Clinical and Radiological Outcomes of 2-level Open versus Minimally Invasive Transforaminal Lumbar Interbody Fusionody Fusion (TLIF)

Presented at SMISS Annual Forum 2014
By Prashant Baid MD
With Yue Mun MD,

Disclosures: Prashant Baid MD None Yue Mun MD None,

Though there are studies comparing single level minimally invasive (MIS) vs. open transforminal lumbar interbody fusion (TLIF), there is none directly comparing 2-level MIS with open TLIF till date. This study aims to compare the clinical and radiological outcomes of 2- level open and MIS TLIF.

Comparison of clinical and radiological outcomes of two -levels open versus minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF) at 6 months and 2-years follow-up. Methods: Thirty-five MIS TLIF patients were matched with 35 Open TLIF based on age, gender, Basal Metabolic Rate(BMI), levels operated upon and pre-operative outcome score. Patient demographics and operative data were collected. Clinical outcomes in terms of North American Spine Society (NASS) Scores, Oswestry Disability Index, Short Form-36, and Visual Analogue scores were administered before surgery, 6 months and 2 years after surgery by independent assessors at our outcomes collection centre .Fusion rates based on Birdwell grading were assessed at 6 months and 2 years.


  • The mean age for MIS and Open procedure were 65.5 and 65.8 years. There were 25 females and 10 males in both groups. Peri-operative analysis revealed that MIS cases have comparable operative duration ( p<0.05), longer fluoroscopic time ( p>0.05), less intraoperative blood loss (p>0.05) and no post-operative drainage ( p>0.05). MIS patients needed less morphine (p>0.05) and were able to ambulate ( p>0.05) faster and discharged from hospital earlier ( p>0.05).
  • At 6 months, clinical outcome analysis showed both groups improving significantly with patient satisfaction >65% and similarly in terms of VAS, ODI, SF-36, return to full function. Radiological analysis at 6 months showed a higher grade 1 fusion rates in MIS cases (p>0.05).
  • At 2 years, continued improvements were observed in both groups though the overall scores at 2 years demonstrated significantly better result for VAS for leg pain(P= 0.09) and NASS score ( P= 0.02 ) for neurogenic symptoms in MIS group and this has resulted in a higher percentage of patients returning to full function and higher satisfaction though not statistically significant .Almost all patients have Grade 1 fusion (open: 94.28 %, MIS: 97.14 %,p>0.05).

MIS TLIF has comparable or improved clinical outcomes and high fusion rates compared to Open TLIF with the additional benefits of less initial postoperative pain, early rehabilitation, shorter hospitalization, and fewer complications.