| Chapter 1 Effect of Pedicle Substract Osteotomy on Pelvic Sagittal Parameters in Patients of Thoracolumbar Kyphosis Secondary to Ankylosing SpondylitisBackground : Ankylosing spondylitis(AS)often occurs progressive thoracolumbar kyphosis deformity,resulting in sagittal imbalance,pelvic compensatory backward tilt,and hip flexion ankylosis.Spinal osteotomy is currently the most commonly used treatment for correction of thoracolumbar kyphosis.It is necessary to study the influence of spinal osteotomy on pelvic sagittal parameters,so as to provide reference for the formulation of surgical strategy for as patients with thoracolumbar kyphosis and hip flexion ankylosis.Objective:To evaluate the safety and feasibility of performing pedicle substract osteotomy(PSO)in lateral position for severe kyphosis with fused hips secondary to AS.To observe the changes of pelvic parameters before and after pedicle substract osteotomy(PSO)in AS patients with thoracolumbar kyphosis,and to explore the surgical strategy of as complicated with thoracolumbar kyphosis and hip ankylosis.Materials and methods : 36 consecutive AS patients with thoracolumbar kyphosis who underwent PSO from January 2015 to January 2020 were reviewed.The following radiographical parameters were measured on standard standing radiographs which were performed before and after surgery:(1)OD-HA angle;(2)Chin-brow vertical angle(CBVA);(3)Global kyphosis angle(GK);(4)thoracic kyphosis angle(TK);(5)lumbar lordosis angle(LL);(6)pelvic incidence(PI);(7)sacral slope(SS);(8)pelvic tilt(PT);(9)anterior pelvic plane angle(APPA);(10)acetabular abduction angle.Acetabular anteversion angles were also measured perioperatively on CT images.Clinical parameters included operative time,estimated blood loss(EBL)and related complications.The preoperative and postoperative parameters were compared by the paired samples t test.P values < 0.05 were considered significant.Results:After the surgery of PSO,(1)Sagittal radiographic parameters of spine: OD-HA angle,CBVA,GK,TK and LL were corrected from 24.8±6.7°,21.7±5.9°,67.3±13.9°,49.4±12.1°,-6.4±11.3° to 3.5±2.3°,6.8±2.3°,46.8±6.2°,30.8±11.9°,-37.9±8.3°,respectively(p<0.05).(2)Pelvic radiology parameters: SS,PT,APPA,right acetabular abduction angle,left acetabular abduction angle,right acetabular anteversion angle and left acetabular anteversion angle were corrected from 13.1±9.0°,30.4±8.2°,-15.7±5.8°,58.5±4.1°,58.7±5.5°,36.7±6.5°,36.9±7.4° to 32.5±8.7°,12.9±9.5°,10.3±5.6°,47.1±5.8°,46.8±6.1°,20.4±3.0°,21.3±2.7°,respectively(P<0.05).(3)The sugical time of PSO in lateral position was 4.2±1.2h,with 417±151ml EBL.(4)complications: There is one case of dural tear,1 case of lower limb radiation pain,1 case of coronal imbalance of spine and 1 case of infection.No cases of death,paraplegia and other serious complications were observed in this cohort.Conclusion:(1)PSO is an effective and safe treatment for AS patients with thoracolumbar kyphosis;(2)after thoracolumbar osteotomy,the pelvic parameters can be well corrected;(3)for AS patients with thoracolumbar kyphosis and hip ankylosis,spinal osteotomy first can reduce the risk of acetabular prosthesis misplacement in THA.Chapter 2 Pedicle Substract Osteotomy in Lateral Position for Severe Kyphosis with Closed Hips Secondary to Ankylosing SpondylitisBackground : Ankylosing spondylitis(AS)is an autoimmune disease that mainly affects the sacroiliac joints,spine,and hips.This progressive inflammation leads to fibrosis and calcification,resulting in kyphotic spine and fused hips.Spine osteotomy and total hip arthroplasty(THA)are the most common surgical interventions to improve quality of life for AS patients whose spine and hips are disabled.Recent studies reveal that performing THA previous to spine osteotomy contributes to a higher dislocation rate of hip prosthesis than undergoing spine osteotomy first.Therefore,performing spine osteotomy first seems to be the logical choice.But patients suffered from severe kyphosis and fused hips are frequently difficult or impossible to be placed in the prone position.A unique surgical position might be considered as the subtitute in the setting of severe