Migliorini Filippo, Baroncini Alice, El Mansy Yasser, Quack Valentin, Prescher Andreas, Mischer Max, Greven Johannes, Tingart Markus, Eschweiler Jörg
Department of Orthopaedic Surgery, RWTH Aachen University Hospital, Pauwelsstraße 30, 52074, Aachen, Germany.
Department of Trauma Surgery, RWTH Aachen University Hospital, Aachen, Germany.
BMC Musculoskelet Disord. 2021 Mar 6;22(1):250. doi: 10.1186/s12891-021-04112-z.
A novel implant for occipitocervical fusion consisting of a median plate with an additional hook inserting in the foramen magnum was tested. Aim of this study was to test the stability of a new implant for occipitocervical fusion against the already available and employed median plate implant without hook.
36 rigid polyurethane foams occipital artificial bones were used. The two occipital implants, namely the occipital plate with hook (Group 1) and the one without hook (Group 2), were applied to the artificial occiput trough three occipital screws and ensured into the experimental setup trough a crossbar. The test parameters were set using the testing machine software as follows: (1) test speed: 10 mm/ min, with 25 mm/ min maximum; (2) preload: 5 N; (3) force switch-off threshold: 90% force drop from F_max. Failure force and path were recorded. Failure force is defined as the maximum reaction force under which failure occurs (F_max), while failure path is the travel path during which failure occurs (dL).
Group 1 (plate with hook) showed a mean failure force of 459.3 ± 35.9 N and a mean failure path of 5.8 ± 0.3 mm Group 2 (plate without hook) showed a mean failure force of 323.9 ± 20.2 N and a mean failure path of 7.2 ± 0.4 mm. The Shapiro-Wilk test score was not significant (P > 0.1), assuming that data were normally distributed. Group 1 had a statistically significant greater F_max (+ 135.37; P > 0.0001) and less dL (- 1.52; P > 0.0001) compared to group 2.
Medial plates with foramen magnum hooks showed to be more stable that plates without a hook. These new implants may represent a new tool in OCJ fixation, but further studies are required to investigate their behavior in an anatomical setting.
测试了一种用于枕颈融合的新型植入物，该植入物由一个中间板和一个插入枕骨大孔的附加钩组成。本研究的目的是测试一种新型枕颈融合植入物相对于已有的无钩中间板植入物的稳定性。
使用36块硬质聚氨酯泡沫枕骨人工骨。将两种枕骨植入物，即带钩枕骨板（第1组）和无钩枕骨板（第2组），通过三根枕骨螺钉应用于人工枕骨槽，并通过横杆固定到实验装置中。使用试验机软件设置测试参数如下：（1）测试速度：10毫米/分钟，最大25毫米/分钟；（2）预载：5牛；（3）力关闭阈值：力从F_max下降90%。记录破坏力和路径。破坏力定义为发生破坏时的最大反作用力（F_max），而破坏路径是发生破坏时的行程路径（dL）。
第1组（带钩板）的平均破坏力为459.3±35.9牛，平均破坏路径为5.8±0.3毫米；第2组（无钩板）的平均破坏力为323.9±20.2牛，平均破坏路径为7.2±0.4毫米。假设数据呈正态分布，Shapiro-Wilk检验得分不显著（P＞0.1）。与第2组相比，第1组的F_max在统计学上显著更高（+135.37；P＞0.0001），dL更低（-1.52；P＞0.0001）。
带枕骨大孔钩的中间板比无钩板更稳定。这些新型植入物可能代表了枕颈交界固定的一种新工具，但需要进一步研究来调查它们在解剖环境中的行为。
