242 - Pulmonary Function Following Adult Spinal Deformity Surgery: Minimum T...

#242 Pulmonary Function Following Adult Spinal Deformity Surgery: Minimum Two Year Follow-up

Oral Posters: Deformity

Presented by: J. Cody

Author(s):

R.A. Lehman (1)
D.G. Kang (1)
L.G. Lenke (2)
J.J. Stallbaumer (2)
B.A. Sides (2)
J. Cody (1)

(1) Walter Reed National Military Medical Center, Orthopaedic Surgery, Bethesda, MD, USA
(2) Washington University School of Medicine, Orthopaedic Surgery, St Louis, MO, USA

Abstract

Introduction: Pulmonary function following adult spinal deformity remains uncertain. We hypothesized patients with pre-op PFT impairment (< 65% pred FEV1) and those undergoing revision surgery may be at risk for exacerbated decline in pulmonary function.

Methods: PFTs were prospectively collected on 164 adult spinal deformity patients (150F, 14M, avg age 45.9) undergoing surgical treatment at a single institution, with minimum 2 yr follow-up (avg 2.81). There were 100 (61%) primary and 64 (39%) revision surgery patients, and the majority had posterior only surgery (77%). Radiographs for 154 patients were analyzed for main thoracic (MT) and sagittal T5-T12 (Sag) curve magnitude/correction.

Results: For all patients, there was a significant change in MT Cobb from 47.4 to 24.9 deg (avg -22.5, p=0.00), and Sag Cobb from 35.5 to 30.0 deg (avg -5.41, p=0.00). We also found a significant decline in absolute and %pred PFT, with %pred FEV1 and %pred FVC decreasing 5.26% (p=0.00) and 5.74% (p=0.00), respectively. A clinically significant decline (≥10%pred FEV1) was observed in 27% of patients. PFT impairment increased from 14 (8%) patients pre-op to 23 (14%) patients after surgery, but was not statistically significant (p=0.31). Interestingly, patients with pre-op PFT impairment had a significant improvement in absolute and %pred FEV1 after surgery compared to those without pre-op impairment (2.8% v -6.19%, p=0.03), with no significant differences in MT/Sag curve correction between the two groups. Revision surgery patients had no difference in post-op %pred PFTs, however there were significantly more patients with a clinically significant decline in PFTs [23 (35%) v 22 (22%), p=0.03].

Conclusion: We performed the largest study to date evaluating pulmonary function tests in adult deformity patients, and found a significant decline in all measures of pulmonary function at 2 years following surgical correction. Surprisingly, patients with pre-op PFT impairment had improvement in absolute and %pred PFTs postoperatively. Revision surgery more frequently resulted in a clinically significant decline in PFTs.