Study design:

Retrospective study.

Objective:

The aim of this study was to investigate whether there is an association between revision surgery rates for adjacent segment degeneration (ASD) and Roussouly type after L4-5 transforaminal lumbar interbody fusion (TLIF) for spondylolisthesis.

Summary of background data:

Revision surgery for ASD is known to occur after spinal fusion; however, it is unclear if rates of ASD are associated with certain Roussouly types.

Methods:

Patients who underwent L4-5 TLIF for spondylolisthesis at the University of California San Francisco from January 2006 to December 2016 with minimum 2-year follow up were retrospectively analyzed by Roussouly type. Revision surgery for ASD was noted and correlated by Roussouly type. Spinopelvic parameters were also measured for correlation. A value of p < 0.05 was significant.

Results:

There were 174 patients who met inclusion criteria, (59 males and 115 females). The average age was 62.3 (25-80) years. 132 patients had grade I spondylolisthesis, and 42 had grade II. Mean follow-up was 45.2 months (24 to 497). A total of 22 patients (12.6%) underwent revision surgery for ASD after L4-5 TLIF. When classified by Roussouly type, revision surgery rates for ASD were: 1, 14.3%; 2, 22.6%; 3, 4.9%; and 4, 15.6% (p = 0.013). Type 3 spines with normal PI-LL (8.85° ± 6.83°) had the lowest revision surgery rate (4.9%), and type 2 spines with PI-LL mismatch (11.06° ± 8.81°) had the highest revision surgery rate (22.6%), a 4-fold difference (p = 0.013). The PI-LL mismatch did not change significantly in each type post-operatively (p > 0.05).

Conclusion:

We found that there may be a correlation between Roussouly type and revision surgery for ASD after L4-5 TLIF for spondylolisthesis, with type 2 spines having the highest rate. Spinopelvic parameters may also correlate with revision surgery for ASD after L4-5 TLIF.

Level of evidence:

4.