Larsen syndrome with C3-C4 spondyloptosis and atlantoaxial dislocation in an adult

Study design This is a clinical case report with a review of relevant literature. Objective To describe a case of Larsen syndrome with C3-C4 spondyloptosis and atlantoaxial dislocation in a middle-aged female patient and to discuss management strategies. Summary of background data Spondyloptosis of the cervical spine is relatively rare and is caused by trauma, destruction of the vertebral bodies by tumors, or tuberculosis. Such gross vertebral displacement is usually associated with significant neurological deficits. Larsen syndrome is characterized by multiple joint displacements and can, very rarely, be associated with nontraumatic spondyloptosis of the cervical vertebra. A single case report of C1-C2 joint laxity causing atlantoaxial dislocation in a patient with Larsen syndrome is available in literature. No reports of any patient (with Larsen syndrome or nonsyndromic) who had both cervical spondyloptosis and atlantoaxial dislocation are available in literature. Methods A 36-year-old female presented with chronic neck pain, bilateral hand deformity, and mild spasticity involving all 4 limbs. Cervical radiograph, computed tomographic scan, and magnetic resonance image revealed C3-C4 spondyloptosis and atlantoaxial dislocation. Results A combined ventral decompression of subaxial spine and instrumentation from C2 to C5, followed by posterior C1-C2 distraction arthroplasty and lateral mass stabilization of the subaxial spine up to C6, was done. The cervical deformity was corrected, and the patient remains symptom free. Conclusion Patients with spondyloptosis of the cervical spine can rarely present with chronic neck pain and minimal neurological deficits. An additional pathology, such as atlantoaxial dislocation, can add to the complexity. Circumferential stabilization and fusion would be required in such cases to achieve a good outcome. Larsen syndrome is a rare cause of nontraumatic cervical displacements.