Heterotopic Osteotomy for Intrathecal Baclofen Test Dose Administration in a Pediatric Patient With Spinal Fusion: A Technical Note

BACKGROUND AND IMPORTANCE: Intrathecal baclofen (ITB) pumps are used for the treatment of pediatric movement disorders that are rapidly progressive or do not respond to medical management. An ITB test dose is indicated in patients who have mixed tone, when the family remains unconvinced, or when insurance companies require it. Test doses are typically delivered by lumbar puncture; however, lumbar puncture in patients with heterotopic ossification of the lumbar vertebrae after a previous spinal fusion is not possible. To our knowledge, we present the first technical note describing a heterotopic osteotomy to access the subarachnoid space for a complex ITB test dose in a pediatric patient with a spinal fusion. CLINICAL PRESENTATION: We present a 14-year-old woman with spastic, dystonic quadriplegic cerebral palsy, neuromuscular scoliosis, and previous T3-pelvis posterior spinal fusion. She continued to have significant dystonia and spasticity despite maximal medical management and was offered ITB therapy. A complex ITB test dose through heterotopic osteotomy was performed with excellent clinical results, and the patient will ultimately receive an ITB pump. CONCLUSION: Heterotopic ossification following spinal fusion is not a contraindication to an ITB test dose. A heterotopic osteotomy is a feasible surgical approach to administer an ITB test dose in these pediatric patients.