St. Mary's Medical Center, San Francisco Orthopaedic Residency Program, San Francisco, CA.
The Taylor Collaboration, San Francisco, CA.
Spine (Phila Pa 1976). 2021 Apr 15;46(8):E467-E473. doi: 10.1097/BRS.0000000000003841.
An in-vitro biomechanical study of human cadaver sacroiliac joints.
Our study aimed to develop a more comprehensive understanding of the native motion of the SIJ within the context of spinal kinematics and spinal implant evaluation.
Increasing attention has been given to the sacroiliac joint (SIJ) as a source of low back pain, despite its limited range of motion. We sought to characterize the rotational and translational motion in each axis utilizing standard pure moment flexion-extension (FE), lateral bending (LB), and axial rotation (AR) testing.
Sixteen sacroiliac joints were evaluated from eight lumbosacral cadaver specimens (six females, two males) from subjects aged 28 to 57 years (mean age 46.8) with body mass index (BMI) 22 to 36 (mean BMI 30). Single leg stance was modeled by clamping the blocks on one ischium in a vise and letting the contralateral ischium hang freely. Pure moment loading was applied in FE, right/left AR, and right/left LB. Relative motions were collected with infrared markers.
The on-axis ratio was significantly lower in LB than in FE (P = 0.012) and in AR (P = 0.017). The rotation deviation angle measured 13.9 ± 9.1° in FE, 17.1 ± 8.7° in AR, and 35.7 ± 25.7° in LB. In LB the rotational deviation angle is significantly higher than both FE and AR (P = 0.003 and P = 0.011, respectively). In-plane translation was significantly higher (P = 0.005) in FE loading than in LB loading.
A nontrivial amount of rotation and translation occurred out of the expected axis of motion. The largest amount of off-axis rotation was observed in lateral bending. Relative to resultant translation, in-plane translation was lowest in lateral bending. Our results indicate that rotation of the SIJ is not fully described with the in-plane metrics which are normally reported in evaluation of fusion devices. Future studies of the SIJ may need to consider including off-axis rotation measurements when describing SIJ kinematics.Level of Evidence: 5.
人体尸骸骶髂关节的体外生物力学研究。
我们的研究旨在更全面地了解 SIJ 在脊柱运动学和脊柱植入物评估背景下的固有运动。
尽管骶髂关节 (SIJ) 的活动范围有限，但人们对其作为腰痛源的关注度越来越高。我们试图利用标准纯力矩屈伸（FE）、侧屈（LB）和轴向旋转（AR）测试来描述每个轴的旋转和平移运动。
从 28 至 57 岁（平均年龄 46.8）、体重指数（BMI）为 22 至 36（平均 BMI 为 30）的 8 具腰骶尸体标本的 16 个骶髂关节进行评估。单腿站立通过将一个坐骨夹在虎钳中并让对侧坐骨自由悬挂来模拟。FE、右/左 AR 和右/左 LB 中施加纯力矩加载。用红外标记收集相对运动。
在 LB 中，与 FE（P = 0.012）和 AR（P = 0.017）相比，同轴比明显较低。FE 中测量的旋转偏差角度为 13.9 ± 9.1°，AR 中为 17.1 ± 8.7°，LB 中为 35.7 ± 25.7°。在 LB 中，旋转偏差角度明显高于 FE 和 AR（分别为 P = 0.003 和 P = 0.011）。FE 加载时的平面内平移明显高于 LB 加载（P = 0.005）。
超出预期运动轴的旋转和平移量相当大。在侧屈时观察到最大的偏轴旋转。相对于总平移，在侧屈时，平面内平移最小。我们的结果表明，SIJ 的旋转不能仅通过通常在融合装置评估中报告的平面内指标来充分描述。当描述 SIJ 运动学时，SIJ 的后续研究可能需要考虑包括偏轴旋转测量。
5 级。
