Risks Associated with Surgical Management of Lumbosacral Transitional Vertebrae: Systematic Review of Surgical Considerations and Illustrative Case.

INTRODUCTION: Lumbosacral transitional vertebrae (LSTV) are congenital anomalies of the L5-S1 segments characterized by either sacralization of the most caudal lumbar vertebra or lumbarization of the most cephalad sacral vertebra. This variation in anatomy exposes patients to additional surgical risks.

METHODS: In order to shed light on surgical considerations reported for lumbar spine cases involving LSTV as described in the extant literature, we performed a systematic review in accordance with PRISMA guidelines. We also present a case example in which wrong-level surgery was avoided due to anatomical understanding of LSTV.

RESULTS: A 48-year-old female presented with severe back pain after sustaining a fall from ten feet. The patient exhibited full motor function in all extremities but had begun to experience urinary retention. On initial imaging read, the patient was suspected to have an L1 burst fracture. A review of the imaging demonstrated a transitional vertebra. Therefore, based on the last rib corresponding to T12, the fractured level was L2. This case illustrates the risk LSTV carries for wrong site surgery; appropriate levels were then decompressed and instrumented. On systematic review of the literature according to PRISMA guidelines, a three database literature search identified 39 studies describing 885 patients with LSTV and relevant surgical considerations. The primary indications for surgery were for disc herniation (37%), Bertolotti's syndrome (35%), and spinal stenosis (25%). This cohort displayed a mean follow-up time of 23 months. Re-herniation occurred in 12 patients (5.5%). Medical management through steroid injection was 24 72% (n = 80) for the sample. Wrong-level surgery occurred in 1.4% (n=12) of patients.

CONCLUSION: LSTV represents a constellation of changes in anatomy beyond just a sacralized or lumbarized vertebrae. These anatomical differences expose the patient to additional surgical risks. This case and review of the literature highlight avoidable complications and in particular wrong level surgery.