The Clinical Significance of Lumbosacral Transitional Vertebrae on the Surgical Outcomes of Lumbar Discectomy: A Retrospective Cohort Study of Young Adults.

OBJECTIVE: To evaluate whether the presence of lumbosacral transitional vertebrae (LSTV) affects the clinical outcomes of microdiscectomy (MD) in young adults with lumbar disc herniation.

METHODS: We retrospectively included 398 patients who were followed-up for at least 2 years after MD for lumbar disc herniation at L4/5 (disc above the LSTV). The patients were divided into 2 groups. Group A was made up of 31 patients in whom LSTV was detected. Group B, in contrast, was made up of 35 patients in whom LSTV was not detected. The LSTV were classified using plain radiographs and three-dimensional computed tomography by Castellvi et al. The primary outcome measure was pain intensity at each follow-up visit assessed with visual analog scale for back and leg. Secondary outcome measures included the Oswestry Disability Index, a 12-item short-form health survey for quality of life, complications, and recurrence rate.

RESULTS: After surgery, the visual analog scale scores for the back and leg decreased significantly in both groups. However, the back pain intensity in group A worsened at 12 and 24 months postoperatively. The Oswestry Disability Index scores and 12-item short-form health survey (both mental and physical) worsened at 12 and 24 months postoperatively in group A. Two cases of reherniation (6.5 %) were observed in group A, who required reoperation.

CONCLUSIONS: LSTV can limit a patient's clinical improvement after MD with regard to pain intensity and recurrence. Caution must be taken when a patient is scheduled to undergo surgery.