Clinical and Radiological Outcomes of Minimally Invasive Versus Open Transforaminal Lumbar Interbody Fusion

Study Design: Prospective study.

Objective: Comparison of clinical and radiologic outcomes of minimally invasive (MIS) versus Open transforaminal lumbar interbody fusion (TLIF).

Summary Of Background Data: Open TLIF has been performed for many years with good results. MIS TLIF techniques have recently been introduced with the aim of smaller wounds and faster recovery.

Methods: From 2004-2006, 29 MIS TLIF were matched paired with 29 Open TLIF. Patient demographics and operative data were collected. Clinical assessment in terms of North American Spine Society, Oswestry Disability Index, Short Form-36, and Visual Analogue scores were performed before surgery, 6 months and 2 years after surgery. Fusion rates based on Bridwell grading were assessed at 2 years.

Results: The mean age for MIS and Open procedures were 54.1 and 52.5 years, respectively. There were 24 females and 5 males in both groups. Fluoroscopic time (MIS: 105.5 seconds, Open: 35.2 seconds, P < 0.05) and operative time (MIS: 216.4 minutes, Open: 170.5 minutes, P < 0.05) were longer in MIS cases. There was less blood loss in MIS (150 mL) versus Open (681 mL) procedures (P < 0.05). The total morphine used for MIS cases (17.4 mg) was less compared to Open (35.7 mg, P < 0.05). MIS (4 days) patients have shorter hospitalization compared to Open (6.7 days, P < 0.05). Both MIS and Open groups showed significant improvement in Oswestry Disability Index (P < 0.05), back pain and lower limb symptoms (North American Spine Society and Visual Analogue scores, P < 0.05), and Quality of Life scores (Short Form-36, P < 0.05) at 6 months and 2 years, but there was no significant difference between the 2 groups. Eighty percent of MIS and 86.7% of Open TLIF levels achieved grade 1 fusion (P > 0.05).

Conclusion: MIS TLIF has similar good long-term clinical outcomes and high fusion rates of Open TLIF with the additional benefits of less initial postoperative pain, early rehabilitation, shorter hospitalization, and fewer complications.