title: Transforaminal lumbar interbody fusion versus instrumented posterolateral fusion in Grade I/II spondylolisthesis.
abstract: BACKGROUND
  Spondylolisthesis refers to slippage of one vertebra over the other, which may be caused by a variety of reasons such as degenerative, trauma, and isthmic. Surgical management forms the mainstay of treatment to prevent further slip and worsening. However, there is no consensus regarding the best surgical option to treat these patients. This study compares TLIF and instrumented PLF in patients with Grade I and II spondylolisthesis and analysis the outcome with respect to functional outcome, pain, fusion rate, adequacy of medial facetectomy for decompression, and complications.
  
  
  METHODS
  Forty patients operated for spondylolisthesis by instrumented posterolateral or transforaminal fusion between January 1, 2010, and June 30, 2012 were included in this retrospective study. They were followed up for 3 years. Twenty one cases were of instrumented posterolateral fusion (PLF) and 19 cases were of transforaminal lumbar interbody fusion (TLIF). The patients were asked to fill up the Oswestry disability index (ODI), Dallas Pain Questionnaire (DPQ), and low back pain rating scale (LBPRS) preoperatively, at 1-month postoperatively, and at 6, 12, 24, and 36 months postoperatively. Radiological parameters were assessed using radiographs.
  
  
  RESULTS
  No significant differences were found in DPQ, LBPRS, or ODI scores preoperative, 1-month postoperative, and at 6, 12, 24 and 36 months followup. No significant difference was found between the two groups in blood loss. The only significant difference between the two groups was in the operative time, in which the instrumented PLF group had a mean of 50 min lesser than the TLIF group (P= 0.02).
  
  
  CONCLUSIONS
  TLIF and instrumented PLF are equally efficacious options in the treatment of Grade I and II spondylolisthesis, except lytic type.
authors.affiliation: Department of Orthopaedics, Saveetha Medical College, Chennai, Tamil Nadu, India.
authors.forename: Shanmugasundaram
authors.initials: S
authors.lastname: Pooswamy
authors.affiliation: Department of Orthopaedics, Saveetha Medical College, Chennai, Tamil Nadu, India.
authors.forename: Niranjanan Raghavn
authors.initials: NR
authors.lastname: Muralidharagopalan
authors.affiliation: Department of Orthopaedics, Saveetha Medical College, Chennai, Tamil Nadu, India.
authors.forename: Sivasubramaniam
authors.initials: S
authors.lastname: Subbaiah
keywords: Instrumented posterolateral fusion; Spinal fusion; degenerative diseases; lumbar vertebrae; spondylolisthesis; transforaminal lumbar interbody fusion