Transpedicular closed wedge osteotomy in ankylosing spondylitis: results of surgical treatment and prospective outcome analysis

Abstract

Surgery in late stage ankylosing spondylitis (AS) most often tends to correct the sagittal balance with an extension osteotomy of the spine. In the literature, extension osteotomy was first described as an open wedge osteotomy but recently closed wedge osteotomy resecting the pedicles and posterior elements have become more popular. Only a limited number of cases have been reported in the literature and with limited focus on outcome of this major surgery. In this study, we reported the results of a large series of extension osteotomy in a population of patients with AS focusing on the technical aspects, complication rates, correction obtained and outcome evaluation using newer spine outcome measuring instruments. In the period from 1995 to 2005, 36 consecutive patients fulfilled the criteria where the files, radiographs and patients were available for further studies. The following data were recorded: Age, sex, comorbidity, indication, operation time and blood loss, level of osteotomy and estimated Correction. Furthermore, perioperative complications and all late complications were registered. The average follow-up was 50 months (3-128). Twenty-one patients also filled out questionnaires (SF36 and Oswestry Disability Index) preoperatively. At the end of the period all patients were contacted and filled out the same questionnaires. Fifteen of the patients had two pedicular resection osteotomies performed, 21 had one, and two had polysegmental osteotomies. Mean operation time was 180 min, bleeding was mean 2,450 ml, stay at the hospital was 13 days. One patient had partial paresis of the lower extremities all other complications were minor. The median correction was 45 degrees . The median Oswestry score improved significantly from 54 (range 20-94) preoperatively to 38 (range 2-94) postoperatively. The SF-36 score significantly increased, when evaluated on the major components Physical Component Summary (PCS) and Mental Component Summary (MCS). The thoracolumbar closed wedge pedicular resection osteotomy used in this series was a safe method for correction of incapacitating kyphosis in AS. There was an acceptable rate of perioperative complications and no mortality. The correction obtained was in average 45 degrees . All of the patients except one maintained their good correction and restored function. Outcome analysis showed a significant improvement in SF-36 and Oswestry Disability Index, and the mental component of the SF-36 showed improvement to values near the normative population. It is concluded that corrective osteotomy of the thoracolumbar spine in AS is an effective and safe treatment with improvements in quality of life.

Pedicle subtraction osteotomy through pseudarthrosis to correct thoracolumbar kyphotic deformity in advanced ankylosing spondylitis

“…Third, the anterior and middle column at the segment of the bony defect will be functionally unstable; an iliac graft packed between the vertebral bodies can support the anterior and middle column structurally to restore the stability, and can achieve bony surfaces contact contributing to a rapid healing. Fourth, the presence of a gap in the anterior column may place excessive loads on the posterior instrumentation and compromise stability of the construct, which increases the incidence of late complications such as loss of correction or instrumentation failure [5,15]. In this situation, an anterior strut graft can effectively reduce the stresses that act on the posterior instrumentation to prevent the above-mentioned complications.…”

“…The chronic inflammation causes progressive ossification of the spinal ligaments and facet joints, which eventually results in a fixed and rigid spine [7,8,15]. In addition, AS is also associated with vertebral osteoporosis [18].…”

Personalised modified osteotomy using computer-aided design–rapid prototyping to correct thoracic deformities

“…However, the degree of correction was not great enough, especially for severe thoracic deformities. Moreover, a rather high complication rate was also shown [18][19][20][21][22][23]. Bridwell et al found an 11.1% rate of neurological deficits and a 2.8% rate of permanent deficits [16,24].…”

Pedicle subtraction osteotomy for sagittal imbalance

“…The surgical technique must be adapted to the amount of correction: PSO average correction is 30°, Smith-Petersen/Chevron: 8-10°per level [6]. Strong sacral or sacroiliac fixation is requested with good posterolateral grafting [7,8]. Cage at the level L5/S1 and L4/L5 is often requested if the disc is high to avoid loss of correction.…”