title: Spinous process-splitting open pedicle screw fusion provides favorable results in patients with low back discomfort and pain compared to conventional open pedicle screw fixation over 1 year after surgery.
abstract: BACKGROUND
  The conventional open pedicle screw fusion (PSF) requires an extensive detachment of the paraspinal muscle from the posterior aspect of the lumbar spine, which can cause muscle injury and subsequently lead to "approach-related morbidity". The spinous process-splitting (SPS) approach for decompression, unilateral laminotomy for bilateral decompression, and the Wiltse approach for pedicle screw insertion are considered to be less invasive to the paraspinal musculature. We investigated whether SPS open PSF combined with the abovementioned techniques attenuates the paraspinal muscle damage and yields favorable clinical results, including alleviation in the low back discomfort, in comparison to the conventional open PSF.
  
  
  METHODS
  We studied 53 patients who underwent single-level PSF for the treatment of degenerative spondylolisthesis (27 patients underwent SPS open PSF and the other 26 underwent the conventional open PSF). The clinical outcomes were assessed using the Japanese Orthopedic Association (JOA) score, the Roland-Morris disability questionnaire (RDQ), and the visual analog scale (VAS) for low back pain and low back discomfort (heavy feeling or stiffness). Postoperative multifidus (MF) atrophy was evaluated using MRI. Follow-up examinations were performed at 1 and 3 years after the surgery.
  
  
  RESULTS
  Although there was no significant difference in the JOA and RDQ score between the two groups, the VAS score for low back pain and discomfort after the surgery were significantly lower in the SPS open PSF group than in the conventional open PSF group. The extent of MF atrophy after SPS open PSF was reduced more significantly than after the conventional open PSF during the follow-up. The MF atrophy ratio was found to correlate with low back discomfort at the 1-year follow-up examination.
  
  
  CONCLUSIONS
  In conclusion, SPS open PSF was less damaging to the paraspinal muscle than the conventional open PSF and had a significant clinical effect, reducing low back discomfort over 1 year after the surgery.
authors.affiliation: Department of Orthopaedic Surgery, Spinal Injuries Center, 550-4 Igisu, Iizuka, Fukuoka, 820-8508, Japan. eijimori@orange.ocn.ne.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Mori
authors.forename: Seiji
authors.initials: S
authors.lastname: Okada
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ueta
authors.forename: Yugue
authors.initials: Y
authors.lastname: Itaru
authors.forename: Takeshi
authors.initials: T
authors.lastname: Maeda
authors.forename: Osamu
authors.initials: O
authors.lastname: Kawano
authors.forename: Keiichiro
authors.initials: K
authors.lastname: Shiba
mesh_terms: D000328:Adult; D000368:Aged; D001863:Bone Screws; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D017116:Low Back Pain / Q000453:epidemiology* / Q000209:etiology* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D009133:Muscular Atrophy / Q000473:pathology; D010147:Pain Measurement; D015995:Prevalence; D013123:Spinal Fusion / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D013168:Spondylolisthesis / Q000601:surgery*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome