Classification of Medial Fractures of the Femoral Neck

The femoral neck angles were determined in 48 pairs of normal specimens from cadavers of elderly Norwegians, 24 males and 24 females. The anteversion angle was found to average 10.4°±6.7° and the neck-shaft angle 127.7°± 7.6°. There were no significant differences between the sexes.

The bilateral differences were analysed. The 95 per cent confidence limits of the anteversion and head-neck-shaft angles were calculated to be 11.8 and 13.8 degrees, respectively.     

全髋关节表面置换术治疗成人髋关节发育不良中假体的安放技术和临床疗效分析

目的探讨全髋关节表面置换术治疗髋关节发育不良（DDH）术中假体安放位置的控制和临床效果。方法2005年1月至2007年9月，对42例45髋因DDH继发骨关节炎的患者行全髋关节表面置换术。其中女39例，男3例，平均年龄46．3岁，单侧39例39髋，双侧3例6髋。按Crowe分型，Ⅰ型17例18髋，Ⅱ型17例19髋，Ⅲ型6例6髋，Ⅳ型2例2髋。术前通过CT三维重建测量股骨颈干角、股骨颈前倾角。入路采用改良后外侧Gibson入路，根据术前测量结果，对于颈干角小于135°，手术时适当增加至135°，大于135°则维持原有角度；DDH患者股骨前倾角均有增加，术中应适当减少，并减少髋臼前倾角和外展角。采用X线检查和Harris功能评分评估术后疗效。结果术前股骨颈干角平均134．1°，术后平均138.2°，其中术前颈干角小于135°的34髋，平均131．7°，术后平均137°；术前颈干角大于135°的12髋，平均140.9°，术后平均141．5°。股骨前倾角术前平均34．5°。术后X线显示所有髋臼均为真臼重建，髋臼外展角平均42°。双侧肢体长度差别术前平均2.1cm，术后平均0．5cm。平均随访14．6个月。Harris功能评分术前平均43．6分，最后一次随访功能评分为平均88．4分。随访期内无股骨颈骨折和假体松动等并发症发生。结论对年青DDH并骨关节炎患者采用髋关节表面置换术的近期效果满意，术中根据个体情况调整假体安放位置有助于提高临床效果。     

Deformity correction with the Taylor spatial frame after growth arrest of the distal radius: A technical note on 2 cases

The anteversion angle (AV-angle) of the femur was measured according to the method of Rippstein in a series of 50 patients with “primary” osteoarthritis of the hip, and in a control group of 30 individuals of the same age without hip disease. The median AV-angle of the hips in osteoarthritic patients was 17.5°, and in the control group 13°. Osteoarthritic patients had a significantly increased AV-angle in relation to the control group (P = 0.0028). The greatest AV-angle in the hips of the control group was 25°. In 18 hips of osteoarthritic patients an AV-angle greater than 25° was found. Osteoarthritis was found in 15 of these hips; there was no osteoarthritis in the remaining 3 hips.

Our results lead to the conclusion that increased femoral anteversion is a predisposing factor for hip osteoarthritis. This implies that derotational osteotomy in children can be a prophylactic procedure.     

