Neurosurgery and Neuroscience

Ossified ligamentum flavum (OLF) is a condition of heterotopic lamellar bone formation within the yellow ligament. Ossification of the ligamentum Flavum (OLF) was discovered by Polgar and further described by Yamaguchi and Isuruni. It is mostly prevalent in Japan and other East Asian countries such as Korea and China. Achondroplasia is a genetic disorder of bone growth with congenital spinal stenosis being a well-known complication. Degenerative changes of the spine, such as disc herniation, degenerative spondylosis and arthrosis result in worsening of stenosis. However, symptomatic spinal stenosis due by ossification of the ligamentum flavum (OLF) in achondroplasia is extremely rare. The case presented here is a rare case of spinal stenosis due to ossified ligamentum flavum in a 30 year old Indian female of achondroplasia, who presented with difficulty in walking along with flexor spasms and along with bilateral lower limb progressive sensory loss. Clinical examination and radiological findings were suggestive of dorsal myelopathy at D10-D11-D12 level. We did bilateral D10-11-12 pedicle screw and rod fixation and D10-D12 laminectomy with cord decompression with good post-operative recovery.