Predictors of Outcomes Following Lumbar Intra-articular Facet Joint Injections and Medial Branch Blocks

Abstract

Study design: A scoping review. Objective: We aimed to identify and describe the factors associated with the patient-reported response following lumbar intra-articular facet joint injections or medial branch blocks. Summary of Background Data: Facet joint osteoarthritis is among the most common causes of chronic low back pain. Management often includes facet joint intra-articular injection and medial branch blocks (which may be followed by radiofrequency ablation of the nerves innervating these joints). However, the success of these approaches is variable, prompting interest in identifying patient characteristics (imaging features, clinical signs, among others) associated with response to these types of facet injections. Methods: We performed a literature search on factors associated with patient-reported outcomes following lumbar facet joint intra-articular injections or medial branch blocks for patients with low back pain published in English or Spanish between 2000 and 2023. We excluded duplicates, papers that did not describe factors associated with outcomes, or those describing other interventions. We collected data on the association of these factors with patient-reported outcomes. Results: Thirty-seven studies met the inclusion criteria and were analyzed. These studies evaluated factors such as age, depression, and single-photon emission computed tomography (SPECT), among variables. Age and imaging findings of facet arthropathy were the most frequently described factors. Imaging findings of facet joint arthropathy and positive SPECT were often associated with positive results following intra-articular facet joint injections or medial branch blocks. In contrast, younger age and smoking were frequently associated with less favorable clinical outcomes. Conclusion: A myriad of factors were analyzed in the thirty-seven studies included in this review. Imaging findings of facet arthropathy, duration of pain, and positive SPECT were consistently associated with favorable results following facet interventions. Future prospective studies should include control groups. Clinicians may find these results useful in deciding whether to recommend facet injections.

Reporting of Facet Joint Inflammation in Lumbar Spine MRI Studies in Patients With low Back Pain

“…18 These readers scored facet joint effusion, bone marrow edema, and soft tissue edema of the facet joints at L3/L4 (right and left), L4/L5 (right and left), and L5/S1 (right and left), using a recently developed atlas system (reported in Acosta Julbe et al, under review). 19 The grading system is summarized in Table 1. The readers recorded these findings in a Research Electronic Data Capture database.…”