成人常见髋关节疾病双侧髋关节解剖参数的研究

目的探讨行全髋关节置换术中利用对侧相对正常髋关节的解剖参数作为模板重建患侧髋关节的准确性。 方法选取2019年9月至2020年12月于大连医科大学附属第一医院关节外科行首次单侧全髋关节置换术的患者作为研究对象。纳入标准：患侧诊断为髋关节骨关节炎、股骨头坏死或髋关节发育不良Crowe Ⅰ型；对侧髋关节形态不影响测量。排除标准：患侧髋关节既往手术史；畸形严重影响测量；髋关节发育不良Crowe Ⅱ型及以上。最后共纳入82例患者，其中33例男性，49例女性，年龄范围29~74岁。根据患者X线及CT影像数据，分别测量患者患侧及对侧髋臼前倾角、髋臼外展角、股骨前倾角、颈干角以及股骨偏心距，并计算其各自的联合前倾角。运用t检验、Pearson相关性分析等统计学方法分析双侧髋关节解剖参数的对称性。 结果对股骨头坏死及髋关节骨关节炎患者来说，除双侧股骨偏心距患侧小于对侧外(t＝0.523，P <0.05)，余双侧髋关节解剖参数包括髋臼前倾角、髋臼外展角、股骨前倾角、联合前倾角及颈干角的差异均无统计学意义(均为P>0.05)。Pearson相关性分析显示股骨头坏死及骨关节炎患者股骨偏心距的不对称性与颈干角有相关性(r＝-0.519，P<0.001)，颈干角的不对称性与股骨前倾角(r＝0.303，P＝0.041)以及股骨偏心距有相关性，联合前倾角的不对称性与髋臼外展角(r＝0.311，P＝0.035)、颈干角(r＝0.049，P＝0.032)有相关性。Crowe Ⅰ型髋关节发育不良患者的髋臼前倾角(t＝2.081，P＝0.045)、股骨偏心距(t＝3.934，P<0.001)患侧小于对侧，颈干角患侧大于对侧(t＝3.792，P＝0.001)；而双侧髋臼外展角、股骨前倾角、联合前倾角差异均无统计学意义(均为P>0.05)。Pearson相关性分析发现股骨偏心距的不对称性与颈干角(r＝-0.709，P<0.001)、股骨前倾角(r＝-0.349，P＝0.037)有相关性。Crowe Ⅰ型髋关节发育不良患者的股骨偏心距小于股骨头坏死患者或髋关节骨关节炎患者，而髋臼前倾角、髋臼外展角、颈干角大于后者。 结论对于股骨头坏死患者及髋关节骨关节炎患者来说利用对侧肢体作为模板重建患侧髋关节是可行的。而Crowe Ⅰ型髋关节发育不良患者双侧髋关节解剖形态差异较大，对这类患者的全髋关节置换术需个体化。     

The Femoral Head Center Shifts in a Mediocaudal Direction During Aging

Background

Accurate reconstruction of hip joint biomechanics is the key stone in total hip arthroplasty. Although proximal femur morphology is known to vary with both age and gender, few studies investigated this in the very elderly (ie, ≥80 years). The purpose of this study was to compare basic morphological parameters describing the position of the femoral head between very elderly and middle-aged subjects.

螺旋CT三维重建在儿童发育性髋关节脱位 治疗中的应用

目的：通过术前术后对髋关节前倾角及髋臼壁发育情况的观察,探讨螺旋CT三维重建技术在儿童发育性髋关节脱位（DDH）治疗中的应用价值。方法：2003年6月至2007年6月,发育性髋关节脱位53例（61髋）,男12例,女41例;左侧34例,右侧11例,双侧8例;年龄3-16岁,平均5．6岁。行双侧髋关节螺旋CT三维重建检查,测量前倾角（FNA）及髋臼壁的发育情况,与术中所见比较。采用Pemberton或Chiari骨盆截骨及股骨近端旋转截骨治疗,术后复查三维CT,测量FNA,观察新髋臼的情况,与术前进行比较。结果：53例患髋前倾角均增大,最大90°,最小35。,平均（45．6±11．4）°。正常45髋前倾角为（23．5±10．2）°。髋臼各壁不同程度发育不良,与术中所见符合。术后前倾角较术前明显降低,前倾角平均（15．6±5．8）°。髋臼对股骨头包容明显改善。结论：髋关节螺旋CT三维重建技术可以全面显示髋关节的病理形态,精确地测量FNA,对术者选择适当的治疗方案具有重要的指导意义,术后能更直观地判断手术效果。评估预后。     

Femoral Morphology in the Dysplastic Hip: Three-dimensional Characterizations With CT

Background

Hip dysplasia represents a spectrum of complex deformities on both sides of the joint. Although many studies have described the acetabular side of the deformity, to our knowledge, little is known about the three-dimensional (3-D) head and neck offset differences of the femora of dysplastic hips. A thorough knowledge of proximal femoral anatomy is important to prevent potential impingement and improve results after acetabular reorientation.

Questions/purposes

(1) Are there common proximal femoral characteristics in patients with symptomatic hip dysplasia undergoing periacetabular osteotomy (PAO)? (2) Where is the location of maximal femoral head and neck offset deformity in hip dysplasia? (3) Do certain subgroups of dysplastic hips more commonly have cam-type femoral morphology? (4) Is there a relationship between hip ROM as well as impingement testing and 3-D head and neck offset deformity?

