TY - JOUR
T1 - Anterior support reduces the stresses on the posterior instrumentation after pedicle subtraction osteotomy
T2 - a finite-element study
AU - Luca, Andrea
AU - Ottardi, Claudia
AU - Lovi, Alessio
AU - Brayda-Bruno, Marco
AU - Villa, Tomaso
AU - Galbusera, Fabio
PY - 2017/10/1
Y1 - 2017/10/1
N2 - Study design: The investigation was based on finite-element simulations. Objective: Pedicle subtraction osteotomy (PSO) is an effective but technical demanding surgical technique, associated with a high risk of rod failure. The present study aims at investigating the role of the anterior support in combination with PSO, with a numerical comparative analysis. Methods: An osteotomy was simulated at the L3 level of a lumbosacral spine. An implantation of various combinations of devices for the anterior (1 or 2 cages of different material) and posterior stabilization (1 or 2 rods) was then performed. ROM, loads, and stresses acting on the rods were calculated. Results: A 4–8% reduction of the ROM was obtained introducing one or two cages in the instrumented model. However, the anterior support had only a minor influence on the ROM. The load on the posterior instrumentation decreased up to 8% using one cage and about 15% with two anterior devices. A 20–30% reduction of the stresses on the rods was calculated inserting one cage and up to 50% using two cages. Following the introduction of the anterior support, the greatest stress reduction was observed in the model having two cages and spinal fixators with two rods. Conclusions: The use of cages is crucial to ensure anterior support and decrease loads and stresses on the posterior instrumentation.
AB - Study design: The investigation was based on finite-element simulations. Objective: Pedicle subtraction osteotomy (PSO) is an effective but technical demanding surgical technique, associated with a high risk of rod failure. The present study aims at investigating the role of the anterior support in combination with PSO, with a numerical comparative analysis. Methods: An osteotomy was simulated at the L3 level of a lumbosacral spine. An implantation of various combinations of devices for the anterior (1 or 2 cages of different material) and posterior stabilization (1 or 2 rods) was then performed. ROM, loads, and stresses acting on the rods were calculated. Results: A 4–8% reduction of the ROM was obtained introducing one or two cages in the instrumented model. However, the anterior support had only a minor influence on the ROM. The load on the posterior instrumentation decreased up to 8% using one cage and about 15% with two anterior devices. A 20–30% reduction of the stresses on the rods was calculated inserting one cage and up to 50% using two cages. Following the introduction of the anterior support, the greatest stress reduction was observed in the model having two cages and spinal fixators with two rods. Conclusions: The use of cages is crucial to ensure anterior support and decrease loads and stresses on the posterior instrumentation.
KW - Cages
KW - Finite elements
KW - Lumbar spine
KW - Osteotomy
KW - Pedicle subtraction osteotomy
KW - Rods
KW - Spinal fixators
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U2 - 10.1007/s00586-017-5084-9
DO - 10.1007/s00586-017-5084-9
M3 - Article
AN - SCOPUS:85018320721
VL - 26
SP - 450
EP - 456
JO - European Spine Journal
JF - European Spine Journal
SN - 0940-6719
ER -