A new study published in Spine examines scoliosis correction using a low dose of bone morphogenic protein-2 for L5-S1 fusion and pelvic fixation were used with and without interbody fusion.
The researchers examined 61 consecutive patients who underwent surgery with the isolated posterior approach and had five or more levels fused, including L5-S1. The patients also had pelvic fixation and no prior procedures at L5-S1.
The researchers found:
1. Fusion rate for L5-S1 was 97 percent — broken into groups:
• Interbody group: 97 percent
• No interbody group: 96 percent
2. There weren't significant differences in the radiographic parameters or deformity correction between the two groups, and the average amount of BMP-2 used in the interbody group was 4.1 mg. There was 2.5 mg used in the disc space and 1.6 mg in the interbody cage.
3. There wasn't any difference in the amount of rhBMP-2 placed posterolaterally between the two groups:
• Interbody fusion: 1.6 mg
• Non-interbody fusion: 2 mg
4. The revision rate for non union at L5-S1 was 1.6 percent.
5. The researchers concluded, "The use of low dose BMP-2 at the L5-S1 level in combination with sacropelvic fixation achieved satisfactory fusion rates in adult deformity surgery. No additional benefit was encountered by adding an interbody cage."