There exists two important pathologies in degenerative lumbosacral kyphosis (flat back), such as loss of lumbar lordosis and posterior rotation of the pelvis. Patients with this deformity complaint marked fatigue in lumbosacral region and disturbances on standing and walking.

Conservative treatment is seemed to be difficult, and surgical treatment may be selected for this deformity. Our surgical strategy is posterior shortening and anterior rotation of pelvis. Surgical procedure is tranvertebral decancellation closed wedge osteotomy, correction by shortening and lumbosacral fixation by intrasacral method. Radiographic assessment around the hip axis was performed by Jackson method on standing entire spine film.

5 females and 2 males were operated on by this method. Mean age at the operation was 67 yrs (57–82). Mean follow-up was 24 months (12–36). Mean operative time was 480 minutes (320–600). Mean estimated blood loss was 1440ml (985–2415). Mean pelvic angle was 41 degrees before the operation. At follow-up, mean value was 33 degrees. Preoperative mean local kyphosis was 4.7 degrees. Postoperative mean local lordosis was 24.1 degrees, average correction was 30 degrees. No loss of correction occurred in fused area. Clinical symptoms were remarkably improved after the operation. There was no major complication in this series.