Clinical Efficacies Of Transpedicular Bivertebral Osteotomy For Correction Of Severe Kyphosis In Ankylosing Spondylilis

Background Transpedicular bivertebral osteotomy for correction of severe kypho-sis in ankylosing spondylilis have a good resume sagittal balance, and a obvious postoperative effect. But the clinical follow-up study is insufficient.Objective To explore the clinical results of transpedicular bivertebral osteotomy in the correction of severe kyphotic deformity in ankylosing spondylitis(AS).Methods From January 2009 to December 2011, a tatal of 34 consecutive patients with AS and severe kyphosis (global thoraco-lumbar kyphosis angle (TLKA) over 70°) undergoing transpedicular bivertebral osteotomy at the department of orthopedics of PLA 306th hospital were reviewed retrospectively. Including 22 males and 12 females, the average age at admission was 38.3±9.6 years (range,23～62 years), the average course of disease at admission was16.2±3.7 years (range,7～30 years). The pre-and post-operative thoracic kyphosis angle(TKA), lumbar lordosis angle(LLA), global thora-co-lumbar kyphosis angle(TLKA), sagittal imbalance(SVA) were measured. Brid-well-Dewald scale was used to evaluate the clinical outcomes.Results All patients were followed up, the average follow-up time was 20±4.6 months (12～30 months), the average blood loss was 3200±147ml (1800～6300ml), and the average operation time was 363±56min (280-510min). The data of height, CBVA, TKA, LLA, TKLA and SVA improved from 125.3+7.8cm,92.4±8.3°,72.3±14°,-30±20.3°,100.4±19.3°,50.3±13.4cm at preoperative to 165.4110.3cm,13.2±11.9°, 63.4±11.5°,29.0±13.1°,26.4±12.4°,15.4±7.2cm, respectively. The discrepancy of height, CBVA, TKA, LLA,TKLA and SVA was significant difference between preopera-tive and post-operation (P<0.05); there was no significant difference between post-operation and final follow-up(P>0.05). Bridwell-Dewald scale average score im-proved from4.0±0.4 to 1.610.2, there was significant difference between preoperative and post-operation (P<0.05). Dura matter tearing was noted in 2 cases and pulmo-nary infection in 1 case,1 case developed transient neurologic deficrts, but all healed after proper intervention. There was no breakage of nails of failure of the internal fixa-tion during the follow up period.Conclusion As a safe and effective operation for correction of severe thoracol-umbar kyphosis, transpedicular bivertebralosteotomy can achieve larger correction angle and satisfactory sagittal reconstruction.