1. INTERRADICULAR BONE-DISC-BONE OSTEOTOMY (BDBO): AN ALTERNATIVE TO OTHER OSTEOTOMY TYPES FOR THE CORRECTION OF THORACOLUMBAR AND LUMBAR SPINE DEFORMITIES Cagatay OZTURK, MD Mehmet AYDOGAN, MD Selhan KARADERELER, MD Mehmet TEZER, MD Ahmet ALANAY, MD Azmi HAMZAOGLU, MD Istanbul Spine Center Florence Nightingale Hospital Istanbul-TURKEY

2. To introduce and evaluate the results of interradicular bone disc bone osteotomy. 12 consecutive patients with thoracolumbar and lumbar deformities managed by BDBO and having more than 2 years of follow-up were evaluated. PURPOSE PATIENT SAMPLE

3. In the surgery; pedicle screws at least 3 levels below and 2 levels above the planned osteotomy level. Wide laminectomies at the vertebrae above and below the disc space planned to be resected. Then, a wedge osteotomy just below the pedicle of the upper adjacent vertebra and a straight osteomy through the upper end plate of the lower adjacent vertebra, including the disc tissue. An anterior mesh cage placed if lengthening of the anterior column is desired. Then, the osteotomy side is closed METHODS

4. Average age of patients (6M, 6F) 51 (7-76) y Average follow-up 47 (24-89) months. Deformities included; kyphosis in 7 patients kyphoscoliosis in 5 patients. RESULTS

5. Preoperative kyphosis of 24 degrees was corrected to -15 degrees of lordosis with an average of 38 degrees of correction. Preoperative scoliosis of 21 degrees was corrected to 8 degrees and found to be 10 degrees at the final follow-up. RESULTS Average number of instrumented vertebrae was 10. Major complications included dural tear in 4 patients. There was no neurological injury.

6. Bone-Disc-Bone Resection 30°-35°40°60°

7. MIA, 59y, F, lumbar kyphoscoliosis, B-D-B resection 44° 38° L2 L3 L2 L3 L2 L3

8. MA, 56y, F, previous operation 40 years ago. L1

9. BDBO is an effective surgery providing an average of 39 degrees of correction in sagittal plane and may be an alternative to PVCR for patients with thoracolumbar and lumbar severe and rigid deformities, particularly if the apex of deformity is a disc level. CONCLUSION

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