Smitha E Mathew1, J Blade Hargiss2, Todd A Milbrandt1, Anthony A Stans1, William J Shaughnessy1, A Noelle Larson3. 1. Department of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA. 2. Mayo Clinic Alix School of Medicine, Rochester, MN, USA. 3. Department of Orthopedic Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA. larson.noelle@mayo.edu.
Abstract
PURPOSE: Direct comparisons between vertebral body tethering (VBT) and posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) are limited. We aimed to evaluate 2-year results of VBT and PSF to report comparative outcomes. METHODS: 26 prospectively enrolled VBT patients were matched 1:1 by age, gender, Risser sign and major curve magnitude with PSF patients. At a minimum 2-year follow-up, surgical results and radiographic outcomes were reviewed. RESULTS: Operative time, anesthesia time, blood loss, and length of stay were significantly lower in the VBT group (< 0.001, p = 0.003, p < 0.001, p < 0.001, respectively). The major curve at 2 years was corrected by 46% in the VBT group vs. 66% in the PSF (p = 0.0004). Success following VBT, defined as no fusion surgery and Cobb angle < 35° at the 2-year follow-up, was seen in 20 VBT patients (77%) (p = 0.0003) and correlated with mean Cobb angle of < 35° on 3-month imaging. 12 VBT patients (46%) showed curve improvement over time, and those patients had significantly lower mean Cobb angle on the 3-month radiograph than non-modulators (23° vs 31°, p = 0.014). At 2 years, cord breakage occurred in five patients (19%). By 2 years, three VBT patients developed complications (2 pleural effusion and 1 overcorrection needing return to OR). In contrast to PSF, growth continued at T1-T12 (mean 13 mm) and over the instrumented levels (mean 10 mm) following VBT, compared to no growth over instrumented segments in the fusion cohort (p = 0.011, p = 0.0001). CONCLUSION: In Sanders stages 3 and 4 patients treated in the USA, Cobb angle < 35° on 3-month imaging was associated with success at the 2-year follow-up. Curve correction was superior in the PSF group with 96% achieving curve correction to < 35° vs. 77% of the VBT patients. Cord breakage was noted in 19% of VBT patients at the 2-year follow-up. Three patients developed complications in both the VBT and PSF cohorts. LEVEL OF EVIDENCE: Level II (prospective study with matched retrospective comparison group).
PURPOSE: Direct comparisons between vertebral body tethering (VBT) and posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) are limited. We aimed to evaluate 2-year results of VBT and PSF to report comparative outcomes. METHODS: 26 prospectively enrolled VBT patients were matched 1:1 by age, gender, Risser sign and major curve magnitude with PSF patients. At a minimum 2-year follow-up, surgical results and radiographic outcomes were reviewed. RESULTS: Operative time, anesthesia time, blood loss, and length of stay were significantly lower in the VBT group (< 0.001, p = 0.003, p < 0.001, p < 0.001, respectively). The major curve at 2 years was corrected by 46% in the VBT group vs. 66% in the PSF (p = 0.0004). Success following VBT, defined as no fusion surgery and Cobb angle < 35° at the 2-year follow-up, was seen in 20 VBT patients (77%) (p = 0.0003) and correlated with mean Cobb angle of < 35° on 3-month imaging. 12 VBT patients (46%) showed curve improvement over time, and those patients had significantly lower mean Cobb angle on the 3-month radiograph than non-modulators (23° vs 31°, p = 0.014). At 2 years, cord breakage occurred in five patients (19%). By 2 years, three VBT patients developed complications (2 pleural effusion and 1 overcorrection needing return to OR). In contrast to PSF, growth continued at T1-T12 (mean 13 mm) and over the instrumented levels (mean 10 mm) following VBT, compared to no growth over instrumented segments in the fusion cohort (p = 0.011, p = 0.0001). CONCLUSION: In Sanders stages 3 and 4 patients treated in the USA, Cobb angle < 35° on 3-month imaging was associated with success at the 2-year follow-up. Curve correction was superior in the PSF group with 96% achieving curve correction to < 35° vs. 77% of the VBT patients. Cord breakage was noted in 19% of VBT patients at the 2-year follow-up. Three patients developed complications in both the VBT and PSF cohorts. LEVEL OF EVIDENCE: Level II (prospective study with matched retrospective comparison group).
Authors: Nicole Michael; Patrick Carry; Mark Erickson; Nikki Bloch; Steven Gibbons; Courtney O'Donnell; Sumeet Garg Journal: Spine (Phila Pa 1976) Date: 2018-02-15 Impact factor: 3.468
Authors: Peter O Newton; Carrie E Bartley; Tracey P Bastrom; Dylan G Kluck; Wataru Saito; Burt Yaszay Journal: J Bone Joint Surg Am Date: 2020-05-06 Impact factor: 5.284