title: Minimal invasive transforaminal lumbar interbody fusion versus open transforaminal lumbar interbody fusion.
abstract: BACKGROUND
  The aim of the present prospective study is to evaluate whether the touted advantages of minimal invasive-transforaminal lumbar interbody fusion (MI-TLIF) translate into superior, equal, or inferior outcomes as compared to open-transforaminal lumbar interbody fusion (O-TLIF). This is the first study from the Indian subcontinent prospectively comparing the outcomes of MI-TLIF and O-TLIF.
  
  
  METHODS
  All consecutive cases of open and MI-TLIF were prospectively followed up. Single-level TLIF procedures for spondylolytic and degenerative conditions (degenerative spondylolisthesis, central disc herniations) operated between January 2011 and January 2013 were included. The pre and postoperative Oswestry Disability Index (ODI) and visual analog scale (VAS) for back pain and leg pain, length of hospital stay, operative time, radiation exposure, quantitative C-reactive protein (QCRP), and blood loss were compared between the two groups. The parameters were statistically analyzed (using IBM®SPSS®Statistics version 17).
  
  
  RESULTS
  129 patients underwent TLIF procedure during the study period of which, 71 patients (46 MI-TLIF and 25 O-TLIF) fulfilled the inclusion criteria. Of these, a further 10 patients were excluded on account of insufficient data and/or no followup. The mean followup was 36.5 months (range 18-54 months). The duration of hospital stay (O-TLIF 5.84 days + 2.249, MI-TLIF 4.11 days + 1.8,P< 0.05) was shorter in MI-TLIF cases. There was less blood loss (open 358.8 ml, MI 111.81 ml,P< 0.05) in MI-TLIF cases. The operative time (O-TLIF 2.96 h + 0.57, MI-TLIF 3.40 h + 0.54,P< 0.05) was longer in MI group. On an average, 57.77 fluoroscopic exposures were required in MI-TLIF which was significantly higher than in O-TLIF (8.2). There was no statistically significant difference in the improvement in ODI and VAS scores in MI-TLIF and O-TLIF groups. The change in QCRP values preoperative and postoperative was significantly lower (P< 0.000) in MI-TLIF group than in O-TLIF group, indicating lesser tissue trauma.
  
  
  CONCLUSIONS
  The results in MI TLIF are comparable with O-TLIF in terms of outcomes. The advantages of MI-TLIF are lesser blood loss, shorter hospital stay, lesser tissue trauma, and early mobilization. The challenges of MI-TLIF lie in the steep learning curve and significant radiation exposure. The ultimate success of TLIF lies in the execution of the procedure, and in this respect the ability to achieve similar results using a minimally invasive technique makes MI-TLIF an attractive alternative.
authors.affiliation: Mumbai Spine Scoliosis and Disc Replacement Centre, Bombay Hospital, Mumbai, Maharashtra, India.
authors.forename: Arvind G
authors.initials: AG
authors.lastname: Kulkarni
authors.affiliation: Mumbai Spine Scoliosis and Disc Replacement Centre, Bombay Hospital, Mumbai, Maharashtra, India.
authors.forename: Hussain
authors.initials: H
authors.lastname: Bohra
authors.affiliation: Mumbai Spine Scoliosis and Disc Replacement Centre, Bombay Hospital, Mumbai, Maharashtra, India.
authors.forename: Abhilash
authors.initials: A
authors.lastname: Dhruv
authors.affiliation: Mumbai Spine Scoliosis and Disc Replacement Centre, Bombay Hospital, Mumbai, Maharashtra, India.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Sarraf
authors.affiliation: Mumbai Spine Scoliosis and Disc Replacement Centre, Bombay Hospital, Mumbai, Maharashtra, India.
authors.forename: Anupreet
authors.initials: A
authors.lastname: Bassi
authors.affiliation: Mumbai Spine Scoliosis and Disc Replacement Centre, Bombay Hospital, Mumbai, Maharashtra, India.
authors.forename: Vishwanath M
authors.initials: VM
authors.lastname: Patil
keywords: MI-TLIF; Spinal column; TLIF; arthrodesis; bone screws; lumbar vertebrae; minimally invasive spine surgery; minimally invasive surgical procedure; percutaneous pedicle screw; spinal fusion