Minimally Invasive Lateral Lumbar Interbody Fusion

Abstract

Retrospective case series. To determine the clinical and radiographic outcomes of patients undergoing minimally invasive lateral lumbar interbody fusion (LLIF) with a minimum 2-year follow-up. Minimally invasive LLIF is performed through a lateral, retroperitoneal, transpsoas approach. This procedure is characterized by the use of a tubular retractor to minimize tissue damage and real-time neuromonitoring to ensure safe passage through the psoas muscle. To date, advantages of minimal invasive LLIF, compared with open procedures, has been limited to early postoperative outcomes and complications, with the longest mean follow-up duration of 22 months. A total of 118 patients who underwent minimally invasive LLIF with a minimum of 2 years follow-up were included in this study. Clinical outcomes were determined by using Visual Analog Score for the degree of pain (trunk or lower extremity), and Oswestry Disability Index and Short Form-12 scoring methods for patient function. Radiographic evaluations included (i) disk height; (ii) segmental coronal angulation; (iii) segmental lordotic angulation; (iv) Cobb angle; (v) cage subsidence; and (vi) fusion status. Data were statistically tested using either paired Students t test or Wilcoxon matched-pair test. Significance level was set at P<0.05. We found that (i) the Visual Analog Score for pain, Oswestry Disability Index, and the physical components summary, but not the mental components summary of Short Form-12 improved significantly at the follow-up; (ii) disk height, coronal angulation, and lordotic angulation at each level and the Cobb angle were restored at the statistically significant extent; (iii) successful fusion was achieved in 209 levels (88%); and (iv) transient thigh pain was the most frequent complication seen in 36% of the patients. Our results support the efficacy of minimally invasive LLIF in improvements of clinical and radiographic features.