Musculoskeletal · Spine · 1.0
Meyerding grading of spondylolisthesis
Radiographic grading of anterior vertebral slip expressed as the percentage translation of the superior vertebral body over the vertebra below, graded I to V.
Purpose
To quantify the degree of anterior translation in spondylolisthesis on a lateral radiograph (or midline sagittal CT/MRI) by expressing the slip as a percentage of the anteroposterior width of the superior endplate of the vertebra below, giving a reproducible grade that guides communication and correlates broadly with severity.
| Grade | Percentage slip | Reporting and management implication |
|---|---|---|
| Grade I | 0-25% | Low grade; commonly managed non-operatively unless symptomatic instability or radiculopathy |
| Grade II | 26-50% | Low grade; assess pars defect, disc degeneration and dynamic instability |
| Grade III | 51-75% | High grade; surgical assessment usually warranted |
| Grade IV | 76-100% | High grade; deformity and sagittal balance assessment required |
| Grade V (spondyloptosis) | >100% | Superior vertebral body has translated completely off the vertebra below; complex reconstructive surgery |
How to use it
- Measure on a true lateral standing radiograph: divide the superior endplate of the caudal vertebra into four equal parts and record which quarter the posteroinferior corner of the slipped vertebral body lies over.
- The denominator is the anteroposterior width of the endplate of the LOWER (caudal) vertebra, not the slipped vertebra; using the wrong denominator changes the grade at L5-S1 where the sacral endplate is wider.
- Grades I-II are conventionally termed low grade and grades III-V high grade; this split, rather than the individual grade, is what usually drives surgical decision-making.
- Meyerding grades severity only. It says nothing about aetiology, which is described separately by the Wiltse classification (dysplastic, isthmic, degenerative, traumatic, pathological, iatrogenic).
- Supine cross-sectional imaging may underestimate the slip; standing lateral and flexion-extension views better demonstrate the true grade and dynamic instability.
Common mistake
Grading a slip on supine MRI or CT and reporting it as the definitive grade, or measuring the translation against the width of the slipped vertebra instead of the vertebra below — both systematically misclassify the grade.
Exam pearl
Quarters of the LOWER endplate: I 0-25%, II 26-50%, III 51-75%, IV 76-100%, V >100% = spondyloptosis. Low grade = I-II, high grade = III-V.
Viva questions
- What does the Meyerding system grade?
- It grades the degree of anterior translation in spondylolisthesis as a percentage of the anteroposterior width of the superior endplate of the vertebra below, on a lateral radiograph.
- Enumerate the Meyerding grades.
- Grade I 0-25%, grade II 26-50%, grade III 51-75%, grade IV 76-100%, and grade V or spondyloptosis when the slip exceeds 100%.
- How exactly do you make the measurement?
- On a true lateral standing film, divide the superior endplate of the caudal vertebra into quarters and see which quarter the posteroinferior corner of the slipped vertebral body overlies; that quarter gives the grade.
- What is meant by low-grade versus high-grade slip?
- Grades I and II are low grade and grades III to V are high grade; the high-grade group generally requires surgical assessment and sagittal balance evaluation.
- How does Meyerding differ from the Wiltse classification?
- Meyerding quantifies severity of the slip, whereas Wiltse classifies aetiology into dysplastic, isthmic, degenerative, traumatic, pathological and iatrogenic types; the two are complementary and both should be reported.
- What are the common pitfalls in applying the grade?
- Using the width of the slipped vertebra rather than the vertebra below as the denominator, and grading only on supine CT or MRI, which can underestimate a slip that reduces when the patient lies down.