Study design: A retrospective comparative study.
Objective: To compare the efficacy and safety of several different anchors in the apical levels of scoliotic curves > or = 100 degrees using radiographic outcomes and clinical complications.
Summary of background data: To the best of our knowledge, no reports have compared various anchors at the apical level for correction of scoliosis curves > or = 100 degrees.
Methods: Sixty-eight scoliosis patients (44 neuromuscular, 21 idiopathic, and 3 congenital) with major curves > or = 100 degrees (mean, 112.7 degrees; range, 100 degrees -159 degrees ) who underwent segmental spinal instrumentation and fusion with different anchors in the apical level were analyzed. All patients had a minimum 2-year follow-up (mean, 4.0 years; range, 2.0-10.5) and were divided into Group W (sublaminar wires n = 26), Group H (hooks n = 18), Group A (anterior vertebral screws n = 7), and Group PS (pedicle screws n = 17) based on the type of apical anchor used. Radiographic parameters and complications were investigated.
Results: The 4 groups did not demonstrate any significant differences in gender, age at surgery, preoperative major Cobb angle, or curve flexibility (all P > 0.05). However, the PS group demonstrated a shorter follow-up period compared with the other 3 groups (P < 0.05). The PS group demonstrated the greatest correction rate, smallest loss of correction (P < 0.05), and greatest amount of correction of the apical vertebral translation (P < 0.0005) at ultimate follow-up. There were 4 cases (5.9%) of pseudarthrosis (3 in Group W, 1 in Group H; P > 0.05), 6 cases (8.8%) of implant failure (4 in Group W, 2 in Group H; P > 0.05). Despite one (1.5%) intraoperative neurologic complication (differences among groups, P > 0.05), there was no permanent neurologic deficit.
Conclusion: All 4 constructs were able to achieve and maintain acceptable correction safely without permanent neurologic deficit and all demonstrated acceptable implant failure rate. Pedicle screw constructs in the apical levels demonstrated the best coronal correction, smallest loss of correction, and greatest amount of apical vertebral translation correction of the major Cobb angle compared with the other constructs without neurologic complications.