Methods

Using our hip preservation database, 153 hips (148 patients) underwent PAO from October 2013 to July 2015. We identified 103 hips in 100 patients with acetabular dysplasia (lateral center-edge angle [LCEA] < 20°) and who had a Tönnis grade of 0 or 1. Eighty-six patients (86%) underwent preoperative low-dose pelvic CT scans at our institution as part of the preoperative planning for PAO. It is currently our standard to obtain preoperative low-dose pelvic CT scans (0.75–1.25 mSv, equivalent to three to five AP pelvis radiographs) on all patients before they undergo PAO unless a prior CT scan is performed at an outside institution. Hips with a history of a neuromuscular disorder, prior trauma, prior surgery, radiographic evidence of joint degeneration, ischemic necrosis, or Perthes-like deformities were excluded. Fifty hips in 50 patients met inclusion criteria and had CT scans available for review. Hips were analyzed with Dyonics Plan software and characterized with regard to version, neck-shaft angle, femoral head diameter, head and neck offset, femoral neck length, femoral offset, head center height, trochanteric height, and alpha angle. The maximum head and neck offset deformity was assessed using an entire clockface and an alpha angle ≥ 55° defined coexisting cam morphology. Subgroups included severity of lateral dysplasia: mild (LCEA 15°–20°) and moderate/severe (LCEA < 15°). Femoral version subgroups were defined as normal (5°–20°), decreased (≤ 5°), or increased (> 20°). The senior author (JCC) performed all physical examination testing.

Results

The mean LCEA was 14° (±4°), whereas the mean femoral anteversion was 19° (±12°). Eight hips (16%) demonstrated relative femoral retroversion (≤ 5°), whereas 26 (52%) showed excessive femoral anteversion (> 20°). Four hips (8%) had ≥ 35° of femoral anteversion. The mean neck-shaft angle was 136° (±5°). The mean maximum alpha location was 2:00 o’clock (±45 minutes) and the mean maximum alpha angle was 52° (±6°). Minimum head-neck offset ratio was located at 1:30 with a mean of 0.14 (±0.03). An anterior head-neck offset ratio of ≤ 0.17 or an alpha angle ≥ 55° was found in 43 (86%) of hips. Twenty-one dysplastic hips (42%) had an alpha angle ≥ 55°. Mildly dysplastic hips had decreased femoral head and neck offset (9 ± 1) and head and neck offset ratio (0.20 ± 0.03) at 12 o’clock compared with moderate/severe dysplastic hips (10 ± 1 and 0.22 ± 0.03, respectively; p = 0.04 and p = 0.01). With the numbers available, we found that hips with excessive femoral anteversion (> 20°) had no difference in the alpha angle at 3 o’clock (42 ± 7) compared with hips with relative femoral retroversion (≤ 5°; 48 ± 4; p = 0.06). No other differences in femoral morphology were found between hips with mild or moderate/severe dysplasia or in the femoral version subgroups with the numbers available. Anterior impingement test was positive in 76% of hips with an alpha angle ≥ 55° and 83% of the hips with an alpha angle ≤ 55°. No correlation was found between proximal femoral morphology and preoperative ROM.

Conclusions

In this subset of dysplastic hips, cam deformity of the femoral head and neck was present in 42% of hips with maximal head-neck deformity at 2 o’clock, and 82% had reduced head-neck offset at the 1:30 point. We conclude that cam-type deformities and decreased head-neck offset in developmental dysplasia of the hip are common. Patients should be closely assessed for need of a head and neck osteochondroplasty, especially after acetabular correction. Future prospective studies should evaluate the influence of proximal femoral anatomy on surgical results of PAO for dysplastic hips.

Level of Evidence

Level IV, prognostic study.

