Analysis and study on distal fusion vertebrae selection for thoracolumbar adolescent idiopathic scoliosis / 重庆医学

ABSTRACT

Objective To investigate a new selection criteria for lower instrumentation vertebrae (LIV) in thoracolumbar adolescent idiopathic scoliosis (AIS).Methods Fifty-two cases of fusion thoracolumbar bend and more than 1.5 years follow up were included.The cases conformed to the AIS selection criteria,i.e.,the first vertebral body touched at the scoliosis distal end in the central sacral vertical line (CSVL) of erect orthotopic X-ray film served as the touch vertebrae (TV),moreover which should meet the following requirementsthe Nash-Moe rotation ≤ degree Ⅱ;CSVL located between bilateral vertebral pedicle in the concave side Bending image;no kyphosis of thoracolumbar and lumbar segments existed;the patients with the distance 3-4 mm from CSVL to TV were also included into the study.The operation of each case was carried out by an experienced spine surgeon team.The internal fixation orthopedic fusion of total pedicle screws was adopted by posterior approach.The spine full length of the anterior-posterior and lateral X-ray film and left and right sides Bending images at clinostatism were taken before operation,instantly after operation and at final follow up.The Cobb angle of main bending,trunk shift (TS) at coronal plane,LIV tilting (LIVT) and LIV distal disc angulation (LIVA) were measured.The positions of TV and stable spine were observed,recorded and performed the statistical analysis.Results All cases were followed up for more than 18 months,with an average follow-up period of (23 ± 3) months.The main bending Cobb angles before operation,instantly after operation and at final follow up were (49.32±11.37)°,(9.08 ± 6.78)°and (10.65±6.68)°respectively,LIVT were (21.76±4.68)°,(5.17±4.09)° and (5.16±3.08)° respectively and LIVA were (7.19±5.16)°,(3.16±2.78)° and (4.17±3.28)° respectively;the above indicators had statistical differences between before operation with instantly after operation and at final follow up (P＜0.05).Twenty seven cases were preoperative trunk decompensation,and 5 cases were complicating trunk decompensation at final follow up,which were not increased compared with those before operation.Comparing TV as LIV with adopting stable vertebrae as LIV,the former could save (1.42 ±0.45) fusion segments.Conclusion Adopting the new criteria to conduct thoracolumbar AIS operation saves the fusion segments as compared with commonly used method in clinic.