Functional outcome analysis: instrumented posterior lumbar interbody fusion for degenerative lumbar scoliosis

Purpose Although instrumented posterior lumbar interbody fusion (PLIF) has been becoming a popular and effective method for treating degenerative lumbar scoliosis, the clinical outcome is rarely reported. We retrospectively evaluated the clinical and radiographic outcomes in patients with degenerative lumbar scoliosis after instrumented PLIF. Materials and methods A total of 58 patient’s clinical characteristics had been reviewed retrospectively including clinical presentations, preoperative medical comorbidities, intraoperative status, and postoperative status. Oswestry disability index (ODI), visual analog scale (VAS), and patient satisfaction were evaluated before surgery and last follow-up period. The relationship between the difference of radiographic parameter and functional outcome was evaluated. Results Functional outcomes including ODI scores and VAS were significantly improved at the last visit. The ODI was 28.1±8.0 before surgery and 12.2±8.8 at the last visit. VAS was 7.4±2.0 before surgery and 2.4±2.0 at the last visit. Patient satisfaction was 72% at the last visit. ODI was significantly related to postoperative radiographic parameters including Cobb’s angle (p<0.001), L4 inclination (p= 0.011), coronal balance (p=0.007), lateral vertebral translation (p<0.001), Nash–Moe grade (p=0.033), Nash–Moe degree (p=0.025), and sagittal balance (p=0.041) Using multiple regression analysis, ODI was significantly related to female gender, number of levels fixed, coronal balance, lateral vertebral translation, and Nash–Moe degree. The was no significant correlation between postoperative radiographic parameters and pain (VAS). Only lateral vertebral translation demonstrated a significant correlation in multiple regression analysis. Conclusions Based on the VAS and ODI instrument, our studies demonstrated that instrumented PLIF for adult degenerative lumbar scoliosis can achieve a high rate of patient satisfaction and improvement in radiographic and clinical outcomes at a minimum of 2 years of follow-up.