Sharma Abhinav K, Grammatopoulos George, Pierrepont Jim W, Madurawe Chameka S, Innmann Moritz M, Vigdorchik Jonathan M, Shimmin Andrew J
Department of Orthopaedic Surgery, University of California, Irvine, School of Medicine, Orange, California.
Division of Orthopaedic Surgery, The Ottawa Hospital, Ottawa, Ontario, Canada.
J Arthroplasty. 2023 Apr;38(4):713-718.e1. doi: 10.1016/j.arth.2022.05.020. Epub 2022 May 16.
Several authors propose that a change in sacral slope of ≤10° between the standing and relaxed-seated positions (ΔSS) identifies a patient with a stiff lumbar spine and has suggested the use of dual-mobility bearings for such patients undergoing a total hip arthroplasty (THA). The aim of this study was to assess how accurately ΔSS can identify patients with a stiff spine.
A prospective, multicentre, consecutive cohort series of 312 patients had standing, relaxed-seated, and flexed-seated lateral radiographs prior to THA. ΔSS was determined by the change in sacral slope between the standing and relaxed-seated positions. Lumbar flexion (LF) was defined as the difference in lumbar lordotic angle between standing and flexed-seated. LF ≤20° was considered a stiff spine. The predictive value of ΔSS for characterizing a stiff spine was assessed.
A weak correlation between ΔSS and LF was identified (r = 0.13). Eighty six patients (28%) had ΔSS ≤10° and 19 patients (6%) had a stiff spine. Of the 86 patients with ΔSS ≤10°, 13 had a stiff spine. The positive predictive value of ΔSS ≤10° for identifying a stiff spine was 15%.
In this cohort, ΔSS ≤10° was not correlated with a stiff spine. Using this simplified approach could lead to a 7-fold overprediction of patients with a stiff lumbar spine and abnormal spinopelvic mobility, unnecessary use of dual-mobility bearings, and incorrect component alignment targets. Referring to patients with ΔSS ≤10° as being stiff is misleading. The flexed-seated position should be used to effectively assess a patient's spine mobility prior to THA.
几位作者提出，站立位和放松坐位之间骶骨斜率变化≤10°（ΔSS）可识别腰椎僵硬的患者，并建议在接受全髋关节置换术（THA）的此类患者中使用双动轴承。本研究的目的是评估ΔSS识别脊柱僵硬患者的准确性。
一项前瞻性、多中心、连续队列研究纳入了312例患者，在THA术前拍摄站立位、放松坐位和屈曲坐位的腰椎侧位X线片。ΔSS通过站立位和放松坐位之间骶骨斜率的变化来确定。腰椎前屈（LF）定义为站立位和屈曲坐位之间腰椎前凸角的差值。LF≤20°被认为是脊柱僵硬。评估了ΔSS对脊柱僵硬特征的预测价值。
确定ΔSS与LF之间存在弱相关性（r = 0.13）。86例患者（28%）的ΔSS≤10°，19例患者（6%）存在脊柱僵硬。在86例ΔSS≤10°的患者中，13例存在脊柱僵硬。ΔSS≤10°识别脊柱僵硬的阳性预测值为15%。
在该队列中，ΔSS≤10°与脊柱僵硬无关。使用这种简化方法可能会导致对腰椎僵硬和脊柱骨盆活动异常患者的预测高估7倍，不必要地使用双动轴承，并导致假体对线目标错误。将ΔSS≤10°的患者称为脊柱僵硬具有误导性。在THA术前，应使用屈曲坐位来有效评估患者的脊柱活动度。
