Loss of sacral fİxation is the most frequently cited compiication of lumbosacral deformity surgery. in this study 58 paîienis who undenvent İumbosacrai fusion and İnstrumentation because of various spinalprobiems were in-cluded for evaluation. 34 patients had various îypes of spondilolisthesis, 6 patients had adult scoiiosis, 5 patients had vertebral maiignancy, 10 patients had degenerative spine and segmental instability, 3 patients had spinal tu-bercuiosis.

Totai number of 116 sacral screws were used. in addİtion to the sacral screws 14 patients' sacral rods were burried in to the sacrum which were named as Jackson's method. İn 26 patients promontorial (medial), İn 18 patients alar (lateral) screw piacement was performed. İn 22 patient long segment fixation, in 36 patients short seg-ment fixatİon were performed. Fixatİon above L4 is considered as iong segment fixation (more than 3 segment s).

Lumbosacral fİxatİon types were in 3 groups: I- Lateral (Alar) fixation (18 patients) II- Medial (promontorial) fix-ation 3- Jackson's method (İlİac butress) (14 patients).

Complİcatİons were 4 (6.8%) sacral screw loosening andpseudoarthrosis. 3 (16.6%) of them were in group I, 1 (3.8%) was in group II and no complications occurred in group III. On the other hand ali complications were in long fusion group (4 patients, %18).

Conclusion:

1- Jackson's method İs a secure İumbosacrai fİxation method. 2- Promontorial fixation is better than atar fixatİon. 3- Long segment fİxation with lumbosacral area is prone to mechanic complications more than short segment fİxatİon.

Keywords: Lumbosacral, posterior, fİxation.