     

成人髋关节发育不良患者股骨近端的解剖形态学特征

目的 探讨成人髋关节发育不良(developmental dysplasia of the hip,DDH)患者股骨近端解剖形态的CT三维重建特征及其临床意义.方法 通过CT三维重建测量70例(76髋)DDH患者与54例(54髋)健康志愿者股骨近端的解剖学参数,包括股骨头直径、股骨头高度、颈干角、头心-千轴距、股骨颈前倾角、股骨髓腔冠状径、股骨髓腔矢状径、股骨髓腔最长径、股骨各断面髓腔扭转角、股骨峡部距小转子距离及髓腔开口指数.比较DDH患者与健康志愿者股骨近端的解剖学参数有无差异,分析DDH患者各解剖参数的相关性,并与国外研究中DDH患者的相关数据进行比较.结果 DDH组与健康志愿者相比,股骨头高度[(4.82±0.95)cm与(5.18±0.57) cm]、头心-千轴距[(2.66±0.74) cm与(3.16±0.51) cm]、髓腔开口指数(4.12±1.05与4.53±0.65)及小转子远端40 mm处(LT-40水平)的股骨髓腔扭转角(46.86°±49.53°与66.38°±28.75°)均较小,差异有统计学意义.DDH组股骨头高度与头心-干轴距呈正相关(r=0.491,P=0.000),股骨头直径与股骨颈前倾角呈负相关(r=-0.443,P=O.001).散点图显示DDH组峡部以上不同股骨冠状面的扭转角差异较大且无规律.与国外同类研究比较,股骨头直径的差异无统计学意义,其他参数的差异有统计学意义.结论 DDH患者股骨的解剖形态与正常股骨存在差异.对DDH患者施行全髋关节置换术前必须进行CT扫描及三维重建评估股骨近端解剖形态,对股骨畸形严重者应使用个体化定制假体.     

液晶数字显示角度仪在全髋关节置换术中的应用价值

目的:探讨在全髋关节置换术中使用液晶数字显示角度仪控制前倾角的应用价值。方法:回顾分析自2018年1月至2019年12月83例行初次全髋关节置换术的患者,其中男28例,女55例;年龄42~81(70.4±7.9)岁。股骨颈骨折63例,股骨头缺血性坏死20例。所有患者术中使用液晶数显角度仪控制髋臼杯假体的前倾角,术后采用CT扫描,测量髋臼杯的前倾角,两者进行比较,了解使用液晶数显角度仪的准确性。结果:术后CT测量提示患者的髋臼前倾角均位于Lewinnek提倡的安全区内,术中使用液晶数显角度仪测量髋臼杯的前倾角度中位数为14.20°(12.80~15.40)°,术后CT扫描测量的髋臼杯的前倾角中位数为14.20°(13.40~15.50)°,两者比较差异无统计学意义(Z=-1.725,P=0.085)。结论:应用液晶数显角仪器对术中控制髋臼杯的前倾角是一种准确可靠的方法,具有良好的辅助参考价值。     

Can Anatomic Measurements of Stem Anteversion Angle Be Considered as the Functional Anteversion Angle?

Background

Stem anteversion angle is important in the combined anteversion theory to avoid implant impingement after total hip arthroplasty (THA). However, anatomic measurements of stem anteversion angle may not represent functional anteversion of the femur if the femur undergoes axial rotation. Herein, the femoral rotational angle (FRA) was measured in supine and standing positions before and after THA to evaluate the difference between anatomic and functional measurements.

Axial plane coverage and torsion measurements in primary osteoarthritis of the hip with good frontal plane coverage and spherical femoral head

Introduction

Mechanical factors play a role in pathogenesis of primary osteoarthritis of the hip. Torsion measures were made to detect whether there is a causal relationship between increase or decrease of femoral anteversion, acetabular anteversion, and osteoarthritis. There are no studies in the literature indicating a relationship between axial plane coverage and osteoarthritis of the hip. Deficient axial plane coverage of femoral head may also play a role in pathogenesis of osteoarthritis.

Materials and methods

Thirty patients with primary osteoarthritis of the hip and 29 control cases were included in the study. We used the method of Anda et al. (Acta Radiol Diagn 27:443–447, 1986; Comput Assist Tomogr 15:115–120, 1991) to measure axial plane anterior, posterior coverages in patients with primary osteoarthritis of the hip. The computerized tomography sections and pelvic radiographs indicated good frontal plane coverage and spherical femoral head. In addition to anterior acetabular sector angle, posterior acetabular sector angle, horizontal acetabular sector angles for axial plane coverage detection, femoral anteversion, acetabular anteversion, and McKibbin instability index were also measured.

