Impact of Scoliosis Surgery on Ambulatory Motor Function in SMA Type 3: A Case Study


Clinical Management

Poster Number: 22


Cara Yochai, PT, DPT, Columbia University Medical Center, Jacqueline Montes, PT, EdD, Columbia University Medical Center, Rafael Rodriguez-Torres, PT, DPT, Columbia University Medical Center, Manroop Chawla, PT, DPT, Columbia University Medical Center, Sally Dunaway Young, PT, DPT, Stanford University Medical Center, Claudia A. Chiriboga, MD, MPH, Columbia University Medical Center, Darryl De Vivo, MD, Columbia University Medical Center

Scoliosis may develop with Spinal Muscular Atrophy (SMA) as well as typically developing adolescents, among other populations. Most literature describes scoliosis in non-ambulatory SMA versus ambulatory, given axial weakness. Conservative management includes bracing and monitoring curves greater than 15-20 degrees. Surgery is considered as curves progress. Surgery has a negative impact on gross motor function but the impact on ambulatory function has not been formally assessed.

We report a male child with SMA Type 3 followed at Columbia University Irving Medical Center’s Pediatric Neuromuscular Clinic from 2010-2021. Scoliosis developed at age 14 years, it is unclear whether the scoliosis is adolescent idiopathic or neuromuscular. Chart review of ambulatory function included the six-minute walk test (6MWT), and other analyses including evaluation of spatial and temporal parameters of gait. Scoliosis was assessed using Cobb angle. Data is presented 10 years prior to the development of scoliosis and 6 months after spinal fusion.

Independent ambulation was achieved at age 14 months with symptom onset at 27 months. Cobb angle at scoliosis diagnosis was right upper thoracic T1-T6: 18 degrees, left thoracic T8-L1: 31 degrees. Disease modifying therapy was initiated at age 11 years. Conservative management included physical therapy, Schroth method, and thoracic bracing 18 hours/day. Spinal fusion was performed at age 14 years when Cobb angle reached right upper thoracic T1-T6: 25 degrees, left thoracic T8-L1:47 degrees. 6MWT ranged from 374-258 meters during the 10 years before scoliosis was identified, 431 meters pre-surgery to 314 meters 6 months post-surgery.

Changes were observed in ambulatory function after scoliosis surgery. Factors including puberty, anxiety, and perception of COVID restrictions (i.e. mask wearing) may have influenced 6MWT trajectories pre and post-surgery. It is imperative that possible co-morbidities such as scoliosis, be monitored and the functional impact understood.