Clinical Results after Corrective Osteotomy of the Kyphotic Deformity in Ankylosing Spondylitis / 대한척추외과학회지

ABSTRACT

STUDY DESIGN: A retrospective analysis of clinical results through questionnaire based instrument and radiologic changes after correction in ankylosing spondylitis. OBJECTIVES: To evaluate the radiographic changes and verify the clinical results of the extension osteotomy through pedicular subtraction and intracorporal decancellization in patients with ankylosing spondylitis who have severely fixed kyphotic deformity. MATERIALS AND METHODS: Total 45 patients were included in this study. In all cases, the deformity was corrected by a onestage pedicle subtraction extension osteotomy. Radiographic assessment for sagittal balance was performed on the criteria of thoracic kyphosis, lumbar lordosis, distance between the vertical line on anterosuperior point of T1 and that of S1 and sacrohorizontal angle. Finally clinical assessment for function, indoor activity, outdoor activity, psychosocial activity, pain and overall subjective satisfaction on the basis of patients' satisfaction(5 grade) were performed. RESULTS: The osteotomy was performed at single level in 43 cases, double levels in 2 cases. The mean follow-up was 36.2 months. The criteriae of radiographic assessment were changed on preoperative, postoperative 3 months and the last follow-up as follows; thoracic kyphosis 50, 51 and 54 degrees, lumbar lordosis 10, 46 and 44 degrees, distance between vertical lines of T1 and S1 94, 15 and 8 mm, sacral inclination 8, 28 and 24 degrees. At the last follow-up, clinical results were high as 3.2 in function, 2.8 in indoor activity, 3.3 in outdoor activity, 3.3 in psychosocial activity, 3.4 in pain and 3.2 in overall subjective satisfaction. There was no any serious complication, such as death or permanent neurologic deficit. CONCLUSIONS: Nearly all the patients have maintained good correction. Eighty five percent of patients have revealed self-satisfaction to corrective osteotomy. But in connection with the clinical results, the changes of parameters of radiographic assessment didn't revealed any significant correlation and so it should be traced much longer with care.