title: Lumbar sagittal balance influences the clinical outcome after decompression and posterolateral spinal fusion for degenerative lumbar spondylolisthesis.
abstract: METHODS
  This study was designed to assess both lumbar sagittal balance and clinical outcomes of decompression and posterolateral fusion for degenerative lumbar spondylolisthesis. As an index for the radiologic evaluation of sagittal alignment, the L1 axis S1 distance was used (i.e., the horizontal distance from the plumbline of the center in the L1 to the back corner of the S1).
  
  
  OBJECTIVE
  To determine whether lumbar sagittal balance affected the clinical outcome after posterolateral fusion.
  
  
  BACKGROUND
  Little is known about whether the sagittal vertical axis influences clinical outcomes in cases of degenerative lumbar spondylolisthesis.
  
  
  METHODS
  A retrospective review of 47 patients (15 men and 32 women), ranging in age from 41 to 79 years, was conducted. The mean follow-up period was 3.6 years. Relations among outcomes including the visual analog pain scale, recovery rate, L1 axis S1 distance, slippage, and lumbar lordosis were evaluated.
  
  
  RESULTS
  Recovery rates were 44% and 62% in patients whose preoperative L1 axis S1 distance, respectively, was more than 35 mm (Group A, n = 16) and less than 35 mm (Group B, n = 31) (P < 0.05). Follow-up assessment found a positive correlation between only lordosis and recovery rate. Severe low back pain and lower recovery rate were observed in patients with in situ fusion in Group A (n = 9), as compared with patients with reduced slippage in Group A (n = 7) and patients in Group B.
  
  
  CONCLUSIONS
  Both preoperative L1 axis S1 distance and lordosis at follow-up assessment affected surgical outcome. Reduction of slippage may improve clinical outcomes of posterolateral fusion for degenerative lumbar spondylolisthesis with an L1 axis S1 distance more than 35 mm.
authors.affiliation: Department of Orthopaedic Surgery, Wakayama Medical University, Wakayama City, Wakayama, Japan. kawakami@wakayama-med.ac.jp
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kawakami
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tamaki
authors.forename: Muneharu
authors.initials: M
authors.lastname: Ando
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hashizume
authors.forename: Munehito
authors.initials: M
authors.lastname: Yoshida
mesh_terms: D000328:Adult; D000368:Aged; D019299:Decompression, Surgical / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008141:Lordosis / Q000150:complications; D008161:Lumbosacral Region; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology; D010147:Pain Measurement; D004856:Postural Balance; D011859:Radiography; D020127:Recovery of Function; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects; D013168:Spondylolisthesis / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome