General Session: Adult Spinal Deformity
Presented by: J. Paluzzi - View Audio/Video Presentation (Members Only)
J. Paluzzi(1), A. Vivas(1), C.-P. Yen(1), J. Janeszewski(1), K. Bach(1), B. Osburn(1), M. Greenberg(1), D. Smith(1), J. Uribe(1)
(1) University of South Florida, Neurosurgery, Tampa, FL, United States
Purpose: Minimally invasive lateral approaches to the lumbar spine have increased the capability of anterior column reconstruction (ACR) in the treatment of adult spinal deformity (ASD). Anterior longitudinal ligament (ALL) release with placement of hyperlordotic interbody cages can increase lumbar lordosis (LL) and restore the sagittal vertical axis (SVA) to a neutral position while reducing the need for three-column osteotomies. Here, we review our experience with minimally invasive lateral approach ACR in the long term preservation of spinopelvic parameters.
Methods: Our patient database was queried from 2010 to 2015 for ASD patients treated surgically with ACR. Patient demographics, surgical course, clinical outcomes, and radiographic data were recorded and retrospectively reviewed. Patients with at least 1 year of postoperative follow up were included. Spinopelvic parameters (LL, SVA, pelvic incidence [PI], pelvic tilt [PT]) were recorded preoperatively and at most recent follow up. Segmental lordosis at the level of ALL release was recorded pre- and postoperatively.
Results: 31 patients undergoing ACR for ASD were followed for an average of 20 months (range: 11-49). 43 ALL releases were performed in total with an average increase in segmental lordosis of 12.9o. Performing a posterior osteotomy during a staged procedure was associated with an additional 6.5o of lordosis per level (p = 0.025). At last follow up, lumbar lordosis was increased by an average of 19.5o. SVA was improved by an average of 2.3 cm for all patients, and 3.3 cm for those who presented with sagittal imbalance (SVA > 5cm). PI-LL mismatch was improved by 12.2o. Patients receiving posterior osteotomies trended towards greater improvement in lumbar lordosis (25.8o vs 17.7o) and greater reduction of sagittal imbalance (-4.2 vs -1.7), but also increased risk of cage subsidence (14.3% vs 12.5%) and radiographic proximal junctional kyphosis (PJK, 28.6% vs 4.2%). Cage subsidence was noted in 4 patients and was more common in patients undergoing multilevel ACR (25% vs 5.3%) and trended towards increased risk of PJK (25% vs 7.4%).
Conclusion: ACR via a minimally invasive lateral approach maintains lumbar lordosis while restoring sagittal balance at 1 year follow up and beyond. Combining ALL release with a posterior osteotomy further increases lordosis and sagittal correction, but may also increase risk of cage subsidence and PJK. Careful patient selection, surgical planning, and technique remain vital in the long term success of ASD patients undergoing ACR.