2021 Volume 12 Issue 4 Pages 663-667
Introduction: Adult spinal deformity surgery has become popular in recent years, and the incidence of proximal junctional kyphosis as post-surgical complication has increased. In this study, we focused on postoperative changes of the fixed upper anteversion in adult spinal deformity surgery and investigated the relationship with various spine parameters, including cervical spine alignment.
Methods: We assessed 24 patients (mean age, 73.2 years; 5 men, 19 women) who corrected adult spinal deformity by fixing from pelvis to middle or lower thoracic vertebra, between December 2013 and February 2018 at our hospital. Various spinal parameters from the standing whole spine X-rays at the time of before operation, immediately after operation, and 1 year after operation (e.g., PI, PT, SS, LL, SVA, TK, T1slope, C2-7 angle, C2-7SVA) were measured. The patients were divided into two groups based on their surgical outcome: Group A is the patients whose fixed upper end tilt angle increased by more than 5° from immediately after surgery to 1 year after surgery and Group B is those in whom there was no such increase.
Results: The results demonstrated a significant difference in the preoperative fixed upper end anteversion between Group A and B. However, there was no significant difference in the fixed upper anteversion immediately after the operation.
Conclusions: The results suggest that, in cases with greater preoperative fixed upper end tilt angle, despite surgical correction of the inclination, the fixed upper end tilt angle might increase again in the post-surgical period, thereby increasing the possibility of proximal junctional kyphosis occurrence.