abnormalities.Objective:To evaluate the safety and feasibility of performing pedicle substract osteotomy(PSO)in lateral position for severe kyphosis with fused hips secondary to AS.Materials and methods:10 consecutive AS patients with severe thoracolumbar kyphosis who underwent PSO in lateral position from January 2015 to January 2020 were reviewed.The following radiographical parameters were measured on standard standing radiographs which were performed before and after surgery:(1)OD-HA angle;(2)Chin-brow vertical angle(CBVA);(3)global kyphosis angle(GK);(4)thoracic kyphosis angle(TK);(5)lumbar lordosis angle(LL);(6)pelvic incidence(PI);(7)sacral slope(SS);(8)pelvic tilt(PT);(9)anterior pelvic plane angle(APPA);(10)acetabular abduction angle.Acetabular anteversion angles were also measured perioperatively on CT images.Harris scoring system was used to evaluate the hip function before and after THA.Clinical parameters included operative time,estimated blood loss(EBL)and related complications.The preoperative and postoperative parameters were compared by the paired samples t test.P values < 0.05 were considered significant.Results:After the surgery of PSO,(1)Sagittal radiographic parameters of spine: OD-HA angle,CBVA,GK,TK and LL were corrected from 46.9±9.3°,33.5±7.5°,106.2±15.7°,84.0±16.6°,-24.8±16.7° to 7.2±2.7°,5.2±2.8°,64.6±5.0°,50.9±13.1°,-44.0±6.9°,respectively(p<0.05).(2)Pelvic radiology parameters: SS,PT,APPA,right acetabular abduction angle,left acetabular abduction angle,right acetabular anteversion angle and left acetabular anteversion angle were corrected from 13.7±7.7°,43.4±9.0°,-21.2±6.4°,59.5±3.8°,58.2±5.9°,38.0±4.3°,37.6±3.6° to 37.3±7.2°,17.2±8.1°,-11.1±6.4°,51.3±5.3°,51.9±4.5°,22.6±2.2,23.8±1.3°,respectively(P<0.05).(3)The Harris hip score was significantly improved from23.6±3.9 preoperatively to 82.4±5.2 postoperatively(P<0.05).(4)The sugical time of PSO in lateral position was 7.3±1.8h with 934±181ml EBL.The sugical time of unilateral THA was 1.9±0.6h with 396±124ml EBL.The sugical time of bilateral THA was 4.2±1.1h with 813±167 EBL.(5)complications: There was 1 case of dural tear,2 cases of lower limb radiation pain and 1 case of infection.All 10 patients received unilateral or bilateral THA 12 weeks after PSO.No cases of prosthesis dislocation,death,paraplegia and other serious complications were observed in this cohort.Conclusion:(1)PSO in lateral position is feasible and safe for the AS patients with severe thoracolumbar kyphosis.(2)PSO in lateral position can be an alternation for severe thoracolumbar kyphosis with fused hips secondary to AS undergoing PSO in prone positon impossible.Chapter 3 Pedicle Substract Osteotomy in the Treatment of Thoracolumbar Kyphosis Secondary to Ankylosing Spondylitis: Complications and Prevention StrategiesBackground:The progression of ankylosing spondylitis(AS)can lead to characteristic thoracolumbar kyphosis.Pedicle wedge osteotomy(PSO)has become the most widely used standard surgery in the treatment of thoracolumbar kyphosis secondary to AS.However,the intraoperative and postoperative complications are relatively high due to the traumatic sugery.Objective:To analyze the causes,risk factors and prevention strategies of perioperative complications of PSO in the treatment of thoracolumbar kyphosis secondary to AS,and to evaluate the safety of surgery.Materials and methods : 46 consecutive AS patients with thoracolumbar kyphosis who underwent PSO from January 2015 to January 2020 were reviewed.The medical records of all patients were collected and consulted.The imaging changes before and after operation were observed.The number of osteotomy, osteotomy segment,operation time and blood loss were recorded.The operation related complications were analyzed and evaluated.Results:A total of 13 patients(28.2%)had complications,of which 3 patients(6.5%)had intraoperative complications and 10 patients(21.7%)had postoperative complications.No severe complications such as paraplegia and death occurred.Conclusion:It is effective and safe to use PSO in the treatment of as with thoracolumbar kyphosis.However,we should pay attention to the complications related to PSO. |
