Clinical outcomes and radiological findings in adult achondroplasia patients with lumbar spinal stenosis

Abstract

Achondroplasia is commonly complicated by lumbar spinal stenosis (LSS), which can cause neurogenic claudication and recurrent neurological symptoms. This research investigated radiological severity, sagittal alignment, thoracolumbar kyphosis (TLK), and paraspinal muscle degeneration in adults with achondroplasia. Lumbar decompression was associated with Schizas grade C/D stenosis or a dural sac cross-sectional area (DSCA) below 62 mm². Sagittal analysis showed increased TLK, pelvic tilt, and sacral slope, with limited compensatory capacity compared with individuals without achondroplasia. Greater TLK was associated with more severe upper lumbar stenosis, while increased sagittal vertical axis and pelvic tilt were associated with reduced DSCA at lower lumbar levels. TLK was also associated with poorer functional outcomes, particularly when combined with severe stenosis. Furthermore, greater fat infiltration of the erector spinae was associated with worse clinical outcomes, suggesting a relationship between spinal alignment and muscle degeneration. Overall, TLK is an important component of spinal pathology in achondroplasia. However, current evidence does not support routine deformity correction; lumbar decompression remains the preferred treatment for most adults.