全髋关节置换术采用髋臼横韧带作髋臼假体前倾定位的CT研究

目的本文通过对全髋关节置换术前髋臼解剖前倾角度和术后髋臼假体前倾角度的CT测量,评估使用髋臼横韧带定位法安放髋臼假体前倾角度的准确性。方法 2015年1月至2016年1月,选择我院关节外科收治初次全髋关节置换术的40例44髋髋关节病患者纳入本研究。术中髋臼假体的前倾角以髋臼横韧带为参照标志,使髋臼假体开口平行韧带进行安放。采用CT测量术前髋臼解剖前倾角和术后髋臼假体前倾角,对手术前后前倾角数据进行统计分析,探讨应用髋臼横韧带定位法安放髋臼假体的准确性。结果本组手术中所有病例都能对髋臼横韧带进行辨认。术后切口Ⅰ期愈合。随访10～18个月,平均14个月,均未发生髋关节脱位。术后髋臼假体平均前倾角为(21.37±9.69)°,与术前髋臼解剖前倾角(19.22±6.76)°比较,差异无统计学意义(P0.05)。其中,术后假体前倾角女性为(24.59±11.57)°,男性为(20.28±8.76)°,与术前女性和男性髋臼解剖前倾角比较差异无统计学意义(P0.05)。女性术前解剖前倾角比男性术前解剖前倾角大,差异有统计学意义(P0.05)。结论在髋臼解剖学相对正常的初次全髋关节置换中,以髋臼横韧带为解剖标志,对髋臼假体前倾角度的精确植入可起到较可靠的参照作用。     

全髋关节置换术中髋臼横韧带对髋臼假体前倾定位的研究

目的 探讨全髋关节置换术中应用髋臼横韧带作为髋臼假体前倾定位参照的临床效果.方法 2006年1月-2007年1月,进行100例100髋人工全髋关节置换术.男67例,女33例;年龄45～82岁,平均64.5岁.股骨颈骨折头下型45例,股骨头无菌性坏死Ⅲ～Ⅳ期32例,成人先天性髋关节发育不良Ⅰ级12例,创伤性髋关节炎6例,髋关节骨性关节炎3例,类风湿性关节炎2例.患者均为初次置换.术中应用髋臼横韧带作为髋臼假体前倾定位的解剖参照标志,术后测量髋臼假体的前倾角,并与正常值比较.结果 术后患者切口均Ⅰ期愈合.获随访6～12个月,平均9个月.无髋关节脱位发生.术后髋臼假体前倾角为(15.17±5.00)°,与正常值(15±10)°比较,差异无统计学意义(P>0.05).结论 髋臼横韧带是髋臼假体前倾定位的可靠解剖参考标志.     

髋臼前倾角研究进展

髋臼前倾角和外展角为全髋关节置换术（THA）中评估髋臼假体位置,术后随访假体位置的两个重要参数。髋臼前倾角的测量目前仍无统一标准。该文就近期文献中髋臼前倾角的定义、测量时骨盆参考平面、各种测量方法、髋臼角安全范围等作一综述。     

髋臼前倾角研究进展

髋臼前倾角和外展角为全髋关节置换术(THA)中评估髋臼假体位置,术后随访假体位置的两个重要参数。髋臼前倾角的测量目前仍无统一标准。该文就近期文献中髋臼前倾角的定义、测量时骨盆参考平面、各种测量方法、髋臼角安全范围等作一综述。     

髋臼前倾角研究进展

髋臼前倾角和外展角为全髋关节置换术(THA)中评估髋臼假体位置,术后随访假体位置的两个重要参数。髋臼前倾角的测量目前仍无统一标准。该文就近期文献中髋臼前倾角的定义、测量时骨盆参考平面、各种测量方法、髋臼角安全范围等作一综述。     

