Larger Lumbar Vertebral Body Osteophyte Volume Is Associated With Older Age and a More Caudal Vertebral Level in Individuals With Chronic Low Back Pain.

BACKGROUND

Chronic low back pain (cLBP) is often accompanied by changes in lumbar spine bony morphology, including osteophyte growth. Knowledge of the volume and location of osteophytes could provide insight into habitual loading that may induce symptomatic disc degeneration and serve to guide treatment. The aim of this study was to develop an automated method to calculate osteophyte volume in lumbar vertebral bodies and to evaluate the relationships between osteophyte volume and vertebral level, age, and sex.

METHODS

Patients with cLBP received computed tomography (CT) scans of their entire lumbar spine. Lumbar bone models were created from the segmented CT scans. A Procrustes-based registration algorithm transformed vertebral bodies from a reference library of bones with no osteophytes to match the patient's vertebral bodies. The best-matched reference bone was then subtracted from the original bone to create a model of the osteophytes. Osteophyte volume and location were calculated from the model, and associations were explored between osteophyte volume, vertebral level, sex, and age. Regional differences in osteophyte volume were also evaluated.

RESULTS

The osteophyte identification algorithm was validated to have a bias of -4.7 mm3 and accuracy of 109.7 mm3. Osteophyte volume increased an average of 147.8 mm3 with each caudal vertebral level. Osteophyte volume was greater in men than in women and increased between 34.3 and 47.7 mm3 with each year of age. The superior half of L1 and L2 had 20%-35% greater osteophyte volume than the inferior half.

CONCLUSIONS

Osteophyte volume increased with more caudal vertebrae, was greater in men than in women, and increased by approximately 40 mm3 with each year of age in 264 individuals with cLBP.