Biomechanical analysis of Ponte and pedicle subtraction osteotomies for the surgical correction of XXXX .

@entity1 @entity85 @entity71212
PURPOSE: Biomechanical analysis of Ponte (PO) and pedicle subtraction osteotomies ( @entity71212 ) in @entity85 instrumentation. METHODS: @entity1 -specific biomechanical model was used to computationally simulate seven hyperkyphotic instrumentation cases with three osteotomy strategies-1-level @entity71212 , 3-level PO, or 6-level PO; forces within the instrumented spine were assessed and results were analyzed through rANOVA tests. RESULTS: Corrections with multi-level PO were close to those with one-level @entity71212 . In upright position, average implant forces were from 225 to 280  N and rod bending moments were around 10 Nm with no significant difference between the three strategies (p  <  0.05). In simulations of 30   flexion, rod bending moments increased by 38, 2, and 8  %, implant forces increased by 28, 23 and 26  % for the 1-level @entity71212 , respectively. Correction per vertebral level was smaller than the maximum correction allowed by PO and @entity71212 . CONCLUSIONS: Multi-level PO allows similar kyphotic correction to 1-level @entity71212 in @entity85 with mixed indications for PO and @entity71212 . Loads on the instrumentation constructs in @entity71212 were higher than multi-level PO and higher in 6-level PO than 3-level PO. High loads were located more on the osteotomy sites. The rod shape should be adapted to the anticipated spine correction on the osteotomy sites.
