Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.
J Arthroplasty. 2022 Feb;37(2):316-324.e2. doi: 10.1016/j.arth.2021.10.029. Epub 2021 Nov 3.
Abnormal spinopelvic mobility is identified as a contributing element of total hip arthroplasty (THA) instability. Preoperative identification of THA patients at risk is still a remaining challenge. We therefore conducted this study to (1) evaluate if preoperative and postoperative spinopelvic mobility differs, (2) determine the interactions between the elements of the spinopelvic complex, and (3) identify preoperative parameters for predicting spinopelvic mobility.
A prospective observational study assessing 197 THA patients was conducted with biplanar stereoradiography in standing and relaxed sitting positions preoperatively and postoperatively. Two independent investigators determined spinopelvic mobility based on 2 different classifications (Δ sacral slope [SS] and Δ pelvic tilt [PT]; Δ from standing to sitting; Δ < 10° stiff, Δ ≥ 10°-30° normal, Δ > 30° hypermobile). Multiple regression analysis and receiver operating characteristic analysis were used to identify predictors for postoperative spinopelvic mobility.
Spinopelvic mobility significantly increased after THA based on ΔPT (Pre/Post: 18.5°/22.8°; P < .000) and ΔSS (Pre/Post 17.9°/22.4°; P < .000). A distinct shift in the ratio from stiff (Pre/Post: 24%/9.7%) to hypermobile (Pre/Post: 10.2%/22.1%) mobility postoperatively was observed. Receiver operating characteristic analysis predicted postoperative stiffness using preoperative PT ≥ 13.0° with a sensitivity of 90% and a specificity of 51% and hypermobility with preoperative SS ≥ 35.2° with a sensitivity of 81% and a specificity of 34%. Age at surgery, preoperative PT, and pelvic incidence were independent predictors of spinopelvic mobility (R = 0.24).
Definition of preoperative stiffness should be interpreted with caution by arthroplasty surgeons as mobility itself is influenced by THA. For the first time thresholds for standing preoperative parameters for predicting postoperative spinopelvic mobility could be provided. For preoperative standing only lateral assessment could serve as a screening tool for spinopelvic mobility.
异常的脊柱骨盆活动度被认为是全髋关节置换术（THA）不稳定的一个促成因素。术前识别有风险的 THA 患者仍然是一个尚未解决的挑战。因此，我们进行了这项研究，目的是：（1）评估术前和术后脊柱骨盆活动度是否不同；（2）确定脊柱骨盆复合体各元素之间的相互作用；（3）确定预测脊柱骨盆活动度的术前参数。
对 197 例接受双平面立体射线照相术的 THA 患者进行前瞻性观察研究，术前和术后分别在站立位和放松坐姿下进行。两名独立的研究者根据两种不同的分类（Δ骶骨倾斜度[SS]和Δ骨盆倾斜度[PT]；站立位到坐位的Δ；Δ<10°僵硬，Δ≥10°-30°正常，Δ>30°活动过度）来确定脊柱骨盆活动度。使用多元回归分析和受试者工作特征分析来识别术后脊柱骨盆活动度的预测因子。
THA 后，脊柱骨盆活动度显著增加，基于ΔPT（术前/术后：18.5°/22.8°；P<0.000）和ΔSS（术前/术后：17.9°/22.4°；P<0.000）。术后观察到僵硬到活动过度的比例明显变化（术前/术后：24%/9.7%）。受试者工作特征分析预测术后僵硬使用术前 PT≥13.0°，灵敏度为 90%，特异性为 51%，使用术前 SS≥35.2°预测术后活动过度，灵敏度为 81%，特异性为 34%。手术时的年龄、术前 PT 和骨盆入射角是脊柱骨盆活动度的独立预测因子（R=0.24）。
关节置换外科医生应谨慎解读术前僵硬的定义，因为活动度本身受 THA 的影响。首次为预测术后脊柱骨盆活动度提供了站立术前参数的阈值。对于术前仅站立位评估，侧位评估可以作为脊柱骨盆活动度的筛查工具。
