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Apical segmental resection osteotomy with dual axial rotation corrective technique for severe focal kyphosis of the thoracolumbar spine.

OBJECT
in this paper, the authors' goal was to evaluate the feasibility, safety, and efficacy of apical segment resection osteotomy with dual axial rotation correction for severe focal kyphosis by examining outcomes.


METHODS
between May 2004 and December 2006, the authors treated 23 patients with severe focal kyphosis (average Cobb angle 86.9°, range 50°-130°) using apical segmental resection osteotomy with dual axial rotation correction and instrumented anterior column reconstruction and fusion. Radiographic assessment of sagittal plane balance and kyphotic Cobb angle (including a scoliosis Cobb angle in 9 cases) was performed in each patient before and immediately after surgery and at the last follow-up (minimum 2 years). The Frankel grading system for neurological function and Oswestry Disability Index for quality of life were evaluated before surgery and at the last follow-up. The patient satisfaction index was also used for clinical evaluation at the last follow-up.


RESULTS
the mean surgical time was 6.7 hours. The average blood loss was 2960 ml. All patients underwent follow-up for 2 or more years after surgery. The fusion rate was 95.65%. The average kyphotic angle improved from 86.9° preoperatively to 25.6° immediately postoperatively, with an average correction rate of 72.17%. At the last follow-up, the average kyphotic angle was 27.4°, making the final correction rate 69.87%. The sagittal plane balance was significantly improved at the last follow-up. Preoperatively, 15 patients had neurological deficits, and the Frankel grade was E in 8 cases, D in 8 cases, C in 6 cases, and B in 1 case. At the last follow-up, 15 cases were Grade E, 5 were Grade D, and 3 were Grade C. The average improvement in the Oswestry Disability Index score was 43.30%. The patient satisfaction index result showed a total satisfaction rate of 91.30%. Complications included 1 case of late neurological deficit due to shifting of an expandable artificial vertebra, 5 cases of nerve root injury, 3 cases of dural tear, and 1 case of transient lower-extremity weakness due to insufficient blood supply to the spinal cord during surgery.


CONCLUSIONS
apical segmental resection osteotomy with dual axial rotation correction and instrumented fusion is an effective and safe way to treat severe focal kyphosis of the thoracolumbar spine.