髂后上棘连线的精确调整对全髋关节置换术中臼杯准确安放影响的临床研究

目的探讨一种减少髋臼杯外展角安放的偏差,提高其在Lewinnek安全范围比率的新方法。方法 2009年1月～2010年4月,共对60例患者(64例髋)采用侧卧位后外侧入路进行全髋关节置换术(THR)。实验组(有调整髂后上棘连线)29例患者(31髋),对照组(未调整髂后上棘连线)31例患者(33髋)。实验组手术时利用激光水平仪调整手术床头尾侧倾斜的角度,通过校正髂后上棘连线,间接使泪滴连线垂直于水平面,从而纠正骨盆的外展或内收。结果实验组术后髋臼杯外展角与目标值偏差5°的比率为25.8%,对照组为60.6%,两者间差异有统计学意义(P0.01);实验组术后髋臼杯外展角位于Lewinnek安全范围的比率为90.3%,对照组为63.6%,两者间差异有统计学意义(P0.05)。结论手术时精确调整髂后上棘连线可纠正骨盆的外展或内收,从而减少髋臼杯外展角安放的偏差,提高其在Lewinnek安全范围的比率。该方法简单,易操作,在临床上具有可靠的实用价值。     

髋臼卵圆窝在实现术前预期髋臼杯外展角中的参考价值

  目的 探讨髋臼卵圆窝的解剖及影像学特点,评价其在实现术前预期髋臼杯外展角中的作用。方法 在16具正常成人骨盆标本上标记髋臼卵圆窝 中轴线,观察卵圆窝中轴线走行特点及其与卵圆窝顶和髋臼骨性边缘交点在标准骨盆正位X线片上的对应关系。通过模板测量观察预期外展角度的髋臼杯中轴线 与髋臼卵圆窝顶点之间的对应关系。于骨盆标本两侧髋臼施行生物髋臼杯植入术,一侧采用卵圆窝参照法,对侧采用髋臼定位器法,在标准骨盆正位X线片上比 较两侧手术前后髋臼杯外展角偏差的差异。结果 卵圆窝中轴与卵圆窝顶和髋臼骨性边缘的交点是较为恒定的解剖标志,在标准骨盆正位X线上分别对应髋臼顶部 关节面软骨下骨的内缘和外缘。髋臼卵圆窝顶点与40°±5°外展角度的髋臼杯中轴线密切相关。卵圆窝参照组手术前后髋臼杯外展角偏差为0.19° ±3.14°（-6°~5°）,髋臼定位器组为2.75°±2.89°（-2°~8°）,两组差异有统计学意义（t=－2.453,Ρ=0.027）。结论 对于患者髋臼解剖相对正常的 初次全髋关节置换,依据术前模板测量获得的预期髋臼杯位置与卵圆窝顶点的关系,可较精确地获得预期髋臼杯外展位置。     

金属对金属髋关节表面置换术两种不同手术入路中假体位置的X线测量比较

[目的]了解外侧入路和后外侧入路两种不同入路中髋关节表面置换中假体位置的差异。[方法]72个关节中,分为两组:A组21例病人,共26个髋关节,采用Hardinge的外侧入路。B组44例,共46个髋关节,采用改良的Gibson入路,股骨头由关节后方脱出。测量的指标包括:(1)术前颈干角和术后股骨假体柄干角;(2)髋臼假体的外展角;(3)股骨假体的中心偏移距;(4)术前髋臼前倾角和术后髋臼假体前倾角;(5)股骨假体侧方中心偏移距;(6)股骨假体的侧方偏移角。[结果]股骨假体的柄干角A组为139.5°,B组为140.5°,2种入路间的柄干角无显著性差异;髋臼假体的外展角A组为37.7°,B组为44.4°;前倾角A组为21.6°,B组为15.2°。[结论]髋关节表面置换可以采用外侧入路和后外侧入路,股骨假体安放位置在两种入路中差别不大,但在髋臼假体安放时,相差显著。与后外侧入路比较,外侧入路中,髋臼假体的外展角较小,但前倾角较大。     