髋臼横韧带可作为臼杯前倾角安放的参考

目的通过对骨盆CT及三维重建图像测量髋臼横韧带(TAL)的解剖学前倾角,以明确其是否可以作为臼杯前倾角安放的参考。 方法研究选取自2017年1月至2018年12月行骨盆CT三维重建且无明显骨性解剖异常的成年人共87例(174髋),其中男49例(98髋),女38例(76髋)。通过三维重建图像测量TAL解剖学前倾角,比较性别、左右侧别及年龄差异,统计位于安全区内的比例。测量髋臼解剖学前倾角,比较其与髋臼横韧带之间的差异。应用独立样本t检验或配对t检验比较性别及侧别间差异,应用单向方差分析比较年龄组间的差异。 结果髋臼解剖学前倾角的均值为(22±4)°,性别之间(t＝-1.491)及侧别组间(t＝-1.518)差异无统计学意义(P>0.05)。TAL解剖学前倾角均值为(18±5)°,性别之间(t＝-0.319)、侧别之间(t＝-1.437)差异无统计学意义(P>0.05),年龄组间差异亦无统计学意义(F ＝0.828,P>0.05),位于安全区内的比例为98.85%。TAL解剖学前倾角小于髋臼解剖学前倾角,差异有统计学意义(t＝7.859,P<0.001)。 结论在无髋臼发育异常患者中,TAL可以作为全髋关节置换术中臼杯前倾角安放的参考。     

全髋置换两种不同手术入路髋臼假体前倾角的比较分析

目的分析后外侧和直接外侧入路在全髋关节置换术中髋臼假体前倾角的差异。方法对初次全髋关节置换术86例90髋采用直接外侧入路40例42髋,后外侧入路46例48髋。术中测量髋臼假体安放时的前倾角,术中髋关节屈伸角度及术后脱位发生率。结果直接外侧入路术中髋臼假体放置的前倾角为8～20°,后外侧入路中髋臼假体放置的前倾角为15～30°,术中髋关节中立位的最大屈曲角度分别为95～120°和90～110°,最大后伸角度分别为10～25°和20～35°。外侧入路组术后未出现髋关节脱位,后外侧入路组术后出现2例髋关节后脱位。结论不同手术入路对髋臼假体前倾角的放置有不同的要求,直接外侧入路中髋臼假体的前倾角应当比后外侧入路中髋臼假体的前倾角小。     

髋关节骨性强直患者行人工全髋关节置换术中髋臼假体定位及其准确性研究

目的探讨髋关节骨性强直行人工全髋关节置换术(total hip arthroplasty,THA)中髋臼假体定位方法及其准确性。方法 2009年1月-2013年3月采用THA治疗33例(49髋)髋关节骨性强直患者,其中男25例,女8例;年龄18~69岁,平均35.8岁。左髋10例,右髋7例,双髋16例。其中强直性脊柱炎18例,结核6例,创伤6例,骨性关节炎2例,化脓性感染1例。病程7~15年,平均10.8年。术中采用髋臼周围骨性标志(闭孔上缘、髋臼切迹等)及软组织标志(髋臼横韧带等)定位髋臼假体位置。术后摄髋关节或骨盆正位X线片,测量髋臼假体前倾角、外展角及上下、内外髋臼偏移度,并以前倾角15°、外展角45°、上下及内外髋臼偏移度为0作为参考值,评价髋关节骨性强直患者髋臼假体位置的准确性。结果术中、术后均无血管神经损伤、骨折、脱位、感染等严重并发症发生。患者均获随访,随访时间13~63个月,平均30.3个月。末次随访时患者髋臼假体前倾角、外展角分别为(13.904±4.034)、(42.898±7.474)°,与参考值比较差异均无统计学意义(t=1.386,P=0.178;t=1.969,P=0.055)。内外及上下髋臼偏移度分别为(2.530±2.261)、(3.886±3.334)mm,与参考值比较差异均有统计学意义(t=7.830,P=0.000;t=8.159,P=0.000);其中5 mm 29髋,5~10 mm 18髋,10 mm 2髋,贴合率达59.2%。结论对于丧失正常解剖结构的骨性强直髋关节,THA术中充分利用残留及永久性解剖结构进行髋臼假体定位是比较准确的。     

