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[Treatment of kyphosis deformity with pedicle subtraction osteotomy and short-segment pedicle screw internal fixation].

OBJECTIVE
To assess the outcomes of pedicle subtraction osteotomy and short-segment pedicle screw internal fixation in kyphosis deformity.


METHODS
From June 2001 to November 2003, 16 cases of kyphosis deformity were treated with pedicle subtraction osteotomy and short-segment pedicle screw internal fixation, including 11 males and 5 females and aging 24-51 years. The kyphosis deformity was caused by ankylosing spondylitis in 12 cases, old lumbothoracic fracture-dislocation in 2 cases, and vertebral dysplasia in 2 cases. The disease course was 7-25 years with an average of 12.8 years. The whole spine radiographs were taken pre- and postoperatively. The sagittal balance was assessed by measuring thoracic kyphosis angle, lumbar lordosis angle, sacrohorizontal angle and distance between posterosuperior point of S1 and the vertical line. The clinical outcomes were assessed by Bridwell-Dewald scale for spinal disorders.


RESULTS
The mean follow-up period was 25. 6 months. The mean bleeding was 1100 ml. Satisfactory bone graft healing was achieved at final follow-up. Complications were paralytic intestinal obstruction in 1 case, dura laceration in 1 case, and temporary lower limb paralysis in 2 cases. Final follow-up radiograph showed an increase in lumbar lordosis angle from 9.6+/-16.4 degrees to 42.6 14.3 degrees (P<0.05), whereas thoracic kyphosis angle remained relative stable. The distance between posterosuperior point of S1 and the vertical line was decreased from 97.5+/-45.6 mm to 10.7+/-9.6 mm (P < 0.05). Satisfactory clinical outcome was achieved by evaluating the changes of pain, social and working status.


CONCLUSION
Pedicle subtraction osteotomy and short-segment pedicle screw internal fixation is effective for correction of kyphosis deformity.