Pongkunakorn Anuwat, Palawong Patanapong, Chatmaitri Swist, Phetpangnga Nawakun
Department of Orthopaedic Surgery, Lampang Hospital and Medical Educational Center, Mueang District, Lampang, Thailand.
Research performed at Lampang Hospital, Lampang, Thailand.
Arch Bone Jt Surg. 2019 Jul;7(4):314-320.
Femoral stem anteversion during hip arthroplasty is generally estimated by eye intraoperatively and has proven to be different from targeted values. This study aims to determine the accuracy of a novel technique using a digital protractor and a spirit level to improve surgeons' estimation of stem anteversion.
A prospective non-randomized study was conducted among 93 patients with femoral neck fracture who underwent cemented hemiarthroplasty via posterolateral approach. In the control group (N=62), five experienced surgeons assessed stem anteversion related to the posterior femoral condylar plane using visual estimation with a target angle of 15°-25°. In the study group (N=31), another two surgeons assessed stem anteversion with the same target angle by placing a digital protractor on the femoral stem inserter handle while the assistant held the leg in the truly vertical position, verified by a spirit level that was attached to the shin with cable ties. Stem anteversion was measured blind, postoperatively, on 2D-CT and compared with the intraoperative results.
The mean postoperative anteversion was 22.4° (-4.2° to 51.3°, SD 11.1°) in the control group and 23.0° (16.0° to 29.9°, SD 3.6°) in the study group (). The study group had more stems positioned in 15°-25° anteversion (71.0% 32.3%, ) and the mean absolute value of surgeon error was -0.2° (-5.4° to 7.0°, SD 3.0°). Twenty-eight stems of the study group (90.3%) had an error within 5°. Surgeon overestimation >5° was found in 1 hip (3.2%) and underestimation >5° was found in 2 hips (6.4%).
Using a digital protractor and a spirit level was reliable with high accuracy and precision to improve the intraoperative estimation of cemented stem anteversion.
髋关节置换术中股骨柄前倾角通常在术中凭肉眼估计，事实证明与目标值存在差异。本研究旨在确定一种使用数字量角器和水平仪的新技术在提高外科医生对柄前倾角估计准确性方面的效果。
对93例股骨颈骨折患者进行了一项前瞻性非随机研究，这些患者均通过后外侧入路接受了骨水泥半髋关节置换术。在对照组（N = 62）中，五名经验丰富的外科医生通过视觉估计评估与股骨后髁平面相关的柄前倾角，目标角度为15° - 25°。在研究组（N = 31）中，另外两名外科医生通过将数字量角器放置在股骨干插入器手柄上，同时助手将腿保持在真正垂直的位置（通过用束带固定在胫骨上的水平仪进行验证），以相同的目标角度评估柄前倾角。术后在二维CT上对柄前倾角进行盲测，并与术中结果进行比较。
对照组术后平均前倾角为22.4°（-4.2°至51.3°，标准差11.1°），研究组为23.0°（16.0°至29.9°，标准差3.6°）。研究组有更多的柄前倾角位于15° - 25°（71.0% 对32.3%），外科医生误差的平均绝对值为-0.2°（-5.4°至7.0°，标准差3.0°）。研究组的28个柄（90.3%）误差在5°以内。在1例髋关节中发现外科医生高估>5°（3.2%），在2例髋关节中发现低估>5°（6.4%）。
使用数字量角器和水平仪在提高骨水泥柄前倾角术中估计的准确性和精确性方面是可靠的。