智能手机在人工全髋关节置换术中测量髋臼假体植入角度的应用

目的探讨利用智能手机角度测量软件在人工全髋关节置换术(total hip arthroplasty,THA)中测量髋臼假体植入角度的准确性以及应用价值。方法 2012年6月-2015年9月,在50例患者THA术中利用智能手机的角度测量软件测定髋臼假体外展角及前倾角。男24例,女26例;年龄37~83岁,平均71岁。左髋22例,右髋28例。关节置换原因:股骨颈骨折34例,股骨头缺血性坏死16例。均排除髋臼发育异常。术后1周摄骨盆正位X线片,利用PACS系统测量髋臼假体外展角及前倾角。采用组内相关系数评估观察者自身测量的可靠性,Mann-Whitney U检验比较术中手机测量及术后PACS系统测量结果差异;定义术后PACS系统测量髋臼假体角度大于手机测量值为+,反之为-,计算术中及术后角度测量误差范围。结果术中手机测量及术后PACS系统测量髋臼前倾角、外展角的组内相关系数为0.84。术中手机测量髋臼假体外展角为(44.02±1.33)°,前倾角为(17.62±2.20)°;术后PACS系统测量髋臼假体外展角为(44.74±4.05)°,前倾角为(17.22±5.57)°;两种方法测量值比较,差异无统计学意义(Z=-1.977,P=0.482;Z=-0.368,P=0.713)。术后PACS系统测量44例髋臼假体角度在安全区范围内;6例前倾角超出安全区范围1~5°,外展角超出安全区范围1~3°。髋臼假体前倾角术中及术后测量前倾角偏差为-21~+10°、外展角为-10~+9°,提示与术后PACS系统测量值比较,术中手机测量髋臼假体前倾角偏大,外展角偏小。结论 THA术中利用智能手机的角度测量软件确定髋臼假体植入前倾角及外展角方便、快捷、准确。     

髋臼外展角和前倾角的动态测量及其临床意义

作者通过对１１２个正常髋臼外展角和前倾角随骨盆前倾度改变而变化的动态测量研究，制作出髋臼两角与骨盆倾度之间的相关变化曲线。根据结果和曲线分析而知：（１）正常成人站立和行走时的髋臼外展角约为４０°～４７°，前倾角为４°～２０°，男性与女性之间无显著性差异（Ｐ＞０．０５）；（２）髋臼前倾角的存在使外展角在屈髋活动时减小比较缓慢，保证了髋臼对股骨头较好的覆盖；（３）骨盆倾度的改变对髋臼前倾角的大小影响较大，骨盆倾度每增大１０°，前倾角即减小６°。该结果为临床全髋置换术前判断髋臼位相，术中正确放置人工臼杯，术后指导髋关节功能锻炼，提供了可靠的解剖依据。     

Anteversion of the acetabular component aligned with the transverse acetabular ligament in total hip arthroplasty

In total hip arthroplasty (THA), accurately positioning the cup is crucial for achieving an adequate postoperative range of motion and stability. For 47 THA cases in which the inferomedial rim of the cup had been positioned parallel to the transverse acetabular ligament, we retrospectively performed the measurements of the radiographic cup anteversion angle relative to the anterior pelvic plane using 3-dimensional reconstruction computed tomography. The mean anteversion angle was 21.2°, with no significant difference detected in mean cup anteversion between the dysplastic hip group (15 hips) and the control group (15 hips). We suggest that the transverse acetabular ligament is a practical anatomical landmark for determining cup anteversion in THA for both dysplastic and nondysplastic hip cases.     

Compliant positioning of total hip components for optimal range of motion.

