Full-Body Radiographic Analysis of Postoperative Deviations From Age-Adjusted Alignment Goals in Adult Spinal
Peter G Passias1, Cyrus M Jalai1, Bassel G Diebo2
1Department of Orthopaedic Surgery, Hospital for Joint Diseases, NYU Langone Medical Center, New York, New York.
International Journal of Spine Surgery
|May 28, 2019
Summary
Adult spinal deformity surgery improves alignment, but undercorrection leads to compensatory pelvic and lower-limb flexion. This study quantifies patient-specific correction against age-adjusted goals for spinal deformity.
Area of Science:
- Spine surgery
- Orthopedic biomechanics
- Radiographic analysis
Background:
- Full-body stereographs aid in assessing adult spinal deformity (ASD) and its impact on lower-limb compensation.
- Age-adjusted goals for ASD parameters enable individualized evaluation of surgical realignment success.
- Postoperative radiographic assessment of patient-specific correction against these goals is crucial.
Purpose of the Study:
- To analyze pre- and postoperative sagittal alignment in ASD patients.
- To quantify patient-specific correction relative to age-adjusted goals.
- To investigate compensatory mechanisms in patients with postoperative alignment deviations.
Main Methods:
- Retrospective review of 122 adult ASD patients with biplanar full-body stereographic X-rays.
- Comparison of postoperative alignment to age-adjusted ideal values for sagittal vertical axis, pelvic tilt, and PI-LL.
- Analysis of spinal alignment and compensatory mechanisms (e.g., pelvic shift, knee flexion) in matched versus unmatched (undercorrected/overcorrected) groups.
Main Results:
- Significant improvements in sagittal vertical axis, pelvic tilt, PI-LL, knee flexion, and pelvic shift postoperatively.
- High rates of undercorrection to age-adjusted targets: 30.3% (SVA), 41.0% (pelvic tilt), 43.6% (PI-LL).
- Undercorrections recruited increased pelvic shift and knee flexion; PI-LL undercorrections showed thoracic hypokyphosis, all leading to larger global sagittal angles.
Conclusions:
- Surgical correction of adult spinal deformity leads to global alignment improvements.
- Undercorrection relative to age-adjusted targets necessitates compensatory pelvic and lower-limb flexion.
- Patient-specific alignment goals are essential for optimizing surgical outcomes in ASD.
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