Introduction: Lumbar spinal stenosis has an incidence of 1.7 to 8% in the general population, which increases after the 5th decade of life.
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. 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: Between April 2009 and September 2013, 280 minimally invasive laminectomies (MIL) were preformed in 155 patients for lumbar spinal stenosis refractory to non-operative treatments.
Charts were review retrospectively and outcome scales (Oswestry Disability Index(ODI) and Visual Analogue Scale (VAS)) were answered prospectively pre-operatively and over a 5 year follow-up period. Facet anatomy was documented as well as stability seen on pre-operative dynamic plain films.
Complication rates and re-operation rates were analyzed.
Results: 155 patient were follow 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.
Patient Care: Surgical advantage of performing minimally invasive laminectomy to preserve para-vertebral muscular anatomy and spinous process while achieving adequate lumbar decompression with low complication rate.
MIL-ISF results in low level of ALP.
Learning Objectives: MI-Laminectomy for degenerative spinal stenosis is safe, great clinical outcomes while having low rate of complications.