Adjacent Level Pathology and Reoperation Rates in Patients Undergoing Minimally Invasive Laminectomy and In-Situ Posterior Fusion For Lumbar Stenosis

Presented at SMISS Annual Forum 2014
By Jorge Mendoza-Torres Spine Fellow, MD
With Mick Perez-Cruet MD, MS,

Disclosures: Jorge Mendoza-Torres Spine Fellow, MD None Mick Perez-Cruet MD, MS None,

Introduction:
Traditional surgical treatment for this disorder includes removal of the spinous process and lamina bilaterally to achieve decompression. This potentially can increase the incidence of adjacent level pathology and need for re-operation.

Aims/Objectives:
Our objective is to evaluate whether minimally invasive laminectomy and In-Situ posterior fusion (MIL-ISF) can improve patient outcomes while reducing adjacent level pathology (ALP) and need for re-operation.

Methods:
280 minimally invasive laminectomies (MIL) were preformed in 155 patients for lumbar spinal stenosis refractory to non-operative treatments. Outcome scales (Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS)) were answered prospectively pre-operatively and over a 5-year follow-up period

Results:
155 patients were following over the 5-year period with average 2.3 year follow-up. MIL-ISF was most commonly preformed at the L3-L4 (n=123, 44%) and L4-L5 (n=98, 35%) levels. Complications occurred in 9 (5.8%) cases and included superficial wound infection (n=2 (1.3%)), and pulmonary embolism (1 (0.6%). Additional transient complication included urinary retention and atelectasis. Re-operation rates occurred in 5 (3.2%) cases due to new onset or persistent symptoms with 4 (2.6%) requiring same level surgery and 1 (0.6%) adjacent segment surgery. VAS improved from 6.5 to 2.4 (p>0.001) and ODI improve from 58 to 19 (p>0.001). Pre-operative facet anatomy and plain films determined optimal candidates

Conclusions:
MIL-ISF for lumbar stenosis is a safe and effective technique with excellent clinical outcomes, low complication rates and very low rate of ALP. This low rate of ALP is felt due to preservation of normal anatomical structures of the spine while allowing for adequate neural decompression.