Results

Posterior coverage was lower at osteoarthritic hips than the control group’s hips (96.0 ± 16.7, 104.2 ± 10.6) (p < 0.05).

Conclusion

The results may indicate that in addition to other mechanical factors, axial plane coverage, especially the posterior coverage deficiency, may play a role in the pathogenesis of hip osteoarthritis.     

How Does Spinopelvic Mobility and Sagittal Functional Cup Orientation Affect Patient-Reported Outcome 1 Year after THA?—A Prospective Diagnostic Cohort Study

BackgroundThis prospective cohort study aimed to characterize how spinopelvic characteristics change post-total hip arthroplasty (THA) and determine how patient-reported outcome measures are associated with 1) individual spinopelvic mobility and 2) functional sagittal cup orientation post-THA.MethodsOne hundred consecutive patients who received unilateral THAs for end-stage hip osteoarthritis, without spinal pathology were studied. Preoperatively and postoperatively, patients underwent clinical and radiographic evaluations. Patient-reported outcomes were collected using the hip disability and osteoarthritis outcome score - physical function shortform (HOOS-PS). Radiographic parameters measured from standing and relaxed-seated radiographs, included the lumbar lordosis angle, pelvic tilt, pelvic femoral angle and cup orientation in the coronal (inclination/anteversion) and sagittal (anteinclination) planes. Spinopelvic mobility was characterized (ΔPT: “stiff” [<10°], “normal” [10°-30°], and “hypermobile” [>30°]).ResultsPreoperative spinopelvic characteristics were not associated with HOOS-PS. Post-THA, the spinopelvic characteristics changed, with less patients having spinopelvic hypermobility (7%) compared with preop (14%). Postoperatively, patients with spinopelvic hypermobility showed significantly worse HOOS-PS scores (21 ± 17 vs 21 ± 22 vs 41 ± 23; ANOVA P = .037). Sagittal but not coronal cup orientation was associated with postoperative spinopelvic characteristics. Cup anteinclination was less in the patients with postoperative spinopelvic hypermobility (27 ± 7° vs 36 ± 8° vs 36 ± 10°; ANOVA: P = .035).ConclusionWe hypothesize that spinopelvic hypermobility is secondary to impingement and reduced hip flexion; to achieve a seated position, impinging hips require more posterior pelvic tilt. Patients with spinopelvic hypermobility are likely impinging secondary to the low cup anteinclination (sagittal malorientation despite optimum coronal orientation) and thus have lower HOOS-PS compared. Sagittal assessments are thus important to adequately study hip mechanics.Level of EvidenceLevel II, diagnostic study.     

Deformities of proximal femur in spastic hip displacement: A reconstructed three-dimensional computed tomography model approach

Background/PurposeSpastic hip displacement is a common musculoskeletal problem in cerebral palsy (CP), leading to further complications in daily life. Deformities of the proximal femur were regarded as a factor in hip displacement, and therefore, femoral osteotomy is often recommended. This study aims to identify the relationship between hip displacement and femoral deformities.MethodsWe retrospectively collected preoperative radiography and three-dimensional computed tomography (3D-CT) images from 19 nonambulatory CP children with unilateral hip displacement (average age: 8.4 years; range: 4.4–13.6). The 3D image of femur was reconstructed for measuring the femur anteversion angle (FAA) and true femoral neck-shaft angle (NSA). The association among migration percentage (MP), acetabular index (AI), FAA, and NSA between nondisplaced and displaced hips was analyzed by paired t test and its correlations were identified.ResultsThe FAA and AI are significantly greater in displaced hips (42.7° vs. 36.3° and 32.8° vs. 22.7°, respectively, p < 0.001). However, the NSA is similar between displaced and nondisplaced hips. The AI and FAA have significantly positive correlations with MP between nondisplaced hips and displaced hips (0.69 and 0.57, respectively).ConclusionUsing reconstructed 3D-CT images we can directly measure and prove these femoral deformities. We found that AI has a positive correlation with MP (0.69), which is consistent with the results of previous studies. The displaced side has greater femur anteversion (42.7° vs. 36.3°), and coxa valga is common in these nonambulatory patients, irrespective of whether or not these patients underwent hip displacement. In addition, the severity of AI and anteversion angle will be affected by the MP.     

