title: Comparison of Clinical and Radiological Results of Posterolateral Fusion and Posterior Lumbar Interbody Fusion in the Treatment of L4 Degenerative Lumbar Spondylolisthesis.
abstract: METHODS
  Multicenter analysis of two groups of patients surgically treated for degenerative L4 unstable spondylolisthesis.
  
  
  OBJECTIVE
  To compare the clinical and radiographic outcomes of posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) for degenerative L4 unstable spondylolisthesis.
  
  
  BACKGROUND
  Surgery for lumbar degenerative spondylolisthesis is widely performed. However, few reports have compared the outcome of PLF to that of PLIF for degenerative L4 unstable spondylolisthesis.
  
  
  METHODS
  Patients with L4 unstable spondylolisthesis with Meyerding grade II or more, slip of >10° or >4 mm upon maximum flexion and extension bending, and posterior opening of >5 degree upon flexion bending were studied. Patients were treated from January 2008 to January 2010. Patients who underwent PLF (n=12) and PLIF (n=19) were followed-up for >2 years. Radiographic findings and clinical outcomes evaluated by the Japanese Orthopaedic Association (JOA) score were compared between the two groups. Radiographic evaluation included slip angle, translation, slip angle and translation during maximum flexion and extension bending, intervertebral disc height, lumbar lordotic angle, and fusion rate.
  
  
  RESULTS
  JOA scores of the PLF group before surgery and at final follow-up were 12.3±4.8 and 24.1±3.7, respectively; those of the PLIF group were 14.7±4.8 and 24.2±7.8, respectively, with no significant difference between the two groups. Correction of slip estimated from postoperative slip angle, translation, and maintenance of intervertebral disc height in the PLIF group was significantly (p<0.05) better than those in the PLF group. However, there was no significant difference in lumbar lordotic angle, slip angle and translation angle upon maximum flexion, or extension bending. Fusion rates of the PLIF and PLF groups had no significant difference.
  
  
  CONCLUSIONS
  The L4-L5 level posterior instrumented fusion for unstable spondylolisthesis using both PLF and PLIF could ameliorate clinical symptoms when local stability is achieved.
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Shugo
authors.initials: S
authors.lastname: Kuraishi
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Takahashi
authors.affiliation: Department of Orthopaedic Surgery, Azumi General Hospital, Nagano, Japan.
authors.forename: Keijiro
authors.initials: K
authors.lastname: Mukaiyama
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Shimizu
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Shota
authors.initials: S
authors.lastname: Ikegami
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Futatsugi
authors.affiliation: Department of Orthopaedic Surgery, Marunouchi Hospital, Matsumoto, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hirabayashi
authors.affiliation: Department of Orthopaedic Surgery, Ina Central Hospital, Ina, Japan.
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Ogihara
authors.affiliation: Department of Orthopaedic Surgery, Shinonoi General Hospital, Nagano, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Hashidate
authors.affiliation: Nagano Prefectural General Rehabilitation Center, Nagano, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Tateiwa
authors.affiliation: Nagano Prefectural General Rehabilitation Center, Nagano, Japan.
authors.forename: Hisatoshi
authors.initials: H
authors.lastname: Kinoshita
authors.affiliation: Department of Orthopaedic Surgery, Shinshu University School of Medicine, Matsumoto, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kato
keywords: Degenerative spondylolisthesis; Instability; Posterior lumbar interbody fusion; Posterolateral fusion