前路辅助上方关节囊入路全髋关节置换对髋臼假体位置及术后早期髋关节功能的影响

目的 探讨前路经皮辅助上方关节囊入路（Anterior SuperPATH）行人工全髋关节置换术（THA）对髋臼假体位置及早期髋关节功能的影响。方法 回顾性分析2019年11月至2022年6月在我院行THA的75例病人的临床资料,根据手术入路不同分为两组,38例采用前路经皮辅助上方关节囊入路的病人纳入前路通道组,37例采用传统后外侧入路的病人纳入后外侧组。记录并比较两组手术时间、术中出血量、术后卧床时间、住院时间、术后24 h疼痛视觉模拟量表（VAS）评分,以及术后1周、1个月的髋关节Harris评分。术后拍摄骨盆正位X线片,测量髋臼假体的外展角与前倾角,并与Lewinnek安全区（髋臼外展角40°±10°、髋臼前倾角15°±10°）进行比较,评估放置髋臼假体的准确性。结果 病人随访8~21个月,平均为12.1个月。所有病人术后6个月均未见脱位。前路通道组手术时间长于后外侧组,手术出血量少于后外侧组,术后卧床时间与住院时间短于后外侧组,术后24 h的VAS评分低于后外侧组,术后1周、1个月的髋关节Harris评分高于后外侧组,两组比较,差异均有统计学意义（P＜0.05）。前路通道组的外展角和前倾角分别为42.78°±4.98°、15.29°±4.97°,二者均在安全区域的比例为84.2%（32/38）;后外侧组的外展角和前倾角分别为41.49°±5.50°、13.58°±4.74°,二者均在安全区域的比例为83.8%（31/37）;两组间比较,差异均无统计学意义（P＞0.05）。结论 采用前路经皮辅助上方关节囊入路和后外侧入路行THA,髋臼假体位置无明显差异。虽然前路经皮辅助上方关节囊入路手术时间更长,但能明显减少手术出血,缓解手术疼痛,缩短住院时间,加速康复。     

髋关节骨性关节炎及髋臼发育不良对髋关节表面置换术中髋臼安装角度的影响

[目的]研究全髋关节表面置换术中,单纯骨性关节炎及髋关节发育不良对髋臼安装角度的影响及两组病例疗效比较。[方法]自2006～2009年,本科共实施全髋表面关节置换术20例23髋,病因包括单纯骨性关节炎10髋及髋关节发育不良13髋。手术假体均采用金属对金属大直径表面置换假体,股骨侧骨水泥固定,髋臼侧生物型固定。[结果]所有患者均获得近期随访(6个月～3年),随访包括临床评估和放射学评估。两组患者术前术后Harris评分均无明显统计学差异。无一发生术后脱位、股骨颈骨折等并发症。其中单纯骨性关节炎患者术后臼杯外展角25.6°～56.0°(平均43.9°±9.9°),平均髋臼覆盖率达95.8%。髋臼发育不良患者术后臼杯外展角22.4°～69.3°(平均46.8°±12.9°),髋臼覆盖率达84.3%。[结论]金属对金属大直径表面置换假体在治疗单纯骨性关节炎及髋关节发育不良早期临床疗效并无明显统计学差异。但是髋关节发育不良患者行髋关节表面置换术中,髋臼假体外展角离散度要明显高于单纯骨性关节炎组,其髋臼杯假体外展角度控制要难于单纯骨性关节炎。     

强直性脊柱炎THA术后假体脱位的危险因素分析

目的研究强直性脊柱炎（AS）全髋关节置换（THA）术后假体脱位的危险因素。方法回顾性分析自2008-07—2014-01行THA的275例（326髋）AS,按是否发生术后假体脱位分为脱位组与未脱位组,分析AS行THA术后假体脱位的危险因素。结果 275例（326髋）中18例（18髋）发生脱位,发生率为5.52%。单因素分析脱位组与未脱位组是否合并脊柱后凸、是否骨盆后倾、髋臼假体外展角及前倾角是否过大比较差异有统计学意义（P〈0.05）。多因素Logistic回归分析显示合并脊柱后凸、骨盆后倾、髋臼假体外展角及前倾角过大是AS行THA术后假体脱位的影响因素。结论脊柱后凸畸形、骨盆后倾、髋臼假体外展及前倾角较大是AS行THA术后假体脱位的高危因素。     

Crowe Ⅲ型髋关节发育不良人工全髋关节置换髋臼解剖重建与非解剖重建髋关节生物力学有限元分析

目的：应用有限元分析研究CroweⅢ型发育性髋关节发育不良(developmental dysplasia of the hip,DDH) 全髋关节置换(total hip arthroplasty,THA)髋臼解剖重建与非解剖重建髋关节的生物力学为临床THA髋臼解剖重建提供理论基础和实验依据。方法：选取1例因左侧Crowe Ⅲ型DDH伴终末期髋骨关节炎于2020年4月就诊并行左侧全髋关节置换的患者,女,57岁。术前、术后分别行骨盆CT平扫三维重建。在Mimics和3-Matic软件里建立14组髋臼杯不同前倾角、外展角、旋转中心高度模型并进行材料赋值,在Abaqus软件里设置边界和负载条件,计算并观察髋关节应力峰值和分布。结果：对于Crowe Ⅲ型DDH全髋关节置换术,当旋转中心解剖重建,髋臼杯外展角设置为40°时,髋臼杯前倾角5°~25°变化时,髋臼杯、聚乙烯内衬最低Von Mises值出现在前倾角20°;当旋转中心解剖重建,髋臼杯前倾角设置为15°时,髋臼杯外展角30°~55°变化时,髋臼杯、聚乙烯内衬最低Von Mises值出现在外展角35°;当髋臼杯前倾角设置为15°、外展角设置为40°时,旋转中心上移0~20 mm变化时,髋臼杯、聚乙烯内衬最低Von Mises值出现在旋转中心上移10 mm。在所有14组髋臼杯参数模型中,旋转中心解剖重建,髋臼杯前倾角15°、外展角35°时,髋臼、髋臼杯、聚乙烯内衬Von Mises值最低。结论：在Crowe Ⅲ型DDH全髋关节置换术中,建议解剖重建旋转中心,髋臼杯前倾角15°、外展角35°,同时进行髋臼外上方植骨并增加螺钉以进一步减少髋关节应力峰值。     

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。     

个性化数字模拟辅助髋臼假体精准植入在CroweⅠ和Ⅱ型髋关节发育不良中的应用

目的:探讨采用个性化数字模拟辅助髋臼假体精准植入在髋关节发育不良应用的疗效。方法：自2017年2月至2019 年7月收治的11例（12髋）髋关节发育不良行全髋关节置换术患者,男4例（5髋）,女7例（7髋）,年龄27~61 （46.64±12.93）岁;Crowe分型Ⅰ型8髋,Ⅱ型4髋。将术前CT薄层扫描导入Mimics 10.01软件,通过术前模拟选择合适髋臼假体尺寸及安放角度,并了解髋臼骨量缺损情况,决定术中是否需要结构植骨,测量患者术前后的双下肢长度、髋臼假体前倾角、外展角、髋臼旋转中心高度、髋关节中心水平距离,观察术后脱位、植骨愈合情况及臼杯松动情况,并采用髋关节Harris评分评价关节功能。结果：所有患者获得随访,时间18~30（23.45±3.70）个月,术后未发生假体脱位、松动、植骨均愈合。1例因术中坐骨神经牵拉出现支配区域麻木,给予营养神经药物治疗于术后1个月恢复。双下肢长度差由术前（31.73±5.98） mm下降至术后3个月的（4.73±1.90） mm（t=15.268,P<0.01）。术后臼杯髋臼前倾角（17.45±3.62）°、外展角（40.10±2.30）°。所有病例外展角及前倾角均位于Lewinnek安全范围内,术后髋关节旋转中心高度（20.64±2.58） mm,术后髋关节水平内移距离（33.46±3.61） mm。Harris评分由术前（45.36±2.34）分提高至术后3个月（91.27±2.37）分 （P<0.05）。结论：髋关节发育不良患者通过术前个性化数字模拟重建髋臼,可以更好的了解髋臼缺损情况,有助于评估髋臼假体的大小、安放角度及是否需要结构植骨,可获得满意的临床疗效。     

