PURPOSE: Vertebral body tethering (VBT) has shown promising results but also a high tether breakage rate, which has been reported in up to 48% of patients. Tether breakages can lead to loss of correction, and the most used definition for tether breakage is a loss of segmental correction of > 5°. However, there may also be some breakages that do not have a negative influence on curve correction. Analyzing the real breakage rate was the aim of this study. METHODS: All patients who underwent anterior revision surgery after VBT were included in this retrospective study. Real (intraoperatively confirmed) tether breakages were compared to preoperatively suspected tether breakages. The definition for a suspected tether breakage was an angular change of more than 5° between an early and the latest radiograph. RESULTS: Ten patients who received 11 revision surgeries with a total of 15 revised curves were analyzed. Of the 80 analyzed segments, 36 were found to have a breakage. Of these 36 segments, 20 were suspected to be broken preoperatively. Sixteen breakages were not identified on preoperative radiographs (44%). One suspected broken tether was intraoperatively found to be intact. CONCLUSION: By using the > 5° rule, only 56% of the tether breakages could be diagnosed. On the other hand, many tether breakages will not result in a loss of correction.
PURPOSE: Vertebral body tethering (VBT) has shown promising results but also a high tether breakage rate, which has been reported in up to 48% of patients. Tether breakages can lead to loss of correction, and the most used definition for tether breakage is a loss of segmental correction of > 5°. However, there may also be some breakages that do not have a negative influence on curve correction. Analyzing the real breakage rate was the aim of this study. METHODS: All patients who underwent anterior revision surgery after VBT were included in this retrospective study. Real (intraoperatively confirmed) tether breakages were compared to preoperatively suspected tether breakages. The definition for a suspected tether breakage was an angular change of more than 5° between an early and the latest radiograph. RESULTS: Ten patients who received 11 revision surgeries with a total of 15 revised curves were analyzed. Of the 80 analyzed segments, 36 were found to have a breakage. Of these 36 segments, 20 were suspected to be broken preoperatively. Sixteen breakages were not identified on preoperative radiographs (44%). One suspected broken tether was intraoperatively found to be intact. CONCLUSION: By using the > 5° rule, only 56% of the tether breakages could be diagnosed. On the other hand, many tether breakages will not result in a loss of correction.
Authors: Alice Baroncini; Per David Trobisch; Christof Birkenmaier; Stephanie Da Paz; Filippo Migliorini Journal: Z Orthop Unfall Date: 2021-04-19 Impact factor: 1.108
Authors: Alice Baroncini; Per David Trobisch; Angelika Berrer; Philipp Kobbe; Markus Tingart; Jörg Eschweiler; Stephanie Da Paz; Filippo Migliorini Journal: Eur Spine J Date: 2021-02-27 Impact factor: 3.134