Anterior Column Realignment has Similar Results to Pedicle Subtraction Osteotomy in Treating Adults with Sagittal Plane Deformity

Objective: Anterior column realignment (ACR) is a minimally invasive surgical technique used for the correction of adult sagittal plane deformity. ACR is performed via a minimally invasive lateral transpsoas approach with anterior longitudinal ligament release and hyperlordotic cage placement. The objective of this study was to compare radiographic outcomes and complications in patients treated by ACR or Pedicle subtraction osteotomy (PSO).

Methods: Patients who underwent ACR were matched with patients from a retrospective PSO dataset, by pelvic incidence, lumbar lordosis, and thoracic kyphosis. Inclusion criteria included pelvic incidence and lumbar lordosis mismatch > 10°, pelvic tilt > 25°, and/or C7 sagittal vertical axis >5 cm, and minimum 1-year follow-up.

Results: All (n = 17) patients who underwent ACR underwent second-stage open posterior instrumented fusion. There were no differences in baseline demographic or radiographic parameters. Both groups were found to have significant improvement from preoperative to final follow-up for lumbar lordosis, T1 spinopelvic inclination, and T1 pelvic angle. Pelvic tilt did not improve with PSO (31° to 28°) at final follow-up but did improve in ACR group (34° to 25°). No differences were identified at 3-month or final follow-up for lumbar lordosis (51° vs. 47°), pelvic tilt (25° vs. 28°), and T1 pelvic angle (23° vs. 24°). The group undergoing PSO achieved greater T1 spinopelvic inclination correction (8° vs. 1.9°). Patients who underwent ACR had significantly less estimated blood loss than patients who underwent PSO (1.6 vs. 3.6 L, respectively), but no difference in the overall major complication rates was found (35.3% vs. 41.2%, respectively).

Conclusions: ACR achieved similar radiographic results as PSO in a matched cohort with significantly less estimated blood loss and similar overall complication rate.