STUDY DESIGN: Basic scientific investigation employing the medical imaging techniques of contrast-enhanced plane film radiographs and computed tomography in addition to gross dissection techniques on a sample of spines. OBJECTIVE: To document the specific posterior/posterolateral pathway of mechanically-induced intervertebral disc (IVD) herniation as the result of repetitive loading and disc geometry. SUMMARY OF BACKGROUND DATA: In vitro cadaveric and animal investigations have indicated that the posterior/posterolateral aspects of the IVD are most susceptible to damage leading to herniation, and that cyclic bending is the most potent variable influencing herniation. The IVD in horizontal cross-section ranges in shape from ovoid to limacon (kidney-shaped) which influences stress distributions. The purpose of this investigation was to determine the role of the IVDs shape and size on influencing the pathway of herniation. METHODS: Compressive loads (1472 N) in conjunction with 7000 repetitive cycles of flexion-extension were applied to 22 porcine motion segments. Computed tomography images and contrast-enhanced plane file radiographs, in addition to dissection techniques were used to evaluate the progression of herniations. A logistical regression assessed the links between endplate size and shape, and the probability of a specific herniation type (directionally diffuse or directionally concentrated). RESULTS: A total of 18 out of the 22 specimens exhibited detectable anular damage in the posterior/posterior lateral direction. Of the 18 specimens, 17 were partial herniations while one incurred a full herniation. IVD shape was found to be predictive of the pathway of herniation (P = 0.0329); oval IVD shapes were more likely to herniate in a directionally diffuse manner (6/18), while limacon IVDs were more likely to herniate in a directionally concentrated manner (12/18). CONCLUSION: The shape of the IVD appears to be predictive of the pathway of IVD herniation.
STUDY DESIGN: Basic scientific investigation employing the medical imaging techniques of contrast-enhanced plane film radiographs and computed tomography in addition to gross dissection techniques on a sample of spines. OBJECTIVE: To document the specific posterior/posterolateral pathway of mechanically-induced intervertebral disc (IVD) herniation as the result of repetitive loading and disc geometry. SUMMARY OF BACKGROUND DATA: In vitro cadaveric and animal investigations have indicated that the posterior/posterolateral aspects of the IVD are most susceptible to damage leading to herniation, and that cyclic bending is the most potent variable influencing herniation. The IVD in horizontal cross-section ranges in shape from ovoid to limacon (kidney-shaped) which influences stress distributions. The purpose of this investigation was to determine the role of the IVDs shape and size on influencing the pathway of herniation. METHODS: Compressive loads (1472 N) in conjunction with 7000 repetitive cycles of flexion-extension were applied to 22 porcine motion segments. Computed tomography images and contrast-enhanced plane file radiographs, in addition to dissection techniques were used to evaluate the progression of herniations. A logistical regression assessed the links between endplate size and shape, and the probability of a specific herniation type (directionally diffuse or directionally concentrated). RESULTS: A total of 18 out of the 22 specimens exhibited detectable anular damage in the posterior/posterior lateral direction. Of the 18 specimens, 17 were partial herniations while one incurred a full herniation. IVD shape was found to be predictive of the pathway of herniation (P = 0.0329); oval IVD shapes were more likely to herniate in a directionally diffuse manner (6/18), while limacon IVDs were more likely to herniate in a directionally concentrated manner (12/18). CONCLUSION: The shape of the IVD appears to be predictive of the pathway of IVD herniation.
Authors: John M Peloquin; Jonathon H Yoder; Nathan T Jacobs; Sung M Moon; Alexander C Wright; Edward J Vresilovic; Dawn M Elliott Journal: J Biomech Date: 2014-04-18 Impact factor: 2.712
Authors: Cornelis P L Paul; Magda de Graaf; Arno Bisschop; Roderick M Holewijn; Peter M van de Ven; Barend J van Royen; Margriet G Mullender; Theodoor H Smit; Marco N Helder Journal: PLoS One Date: 2017-04-06 Impact factor: 3.240
Authors: Friska Natalia; Hira Meidia; Nunik Afriliana; Julio Christian Young; Reyhan Eddy Yunus; Mohammed Al-Jumaily; Ala Al-Kafri; Sud Sudirman Journal: PLoS One Date: 2020-11-02 Impact factor: 3.240