J Pediatr Orthop. 2026 Feb 23. doi: 10.1097/BPO.0000000000003226. Online ahead of print.
ABSTRACT
BACKGROUND: Vertebral body tethering (VBT) is a growth-modulating technique in treatment of AIS. While the use of a double row of screws for anchoring of the tether in the apex has been proposed to reduce the risk of tether breakage and improve correction, there is limited evidence supporting this.
METHODS: Patients ≤16 years of age with AIS who underwent anterior VBT with 2-year minimum follow-up were included in the study. We performed 3 separate analyses comparing main thoracic only (T), thoracolumbar only (TL), and combined thoracic/thoracolumbar (T/TL) tether constructs used in either single-row (SRVBT) or double-row VBT (DRVBT). Independent sample t tests and χ2 analyses were performed for comparison of characteristics and main outcomes, including percent surgical correction, rates of tether breakage, and rates of revision.
RESULTS: A total of 227 patients were enrolled in the study (190 SRVBT: 37 DRVBT). Across T, TL, and T/TL cohorts, DRVBT patients were more skeletally mature based on differences in mean Rissers (2.9 vs. 0.7, P<0.05). In our TL cohorts, patients with DRVBT had significantly greater percent correction at early post-op (75% vs. 51%, P=0.003) and better correction at 2 years (DRVBT 50% vs. SRVBT 33%, P=0.279). SRVBT experienced higher rates of revision (39% vs. 7%, P=0.077) and had a higher conversion to fusion rate (23% vs. 0%, P=0.098) compared with DRVBT in the setting of a thoracolumbar tether. In our T analysis, though DRVBT had greater correction at post-op and 2 years, this was not statistically significant (P>0.05). In addition, no significant differences were found in tether breakage (SRVBT 53% vs. DRVBT 50%, P=1.000) or revision (SRVBT 7% vs. DRVBT 0%, P=1.000). In patients with T/TL constructs, 2-year outcomes for correction, tether breakage (DRVBT 85% vs. SRVBT 79%, P=1.000), and revision (DRVBT 15% vs. SRVBT 0%, P=0.206) were statistically nondifferent between groups.
CONCLUSIONS: While results of tether breakage were not statistically different between the SRVBT and DRVBT, DRVBT had greater initial and long-term correction for TL curves along with lower revision and fusion rates.
LEVEL OF EVIDENCE: Level III.
PMID:41725412 | DOI:10.1097/BPO.0000000000003226