In vivo kinematics,component alignment and hardware variables influence on the liner-to-neck clearance during chair-rising after total hip arthroplasty

BackgroundThere is an interest in quantifying dynamic hip kinematics before and after total hip arthroplasty (THA) during chair-rising: one of daily life activities.MethodsThe study consisted of 21 patients who underwent unilateral total hip arthroplasty for symptomatic osteoarthritis. We obtained continuous radiographs using a flat-panel X-ray detector while the participants rose from chair. We assessed the pre and postoperative hip joint's movements using three-dimensional-to-two-dimensional model-to-image registration techniques. We also measured minimum liner-to-neck distances at maximum hip flexion and extension as anterior and posterior liner-to-neck distances, respectively. Multivariate analyses were applied to determine which factors were associated with liner-to-neck distances.ResultsThe cup inclination, cup anteversion, and stem anteversion averaged 37.4°, 23.1°, and 30.1°, respectively. Significantly larger maximum hip flexion angle (72°) was found during chair-rising after THA compared to that before THA (63°, P < 0.01). The anterior pelvic tilt at the maximum hip flexion after THA (3° of anterior tilt) was significantly (P < 0.05) anterior compared to that before THA (1° of posterior tilt). The anterior and posterior liner-to-neck distances averaged 12.3 mm and 8.1 mm, respectively, with a significant difference (P < 0.01). No liner-to-neck contact was found in any hips. In multivariate analysis, the hip flexion angle, cup inclination, stem anteversion and head diameter were significantly associated with the anterior liner-to-neck distance (P < 0.05), the hip extension angle, cup anteversion, neck length and with or without elevated rim were significantly associated with the posterior liner-to-neck distance (P < 0.05, 0.01, 0.05, 0.01, respectively).ConclusionThis study indicates that well-positioned THA provide increased range of hip flexion with sufficient anterior liner-to-neck clearance during chair-rising. Dynamic hip kinematics, component position, and hardware variables significantly influenced on the liner-to-neck clearance under weight-bearing conditions.     

Sex differences in reference values of hip acetabular measurements using computed tomography in Japanese adults and the effect of aging on the measurement parameters

BackgroundIt is very important to understand the acetabular morphology of the normal hip joint to assist in diagnosis and surgical planning of hip disorders. The purpose of the present study was to obtain gender-based reference values for the acetabular measurements of a normal hip using computed tomography data and investigate the effect of aging on the measurement values.MethodsWe measured acetabular parameters (center-edge angle, Sharp angle, vertical center anterior angle, acetabular anteversion) on computed tomography corrected for changing the obliquity, rotation, and tilt of the pelvis. We performed measurements in 245 patients (490 joints; 120 men [240 joints] and 125 women [250 joints]). The mean age was 64.7 ± 14.3 (31–88) years for men and 63.2 ± 15.2 (30–88) years for women.ResultsIn men and women, the mean center-edge angle was 31.8° ± 6.4° and 30.6° ± 6.5°, the mean Sharp angle was 38.6° ± 3.2° and 40.6° ± 3.8°, the mean vertical center anterior angle was 44.3° ± 7.9° and 40.0° ± 8.5°, and the mean acetabular anteversion angle was 14.3° ± 5.2° and 18.8° ± 5.4°, respectively. All differences were statistically significant. The center-edge angle increased with age in women; however, such an effect was not observed in men. The other measurements showed a similar trend, such as larger vertical center anterior angle and smaller Sharp and acetabular anteversion angles, with aging in both men and women.ConclusionsWe used computed tomography data to quantitatively assess the coverage and shape of the acetabulum in adult Japanese subjects and obtain the estimated reference ranges by gender. The results also proved that the measurements changed with aging in both sexes. These facts must be taken into account during the diagnosis of hip disease and planning of surgery.     

