Biomechanical Evaluation of the Kinematics of the Cadaver Lumbar Spine Following Disc Replacement With the Prodisc-L Prosthesis
Biomechanical Evaluation of the Kinematics of the Cadaver Lumbar Spine Following Disc Replacement With the Prodisc-L Prosthesis
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DOI：
10.1097/brs.0b013e3181c4eb9a
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发表时间：
2010-01-01
期刊：
影响因子：
3
通讯作者：
Herkowitz, Harry N.
中科院分区：
文献类型：
--
作者：
Demetropoulos, Constantine K.;Sengupta, Dilip K.;Herkowitz, Harry N.
研究设计. ProDisc-L在纯力矩载荷下在尸体模型中的生物力学研究。确定尸体脊柱ProDisc-L椎间盘置换术后腰椎运动节段和相邻节段的运动学特性。背景数据总结。全椎间盘置换术旨在保留自体运动，以防止相邻节段加速退变。TDR后关节活动的质量和数量对同一运动节段的小关节以及假体组件界面的运动有重要影响。对10个尸体腰椎进行X线摄影（L3-L5），并在纯力矩（+10 Nm至-10 Nm）和施加的从动载荷（200 N）下进行测试。在屈曲/伸展、侧弯（LB）和轴向旋转（AR）中测试载荷-变形。记录活动度（ROM）数据。使用超小型压力传感器测量上级相邻椎间盘压力（L3-L4）。随后使用ProDisc-L对L4-L5椎间盘进行内固定。重复进行X线片和生物力学测试。椎间盘置换术显著降低了伸展（内固定前ROM为2.2 ° ± 0.5 °，内固定后为1.2 ° ± 0.7 °）（P = 0.001），但未降低屈曲（内固定前ROM为5.6 ° ± 3.1 °，内固定后为6.2 ° ± 1.2 °）（P = 0.34）。屈曲/伸展联合运动略微减少（P = 0.517）。LB ROM（7.4度+/- 2.0度）在内固定（6.2度+/- 2.5度）后略微降低（P = 0.072），而AR的ROM（3.4度+/- 1.1度）显著增加（4.4度+/- 1.2度）（P = 0.001）。相邻节段上级活动度得以保留，相邻节段的椎间盘压力在置换前（最大屈曲时199 kPa，最大伸展时171 kPa）和置换后（分别为52 kPa和208 kPa）均无显著差异。在尸体脊柱中，ProDisc-L插入后保留了手术节段和相邻运动节段的ROM。切除前环可能会增加松弛，这是通过恢复椎间盘高度和脊柱前凸来实现的，代价是屈曲/伸展运动中度丧失。TDR后相邻节段运动学未受影响。
Study Design. Biomechanical study of the ProDisc-L in a cadaveric model under pure moment loading.Objective. To determine the kinematic properties of a lumbar spine motion segment and the adjacent level following ProDisc-L disc replacement in the cadaveric spine.Summary of Background Data. Total disc replacement is intended to preserve native motion, in an attempt to prevent accelerated adjacent segment degeneration. The quality and quantity of the motion following TDR may have important consequences on the facet joints of the same motion segment, as well as the motion at the prosthetic component interface.Methods. Ten cadaveric lumbar spines were radio-graphed (L3-L5) and tested under pure moments (+10 Nm to -10 Nm) with an applied follower load (200 N). Load-deformation was tested in flexion/extension, lateral bending (LB), and axial rotation (AR). Range of Motion (ROM) data were recorded. Superior adjacent disc pressure (L3-L4) was measured using subminiature pressure transducers. The L4-L5 disc was subsequently instrumented with a ProDisc-L. Radiographs and biomechanical tests were repeated.Results. Disc replacement significantly reduced extension (ROM 2.2 degrees +/- 0.5 degrees before and 1.2 degrees +/- 0.7 degrees after instrumentation) (P = 0.001), but not flexion (ROM 5.6 degrees +/- 3.1 degrees before and 6.2 degrees +/- 1.2 degrees after) (P = 0.34). Combined flexion/extension motion was marginally reduced (P = 0.517). LB ROM (7.4 degrees +/- 2.0 degrees) was marginally reduced (P = 0.072) following instrumentation (6.2 degrees +/- 2.5 degrees), while ROM in AR (3.4 degrees +/- 1.1 degrees) was significantly increased (4.4 degrees +/- 1.2 degrees) (P = 0.001). Superior adjacent segment ROM was preserved.No significant differences in disc pressure were observed at the adjacent motion segment before (199 kPa at maximum flexion and 171 kPa at maximum extension) or after disc replacement (52 kPa and 208 kPa, respectively).Conclusion. In cadaveric spines, ROM of operated and adjacent motion segments was preserved following ProDisc-L insertion. Excision of the anterior anulus may increase laxity, which is taken up by the restoration of disc height and lordosis, at the cost of a moderate loss of flexion/extension motion. Adjacent segment kinematics were unaffected following TDR.