Ideal sagittal profile restoration and ideal lumbar apex positioning play an important role in postoperative mechanical complications after a lumbar PSO.


Pizones J., Perez-Grueso F. J. S. , Moreno-Manzanaro L., Vila-Casademunt A., Boissiere L., Yilgor C. , ...More

Spine deformity, vol.8, pp.491-498, 2020 (Journal Indexed in ESCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 8
  • Publication Date: 2020
  • Doi Number: 10.1007/s43390-019-00005-3
  • Title of Journal : Spine deformity
  • Page Numbers: pp.491-498
  • Keywords: Pedicle subtraction osteotomy, Sagittal alignment, Roussouly sagittal profile, Lumbar distribution, Mechanical complications, PEDICLE SUBTRACTION OSTEOTOMY, PROXIMAL JUNCTIONAL KYPHOSIS, 3-COLUMN OSTEOTOMY, RISK-FACTORS, DEFORMITY, ALIGNMENT, PARAMETERS, SPINE, IMBALANCE, SURGERY

Abstract

Study designRetrospective analysis of prospectively collected data.ObjectiveTo determine the influence of postoperative ideal lordosis distribution and ideal sagittal harmony on mechanical complications in patients undergoing one-level lumbar pedicle subtraction osteotomy (L-PSO).Summary of background dataMany variables have been associated with mechanical complications after L-PSO. However, the impact of restoring the ideal inflexion point, lumbar apex, and sagittal shape is still underexplored.MethodsAnalyzed risk factors were: age and patient-related variables, PSO level, interbody cages, rod material/diameter, number of rods, upper instrumented vertebra, lower instrumented vertebra, PI-LL mismatch, global tilt (GT), postoperative level of lumbar apex (LApex), postoperative level of inflexion point (InfxP), and postoperative type of Roussouly sagittal profile (R-type). These last variables were compared to ideal (based on pelvic incidence). Univariate and multivariate analyses were performed to identify risks for mechanical complications with a minimum 2-year follow-up.ResultsA total of 87 patients were included. Mean follow-up was 4.51.7 years. 40.2% of the patients suffered postoperative mechanical complications (7 PJK, 4 PJF, 18 pseudoarthrosis/rod breakage, 6 screw pullout). Mean time for complications was 584416 days from surgery. Univariate analysis showed that age (63 vs 57 years; P=0.04), BMI (28.1 vs 25.9; P=0.024), preoperative-GT (50.7 degrees vs 38.7 degrees; P<0.001), postoperative-GT (28.9 degrees vs 23.4 degrees; P=0.018), postoperative LApex location mismatched from ideal (77.8% vs 22.2%; P=0.036), and postoperative R-type mismatched from ideal (67.6% vs 22.6%; P<0.001) were significantly related to mechanical complications. The independent factors selected by multivariate analysis were: postoperative R-type mismatched from ideal OR 11.3 (95% CI 3.9-32.6; P<0.001), age OR 1.05 (95% CI 1-1.1; P=0.03), and LApex matching OR 0.5 (95% CI 0.27-0.97; P=0.04). The further the LApex was from its ideal position, the higher the risk of mechanical complications (P=0.036).Conclusions Over other multiple suspected risk factors, proper lumbar apex position and ideal sagittal shape restoration played an important role in postoperative mechanical complications after L-PSO.Level of evidence III.