Outcome and complication following single-staged posterior minimally invasive surgery in adult spinal deformity

Background The aging population is experiencing a rising incidence of musculoskeletal problems and degenerative spinal deformities. Adult spinal deformity (ASD) presents challenges, with associated risks in open surgery. Minimally invasive surgery (MIS) is becoming increasingly popular due to its positive outcomes and potential benefits. This study aims to explore the clinical outcome and complications of posterior approach MIS in patients with ASD. Methods We conducted a retrospective analysis of patients with adult spinal deformity who underwent posterior minimally invasive surgery. 46 patients meeting the criteria were identified between June 2017 and September 2023. Comprehensive data were collected, including demographic details, surgical information, full-length radiographic measurements, and visual analog scale (VAS) pain scores. These data were obtained preoperatively, postoperatively, and at the final follow-up. Results A total of 46 patients were included in the study, with a mean age of 68.58 years and a minimum follow-up period of 6 months. The mean operative time was 327 min, and the mean blood loss was 307 ml. Preoperative radiographic measurements were as follows: Coronal Cobb angle, 18.60 +/- 11.35 degrees; lumbar lordosis (LL), 22.79 +/- 21.87 degrees; pelvic incidence (PI), 53.05 +/- 14.13 degrees; PI-LL mismatch, 30.26 +/- 23.48 degrees; pelvic tilt (PT), 32.53 +/- 10.38 degrees; T1 pelvic angle (TPA), 31.91 +/- 12.39 degrees; and sagittal vertical axis (SVA), 77.77 +/- 60.47 mm. At the final follow-up, coronal Cobb angle was 10.08 +/- 6.47 degrees (P <0.0001), LL was 26.16 +/- 16.92 degrees (P = 0.4293), PI was 54.17 +/- 12.13 degrees (P = 0.6965), PI-LL mismatch was 28.00 +/- 17.03 degrees (P = 0.6144), PT was 27.74 +/- 10.24 degrees (P = 0.0345), TPA was 25.10 +/- 10.95 (P = 0.0090) and SVA was 47.91 +/- 46.94 mm (P = 0.0129). Functional outcomes improved as well, with the mean Oswestry Disability Index (ODI) decreasing from 34.9 to 23.6 and the Visual Analog Scale (VAS) score for back pain reducing from 8.4 to 3.4. Surgical complications occurred in 39.1% of cases, with a low reoperation rate of 4.3%. Conclusion Single-staged posterior MIS effectively corrects global alignment in adult spinal deformities, satisfying patient demand and yielding positive clinical outcome with low re-operation rate.