Impingement between femoral neck and endoprosthetic cup is one of the causes for dislocation in total hip arthroplasty (THA). Choosing a correct combined orientation of both components, the acetabular cup and femoral stem, in manual or computer-assisted implantation will yield a maximized, stable range of motion (ROM) and will reduce the risk for dislocation. A mathematical model of a THA was developed to determine the optimal combination of cup inclination, cup anteversion, and stem antetorsion for maximizing ROM and minimizing the risk for cup-neck impingement. Single and combined hip joint motions were tested. A radiographic definition was used for component orientation. Additional parameters, such as stem-neck (CCD) angle, head-neck ratio, and the design of the acetabular opening, were also considered. The model showed that a maximized and safe ROM requires compliant, well-defined combinations of cup inclination, cup anteversion, and stem antetorsion depending on the intended ROM. Radiographic cup anteversion and stem antetorsion were linearly correlated. Additional internal rotation reduced flexion, and additional external rotation reduced extension, abduction and adduction. The articulating hemispheric surface of acetabular cups should be oriented between 40 degrees and 45 degrees of radiographic inclination, between 20 degrees and 28 degrees of radiographic cup anteversion, and should be combined with stem antetorsion so that the sum of cup anteversion plus 0.7 times the stem antetorsion equals 37 degrees. Final component orientation must also consider cup containment, implant impingement with bone and soft tissue, and preoperative skeletal contractures or deformities to achieve the optimal compromise for each patient.     

Comparison of extracapsular pseudotumors seen in magnetic resonance imaging and in revision surgery of 167 failed metal-on-metal hip replacements

Background and purpose It is controversial whether the transverse acetabular ligament (TAL) is a reliable guide for determining the cup orientation during total hip arthroplasty (THA). We investigated the variations in TAL anatomy and the TAL-guided cup orientation.

Methods 80 hips with osteoarthritis secondary to hip dysplasia (OA) and 80 hips with osteonecrosis of the femoral head (ON) were examined. We compared the anatomical anteversion of TAL and the TAL-guided cup orientation in relation to both disease and gender using 3D reconstruction of computed tomography (CT) images.

Results Mean TAL anteversion was 11° (SD 10, range –12 to 35). The OA group (least-square mean 16°, 95% confidence interval (CI): 14–18) had larger anteversion than the ON group (least-square mean 6.2°, CI: 3.8 – 7.5). Females (least-square mean 20°, CI: 17–23) had larger anteversion than males (least-square mean 7.0°, CI: 4.6–9.3) in the OA group, while there were no differences between the sexes in the ON group. When TAL was used for anteversion guidance with the radiographic cup inclination fixed at 40°, 39% of OA hips and 9% of ON hips had more than 10° variance from the target anteversion, which was 15°.

Interpretation In ON hips, TAL is a good guide for determining cup orientation during THA, although it is not a reliable guide in hips with OA secondary to dysplasia. This is because TAL orientation has large individual variation and is influenced by disease and gender.     

New method for measuring acetabular component positioning with EOS imaging: feasibility study on dry bone

Purpose

Malposition of the acetabular cup is the most common cause of total hip arthroplasty (THA) dislocation. The position of a total hip implant is usually analysed on computed tomography (CT) scan. We aim to prove it is possible to measure, with good accuracy, the position of an acetabular cup using the low-dose irradiation (EOS) imaging.

Material and methods

We implanted an acetabular cup in a pelvic dry bone and measured cup anteversion and inclination with scanography. We performed 14 series of EOS acquisitions with different inclination, rotation and pelvic tilt, which were analysed by five observers. Two observers repeated angle measurements. We then calculated measurement inter- and intrareproducibility and accuracy.

Results

Using a confidence interval (CI) of 95 %, inter- and intra-observer reproducibility were ±1.6, and ±1.4°, respectively, for cup inclination; accuracy in comparison with CT was ±2.6°. Using a 95 % CI, inter- and intra-observer reproducibility for cup anteversion were ±2.5° and ±2.3°, respectively. Measurement accuracy compared with CT was ±3.9°.