Femoral anteversion, femoral offset, and abductor lever arm after total hip arthroplasty using a modular femoral neck system

We studied the effectiveness of a modular femoral neck system for the adjustment of femoral anteversion, femoral offset, and abductor lever arm during total hip arthroplasty (THA) using computed tomography data, and comparing findings in patients with a modular neck femoral component (116 hips) with those in patients with a cemented femoral component (23 hips). In the modular neck group, we intraoperatively evaluated various impingements using trial necks and heads, and selected the appropriate combination of modular neck and head from two types of straight neck, four types of anteverted/retroverted neck, two types of medialized/lateralized neck, and two types of varus/valgus neck. In the cement group, femoral anteversion was not changed using undersized stems, and an appropriate modular head was selected. While the 15° retroverted necks effectively corrected femora with a mean anteversion of 40.0° (range 28.8°–53.1°), the 15° anteverted necks were effective for femora with a mean anteversion of 14.2° (range, 3.3°–21.9°). Use of the straight or varus necks resulted in an average abductor lever arm value of more than 40 mm, with a mean anteversion of 26.4°. In patients with preoperative anteversion of more than 30°, postoperative anteversion was significantly smaller in the modular neck group than in the cement group (29.6 ± 4.2° vs. 35.3 ± 3.6°). This modular neck system effectively adjusted femoral anteversion and abductor lever arm in femora with various preoperative anteversion values. Received: March 21, 2001 / Accepted: August 20, 2001     

仰卧位常规器械OCM入路与后外侧入路全髋关节置换术的疗效对照

目的:比较仰卧位常规器械OCM入路与后外侧入路全髋关节置换术的临床疗效。方法 :2017年2月至2019年1月因髋关节疾病行髋关节置换患者67例,其中微创组21例采用OCM入路,男12例,女9例;股骨颈骨折10例,股骨头无菌性坏死5例,髋关节骨性关节炎6例。传统组46例采用传统后外侧入路,男28例,女18例;股骨颈骨折24例,股骨头无菌性坏死12例,髋关节骨性关节炎10例。所有患者使用生物型陶-陶人工关节假体。观察比较两组患者手术时间、术中出血量、切口长度、手术前后肌酸激酶(CK-NAC)、下地活动时间、住院时间、术后假体的外展角及前倾角。比较两组术前及术后12个月Harris评分。结果:所有病例获得随访,时间14～26(18.4±3.6)个月。两组患者术中出血、术后前倾角及外展角比较,差异均无统计学意义(P0.05)。两组病例手术时间、切口长度、术后肌酸激酶、下地时间、住院时间差异均有统计学意义(P0.05)。两组术前及术后12个月Harris功能评分差异均无统计学意义(P0.05)。结论:两种入路人工全髋关节置换术均可获得满意的疗效,OCM入路损伤小,术后康复快,是可靠的手术入路。     

Lateral Center-edge Angle of 18° (Bone-Edge): Threshold for Hip Arthroscopy Treatment in Patients with Borderline Developmental Dysplasia of the Hip?

Objective

Hip arthroscopy for the treatment of symptomatic borderline developmental dysplasia of the hip (BDDH) has been controversial. The purpose of this study was to retrospectively analyze minimum 2-year outcomes of BDDH after arthroscopic surgery and explore the criteria and thresholds of the lateral center-edge angle (LCEA) in arthroscopic surgery for BDDH.

Methods

Data were retrospectively collected from patients aged 18–50 who underwent arthroscopic surgery for BDDH and had an LCEA 18–25° between September 2016 and June 2020. The consistency of interobserver and intraobserver measurements of bone-edge LCEA was analyzed. Patients were divided into two groups based on LCEA (18–20°and 20–25°) and the results of arthroscopy compared between groups. Patient-reported outcome (PRO) scores, consisting of the modified Harris hip score (mHHS), the visual analogue scale (VAS) and the international hip outcome tool-12 (IHOT-12), the minimal clinically important difference (MCID) and patient acceptable symptom status (PASS) were calculated.

