Department of Orthopaedic Surgery, University of California, Davis, Medical Center, Sacramento, CA 95817, USA.
Spine (Phila Pa 1976). 2010 Aug 15;35(18):1676-83. doi: 10.1097/BRS.0b013e3181c55bcd.
Benchtop biomechanics study examining kinematic effects of progressive resection in a human cadaveric spine model.
To determine the effects of posterior longitudinal ligament (PLL) resection, unilateral and bilateral foraminotomy, and laminectomy on cervical intervertebral rotation and translation after cervical disc arthroplasty (CDA).
Although the clinical results after CDA have been studied, there remain unanswered questions regarding the surgical techniques used at the time of device insertion. For example, it is unclear whether a surgeon should retain or resect the PLL and uncinate processes at the time of primary surgical intervention. Further, the effect of a subsequent posterior decompression (foraminotomy or laminectomy) on the stability of a motion segment containing a disc arthroplasty is unknown.
Three-dimensional intervertebral motion was measured by biplanar videography in human cadaveric spines at C4-C5 or at C5-C6 subjected to a 1.5-Nm moment applied to induce motion in the sagittal plane. Coupled motions were not constrained. After measuring intact spine motion, disc arthroplasty with bilateral ventral foraminotomy was performed without PLL resection. Sequentially, rotations and translations were measured after PLL resection, unilateral foraminotomy, bilateral foraminotomy, and laminectomy.
CDA with bilateral ventral foraminotomy increased sagittal rotation by 0.4 degrees (16%) compared with the intact spine. The addition of PLL resection increased rotation by 0.5 degrees (14% increase). Unilateral and bilateral foraminotomy had negligible effects on sagittal rotation or anteroposterior (AP) translation. Laminectomy resulted in an additional sagittal plane rotation of 2 degrees. The sagittal-plane interverterbal rotation resultant after all interventions was 6 degrees , with 1.5 mm of AP translation occurring only.
Given that a greater degree of motion was seen with PLL resection combined with ventral foraminotomy, we recommend that PLL resection be performed when performing CDA. In our benchtop model, unilateral and bilateral posterior foraminotomies were not associated with the creation of significant sagittal rotational or AP translational instability.
本研究为桌面生物力学研究，通过人体尸体脊柱模型来检验颈椎间盘置换术（CDA）过程中渐进性切除对运动学的影响。
明确后纵韧带（PLL）切除、单侧和双侧椎间孔切开术以及椎板切除术对颈椎间盘置换术后颈椎椎间旋转和移位的影响。
尽管已经对 CDA 的临床结果进行了研究，但在器械插入时使用的手术技术仍存在一些悬而未决的问题。例如，在初次手术干预时，外科医生是否应该保留或切除 PLL 和钩突仍存在争议。此外，后续的后路减压（椎间孔切开术或椎板切除术）对包含椎间盘置换的运动节段稳定性的影响尚不清楚。
通过双平面视频摄像技术在 C4-C5 或 C5-C6 节段的人体尸体脊柱上测量三维椎间运动，施加 1.5N·m 的力矩以诱导矢状面运动。对耦合运动不进行约束。测量完整脊柱运动后，在不切除 PLL 的情况下行双侧腹侧椎间孔切开术的 CDA。随后，在切除 PLL、单侧椎间孔切开术、双侧椎间孔切开术和椎板切除术之后，测量旋转和移位。
与完整脊柱相比，双侧腹侧椎间孔切开术的 CDA 增加了 0.4 度（16%）的矢状面旋转。PLL 切除增加了 0.5 度（14%的增加）。单侧和双侧椎间孔切开术对矢状面旋转或前后（AP）移位几乎没有影响。椎板切除术导致矢状面额外旋转 2 度。所有干预后的矢状面椎间旋转总和为 6 度，仅出现 1.5 毫米的 AP 移位。
鉴于 PLL 切除联合腹侧椎间孔切开术会导致更大程度的运动，因此我们建议在进行 CDA 时应切除 PLL。在我们的桌面模型中，单侧和双侧后路椎间孔切开术不会导致明显的矢状面旋转或 AP 不稳定。