ABGⅠ代髋臼杯假体翻修原因分析

目的分析半球形ABGⅠ代羟基磷灰石(HA)涂层髋臼杯假体翻修原因,评价其中长期随访结果。方法对299例(366髋)行半球形ABGⅠ代HA涂层髋臼假体置换患者的病历和X线片进行回顾性研究,截止2004年7月30日随访121例(141髋),其中68例(77髋)髋臼杯进行了翻修,男48例(53髋),女20例(24髋);年龄30～72岁,平均51.4岁;全髋翻修7髋,髋臼杯翻修70髋。测量髋臼假体外展角和前倾角位置,将外展角>50°、前倾角>20°、髋臼杯露出髋臼外>10%定义为髋臼假体位置不良,并根据测量随访时正位X线片上的股骨头偏移距离计算内衬磨损率。根据X线片对髋臼假体翻修原因进行分析。结果翻修68例77髋中术后5年内翻修11髋,6￣12年翻修66髋,翻修病例集中在术后7～9年。X线片示假体松动42髋、严重骨溶解43髋、轻度骨溶解12髋,均有不同程度内衬磨损。翻修患者中髋臼杯位置不良18髋,髋臼发育不良患者髋臼植骨6髋,术后外伤2髋,术后脱位2髋,其余49髋的翻修原因推测与假体有关。内衬磨损率为每年(0.26±0.10)mm。翻修手术中取出的假体表面没有很好的骨生长。结论ABGⅠ代HA涂层髋臼假体的中期随访结果较好,长期随访结果不满意。导致翻修率高的原因包括髋臼发育不良、髋臼假体安放位置不正确、高内衬磨损率和过多的螺钉孔导致的骨溶解松动。     

Preoperative Leg Length Discrepancy >2 cm in the Supine Decubitus Position May Induce Compensatory Pelvic Obliquity in Patients during Total Hip Arthroplasty

Objectives

The leg length discrepancy (LLD) in the supine decubitus position may influence the inclination angle of the acetabular component during total hip arthroplasty (THA). The relationship among LLD, pelvic obliquity, and inclination angle of the acetabular component has not been well studied. This study aimed to evaluate the relationship between LLD in supine position and changes in the inclination angle of the acetabular components during THA, and the compensatory ability of the pelvis based on LLD and inclination.

Methods

A total of 135 patients were prospectively classified into three groups according to the preoperative LLD in the supine decubitus position: the cranial type group had a positive LLD value; the fixed type group had LLD = 0; and the caudal type group had a negative LLD value. Patients in the cranial type group and caudal type group were divided into four subgroups based on the LLD value (either positive or negative): LLD >3 cm subgroup; 2 ≤ LLD ≤ 3 cm subgroup; 1 ≤ LLD < 2 cm subgroup; and LLD <1 cm subgroup. The targeted and final inclination of the acetabular component was measured intra- and postoperatively.

Results

The results showed a significant difference in the targeted and final inclination angles among the patients in the cranial type and the caudal type groups. In the caudal type group, increased inclination was observed in the patients of LLD >3 cm subgroup (mean 3.13°) and 2 ≤ LLD ≤ 3 cm subgroup (mean 5.17°) after THA, respectively. Decreased inclination (mean, 6.16°) was observed in 2 ≤ LLD ≤ 3 cm subgroup in the cranial type group after THA.

Conclusions

Our findings revealed that in patients with discrepancy greater than 2 cm, postural pelvic obliquity imposed a remarkable influence on the inclination.     

Efficacy of a Pelvic Lateral Positioner With a Mechanical Cup Navigator Based on the Anatomical Pelvic Plane in Total Hip Arthroplasty

Background

The acetabular component orientation in total hip arthroplasty (THA) is of critical importance to the good clinical results. However, traditional widely used cup alignment guides for cup placement are reported to be relatively unreliable. The present study aims at comparing a novel cup alignment guide, which can be attached to our anatomical pelvic plane (APP) pelvic lateral positioner for reducing discrepancies in sagittal pelvic tilt and indicate a targeted cup angle based on the APP, with a conventional cup alignment guide.

