Achondroplasia

Background

 

Among the skeletal dysplasias, spinal deformity is seen most commonly in patients with achondroplasia. 

 

Issues

 

1.  Thoracolumbar kyphosis

 

Occurs in almost all patients prior to walking

- non rigid, likely due to hypotonia

- resolves with ambulation

 

Bracing may help to prevent clinically significant kyphosis

- persists in approximately 15% to 20% of patients

 

2.  Spinal Stenosis

 

Pathology

- Short pedicles

- narrow interpedicular distance 

- Stenosis may be present at any level from the foramen magnum down

- most commonly L1-S1

 

Symptoms

 

Over 50% of patients with achondroplasia have back pain

- other symptoms may include leg pain, claudication, paresthesias, weakness, and paraplegia. 

- Bowel and bladder difficulties may occur with stenosis in the lower thoracic spine

 

Symptoms usually occur in early adulthood and are slowly progressive

- Occasionally, symptoms may arise in childhood

 

Surgical decompression

 

Wide, multilevel laminectomies

- Disc removal usually is not indicated 

- unless radiculopathy is present

- Early surgical intervention leads to a better outcome

 

Postlaminectomy instability may occur

- fusion probably should be added in cases of multilevel decompression

 

3.  TL kyphosis + stenosis

 

Anterior decompression and strut grafting should be added