title: Spinous Process splitting Laminectomy: Clinical outcome and Radiological analysis of extent of decompression.
abstract: BACKGROUND
  Spinous process splitting laminectomy (SPSL) is a useful technique in achieving adequate decompression for lumbar canal stenosis, has the advantage of simultaneously decompressing multiple levels and minimising injury to the paraspinal muscles. Some concern has been expressed over the efficacy of this technique in decompressing lateral recesses. This study was undertaken to assess the clinical outcome of SPSL technique and radiologically assess the extent of decompression.
  
  
  METHODS
  Thirty-nine consecutive patients treated by SPSL for degenerative lumbar spinal stenosis were methodically assessed for demographic data, clinical findings, Pre- and post-op VAS, JOA scores and spinal canal dimensions on imaging. Surgical technique for SPSL is described.
  
  
  RESULTS
  The mean age of the patients was 66.9 yrs. The mean follow-up was 7.3 months. The mean pre- and post-operative VAS scores were 7.8 and 3.7, respectively. The mean pre- and post-operative JOA scores were 6.3 and 11.2, respectively. The mean JOA recovery rate was 57.3%. 77% of the patients were in the 'good' or 'excellent' McNab's grades at follow-up. Radiologic results were assessed separately at the 118 levels decompressed by the SPSL technique. The ratio increase for the spinal canal dimensions on post-operative images were as follows - Interfacet distance-116.6%; Effective AP distance-67.6%; Right lateral recess depth-165.1%; Right lateral recess angle-145.5%; Left lateral recess depth-149.3%; Left lateral recess angle-133.6%; Cross-sectional spinal canal area-163.8%. There was no worsening of pre-existing degenerative listhesis or scoliosis in any case.
  
  
  CONCLUSIONS
  SPSL achieves effective central and lateral recess decompression, at the same time minimising injury to the paraspinal muscles thus reducing post-operative pain and aiding in quicker mobilisation and recovery. It is an effective tool to treat multiple level spinal stenosis, especially in elderly patients who have pre-existing spinal deformities which can precipitate into frank instability after conventional procedures.
authors.affiliation: Department of Neurosurgery, Barunsesang Hospital, Seongnam-si, Republic of Korea.
authors.forename: Seungcheol
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, M S Ramaiah Medical Teaching Hospital, Bangalore, India.
authors.forename: Umesh
authors.initials: U
authors.lastname: Srikantha
keywords: Laminectomy; Lumbar stenosis; Multiple level decompression; Paraspinal muscle; Spinous process splitting; minimally invasive spine surgery