Indirect Decompression And Closed Reduction Of Lumbar Spondylolisthesis Using Less Invasive Anterior Column Interbody Fusion Techniques: Incidence Of Neurologic Complication And Clinical Outcomes

Presented at SMISS Annual Forum 2014
By Joshua Beckman MD
With Juan S. Uribe MD, FACS, Konrad Bach MD,

Disclosures: Joshua Beckman MD None Juan Uribe MD, FACS A; Nuvasive. B; Nuvasive. C; Nuvasive. D; Nuvasive. F; Nuvasive, Konrad Bach MD None,

Introduction:
Current belief is that surgical treatment of degenerative spondylolisthesis must always involve decompressive laminectomy/facetectomy and fusion at the involved levels to avoid potential neurological complications. Less invasive lateral interbody fusion (MIS-LIF) and anterior lumbar interbody fusion (ALIF) offer the potential for reduction of the spondylolisthesis and indirect decompression of the both the central canal and neuroforamina by restoration of neuroforaminal and disc height. These MIS techniques can potentially reduce perioperative morbidity and obviate the need for bony resection.

Aims/Objectives:
Identify the incidence of foot drop and neurologic complication in grade 1 or 2 lumbar degenerative spondylolisthesis in patients treated with indirect decompression using MIS-LIF, ALIF, or Axial lumbar interbody fusion (Axial LIF).

Methods:
A retrospective chart review of a single center prospectively collected database of patients who underwent treatment with less invasive LIF, ALIF, or Axial LIF with or without posterior instrumentation between 2008-2014. Patients with primary diagnosis of lumbar degenerative spondylolisthesis Meyerding grade 1 or 2 were identified. Outcomes measured included complication rates (specifically neurological deficit including foot drop), incidence of reoperation, fusion rate, and patient self-reported quality of life questionnaire scores (visual analog scale (VAS) and Oswestry Disability Index (ODI)). Statistical analysis was performed comparing clinical outcome measures.

Results:
A total of 69 patients treated with MIS-LIF, ALIF, or Axial LIF for degenerative spondylolisthesis were identified with 34 meeting our inclusion criteria. The average age of the patient cohort was 58 years (range 32-79 years) and 24 (71%) were female. 35 lumbar spondylolisthesis levels, of which 22 were Meyerding grade 1 and 13 were grade 2, were treated with an overall fusion rate of 94% at 12 months. Reoperation rate was 3%. Average length of follow up was 21.4 months. VAS and ODI scores improved by 2.1 (p<0.005) and 15.3 (p<0.005) points respectively. Total complication rate was 27%, of which 6% was transient right lower extremity weakness or numbness (n=5). Four of the transient neurological deficits were related to the lateral approach. There was no incidence of foot drop or neurologic complication involving injury of the indirectly decompressed nerve root.

Conclusions:
Indirect decompression and anatomical reduction for treatment of spondylolisthesis using the less invasive anterior column fusion techniques (ALIF, LIF, and Axial LIF) was not associated with an increased risk of foot drop or neurologic deficit.