Thoracoscopic Vertebral Body Tethering for Adolescent Idiopathic Scoliosis

Abstract

Study Design. Retrospective analysis of prospectively collected data. Objective. To report the follow-up curve behaviors in different Sanders staging groups. Summary of Background Data. Vertebral body tethering (VBT) is a growth modulation technique that allows gradual spontaneous follow-up curve correction as the patient grows. There is a lack of scientific evidence regarding appropriate patient selection and timing of implantation. Methods. Patients were grouped into five as: Sanders 1, 2, 3, 4–5, and 6–7. Data were collected preoperatively, at the day before discharge, and at each follow-up. Outcome measures were pulmonary and mechanical complications, readmission, and reoperation rates. Demographic, perioperative, clinical, radiographic, and complication data were compared using Fisher–Freeman–Halton exact tests for categorical variables and Kruskal-Wallis tests for the continuous variables. Results. Thirty-one (29 F, 2 M) consecutive patients with a minimum of 12 months of follow-up were included. The mean age at surgery was 12.1 (10–14). The mean follow-up was 27.1 (12–62) months. The mean preoperative main thoracic curve magnitude was 47° ± 7.6°. For all curves, preoperative and first erect curve magnitudes, bending flexibility, and operative correction percentages were similar between groups (for all comparisons, P > 0.05). The median height gained during follow-up was different between groups (P < 0.001), which was reflected into median curve correction during follow-up. Total curve correction percentage was different between groups (P = 0.009). Four (12.9%) patients had pulmonary and six (19.4%) had mechanical complications. One (3.2%) patient required readmission and two (6.5%) required reoperation. Occurrence of pulmonary complications was similar in Sanders groups (P = 0.804), while mechanical complications and overcorrection was significantly higher in Sanders 2 patients (P = 0.002 and P = 0.018). Conclusion. Follow-up curve behavior after VBT is different in patients having different Sanders stages. Sanders 2 patients experienced more overcorrection, thus timing and/or correction should be adjusted, since Sanders 3, 4, and 5 patients displayed a lesser risk of mechanical complications. Level of Evidence: 3.

Radiographic Results after Vertebral Body Tethering

“…A further 137 studies were excluded for the following reasons: not matching the topic of interest (n = 107), not a clinical study (n = 19), insufficient clinical details or insufficient follow-up (n = 8), fewer than 5 patients (n = 1). Nine studies met all inclusion criteria and were analysed for the present study 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 . The literature search is shown in Fig.…”

“…Weitere 137 Studien wurden aus folgenden Gründen ausgeschlossen: thematisch nicht zutreffend (n = 107), keine klinische Studie (n = 19), unzureichende klinische Angaben oder nicht ausreichendes Follow-up (n = 8), weniger als 5 Patienten (n = 1). Neun Studien erfüllten alle Einschlusskriterien und wurden für die vorliegende Arbeit analysiert 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 . Die Literaturrecherche ist in Abb.…”

Vertebral body tethering: An alternative to posterior spinal fusion in idiopathic scoliosis?

“…Miyanji et al published on 55 immature patients Risser 0.5 showing clinical success in 77% and 8% insufficient correction requiring conversion to PSF ( 19 ). Alanay et al reported on mature cohort of Sanders score 6–7 with 100% success, 55% correction and residual curve (9°–27°) at 20 months and Meyers et al reported on 49 mature patients with 76% success, 41% tether breakage and 2% revision with PSF at 32.5 months ( 8 , 26 ). Figures 4 – 6 showcase a 14-year-old female (Sanders 7) that underwent T12-L4 anterior tethering with correction of the curve from 42° to 17° postoperatively and the patient being well balanced at 6-months post surgery.…”

“…Newton et al was first to report that skeletally immature patients continue to correct and even go to overcorrection to 121% as compared to mature adolescents whose tethers act as permanent tether rather than as true growth modulators ( 9 , 23 , 24 ). Alanay and colleagues noticed that overcorrection and mechanical complications are more common in Sanders 2 group ( 26 ). Such observation is avoided by delaying VBT until patient skeletally matures to Sanders stage 3 and is treated with removal of tether to avoid further curvature modification ( 23 , 26 ).…”

Motion preservation surgery for scoliosis with a vertebral body tethering system: a biomechanical study

“…Primary stability is an important requirement for VBT implants, and it would be preferred if the implants last at least until skeletal maturity, which in some cases, could last a few years from the time of surgery. Short-term success rates (no fusion required) after VBT have been observed [27], but tether breakages seem to be one of the most frequently observed implant-related complications, which may make results after VBT less predictable. However, the definition of success remains controversial.…”