Reduction of low grade spondylolisthesis, TLIF w/ rhBMP-2: technique, complications, and 4yr outcomes

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2011

SUMMARY

Four year clinical outcomes, complications are described in 92 adults with spondylolisthesis treated with reduction, TLIF, BMP, followed 4 years; 99% fused, few BMP complications, none at 4mg/disc.

INTRODUCTION

Spondylolisthesis reduction allows indirect decompression, improved sagittal balance, and more room for interbody cage. Achieving both slip reduction and TLIF can be technically demanding. This study represents the largest series with longest follow-up analyzing complications and outcomes for low-grade spondylolisthesis reduction and TLIF using BMP.

METHODS

We retrospectively reviewed prospective outcomes on 92 consecutive adults with spondylolisthesis (degenerative-73, isthmic-19) undergoing decompression/fusion, followed 52 months (24-76mo). Age averaged 62years (19-84 yrs), 6 smokers, 30 were revisions. Fusions averaged 1.7 levels (1-3 levels). Technique: All patients underwent laminectomy, posterior instrumented translational spondylolisthesis reduction with a single rod prior to TLIF (2nd rod placed after TLIF). Interbody BMP 8.5mg/disc (4-12mg/disc) was inserted prior to insertion of autograft filled PEEK cage, and backfill with local autograft. Outcomes included VAS, Oswestry Disability Index (ODI), pain medication records, and radiographic imaging pre-op, 1 year, 2 years, and latest follow-up.

RESULTS

91/92 patients fused (156/157 levels), the nonunion being a smoker with 2-level spondy. BMP related complications: seroma-2(6mg, 8mg/disc, resolved with decompression), bony overgrowth-1(6mg/disc, resolved with decompression). Additional complications: adjacent degeneration- 23(5 revised late), adjacent level fractures-2(none revised), infection-1. There were no neuro deficits or implant failures. Significant improvements were noted in VAS (pre-5.64, 1 yr-2.1, 2 yrs-2.2, P<.001) and ODI (pre-42, 1 yr-19, 2 yrs-21, P<.001).

CONCLUSIONS

Posterior reduction and TLIF significantly improved outcomes in patients with low-grade spondylolisthesis. There were no complications related to the reduction, and few problems related to the use of interbody BMP with TLIF