Comparative study of functional outcome analysis and extent of paraspinal muscle damage between lumbar spinous process splitting decompression and conventional midline decompression for lumbar canal stenosis

Abstract

INTRODUCTION Lumbar spinal canal stenosis is a clinical syndrome of back or leg pain with characteristic provocative and palliative features, which occurs due to narrowing of spinal canal, nerve root canal and the intervertebral foramen. Lumbar spinal canal stenosis has been regarded as “the forgotten spinal disease” for more than 100 years. This neglect occurred because of the association between herniated intervertebral discs and sciatica received most of the attention after it was discovered by Mixter and Barr in 1934. However, Lumbar spinal canal stenosis was not widely understood until Verbiest in 1954 described the classic finding of this syndrome. It occurs in middle aged and older adults with back pain and lower extremity pain precipitated by standing and walking and aggravated by hyperextension. The secondary degenerative changes that further narrow the lumbar spinal canal precipitated symptoms. Lumbar spinal canal stenosis now is an accepted clinical entity. The degenerative lumbar spinal canal stenosis is due to thickening of interspinous ligament, ligamentum flavum and facet joint hypertrophy. Lumbar spinal canal stenosis cause signs of intermittent neurogenic claudication, and it can lead to decreased quality of life. Conservative measures provide relief from symptoms for a shorter period only, but finally surgical decompression of the neurovascular structures will be needed. AIM OF THE STUDY: This prospective Randomised Control Study compares the the functional outcome and extent of paraspinal muscle damage between Lumbar spinous process splitting decompression (LSPSD) and Conventional Midline Decompression(CMD) by laminectomy surgical approaches in degenerative lumbar canal stenosis and their aim was whether 1) Lumbar spinous process splitting decompression (LSPSD ) approach provide sufficient decompression. 2) Preserve posterior musculoligamentous complex and reduces associated morbidity. MATERIALS AND METHODS : This randomized prospective control study was approved by the medical ethics committee of the Institutional Review Board in our hospital. Patients meeting the following inclusion criteria were enrolled for the study after obtaining written informed consent. 20 patients with degenerative lumbar canal stenosis are randomly divided into two groups and recruited into the study based on the following criterias INCLUSUION CRITERIA: Degenerative LCS affecting 3 or less levels, -Typical neurogenic claudication symptoms, - Magnetic resonance image demonstrating good clinical correlation, - Failure of conservative methods of treatment for a minimum period of 6 months. EXCLUSION CRITERIA: -Spondylolisthesis with slip grade 2 or greater (Meyerding grade). - Instability at the level of stenosis (as defined by >3-mm translation or >10° angular change on flexion extension lateral radiographs) - Associated symptomatic cervical or thoracic stenosis. - Multiple level canal stenosis. -Spinal canal stenosis due to congenital, traumatic , iatrogenic causes. - Presence of spinal disorders( ankylosing spondylitis, neoplasm ) - Comorbidities ( such as cardiopulmonary insufficiency, peripheral neuropathy, peripheral vascular disease, prior lumbar spine surgery, and severe hip or knee disease). RESULTS: 20 patients were followed up for 6-18 months with mean average follow up of 11.4 months. Data of 10 patients (5 men and 5 women) in the lumbar spinous process splitting decompression group and 10 patients (4 men and 6 women) in the Conventional Midline Decompression group were included in the final analysis. The mean age was 58.9 (range 54-65) yrs for the lumbar spinous process splitting decompression group and 60.4 (range 55-65) yrs for Conventional Midline Decompression group. Mean number of decompressed levels were 1.30 for Conventional Midline Decompression group and 1.20 for lumbar spinous process splitting decompression. CONCLUSION: In our study, Lumbar Spinous Process Splitting Decompression provides minimal exposure for decompression in lumbar canal stenosis while preserving musculoligamentous attachments of the posterior elements of spine and good postoperative results after one year with favourable outcomes of atleast 70% on the Japanese orthopaedic association score and Neurogenic claudication outcome score. With both these surgical techniques, a significant improvement in the outcome after surgical decompression could be demonstrated. There was no significant difference between the Lumbar Spinous Process Splitting decompression and Midline decompression by laminectomy techniques regarding the later outcome. But Lumbar Spinous Process Splitting decompressive approach is not suitable for cases with bilateral intervertebral disc protrusion and bilateral fac et joint arthritis with hypertrophy causing degenerative lumbar canal stenosis and foraminal stenosis