Risk of Progression in De Novo Low-Magnitude Degenerative Lumbar Curves: Natural History and Literature Review

Natural history studies have focused on risk for progression in lumbar curves of more than 30°, while smaller curves have little data for guiding treatment. We studied curve progression in de novo degenerative scoliotic curves of no more than 30°.

Radiographs of 24 patients (17 women, 7 men; mean age, 68.2 years) followed for up to 14.3 years (mean, 4.85 years) were reviewed. Risk factors studied for curve progression included lumbar lordosis, lateral listhesis of more than 5 mm, sex, age, convexity direction, and position of intercrestal line.

Curves averaged 14° at presentation and 22° at latest follow-up and progressed a mean of 2° (SD, 1°) per year. Mean progression was 2.5° per year for patients older than 69 years and 1.5° per year for younger patients. Levoscoliosis progressed 3° per year and dextroscoliosis 1° per year (P<.05). Forty-six percent of patients had lateral listhesis of more than 5 mm at L3 and L4.

Curve progression was not linear and might occur rapidly, particularly in women older than 69 with lateral listhesis of more than 5 mm and levoscoliosis. Small curves can progress and therefore should be individualized in the context of other risk factors.