Results

In 52 patients with ≥2-year follow-up, female patients accounted for 71.2% and the mean age was 30.8 ± 8.4 years (range: 18 to 49 years). There was a high level of agreement when measuring the bone-edge LCEA definition of BDDH (Kappa = 0.921). Interobserver repeatability (ICC = 0.909, 95%CI: 0.847–0.947) and intraobserver repeatability (ICC = 0.944, 95%CI: 0.905–0.968) were excellent for bone-edge LCEA measurements. In addition to LCEA and Tönnis angle, there were no significant differences in α angle, neck stem angle, femoral anteversion angle, medial joint space, Tönnis grade of osteoarthritis, acetabular retroversion (8 sign), Cam deformity and anterior inferior iliac spine (AIIS) morphology between the two groups (p > 0.05). Intraoperative findings and procedures showed no statistical difference between groups (p > 0.05). The mean follow-up time was 44.4 ± 11.0 months (range: 25 to 64 months). Postoperative VAS, mHHS and IHOT-12 scores in the LCEA 18–20° group and the LCEA 20–25° group were significantly improved compared with those before surgery, and there was no statistically significant difference in the percentage of MCID and PASS (mHHS and iHOT-12) between the groups (p > 0.05).

Conclusion

Patients in the LCEA 18–20° group and the LCEA 20–25° group achieved favorable outcomes after arthroscopic surgery. LCEA 18° (bone-edge) should be the threshold for hip arthroscopic surgery in BDDH patients without obvious hip instability.     

3D打印技术测量儿童发育性髋关节脱位股骨颈前倾角

目的:探讨利用3D打印技术测量发育性髋关节脱位儿童股骨颈前倾角的方法及准确性以期找到准确测量该类患儿股骨颈前倾角的方法并指导制定手术方案。方法:纳入2016年6月至2018年9月需行手术治疗的单侧发育性髋关节脱位患者17例,男2例,女15例;年龄2～13(5.47±0.81)岁;左侧11例,右侧6例。用CT测量法(CT法)、3D打印的股骨实物模型测量法(模型法)和术中股骨颈前倾角测量法(术中法)分别测量患儿股骨颈前倾角,以术中法测量值作为标准参考值,进行统计学分析,比较前两种测量方法的准确性。结果:CT法测量平均值为(36.00±1.66)°,模型法测量平均值为(43.91±1.62)°,术中法测得股骨前倾角平均值为(44.21±1.62)°。CT法测量值与模型法测量值、术中法测量值的比较差异均有统计学意义(P0.05)。模型法测量值与术中法测量值差异无统计学意义(P0.05)。结论:利用3D打印技术的模型法测量儿童发育性髋关节脱位股骨颈前倾角与传统CT测量法相比更简单、准确、可重复性强,而且可以术前模拟术中操作,是目前比较理想的测量股骨颈前倾角的方法。     

Strict component positioning is necessary in hip resurfacing

Background

Hip resurfacing arthroplasty has some advantages, including improved metal-on-metal articulation, a lower dislocation rate and preserved femoral bone. This procedure is a surgical option for younger and more active patients with osteoarthritis and osteonecrosis of the femoral head. Although there have been some reports about the efficacy of this technique, others report serious complications caused by metal debris. Additionally, femoral neck preservation adversely decreases the head–neck ratio and results in postoperative impingement.

Methods

We evaluated the range of motion after hip resurfacing with various component orientations and optimal component orientations to avoid postoperative impingement using computer simulations in 10 male patients with osteonecrosis.

Results

The mean ranges of motion in flexion, extension, abduction, adduction and internal rotation at 90° of flexion were 92.4° ± 13.8°, 25.7° ± 13.8°, 38.0° ± 11.1°, 29.1° ± 10.0° and 20.9° ± 11.5°, respectively. The oscillation angle in flexion and extension motion was 118.1° ± 10.3°. More than 100° of flexion was acquired in 79 of 240 simulations (32.9 %), and more than 20° extension was acquired in 142 simulations (59.2 %). Combined anteversion was significantly correlated with maximal flexion and extension angles. The component safe zone to fulfill the range of motion criteria varied among patients, and 4 of 10 patients had no safe zone.

Conclusions

Postoperative impingement occurs relatively frequently in hip resurfacing because of preservation of the femoral neck and component malpositioning. The safe zone of the acetabular component to avoid postoperative impingement is very narrow. Greater care should be taken regarding patient selection, rigorous preoperative planning and accurate component positioning.