The Global Alignmnet and Proportion (GAP) score is a PI-based individualized method of analyzing the sagittal plane that effectively predicts mechanical complications of surgery for adult spinal deformity.
| Parameters |
Results |
Subgroups |
Scores |
| Age Factor ⓘ |
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| RPV ⓘ |
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| RLL ⓘ |
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| LDI ⓘ |
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| RSA ⓘ |
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ⓘ
GAP Score
The GAP score comprises the relative pelvic version (RPV= Measured minus Ideal SS), relative lumbar lordosis (RLL= Measured minus Ideal LL), lordosis distribution index (LDI= L4-S1 lower-arc lordosis / L1-S1 total lordosis x100), relative spinopelvic alignment (RSA= Measured minus Ideal GT), and an age factor (<60 vs ≥60).
| Preoperative Planning |
| SS |
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| L1-S1 |
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| L4-S1 |
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| GT |
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The GAP score is a continuum of states that provides an individualized indication of pelvic version, magnitude and distribution of lumbar lordosis, and global spinopelvic alignment to assess disproportion compared with the calculated “ideal” for any given subject.
Setting surgical goals in the sagittal plane on the basis of the proportional indices reflected by the GAP score may decrease the rate of mechanical complications.
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