Restoration of Lumbar XXXX in Flat Back Deformity: Optimal Degree of Correction.

@entity1 @entity17590 @entity1515 @entity179 @entity717 @entity85
STUDY DESIGN: A retrospective comparative study. PURPOSE: To provide an ideal correction angle of @entity1515 ( @entity1515 ) in @entity85 . OVERVIEW OF LITERATURE: The degree of correction in @entity179 in relation to pelvic incidence (PI) remains controversial. METHODS: Forty-nine @entity1 with @entity85 who underwent corrective surgery were enrolled. Posterior-anterior-posterior sequential operation was performed. Mean age and mean follow-up period was 65.6 years and 24.2 months, respectively. We divided the @entity1 into two groups based on immediate postoperative @entity17590   <= @entity1515 <PI+9  ) and under-correction (UC) group ( @entity1515 <PI-9  ). We also classified the @entity1 according to the PI of each @entity1 -low PI group (PI<55  ) and high PI group (PI>= 55  ). Radiological and clinical results were analyzed. RESULTS: @entity1 in @entity17590 had significantly less correction loss and maintained normal sagittal alignment (sagittal vertical axis<5 cm), as compared to @entity1 in UC group (p<0.05). @entity1515 of low PI group significantly maintained within 9   better than high PI group (p<0.05). @entity717 index (ODI) significantly decreased at last follow-up, as compared to preoperative state. However, there was no significant difference in last follow-up ODI between the groups. CONCLUSIONS: In @entity85 , correction of @entity1515 to within 9   of PI will result in better sagittal balance. Thus, we recommend sufficient @entity1515 to prevent correction loss, especially in @entity1 with high PI.
