Lessons learned from surgical management of craniovertebral instability in Morquio syndrome: A series of four unusual cases.

Morquio syndrome (MS) is an autosomal recessive defect caused by the deficiency of N-acetylgalactosamine-6-sulfatase. Odontoid hypoplasia, periodontoid soft tissue deposition, and cervical stenosis lead to myelopathy and quadriparesis in these patients. Craniovertebral junction instability in MS possesses a surgical challenge as bones are yet to completely ossify. The atlantoaxial dislocation (AAD) is reducible, and the need of transoral decompression for the soft tissue deposition ventral to odontoid is debatable. We present a series of four cases (mean age 4.3 ± 0.4 years) operated through posterior-only approach (n = 2, C1-lateral mass to C2 pars-interarticularis [Goel's technique]; n = 1 sublaminar wiring followed by C1-lateral mass to C2 pars-interarticularis; and n = 1 suboccipital plate with pars-interarticularis of C2 screw and pedicle of C3 and rod fixation). All patients had acceptable outcome and doing well at the last follow-up (12-96-follow-up). None of our patient needed transoral decompression. Patients with MS frequently manifest with spastic quadriparesis at an early age due to reducible AAD. Early surgical fixation with posterior C1-C2 screw and rod technique is recommended for the favorable surgical outcome and long-term stability of the cervical spine.