Radiographic and clinical outcomes following combined lateral lumbar interbody fusion and posterior segmental stabilization in patients with adult degenerative scoliosis

Abstract

Object: A hybrid approach of minimally invasive lateral lumbar interbody fusion (LLIF) followed by supplementary open posterior segmental instrumented fusion (PSIF) has shown promising early results in the treatment of adult degenerative scoliosis. Studies assessing the impact of this combined approach on correction of segmental and regional coronal angulation, sagittal realignment, maximum Cobb angle, restoration of lumbar lordosis, and clinical outcomes are needed. The authors report their results of this approach for correction of adult degenerative scoliosis. Methods: Twenty-six patients underwent combined LLIF and PSIF in a staged fashion. The patient population consisted of 21 women and 5 men. Ages ranged from 40 to 77 years old. Radiographic measurements including coronal angulation, pelvic incidence, lumbar lordosis, and sagittal vertical axis were taken preoperatively and 1 year postoperatively in all patients. Concurrently, the visual analog score (VAS) for back and leg pain, the Oswestry Disability Index (ODI), and Short Form-36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores were used to assess clinical outcomes in 19 patients. Results: At 1-year follow-up, all patients who underwent combined LLIF and PSIF achieved statistically significant mean improvement in regional coronal angles (from 14.9° to 5.8°, p < 0.01) and segmental coronal angulation at all operative levels (p < 0.01). The maximum Cobb angle was significantly reduced postoperatively (from 41.1° to 15.1°, p < 0.05) and was maintained at follow-up (12.0°, p < 0.05). The mean lumbar lordosis-pelvic incidence mismatch was significantly improved postoperatively (from 15.0° to 6.92°, p < 0.05). Although regional lumbar lordosis improved (from 43.0° to 48.8°), it failed to reach statistical significance (p = 0.06). The mean sagittal vertical axis was significantly improved postoperatively (from 59.5 mm to 34.2 mm, p < 0.01). The following scores improved significantly after surgery: VAS for back pain (from 7.5 to 4.3, p < 0.01) and leg pain (from 5.8 to 3.1, p < 0.01), ODI (from 48 to 38, p < 0.01), and PCS (from 27.5 to 35.0, p = 0.01); the MCS score did not improve significantly (from 43.2 to 45.5, p = 0.37). There were 3 major and 10 minor complications. Conclusions: A hybrid approach of minimally invasive LLIF and open PSIF is an effective means of achieving correction of both coronal and sagittal deformity, resulting in improvement of quality of life in patients with adult degenerative scoliosis. © AANS, 2014.