Department of Orthopaedic Surgery, University Spine Center Zürich, Balgrist University Hospital, University of Zurich, Forchstrasse 340, 8008, Zurich, Switzerland.
Institute for Biomechanics, Balgrist Campus, ETH Zurich, Lengghalde 5, CH-8008, Zurich, Switzerland.
Eur Spine J. 2023 Jun;32(6):1876-1886. doi: 10.1007/s00586-023-07694-5. Epub 2023 Apr 24.
The aim of this study was to elucidate segmental range of motion (ROM) before and after common decompression and fusion procedures on the lumbar spine.
ROM of fourteen fresh-frozen human cadaver lumbar segments (L1/2: 4, L3/4: 5, L5/S1: 5) was evaluated in six loading directions: flexion/extension (FE), lateral bending (LB), lateral shear (LS), anterior shear (AS), axial rotation (AR), and axial compression/distraction (AC). ROM was tested with and without posterior instrumentation under the following conditions: 1) native 2) after unilateral laminotomy, 3) after midline decompression, and 4) after nucleotomy.
Median native ROM was FE 6.8°, LB 5.6°, and AR 1.7°, AS 1.8 mm, LS 1.4 mm, AC 0.3 mm. Unilateral laminotomy significantly increased ROM by 6% (FE), 3% (LB), 12% (AR), 11% (AS), and 8% (LS). Midline decompression significantly increased these numbers to 15%, 5%, 21%, 20%, and 19%, respectively. Nucleotomy further increased ROM in all directions, most substantially in AC of 153%. Pedicle screw fixation led to ROM decreases of 82% in FE, 72% in LB, 42% in AR, 31% in AS, and 17% in LS. In instrumented segments, decompression only irrelevantly affected ROM.
The amount of posterior decompression significantly impacts ROM of the lumbar spine. The here performed biomechanical study allows creation of a simplified rule of thumb: Increases in segmental ROM of approximately 10%, 20%, and 50% can be expected after unilateral laminotomy, midline decompression, and nucleotomy, respectively. Instrumentation decreases ROM by approximately 80% in bending moments and accompanied decompression procedures only minorly destabilize the instrumentation construct.
本研究旨在阐明腰椎常见减压融合术后节段活动范围（ROM）。
对 14 个新鲜冷冻人体腰椎节段（L1/2：4，L3/4：5，L5/S1：5）的 ROM 进行了评估，评估方向有六个：屈伸（FE）、侧屈（LB）、侧方剪切（LS）、前剪切（AS）、轴向旋转（AR）和轴向压缩/拉伸（AC）。ROM 在以下条件下进行了测试，分别有无后路器械固定：1）正常状态；2）单侧椎板切开术后；3）正中减压后；4）髓核切除术后。
中位正常 ROM 为 FE 6.8°，LB 5.6°，AR 1.7°，AS 1.8mm，LS 1.4mm，AC 0.3mm。单侧椎板切开术使 ROM 增加了 6%（FE）、3%（LB）、12%（AR）、11%（AS）和 8%（LS）。正中减压术使这些数值分别增加到 15%、5%、21%、20%和 19%。髓核切除术后进一步增加了所有方向的 ROM，其中 AC 增加了 153%。椎弓根螺钉固定使 FE 减少了 82%，LB 减少了 72%，AR 减少了 42%，AS 减少了 31%，LS 减少了 17%。在器械固定的节段中，减压仅对 ROM 产生轻微影响。
后路减压的程度对腰椎 ROM 有显著影响。本生物力学研究可制定一条简化的经验法则：单侧椎板切开术、正中减压术和髓核切除术分别可使节段 ROM 增加约 10%、20%和 50%。器械固定使 ROM 减少约 80%，同时伴随减压的处理仅会轻微破坏器械的稳定性。
