Stratifying outcome based on the Oswestry Disability Index for operative treatment of adult spinal deformity on patients 60 years of age or older: a multicenter, multi-continental study on Prospective Evaluation of Elderly Deformity Surgery (PEEDS).

BACKGROUND CONTEXT

Patients with adult spinal deformity suffer from disease related disability as measured by the Oswestry Disability Index (ODI) for which surgery can result in significant improvements.

PURPOSE

The purpose of this study was to show the change in overall and individual components of the ODI in patients aged 60 years or older following multi-level spinal deformity surgery.

STUDY DESIGN

Prospective, multicenter, multi-continental, observational longitudinal cohort study PATIENT SAMPLE: Patients ≥60 years undergoing primary spinal fusion surgery of ≥5 levels for coronal, sagittal or combined deformity.

OUTCOME MEASURES

Oswestry Disability Index (ODI) METHODS: : Patients completed the ODI pre-operatively for baseline, then at 10 weeks, 12 months and 24 months post-operatively. ODI scores were grouped into deciles, and change was calculated with numerical score and improvement or worsening was further categorized from baseline as substantial (≥20%), marginal (≥10-<20%) or no change (within 10%).

RESULTS

Two-hundred nineteen patients met inclusion criteria for the study. The median number of spinal levels fused was 9 [Q1=5.0, Q3=12.0]. Two-year mean (95% CI) ODI improvement was 19.3% (16.7%; 21.9%; p<.001) for all age groups, with mean scores improved from a baseline of 46.3% (44.1%; 48.4%) to 41.1% (38.5%; 43.6%) at 10 weeks (p<.001), 28.1% (25.6%; 30.6%) at 12 months (p<.001), and 27.0% (24.4%; 29.5%) at 24 months (p<.001). At 2 years, 45.5% of patients showed 20% or greater improvement in ODI, 23.7% improved between 10% and 20%, 26.3% reported no change (defined as±10% from baseline), 4.5% of patients reported a worsening between 10% to 20%, and none reported worsening greater than 20%. 59.0% of patients were severely disabled (ODI >40%) pre-operatively, which decreased to 20.2% at 2 years. Significant improvement was observed across all 10 ODI items at 12 and 24 months. The largest improvements were seen in pain, walking, standing, sex life, social life and traveling.

CONCLUSIONS

In this prospective, multicenter, multi-continental study of patients 60 years or older undergoing multi-level spinal deformity surgery, almost 70% of patients reported significant improvements in ODI without taking into account surgical indications, techniques or complications. Clear data is presented demonstrating the particular change from baseline for each decile of pre-operative ODI score, for each sub-score, and for each age group.