General University Hospital of Castellon, Castellon, Spain.
University of Valencia, Valencia, Spain.
Clin Biomech (Bristol). 2024 Feb;112:106185. doi: 10.1016/j.clinbiomech.2024.106185. Epub 2024 Jan 17.
Most total disc replacements provide excessive mobility and not reproduce spinal kinematics, inducing zygapophyseal joint arthritic changes and chronic back pain. In cadaveric lumbosacral spines, we studied if a new lumbar disc prosthesis kinematics mimics the intact intervertebral disc.
In eight cold preserved cadaveric lumbosacral spines, we registered the movement ranges in flexion, extension, right and left lateral bending, and rotation in the intact status, post-discectomy, and after our prosthesis implantation, comparing them for each specimen.
Comparing the intact lumbosacral spine with the L-L prosthesis implanted specimens, we saw statistically significant differences in lateral bending and right rotation but not in the full range of rotation. Analyzing segments, we also noticed statistically significant differences at L-L in flexion-extension and rotation. On the other hand, the L-L discectomy, compared to the baseline spine condition, showed a statistically significant mobility increase in flexion, extension, lateral bending, and axial rotation, with an abnormal instantaneous center of rotation, which destabilizes the segment partly due to anterior annulus surgical removal. Disc prosthesis implantation reversed these changes in instantaneous center of rotation, but the prosthesis failed to restore the initial range of motion due to the destabilization of the ligaments in the operated disc.
The ADDISC total disc replacement reproduces the intact disc kinematics and Instantaneous Center of Rotation, but the prosthesis fails to restore the initial range of motion due to ligament destabilization. More studies will be necessary to define a technique that restores the damaged ligaments when implanting the prosthesis.
大多数全椎间盘置换提供了过多的活动度，而不能再现脊柱运动学，导致关节突关节关节炎改变和慢性背痛。在尸体腰骶部脊柱中，我们研究了一种新的腰椎间盘假体运动学是否能模拟完整的椎间盘。
在 8 个冷藏保存的尸体腰骶部脊柱中，我们在完整状态、椎间盘切除术后和我们的假体植入后，记录了每个标本在屈伸、左右侧屈和旋转方面的运动范围，并对每个标本进行了比较。
将完整的腰骶部脊柱与植入的 L-L 假体标本进行比较，我们发现侧屈和右旋转方面存在统计学显著差异，但在全旋转范围内没有差异。分析节段时，我们还注意到在屈伸和旋转方面 L-L 也存在统计学显著差异。另一方面，与基线脊柱状态相比，L-L 椎间盘切除术在屈伸、侧屈和轴向旋转方面显示出统计学显著的活动度增加，瞬时旋转中心异常，这部分由于前环手术切除导致节段不稳定。椎间盘假体植入术逆转了瞬时旋转中心的这些变化，但由于韧带在手术节段的不稳定，假体未能恢复初始运动范围。
ADDISC 全椎间盘置换可再现完整椎间盘的运动学和瞬时旋转中心，但由于韧带不稳定，假体未能恢复初始运动范围。需要进一步研究以确定在植入假体时恢复受损韧带的技术。
