Comparative Analysis of Three Different Surgical Strategies for Adult Spinal Deformity with Moderate Sagittal Imbalance

Presented at SMISS Annual Forum 2016
By Junseok Bae
With Vedat Deviren MD, Praveen Mummaneni MD, Christopher Ames MD, Dean Chou MD, Alexander A. Theologis , Russel Strom , Bobby Tay , Shane Burch , Sigurd Berven ,

Disclosures: Junseok Bae B; Joimax GmbH. Vedat Deviren MD A; AOSpine, Globus, Nuvasive. B; Nuvasive. F; Nuvasive., Praveen Mummaneni MD B; Globus, Christopher Ames MD A; Trans1. B; Medtronic, Stryker, Depuy. D; Trans1, Visualase, Doctors Research Group. F; Lanx, Stryker, Aesculap/B. Braun., Dean Chou MD None, Alexander Theologis A; DePuy Synthesis., Russel Strom None, Bobby Tay A; AO Spine, Globus medical, NuVasive. B; DePuy Synthes, Stryker Spine, Biomet., Shane Burch A; Medtronic, Lily., Sigurd Berven A; AO Spine, Globus medical. B; Globus medical, Medtronic, Striker Spine. C; RTI. F; Medtronic. A; NIH, NSF, AOSpine, Empirical Spine. B; Medtronic, Stryker, Globus Medical, Innovasis, Medicrea. D; Gr,

Introduction

Surgical treatment of adult spinal deformity (ASD) is a cost effective endeavor that may be accomplished using a variety of surgical strategies.

Aims/Objectives

We assess and compare radiographic data, complications, and health-related quality of life outcome (HRQoL) scores between ASD patients who underwent operation using a posterior-only approach (PSF only), posterior approach combined with lateral lumbar interbody fusion (LLIF+PSF), and a posterior approach combined with anterior lumbar interbody fusion (ALIF+PSF). 

Methods

Consecutive adults who underwent thoracolumbar fusions for ASD (2003-2013) were reviewed. Inclusion criteria: instrumentation from pelvis to L1 or above, SVA<10cm, and minimum 2 years follow-up. Three-column osteotomies were excluded. Three groups were compared: LLIF+PSF, ALIF+PSF, and PSF only. Peri-op spinal deformity parameters, complications, and HRQoLs (SRS-22, SF-36, VAS back and leg pain) were assessed for each group and compared to each other using ANOVA tests. MCID (minimal clinically important difference) was defined as following: VAS back pain -1.2, VAS leg pain -1.6, ODI -15, SRS pain +0.587/function +0.375/self-image +0.8/mental +0.42, and SF-36/PCS +5.2. 

Results

Two hundred twenty one patients (LLIF: 58, ALIF: 91, PSF only: 72) met inclusion criteria. Average deformities consisted of SVA <10cm, PI-LL mismatch >100, PT>200, lumbar Cobb>200, and thoracic Cobb>150. Preoperative SVA, LL, PI-LL mismatch, lumbar and thoracic Cobb angles were similar among groups. PSF only patients had more comorbidities. ALIF+PSF patients were on average younger and had lower BMIs than LLIF+PSF. LLIF+PSF had higher average interbody fusion than ALIF+PSF and PSF only. At final follow-up, all radiographic parameters were similar between groups. Proximal junctional angle between UIV and UIV+2 was higher in PSF only with marginal significance. Average number of complications was similar among groups. LLIF+PSF patients had significantly fewer PJKs and fewer UIV fractures and spondylolisthesis. All preoperative HRQoL scores were similar between groups. After surgery, LLIF+PSF patients had significantly lower ODI, higher SRS self-image/total scores, and higher achievement of MCID in SRS pain.

Conclusions

Satisfactory radiographic outcomes can be achieved similarly and adequately with different surgical approaches for ASD. Patients treated with LLIF+PSF in this single institution,
multi-surgeon cohort had lower rates PJK and mechanical failures at UIV as well as less back pain, less disability, and better SRS
scores than patients treated with ALIF+PSF or a posterior-only surgical strategy.