Surgical Outcomes After Segmental Limited Surgery for Adjacent Segment Disease: The Consequences of Makeshift Surgery

To minimize surgical morbidity, surgeons may opt to perform segmental limited surgery instead of fusion extension for adjacent segment disease (ASD) after lumbar fusion surgery. This study evaluated clinical outcomes from segmental limited surgery without fusion extension for ASD and assessed which clinical factors were associated with reoperation after segmental limited surgery.

Medical data of 50 patients who underwent segmental limited surgery for ASD after lumbar fusion surgery between 2005 and 2015 were reviewed. Demographic data, ASD type, preoperative disc and facet degeneration, ASD location, and surgical summary were collected. The primary outcome was reoperation rate at 24 months after surgery.

Of patients, 28 (56%) experienced recurrent radiculopathy (visual analog scale score ≥4). Revision surgery was performed in 22 patients (44%). Reoperation was performed more frequently in multilevel fusion first-surgery cases (15/23; 65.2%) than single-level fusion first-surgery cases (7/27; 25.9%; P = 0.005). The lowermost mobile segment group had a lower reoperation-free survival rate than the other group (hazard ratio = 9.85, 95% confidence interval 1.32-73.54, P = 0.01 [log-rank]). The 2-year reoperation-free survival rate for the lowermost mobile segment group was 31.5%, whereas the rate for the other group was 83.3%.

Segmental limited surgery as a treatment for ASD after lumbar fusion surgery is likely to fail frequently and result in a high rate of recurrent radiculopathy and revision surgery. Fusion extension surgery is especially recommended for ASD at the lowermost mobile segment owing to the high failure rate.