral anteversion in infants. The method involves imaging of the proximal femur using a vertical transducer with the infant in the lateral position. Anterior femoral anteversion is measured using a vertical baseline and a line tangential to the anterior femoral head and the trochanter (anterior anteversion). We similarly measured true femoral anteversion using a line passing through the centre of the femoral head and the femoral neck (true anteversion). Anteversion measurements were taken at the time of routine ultrasound screening for developmental dysplasia of the hip when infants were an average of 10.4 weeks old. Anteversion measurements were made in 74 hips (37 infants).Results Our results showed that for the anterior anteversion measurements intra-observer repeatability was ±6.2° and inter-observer repeatability was ±7.8°. For true anteversion measurements intra-observer repeatability was ±9.5°, but inter-observer repeatability was ±23.5°.Conclusions Our results have shown that our method for measuring "anterior femoral anteversion" has an acceptable level of inter- and intra-observer agreement. The method used to determine "true anteversion", however, proved to have an unacceptable level of inter-observer variability.     

成人髋臼发育不良性骨关节病的X线及CT表现分析

目的:探讨成人髋臼发育不良性骨关节病的X线及CT表现特征。方法:对73例92个成人髋臼发育不良性骨关节病的X线及CT资料进行回顾性分析,73例均拍摄标准的骨盆前后位X线片,42例行CT扫描。X线片上测量反映髋臼发育的指标:外侧中心边缘角(LCE角)、臼顶倾斜角(AI角)、髋臼角(Sharp角)及股骨头突出指数(FEI)。结果:92个成人髋臼发育不良性骨关节病的X线改变为:髋臼发育不良及继发性骨性关节炎,均符合髋臼发育不良的测量指标。42例53个髋CT显示髋臼顶发育不良16髋,髋臼前部发育不良28髋,髋臼前后部均发育不良9髋。结论:髋臼浅小、倾斜及髋臼关节面下囊变、股骨头骨赘是成人髋臼发育不良性骨关节病的常见及较特征性的表现,CT能够比X线片更早且更详细显示。髋臼指标测量能够量化评估髋臼发育不良的程度。     

Iliopsoas impingement on the acetabular component: radiologic and computed tomography findings of a rare hip prosthesis complication in eight cases

OBJECTIVE: To describe the radiographic and computed tomography (CT) scan features of iliopsoas impingement on the acetabular component (IPI) in total hip arthroplasty. METHOD: Eight cases of iliopsoas impingement were diagnosed and confirmed by surgical revision. The plain film radiograph findings and CT scan findings were compared with those of two control populations (8 patients with painless total hip prosthesis and 16 patients with other complications confirmed by surgical revision). RESULTS: An oversized cup was found in four hips with IPI (50%) and in one hip with another complication (6%). Coronal inclination of the acetabular cup was normal in the IPI group and in the two control groups, with a similar mean cup size. All patients with IPI had an acetabular cup overhang of more than 12 mm. Conversely, in the two control groups, the overhang, present in three and two cases, respectively, was always less than 8 mm. Iliopsoas bursal effusion was present in four hips with IPI and three hips with other complications and was never present in normal prostheses. CONCLUSION: More than a 12-mm overhang of the acetabular cup is a sensitive and specific parameter for diagnosing IPI.     

A new method using ultrasound for measuring femoral anteversion (torsion): technique and reliability

This paper reports details of a new method using medical ultrasound for measuring femoral anteversion (strictly torsion), and a reliability study of the method separately on each of 10 healthy children and 20 adults. The method involves using a static-image B-mode ultrasound scanner to obtain scans at the hips and knees of the lower limbs. A technique using bone-surface contours is reported for defining, on each hip scan, the head-neck line and, on each knee scan, the transcondylar line. By superimposing the transcondylar line on the head-neck line, the angle of femoral anteversion (torsion) was calculated for each limb. In the reliability study, scans were obtained three times at both hips and knees of each subject. The femoral anteversion was measured for each limb. The intra-observer error was within +/- 2.3 degrees (95% confidence limits) between scans, which was not statistically significant for the measured anteversion in each of the right and left femora of children and adults separately. To test the validity of the tracing method used to calculate femoral anteversion, one set of scans from the hip and knee of each subject was measured four times; no significant difference was found between tracings for the measurements of femoral anteversion. The ultrasound method is recommended for clinical use. We consider the static-image B-mode scanner to be the instrument of choice for measuring femoral anteversion in living subjects.