Posterior decompression and spinous process reconstruction for lumbar spinal stenosis in a pediatric patient with achondroplasia: a case report.

BACKGROUND: Achondroplasia is the most prevalent form of skeletal dysplasia and is characterized by rhizomelia, short stature, and distinctive facial features. Achondroplasia is frequently accompanied by spinal canal stenosis because of the distinctive morphology of the spine. For pediatric lumbar spinal canal stenosis, a meticulously constructed surgical plan is needed to prevent complications such as the development of thoracolumbar kyphosis. CASE PRESENTATION: An 11-year-old Asian boy with achondroplasia presented with bilateral lower limb numbness and intermittent claudication, which limited his walking distance to 100 m. Imaging revealed multilevel lumbar spinal canal stenosis from T12 to S1, with the most stenosis at the L4/5 level. Laminotomy with spinous process reconstruction using mini plates was performed to preserve the midline posterior tension band. The patient's postoperative course was uneventful, with immediate symptom resolution and no symptoms of recurrence or signs of kyphotic deformity at the 2-year follow-up. DISCUSSION: Achondroplasia-associated lumbar spinal canal stenosis arises from anatomical constraints, such as shortened pedicles and short interpedicular distances. Surgical intervention must provide effective decompression without increasing the risk of postoperative thoracolumbar kyphosis. This case highlights the importance of preserving posterior elements that are responsible for maintaining spinal stability and the pertinence of avoiding extensive fixation, particularly in pediatric patients with achondroplasia. CONCLUSION: This case demonstrates that, in patients with achondroplasia, laminotomy with spinous process reconstruction can effectively address lumbar spinal canal stenosis and preserve posterior elements with a minimal risk of complications. Long-term follow-up remains crucial for monitoring the potential development of thoracolumbar kyphosis.