Impact of Different Operative Techniques for Patients With Adolescent Idiopathic Scoliosis on Frontal Curve Correction and Sagittal Balance.

BACKGROUND: Surgical correction of adolescent idiopathic scoliosis from the posterior approach can be performed by the "all screws" technique; hybrid technique with screws and hooks; hybrid technique or with screws, hooks, and tapes; or selective fusion (SF) or nonselective fusion (NSF). The aim of the present investigation was to analyze the influence from different operative techniques on frontal curve correction and sagittal profile in patients with adolescent idiopathic scoliosis. METHODS: We conducted a retrospective analysis on 55 consecutive patients with scoliosis who had been treated by posterior instrumented fusion. We collected demographic data and analyzed pre- and postoperative radiographs. Statistical analysis was performed using SPSS version 25. Because data showed normal distribution, t tests were performed. RESULTS: Twenty-two patients were treated using the hybrid technique with screws and hooks; 25 were treated using the hybrid technique with screws, hooks, and tape; and 8 were treated using the all screws technique. An SF was performed in 32 patients and NSF in 23 patients. There was no significant difference with regard to curve correction of the main curve between the different techniques. Correction of the minor curve was significantly higher in NSF than in SF patients. In SF, there was a correction of the minor curve of 43.9%. Impact on sagittal balance showed no significant differences between NSF and SF. CONCLUSION: The different operative techniques did not show a difference with regard to the correction of the main curve. NSF showed a significantly higher degree of correction of the minor curve than SF. However, we still found a correction of 43.9% of the noninstrumented minor curve in SF. Thus, SF and hybrid techniques do not lead to inferior radiographic outcome. CLINICAL RELEVANCE: SF and hybrid techniques are safe and effective techniques that could be used as an alternative to NSF and all screw fixation in the operative treatment for scoliosis.

The Impact of the Lowest Instrumented Vertebra on the Correction of the Minor Curve During Selective Fusion in Patients With Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective single-center data analysis. OBJECTIVE: The aim of this investigation was to give advises for choosing the LIV in selective fusion to reach the best correction of the minor curve and sagittal profile. SUMMARY OF BACKGROUND DATA: Scoliotic curves can be classified as structural or nonstructural. If selective fusion is performed, the nonstructural curves are not instrumented. The choice of the lowest instrumented vertebra (LIV) and the impact of different levels of the LIV on the correction of the minor curve in the frontal profile and on the sagittal balance is under debate. METHODS: Forty-seven consecutive patients treated by posterior instrumented fusion were included in this retrospective investigation. Impact of the level of the LIV with regard to distance to end vertebra (EV), to the stable vertebra (StV), to the sagittal infliction point (IP), and to the apex of the lumbar lordosis on the correction of the minor curve was analyzed. RESULTS: Distance of LIV to EV was significant with regard to correction of the minor curve if it was more than 5 levels (P<0.001). Distance of LIV to StV was significant with regard to correction of the minor curve if it was more than 4 levels (P<0.01). Distance of LIV to IP was significant with regard to correction of the minor curve if it was more than 2 levels (P<0.01). CONCLUSIONS: Choosing a LIV that was more than 2 levels higher or lower than the sagittal infliction point showed a significantly higher correction of the minor curve. We therefore recommend to keep that distance when LIV is chosen.