Retrospective review of outcomes in patients with Bertolotti's syndrome who underwent fluoroscopically-guided pseudojoint injections.

Introduction: A lumbosacral transitional vertebra (LSTV) is an articulation or fusion of the transverse process of the fifth lumbar vertebra and the sacrum or ilium, and, when associated with pain, it is referred to as Bertolotti's syndrome. Few studies have examined the diagnostic utility of LSTV injections and their ability to provide relief in cases of Bertolotti's syndrome. In this study, we investigate predictors of positive clinical outcomes following LSTV injection and examine the relationship between a positive diagnostic injection and outcomes after LSTV resection in patients with Bertolotti's syndrome. Methods: This study was a retrospective analysis of 56 patients from September 2013 through August 2024 who were diagnosed with Bertolotti's syndrome and who had received a pseudojoint injection with a steroid and an anesthetic. Demographic information, comorbid conditions, and information about pain and multiple validated outcomes were extracted from the electronic health record. Results: The patients had a mean age of 44 years, and 62.5 % (35/56) of the patients were female. Lumbar spondylolisthesis was found in 20.0 % of patients (11/55). Using the Castellvi classification, the most common type of LSTV was Type 2a (42/56, 75.0 %). Of the patients, 55.4 % had an anxiety disorder (N = 31/56) and 42.9 % had depression (24/56). Numeric rating scale (NRS) scores significantly improved from preprocedure to immediate postprocedure (P < 0.001), with 39/45 (86.7 %) achieving a minimal clinically important difference (MCID) of 2.5, and from preprocedure to follow-up (P < 0.001), with 8/25 (32.0 %) achieving an MCID of 2.5. The median duration of pain relief was 14 days. There was no statistically significant difference in PROMIS-GH physical and mental scores, and no difference in PHQ-9 in patients between preprocedure and follow-up. Patients with a higher American Society of Anesthesiologists (ASA) physical status classification were less likely to experience relief (p = 0.025). Additionally, patients who received an injection of Triamcinolone (p = 0.018) were less likely to experience relief at follow-up than those who received methylprednisolone, although this difference was not observed immediately after injection. Only 13 patients underwent a resection of the pseudojoint, of which 8 (61.5 %) reported improvement after resection. Discussion: Injections into the pseudojoint under fluoroscopic guidance may provide therapeutic benefits and may have some diagnostic impact on surgical intervention. Future randomized prospective research should be performed to determine the appropriate utilization of pseudojoint injections and create an evidence-based diagnostic and therapeutic algorithm to isolate pain generators in Bertolotti's syndrome and create an appropriate individualized treatment.