Conclusion

EOS imaging system is superior to standard radiography in terms of measuring acetabular anteversion and inclination.     

Is the transverse acetabular ligament a reliable cup orientation guide?: Computer simulation in 160 hips

Background and purpose

It is controversial whether the transverse acetabular ligament (TAL) is a reliable guide for determining the cup orientation during total hip arthroplasty (THA). We investigated the variations in TAL anatomy and the TAL-guided cup orientation.

Methods

80 hips with osteoarthritis secondary to hip dysplasia (OA) and 80 hips with osteonecrosis of the femoral head (ON) were examined. We compared the anatomical anteversion of TAL and the TAL-guided cup orientation in relation to both disease and gender using 3D reconstruction of computed tomography (CT) images.

Results

Mean TAL anteversion was 11° (SD 10, range –12 to 35). The OA group (least-square mean 16°, 95% confidence interval (CI): 14–18) had larger anteversion than the ON group (least-square mean 6.2°, CI: 3.8 – 7.5). Females (least-square mean 20°, CI: 17–23) had larger anteversion than males (least-square mean 7.0°, CI: 4.6–9.3) in the OA group, while there were no differences between the sexes in the ON group. When TAL was used for anteversion guidance with the radiographic cup inclination fixed at 40°, 39% of OA hips and 9% of ON hips had more than 10° variance from the target anteversion, which was 15°.

Interpretation

In ON hips, TAL is a good guide for determining cup orientation during THA, although it is not a reliable guide in hips with OA secondary to dysplasia. This is because TAL orientation has large individual variation and is influenced by disease and gender.Malalignment of the acetabular cup may lead to dislocation (Jolles et al. 2002, Shon et al. 2005), accelerated wear or breakage of the bearing, and component loosening (Kennedy et al. 1998). The use of a mechanical guide for cup implantation may give inaccurate results because of pelvic rotation on the operating table (Sugano et al. 2007, Minoda et al. 2010).Recently, the transverse acetabular ligament (TAL), which bridges the acetabular notch (Löhe et al. 1996) as part of the acetabular labrum, has been reported to be useful for determining proper orientation of the acetabular components (Archbold et al. 2006, 2008, Pearce et al. 2008, Kalteis et al. 2011). TAL-guided cup orientation has been reported to guide the cup placement within Lewinnek’s safe zone (Lewinnek et al. 1978). Other studies have shown that the TAL is not a reliable guide (Epstein et al. 2010, Viste et al. 2011). We hypothesized that these divergent results could be explained by individual anatomical variation; in addition, orientation of the TAL may be affected by hip disease and gender. Furthermore, cup orientation is influenced by sagittal pelvic tilt (Nishihara et al. 2003, DiGioia et al. 2006).We determined (1) the variation in the TAL orientation and the influence of hip disease and gender on this variation, (2) the reliability of using the TAL for guiding cup orientation, and (3) the influence of pelvic tilt on the TAL-guided cup orientation, using computed tomography (CT) scan and computer simulation.     

骨盆旋转对全髋关节置换术中髋臼假体安放角度的影响

目的：研究骨盆沿人体三维方向旋转对全髋关节置换术中髋臼假体实际安放角度的影响规律。方法：采集正常成人的骨盆CT影像学资料,采用电脑软件三维重建骨盆髋臼并模拟骨盆分别围绕与人体矢状面、横断面和冠状面垂直的X轴、Y轴和Z轴旋转时,以标准角度植入髋臼假体时测量臼杯的放射外展角（radiographic inclination,RI）和放射前倾角（radiographic anteversion,RA）。采用相关性分析量化各个轴向旋转角度与髋臼实际角度的关系。结果：骨盆沿X轴及Y轴旋转时对髋臼的RA影响较小,但对RI影响较大并呈线性相关,回归方程分别为RA=0.682 4X+10.256（r²=0.308 4）和RA=-0.714 1Y+10.424（r²=0.999 8）;骨盆沿Z轴旋转时对RA几乎无影响,但与RI呈线性相关,回归方程为RI=1.0Z+46（r²=1.0）。结论：骨盆的前后旋转或沿躯体的纵轴旋转均明显影响髋臼的前倾角,但对外展角影响较小;相反,骨盆在冠状面上的左右歪斜可明显影响髋臼的外展角,但不影响其前倾角。     

