Pelvic balance in sagittal and Lewinnek reference planes in the standing, supine and sitting positions
Pelvic balance in sagittal and Lewinnek reference planes in the standing, supine and sitting positions
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DOI：
10.1016/j.otsr.2008.01.001
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发表时间：
2009-02-01
影响因子：
2.3
通讯作者：
Fessy, M. H.
中科院分区：
文献类型：
--
作者：
Philippot, R.;Wegrzyn, J.;Fessy, M. H.
介绍。在全髋关节置换术植入过程中，骨盆平衡是公认的影响目标髋臼组件前倾的因素。然而，文献中没有研究系统地报告站立、坐位和仰卧位的骨盆参数数据。髋臼杯方向的变化可以追溯到这三种常见位置之一的最终骨盆平衡变化。材料和方法。在这三个位置（仰卧位，站立位和坐位），骨盆解剖参数和参考平面从一组67名患者（平均年龄：70.2 +/- 3.2岁）的放射学定义。将完整的X线片个体集数字化，并由一名操作员使用Spineview软件获得测量值（之前对此类测量值进行了严格验证）。定位根据Lewinnek骨盆坐标系，这被认为是一个可能的错误来源时，垂直站立或水平躺，也进行了调查。平均骨盆发生率为59.6度，在坐位、仰卧位或站立位没有变化，性别之间没有统计学显著差异。验证了Legaye公式，即骨盆倾角等于骨盆倾斜角加骶骨倾斜角。从坐位到仰卧位或站立位，骨盆倾斜度平均增加22度。骶骨倾斜度的变化顺序相反。从站立位到仰卧位，骨盆-股骨角（PFA）减小了20度。Lewinnek平面位于垂直平面后4度。无论采用何种体位，骨盆-Lewinnek角似乎是恒定的，平均为12度。该系列的平均盆腔发病率较高，最可能与患者年龄和/或病理学有关。功能性前倾（坐、卧或站）姿势的概念。Lewinnek平面通常被接受为髋关节导航的参考平面，针对每位患者进行个性化设置，不应与垂直平面混淆;股骨相对于Lewinnek平面的定位也针对每位患者。手术时这两个参数的累积近似值导致站立时的组合不精确度为26度，躺下时为36度。因此，我们定义了计算机辅助髋关节手术软件中要集成的关键参数：骨盆前倾角（功能性前倾）的位置变化，Lewinnek平面的定位和PFA值（两者均取决于患者）。如果将这些参数整合到新的软件版本中似乎是可能的，这将代表最大假体稳定性、最大关节振幅和消除可能的假体冲突之间的可靠折衷。(C)2008年，Elsevier Masson SAS。All rights reserved.
Introduction.-Sagittal pelvic balance is a recognized factor influencing targeted acetabular-component anteversion during total hip arthroplasty implantation. However, no studies in the literature have systematically reported pelvic parameters data in the standing, sitting and supine positions.Hypothesis.-Variations in acetabular cup orientation can be traced to eventual pelvic balance changes in one of these three usual positions.Materials and methods.-In these three positions (supine, standing and sitting), pelvic anatomical parameters and reference planes were radiologically defined from a group of 67 patients (average age: 70.2 +/- 3.2 years). The complete X-rays individual sets were digitized and measurements were obtained by a single operator using a Spineview software (previously, strictly validated for these kind of measurements). Positioning according to the Lewinnek pelvic coordinate system, which is considered as a possible source of errors when vertically standing or horizontally lying, was also investigated.Results.-The average pelvic incidence of 59.6 degrees did not vary in the sitting, supine or standing positions, with no statistically significant difference between sexes. The Legaye equation-pelvic incidence is equals to pelvic version plus sacral slope-was verified. Pelvic version increased by an average 22 degrees from the sitting to the supine or standing positions. Sacral slope varied in a reverse order. Pelvic-femoral angle (PFA) decreased by 20 degrees from the standing to the supine position. The Lewinnek plane was located 4 degrees posterior to the vertical plane. Whatever the position adopted, pelvi-Lewinnek angle appeared constant, averaging 12 degrees.Discussion.-The average pelvic incidence in this series was high, most probably associated with advancing patient age and/or pathology. The concept of functional anteversion sitting, supine or standing) positions. The Lewinnek plane, commonly accepted as the reference plane for hip navigation, was individualised to each patient and should not be mistaken with the vertical plane; positioning of the femur in relation to the Lewinnek plane was also specific to each patient. Cumulative approximation on these two parameters at surgery resulted in a combined imprecision of 26 degrees when standing and 36 degrees when lying down. We have thus defined crucial parameters to be integrated in computer-assisted hip surgery softwares:positional variations of the pelvic version (functional anteversion), positioning of the Lewinnek plane, and PFA value (both specifically patient's dependant). If integration of these parameters into new sofwares versions appears possible, this would represent a reliable compromise between maximum prosthetic stability, maximum joint amplitudes and elimination of possible prosthetic conflict. (C) 2008 Elsevier Masson SAS. All rights reserved.