Two-level fusion for Bertolotti syndrome and concomitant adjacent segment disease: patient series.

backgroundBertolotti syndrome is characterized by low back pain and a lumbosacral transitional vertebra (LSTV). LSTVs are classified into four types by the Castellvi system. Pain is thought to be due to degeneration or strain at a pseudoarticulation of the enlarged transverse process and the sacrum. At times, patients with Bertolotti syndrome develop severe degeneration and/or instability adjacent to the LSTV. Treatments range from conservative measures, such as therapeutic injections, to surgical interventions, such as fusion, resection, and decompression. OBSERVATIONS: This study examines two-level fusion surgeries performed via open, minimally invasive (MIS), or robotic approaches for Bertolotti syndrome and associated adjacent level degeneration. Eight patients were identified retrospectively. All underwent two-level fusion at L4-L5-S1 or L5-L6-S1. Six surgeries were MIS (one with robotic assistance), and two were open. MIS/robotic procedures had a median surgery duration of 3 hours 30.5 minutes and a median blood loss of 50 ml, while open surgeries averaged 5 hours 49.5 minutes, with 300 ml of blood loss. No patients had 90-day or 12-month readmissions or reoperations. LESSONS: Patients undergoing two-level fusion for Bertolotti syndrome had similar outcomes across surgical approaches. Both groups improved in physical health above the minimal clinically important difference. https://thejns.org/doi/10.3171/CASE25551.