A new CT method for measuring cup orientation after total hip arthroplasty: a study of 10 patients

BACKGROUND: It is difficult to assess the orientation of the acetabular component on routine radiographs. We present a method for determining the spatial orientation of the acetabular component after total hip arthroplasty (THA) using computed tomography. PATIENTS AND METHODS: Two CT-scans, 10 min apart, were obtained from each of 10 patients after THA. Using locally developed software, two independent examiners measured the orientation of the acetabular component in relation to the pelvis. The measurements were repeated after one week. To be independent of the patient position during scanning, the method involved two steps. Firstly, a 3D volumetric image of the pelvis was brought into a standard pelvic orientation, then the orientation of the acetabular component was measured. The orientation of the acetabular component was expressed as operative anteversion and inclination relative to an internal pelvic reference coordinate system. To evaluate precision, we compared measurements across pairs of CT volumes between observers and trials. RESULTS: Mean absolute interobserver angle error was 2.3 degrees for anteversion (range 0-6.6 degrees), and 1.1 degrees for inclination (range 0-4.6 degrees). For interobserver measurements, the precision, defined as one standard deviation, was 2.9 degrees for anteversion, and 1.5 degrees for inclination. A Student's t-test showed that the overall differences between the examiners, trials, and cases were not significant. Data were normally distributed and were not dependent on examiner or trial. INTERPRETATION: We conclude that the implant angles of the acetabular component in relation to the pelvis could be detected repeatedly using CT, independently of patient positioning.     

Measuring anatomical acetabular cup orientation with a new X-ray technique.

Proper alignment of the acetabular cup component is one of the most important requisites for a successful long-term outcome in total hip replacement. However, measurement and indication of cup orientation in an anatomical pelvic reference system is very difficult. We propose a new C-arm-based X-ray technique for determining the values for inclination and anteversion of the acetabular cup component. The proposed method is validated by computer simulation and sources of error are evaluated. The method predicts an accuracy of better then 5 degrees for determination of anteversion of the cup.     

A new CT method for measuring cup orientation after total hip arthroplasty

Background It is difficult to assess the orientation of the acetabular component on routine radiographs. We present a method for determining the spatial orientation of the acetabular component after total hip arthroplasty (THA) using computed tomography.

Patients and methods Two CT-scans, 10 min apart, were obtained from each of 10 patients after THA. Using locally developed software, two independent examiners measured the orientation of the acetabular component in relation to the pelvis. The measurements were repeated after one week. To be independent of the patient position during scanning, the method involved two steps. Firstly, a 3D volumetric image of the pelvis was brought into a standard pelvic orientation, then the orientation of the acetabular component was measured. The orientation of the acetabular component was expressed as operative anteversion and inclination relative to an internal pelvic reference coordinate system. To evaluate precision, we compared measurements across pairs of CT volumes between observers and trials.

Results Mean absolute interobserver angle error was 2.3° for anteversion (range 0-6.6°), and 1.1° for inclination (range 0-4.6°). For interobserver measurements, the precision, defined as one standard deviation, was 2.9° for anteversion, and 1.5° for inclination. A Student's t-test showed that the overall differences between the examiners, trials, and cases were not significant. Data were normally distributed and were not dependent on examiner or trial.

Interpretation We conclude that the implant angles of the acetabular component in relation to the pelvis could be detected repeatedly using CT, independently of patient positioning.