Portable Accelerometer-Based Navigation System for Cup Placement of Total Hip Arthroplasty: A Prospective,Randomized, Controlled Study

BackgroundMalposition of the acetabular component during total hip arthroplasty (THA) is associated with increased risk of dislocation, reduced range of motion, and accelerated wear. The purpose of this study is to compare cup positioning with a portable, accelerometer-based hip navigation system and conventional surgical technique.MethodsIn a prospective, randomized, clinical study, cups were implanted with a portable, accelerometer-based hip navigation system (navigation group; n = 55) or conventional technique (conventional group; n = 55). THA was conducted in the lateral position and through posterior approach. The cup position was determined postoperatively on pelvic radiograph and computed tomography scans.ResultsAn average cup abduction of 39.2° ± 4.6° (range, 27° to 50°) and an average cup anteversion of 14.6° ± 6.1° (range, 1° to 27.5°) were found in the navigation group, and an average cup abduction of 42.9° ± 8.0° (range, 23° to 73°) and an average cup anteversion of 11.6° ± 7.7° (range, −12.1° to 25°) in the conventional group. A smaller variation in the navigation group was indicated for cup abduction (P = .001). The deviations from the target cup position were significantly lower in the navigation group (P = .001, .016). While only 37 of 55 cups in the conventional group were inside the Lewinnek safe zone, 51 of 55 cups in the navigation group were placed inside this safe zone (P = .006). The navigation procedure took a mean of 10 minutes longer than the conventional technique.ConclusionUse of the portable, accelerometer-based hip navigation system can improve cup positioning in THA.     

Reduction in variability of acetabular cup abduction using computer assisted surgery: a prospective and randomized study.

Optimal orientation of the acetabular component of a total hip prosthesis is an important factor in determining the early and long-term result of a total hip arthroplasty (THA). Conventional positioning of the cup component is usually done using a free-hand method, or with the help of a mechanical acetabular alignment guide. However, these methods have proven to be inaccurate, and a great variation in orientation of the cup is found postoperatively. In this study, we wished to determine if the variability of the abduction angle of acetabular cups could be reduced with the use of computer navigation. The abduction angles of the acetabular components of three groups of 50 THAs were assessed. In the first group, a free-hand method was used to position the cup component. This group was operated in the period before we started using computer navigation for hip surgery. In the second group, CT-based computer navigation was used to plan and help position the cup. The third group consisted of 50 THA cases in which a free-hand method was used to position the cup, although these procedures were performed in the period after we had begun using the Computer Assisted Surgery (CAS) system. The variability in cup abduction angle was assessed in all three groups and compared. There was a significant reduction in variability in the CAS group compared to the first group. There was also a reduction in variability in the CAS group compared to the third group, although this was not statistically significant. It is concluded that the use of computer navigation helped the surgeon to place the cup component with less variability of the abduction angle, and, more importantly, we found that no cups were placed in the more extreme positions (outliers).     

Acetabular component orientation in intra- and postoperative positions in total hip arthroplasty

Introduction  In total hip arthroplasty (THA), acetabular component orientation has critically important effects on dislocation, range of motion, polyethylene wear, pelvic osteolysis, and component migration. The differences in the pelvic orientation in the intraoperative lateral position for insertion of acetabular component during operation and that in the postoperative supine position for evaluation of acetabular component orientation will be one of the factors, which make outliers in acetabular component orientation. We compared acetabular component orientation between intraoperative lateral position and postoperative supine position in 100 consecutive primary THAs. Materials and methods  A total of 100 consecutive primary THAs (between October 2004 and December 2005) in 100 patients performed by a single surgical team were investigated. Intraoperative anteroposterior radiographs of pelvis in the lateral position and postoperative anteroposterior radiographs of pelvis in the supine position were taken. Acetabular component orientation (vertical tilt and anteversion) were measured using computer software. Results  The absolute values of difference between measurements in the two positions were 5.3° ± 4.5° (mean ± SD) for vertical tilt and 5.1° ± 3.7° for anteversion. The difference in the vertical tilt between the two positions was significant (P < 0.0001). Conclusion  The difference in the acetabular component orientation between the two positions, which might be caused by the difference between intra- and postoperative pelvic orientation, should be considered during THA.     

