481 - Mini-open Pedicle Subtraction Osteotomy for the Correction of Spinal D...

#481 Mini-open Pedicle Subtraction Osteotomy for the Correction of Spinal Deformities: Radiographic Results with Minimum One-year Follow-up

MIS Techniques and Outcomes

Poster Presented by: M.Y. Wang

Author(s):

M.Y. Wang (1)

(1) University of Miami, Neurological Surgery, Miami, FL, United States

Abstract

Introduction: The advent of minimally invasive surgery (MIS) for treating adult spinal deformities (ASD) has resulted in a potential solution for managing this challenged population with less morbidity. Previous reports of MIS techniques have been shown to be limited for correcting severe scoliosis and sagittal balance. In an effort to correct kyphosis with a less invasive method we have explored using a mini-open approach for pedicle subtraction osteotomy (PSO) coupled with MIS TLIF for long segment MIS fusions.

Methods: Over an 18 month period 7 patients with a mean age of 66 years were treated with a mini-open PSO for ASD. All patients had kyphosis or scoliosis defined as a Cobb angle of greater than 35° or sagittal vertical axis (SVA) greater than 5 cm. All patients had greater than one-year follow-up and were assessed with pre- and post-operative 36” standing X-Rays, Oswestry Disability Index (ODI) and SF-36.

Results: The mean operative time was 364 minutes with an average of 793 cc of blood loss. Average inpatient length of stay was 5.4 days, with 57% discharged to inpatient rehabilitation. The pre-operative mean Cobb angle was 44.4°, corrected to 15.9°. The pre-operative mean coronal alignment was 5.8 cm, corrected to 1.8 cm. The pre-operative mean lumbar lordosis was 16.1°, corrected to 45.3°. The pre-operative mean SVA was 9.5 cm, corrected to 3.2 cm. The pre-operative pelvic tilt was 35.6°; at last follow-up it was 26°. A mean preoperative ODI of 39.3 improved to 13.7 at last follow-up.

Conclusions: Mini-open PSO is a promising method with sufficient power to correct sagitally imbalanced spinal deformities. More research with larger case series and long-term follow-up will be necessary to validate the widespread applicability of this technique, but these initial results show substantial increases in lumbar lordosis with lower blood loss than traditional open surgery.