PURPOSE: Restoring sagittal alignment is an important factor in the treatment of spinal deformities. Recent investigations have determined that releasing the anterior longitudinal ligament (ALL) and placing hyperlordotic cages can increase lordosis, while minimizing need for 3 column osteotomies. The influences of parameters such as cage height and angle have not been determined. Finite element analysis was employed to assess the extent of lordosis achievable after placement of different sized lordotic cages. METHODS: A 3-dimensional model of a L3-4 segment was used. Disc distraction was simulated by inserting interbody cages mid-body in the disc space. Analyses were performed in the following conditions: (1) intact, (2) ALL release, (3) ALL release + facetectomy, and (4) ALL release + posterior column osteotomy. Changes in segmental lordosis, disc height, foraminal height, and foraminal area were measured. RESULTS: After ALL resection and insertion of hyperlordotic cages, lordosis was increased in all cases. The lordosis achieved by the shorter cages was less due to posterior disc height maintained by the facet joints. A facetectomy increased segmental lordosis, but led to contact between the spinous processes. For some configurations, a posterior column osteotomy was required if the end goal was to match cage angle to intradiscal angle. CONCLUSION: Increased segmental lumbar lordosis is achievable with hyperlordotic cages after ALL resection. Increased cage height tended to increase the amount of lordosis achieved, although in some cases additional posterior bone resection was required to maximize lordosis. Further studies are needed to evaluate the impact on regional lumbar lordosis.
PURPOSE: Restoring sagittal alignment is an important factor in the treatment of spinal deformities. Recent investigations have determined that releasing the anterior longitudinal ligament (ALL) and placing hyperlordotic cages can increase lordosis, while minimizing need for 3 column osteotomies. The influences of parameters such as cage height and angle have not been determined. Finite element analysis was employed to assess the extent of lordosis achievable after placement of different sized lordotic cages. METHODS: A 3-dimensional model of a L3-4 segment was used. Disc distraction was simulated by inserting interbody cages mid-body in the disc space. Analyses were performed in the following conditions: (1) intact, (2) ALL release, (3) ALL release + facetectomy, and (4) ALL release + posterior column osteotomy. Changes in segmental lordosis, disc height, foraminal height, and foraminal area were measured. RESULTS: After ALL resection and insertion of hyperlordotic cages, lordosis was increased in all cases. The lordosis achieved by the shorter cages was less due to posterior disc height maintained by the facet joints. A facetectomy increased segmental lordosis, but led to contact between the spinous processes. For some configurations, a posterior column osteotomy was required if the end goal was to match cage angle to intradiscal angle. CONCLUSION: Increased segmental lumbar lordosis is achievable with hyperlordotic cages after ALL resection. Increased cage height tended to increase the amount of lordosis achieved, although in some cases additional posterior bone resection was required to maximize lordosis. Further studies are needed to evaluate the impact on regional lumbar lordosis.
Authors: Christine R Baldus; Keith H Bridwell; Lawrence G Lenke; Gbolahan O Okubadejo Journal: Spine (Phila Pa 1976) Date: 2010-01-15 Impact factor: 3.468
Authors: Giuseppe Costanzo; Carmine Zoccali; Philip Maykowski; Christina M Walter; Jesse Skoch; Ali A Baaj Journal: Eur Spine J Date: 2014-09-13 Impact factor: 3.134
Authors: Jacob M Buchowski; Keith H Bridwell; Lawrence G Lenke; Craig A Kuhns; Ronald A Lehman; Youngjung J Kim; David Stewart; Chris Baldus Journal: Spine (Phila Pa 1976) Date: 2007-09-15 Impact factor: 3.468
Authors: Behrooz A Akbarnia; Gregory M Mundis; Payam Moazzaz; Nima Kabirian; Ramin Bagheri; Robert K Eastlack; Jeff B Pawelek Journal: J Spinal Disord Tech Date: 2014-02
Authors: Jotham C Manwaring; Konrad Bach; Amir A Ahmadian; Armen R Deukmedjian; Donald A Smith; Juan S Uribe Journal: J Neurosurg Spine Date: 2014-03-14
Authors: Luigi La Barbera; Hans-Joachim Wilke; Christian Liebsch; Tomaso Villa; Andrea Luca; Fabio Galbusera; Marco Brayda-Bruno Journal: Eur Spine J Date: 2019-08-14 Impact factor: 3.134
Authors: Nathan Han; Nathan Pratt; M Farooq Usmani; Erik Hayman; Salazar Jones; Parker Johnsen; Alexandra E Thomson; Ivan Ye; Timothy Chryssikos; Ashish Sharma; Joshua Olexa; Daniel L Cavanaugh; Eugene Y Koh; Kendall Buraimoh; Steven Ludwig; Charles Sansur Journal: Eur Spine J Date: 2022-01-03 Impact factor: 2.721
Authors: Jakub Godzik; Bernardo de Andrada Pereira; Courtney Hemphill; Corey T Walker; Joshua T Wewel; Jay D Turner; Juan S Uribe Journal: Global Spine J Date: 2020-05-28
Authors: Stavros Oikonomidis; Vincent Heck; Sonja Bantle; Max Joseph Scheyerer; Christoph Hofstetter; Stefan Budde; Peer Eysel; Jan Bredow Journal: Int Orthop Date: 2020-07-13 Impact factor: 3.075
Authors: Jacob Januszewski; Joshua M Beckman; Jeffrey E Harris; Alexander W Turner; Chun Po Yen; Juan S Uribe Journal: Surg Neurol Int Date: 2017-09-06