Improved outcomes after anterior vertebral tethering for AIS using ideal versus acceptable indications
摘要
Though anterior vertebral tethering (AVT) has been proposed as an alternative to fusion surgery for AIS, ideal versus acceptable indications for this novel procedure have yet to be established. This study compared outcomes after AVT in AIS patients with ideal indications versus those with acceptable indications and 1, 2, or 3 risk factors.
MethodsOne hundred eighty-five consecutive AIS patients were treated with AVT for thoracic and thoracolumbar curves 33–72° with 140 patients having 2–11 year follow-up data. Four groups were analyzed: 1 group with ideal indications and no risk factors and 3 groups with acceptable indications and 1, 2, or 3 risk factors. Ideal indications included curve magnitude of 40–60°, curve flexibility ≥ 50%, and skeletal maturity graded at Risser 0–2 and/or Sanders 3–5. Those patients with acceptable indications were considered to have 1, 2, or 3 risk factors if they failed to meet 1, 2, or 3 of these criteria. Radiographic outcomes were graded as excellent ≤ 25°, good 26–39° fair ≥40°, or poor ≥ 50° and/or requiring fusion.
ResultsOne hundred forty AIS patients (118F/22 M) treated with AVT had 2–11 year follow-up. Patients with ideal indications (n = 42) demonstrated 95% good or excellent outcomes with a 27% overall tether rupture rate and 2% revision surgery rate. Patients with acceptable indications and 1 risk factor (n = 72) had 86% good or excellent outcomes with a 36% overall tether rupture rate and 15% revision surgery rate. Those with 2 risk factors (n = 21) had 67% good or excellent outcomes with a 33% overall tether rupture rate and 19% revision surgery rate. And those with 3 risk factors (n = 5) had 40% good or excellent outcomes with a 40% overall tether rupture rate and 40% revision surgery.
ConclusionOutcomes after AVT for AIS were better in patients with ideal versus acceptable indications. Though the chance of a good or excellent outcome at final follow-up was best in patients with ideal indications (95%), this dropped steadily with the accumulation of 1 (86%), 2 (67%), or 3 (40%) risk factors (p < 0.001). The risk of complications and revision surgery, especially fusion, was also the lowest in patients with ideal indications but steadily increased with the accumulation of risk factors.
Level of EvidenceIII.