Lenke 5 curves. Is thoracic fusion really necessary?

Abstract

Objective: The recommended surgery for Lenke type 5 curve is only the fusion of structural curve (SF: Selective fusion). However, some surgeons prefer to fuse both the thoracolumbar and lumbar (TL/L) curve and the non-structural thoracic (T) curve (NSF: Non-selective fusion). There is a lack of data with regard to the mid-to-long-term outcomes of the SF and NSF. In this study, it was aimed to compare SF and NSF in terms of TL/L and T curve correction rates and the prognosis of the corrected curves. Materials and Methods: A retrospective study of AIS patients treated at a single institution was conducted. A total of 59 patients (55F/M4) were included in the study. Preoperative, early postoperative, and last follow-up TL/L Cobb and T Cobb angles were measured with software. SF and NSF correction rate comparison was done using the Mann-Whitney U test. Results: Overall, 35 patients underwent NSF while 24 patients underwent SF. The mean follow-up duration was 43±18.05 months (54-98). Early T Cobb correction rate was 69% in group 1 (SF) and 79% group 2 (NSF); however, this difference was not statistically significant when the groups were compared (p=0.71138). The last follow-up T Cobb correction rates for group 1 and group 2 were 66% and 79%, respectively (p=0.5485). Early TL/ L Cobb correction rate was 78% in group 1 and it was 79% in group 2 (p=0.8493). Last follow-up TL/L Cobb follow-up correction rates for groups were 79% and 76%, respectively (p=0.9203).Conclusion: This study concluded that SF had favorable outcomes without loss of correction for the patients with Lenke type 5C AIS in the mid-to-long-term.Keywords: Lenke type 5C AIS, selective fusion, non-selective fusion, loss of correction, prognosis