الفهرس 
Anatomy of the Lumbar SpineOnly 14 pages are availabe for public view
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Abstract
Background:
For years, the gold standard treatment for symptomatic lumbar canal stenosis refractory to conservative management is a facet-preserving laminectomy. However, it has been suggested that extensive resection of the posterior bone, posterior ligaments and muscular structures leads to increases in postoperative pain, perioperative blood loss, complications and length of hospital stay (Celik et al., 2010).
Controversy continues about the extent of bony decompression required to effectively decompress the spinal canal. As narrowing of the spinal canal occurs predominantly at the interlaminar region involving the hypertrophy of the facet joints and bulging of the intervertebral disc and the ligamentum flavum, resection of the whole vertebral arch may not be necessary. Alternatively, an interlaminar or undercutting laminectomy can be performed to decompress the spinal canal (Delank et al., 2002).
More recently, various authors have recommended surgical techniques that preserve posterior midline structures (i.e. spinous processes, vertebral arches, interspinous and supraspinous ligaments), as removal of these structures may contribute to instability after surgery (Bresnahan et al., 2009).
Laminotomy is the most commonly described decompressive procedure that preserves the posterior midline structures. Other techniques that are designed to preserve the posterior midline structures include endoscopic laminotomy and spinous process osteotomies. The amount of decompression achieved with these techniques has been shown to be approximately equal to that attained with laminectomy (Guiot et al., 2002).
Objective:
The purpose of our prospective study is to evalute the surgical outcome of Microdecompression in comparison to decompressive laminectomy in the treatment of degenerative lumbar canal stenosis.
Methods:
This prospective comparative study includes two groups of patients that were operated upon in Ain Shams University hospitals in the period between January 2012 and March 2016. In group 1 (Laminectomy Group), we treated 20 patients (29 stenotic levels) with decompressive laminectomy and in group 2 (Microdecompression group), 28 patients (32 stenotic levels) were treated either by bilateral or unilateral Microdecompression, 16 and 4 cases respectively. Pre- and postoperatively disability and pain scores were measured using the Oswestry Disability Index (ODI) and Visual Analog Score (VAS).
The selection of surgical approach was according to the surgeon preference.
Results:
Our statistical results revealed that there was a statistically significant difference in the outcome between the two groups after follow up period of 12 months regarding VAS for back pain and leg pain which were better in the Microdecompression group. Postoperative ODI shows no statistically significant difference in the two groups, however the change in the ODI was significantly better in the Microdecmpression group.
There was no significant difference regarding operation time and postoperative hospital stay between the two groups, however Blood loss was significantly lower in the Microdecompression group. Complications rates was higher in the Laminectomy group (30%) compared to Microdecompression group (20%).
Conclusion:
Microdecompression with less bony work and preservation of the spinous process, supraspinous and interspinous ligaments seems to be a safe and effective procedure in management of degenerative lumbar canal stenosis. It also shows better improvement in the clinical outcome at the 12-month follow up interval compared to the traditional decompressive laminectomy.
However, longer periods of follow up is needed to can assess the effect of both treatment groups on the spine stability. As most translational and rotational spinal stability is provided by the intervertebral disc and the facet joints, and the momentum generated by the posterior ligaments during flexion is small compared with the force exerted by back muscles.
So, the relevance of preservation of the posterior midline structures should be clarified in further studies.