Direct Anterior Approach for Total Hip Arthroplasty in the Lateral Decubitus Position: Our Experiences and Early Results

Background

The direct anterior approach (DAA) for total hip arthroplasty (THA) is typically performed in the supine position using a specially designed operating room table, which makes this approach more accessible to orthopedic surgeons. We attempted to perform this procedure in the lateral decubitus position on an ordinary operation table to avoid dependence on a special operating room table. There is an obvious absence of literature regarding this subject.

Accuracy of the acetabular index using the percutaneous assisted total hip technique

In minimally invasive total hip arthroplasty (THA), proper acetabular component positioning can be difficult to achieve without navigational or intraoperative radiographic methods. Acetabular components placed in excessive abduction can lead to early failure and dislocation. This article describes a series of 74 consecutive primary THAs (71 patients, 3 bilateral) performed using a percutaneous assisted THA technique that does not require navigation, yet allows adequate visualization for accurate acetabular cup placement. No patients were excluded (because of body mass index or abnormal anatomy) from the study. Mean abduction angle for all hips was 45°. The goal was acetabular abduction angle between 35° and 55°. This goal was achieved in 72 of the 74 hips (97.3%). Proper acetabular abduction angle can be achieved in the majority of cases using this new soft-tissue sparing approach for THA.     

侧卧位直接前方入路全髋关节置换的可行性和效果

目的探讨侧卧位直接前方入路(DAA)全髋关节置换术的可行性和临床效果。方法对307例患者(332髋)行侧卧位DAA全髋关节置换术,评估临床功能,观察影像学结果和并发症。结果单侧髋关节置换手术时间41~73(52.0±5.6)min,术中失血量60~210(94.0±37.4)ml。患者均随访1年。髋关节Harris评分术后1、3、12个月均较术前明显改善(F=237.2,P<0.001)。术后第2天,髋臼假体前倾角为7°~22°(14.4°±6.0°),外展角为26°~57°(43.8°±4.4°)。双下肢长度的差异由术前0~2.5 cm纠正为术后0~1.5 cm(Z=-14.71,P<0.001)。18髋发生股外侧皮神经损伤,3髋发生术中股骨近端骨折,2髋术后早期出现髋关节脱位,1髋髋臼杯未完全打入臼窝,该24例经对症治疗后均愈合、复位良好。术后1年未发生假体周围骨折,无菌性假体松动。结论侧卧位DAA全髋关节置换术安全可行,临床效果良好。     

Higher Acetabular Anteversion in Direct Anterior Total Hip Arthroplasty: A Retrospective Case-Control Study

Background

Surgical approach is known as a risk factor that influences cup malposition while performing total hip arthroplasty (THA). However, no study has been conducted comparing cup positioning between the supine direct anterior (DA) and supine direct lateral (DL) THA approaches.

Questions/Purposes

(1) Is there a difference in acetabular cup positioning between supine DA and supine DL THA approaches?(2) Are there differences in complications based on acetabular cup positioning between the two approaches?

Methods

From 2012 to 2014, 186 patients who underwent primary THAs using DA approach were matched with 186 patients using DL approach by body mass index, age, and gender. Cup anteversion and abduction angles were measured from standing anteroposterior pelvis radiographs by two blinded observers. The Lewinnek safe zone was used as the standard for cup positioning. Cup anteversion, abduction angles, and complications were recorded and compared.

Results

Cup anteversion was on average 3° higher in the DA approach compared to the DL approach. The abduction angle for the DA approach was equivalent to the DL approach both averaging 46° to 47°. There were more DA hips outside of the safe zone (10%) for anteversion than DL (3%) hips. There were no differences in complications between DA and DL approaches.

Conclusion

There is a tendency to antevert the acetabular cup when performing THAs using the DA approach, and one must be mindful of this when implanting the acetabular component.