LIV selection in selective thoracic fusions

Transcription

1 Russian Research Institute for Traumatology and Orthopedics named after R.R.Vreden, St.Petersburg LIV selection in selective thoracic fusions Ptashnikov D. Professor, The chief of spine surgery & oncology of Russian Research Institute of Traumatology and Orthopedics named after R.R. Vreden The chief of orthopedic department of Nord-West State Medical University named after I.I.Mechnikov North-West Medical University named after I.I.Mechnikov St.Petersburg, Russia

2 The goals of surgery for AIS 1. Halt curve progression and correct deformity 2. Maintain a balanced spine in the coronal and sagittal planes 3. Preserve as many mobile spinal segments as possible BACKGROUND 4. Prevent surgical complications such as junctional kyphosis, adding-on, and revision surgery Fischer C. R., Kim Y. Selective fusion for adolescent idiopathic scoliosis: a review of current operative strategy //European Spine Journal. 2011

3 BACKGROUND Lowest instrumented vertebra (LIV) selection - is determination of the distal end of the fusion. LIV selection is crucial because is highly correlated with post-op outcome. Inappropriate LIV selection can result in aggravation of the unfused curve, distal adding on, or spinal imbalance. Newton PO, Faro FD, Lenke LG, et al. Spine. 2003;28(20):S217 S223. Newton PO, Upasani VV, Bastrom TP, et al. Spine. 2009;34(10):

4 Factors for selective fusion of thoracic curves Fischer C. R., Kim Y. Selective fusion for adolescent idiopathic scoliosis: a review of current operative strategy //European Spine Journal. 2011

5 Factors for selective fusion of thoracolumbar/lumbar curves Fischer C. R., Kim Y. Selective fusion for adolescent idiopathic scoliosis: a review of current operative strategy //European Spine Journal. 2011

6 Factors for LIV selective - Choosing LAV or a vertebra below LAV as LIV can significantly improve the deviation of the lumbar curve, while choosing a vertebra above LAV as LIV cannot. Wang Y. et al. European Spine Journal SV, LEV and NV are commonly used for determining LIV Schlechter J, Newton P, Upasani V et al (2009) American association of orthopaedic surgeons annual meeting, p 130. Parisini P, Di Silvestre M, Lolli F, et al. Eur Spine J. 2009;18(Suppl 1):82 88.

7 Bending-test /16 LIV T12? <5 0 LIV L1 Ni H. J. et al. Using side-bending radiographs to determine the distal fusion level in patients with single thoracic idiopathic scoliosis undergoing posterior correction with pedicle screws //Journal of spinal disorders & techniques. 2011

8 Bending-test m/15 LIV T12? < rigid lumbar curve LIV L3 Ni H. J. et al. Using side-bending radiographs to determine the distal fusion level in patients with single thoracic idiopathic scoliosis undergoing posterior correction with pedicle screws //Journal of spinal disorders & techniques. 2011

9 The most cephalad lumbar vertebra that is intersected by the CSVL and neutral in rota9on. LIV Lenke 1,2 A,B The LIV will usually fall between the end vertebra of the main thoracic curve and the stable vertebra. LIV CSVL

10 LIV Lenke 1,2 C Lumbar modifier C curves are eligible for selective thoracic fusions LIV (T11-L1) CSVL

11 Ries Z. et al. Selective Thoracic Fusion of Lenke I and II Curves Affects Sagittal Profiles But Not Sagittal or Spinopelvic Alignment: A Case-Control Study //Spine. 2015

12 Characteristics of Sagittal Vertical Alignment in Adolescent Idiopathic Scoliosis Ries Z. et al. Selective Thoracic Fusion of Lenke I and II Curves Affects Sagittal Profiles But Not Sagittal or Spinopelvic Alignment: A Case-Control Study //Spine. 2015

13 LIV Lenke 3,4,5 A,B and Lenke 6 L3-4 AO Surgery Reference

14 LIV L3 Lenke 3,4,5 A,B and Lenke 6 v The L3- L4 disc is parallel or closed on the convexity v L3 is neutral or no more than grade 1 rota9on v On opposite side bending L3 centers and horizontalize on the sacrum L3 AO Surgery Reference

15 LIV Lenke 3,4,5 C stable vertebra (T11-L1) AO Surgery Reference

16 Lenke 3,6C: short vs. classic LAV Group A - the LIV was above the LAV Group B - the LIV was at the LAV Group C - the LIV was below the LAV Wang Y. et al. Lowest instrumented vertebra selection in Lenke 3C and 6C scoliosis: what if we choose lumbar apical vertebra as distal fusion end? // European Spine Journal. 2012

17 Lenke 3,6C: short vs. classic Group A - the LIV was above the LAV Group B - the LIV was at the LAV Group C - the LIV was below the LAV Wang Y. et al. Lowest instrumented vertebra selection in Lenke 3C and 6C scoliosis: what if we choose lumbar apical vertebra as distal fusion end? // European Spine Journal. 2012

18 Algorithm of surgery Phan P. et al. A rule-based algorithm can output valid surgical strategies in the treatment of AIS //European Spine Journal. 2015

19 Algorithm of surgery Phan P. et al. A rule-based algorithm can output valid surgical strategies in the treatment of AIS //European Spine Journal. 2015

20 Posterior selection surgery Phan P. et al. A rule-based algorithm can output valid surgical strategies in the treatment of AIS //European Spine Journal. 2015

21 Conclusion v Selective AIS fusion allows preserve mobile spinal segments. v Selective thoracic fusions (UIV & LIV) should be performed after careful consideration of curve magnitudes apical vertebral rotation and translation, sagittal profile and clinical deformity assessment (angle of truncal rotation, waist line asymmetry, shoulder balance, skeletal maturity). v In case of failure we have ability to extent the fusion.

22 Russian Research Institute for Traumatology and Orthopedics named after R.R.Vreden, St.Petersburg North-West Medical University named after I.I.Mechnikov St.Petersburg, Russia