Evaluation and Interventional Management of Pain After Vertebral Augmentation Procedures

INTRODUCTION A small subset of patients who underwent successful vertebral compression fracture (VCF) augmentation procedures may develop subsequent pain requiring spinal injections. In a retrospective analysis, we determined whether the pain was related to the original fracture site or to another area within the lumbar or thoracic spine. The pain occurred either at the same/adjacent level and/or non-adjacent level as the VCF. Interventional treatments primarily targeted the facet joints, specifically in the form of facet joint blocks and/or radiofrequency ablation to the medial branches. The pattern of facet injections relative to the original fracture level was studied. Additionally, the elapsed time between the vertebral augmentation and the subsequent interventional blocks was also evaluated. METHODS A total of 56 patients sustained VCFs. 12 of these patients underwent interventional procedures after vertebral augmentation procedures. The level(s) of same/adjacent level and non-adjacent level pain were determined via physical examination and/or imaging studies. These levels were subsequently treated with interventional procedures primarily focused on the facet joints. The time period of the injections varied from two weeks status post-vertebral augmentation to as late as 304 weeks (5.8 years) status post-vertebral augmentation. RESULTS We performed 25 vertebral augmentation procedures on these 12 patients. 15 lumbar, eight lower thoracic, and two mid-thoracic VCFs were augmented. 9/14 cases of blocks included those performed at non-adjacent levels, whereas 5/14 cases of blocks were performed only at the same and/or adjacent levels as the VCF. For the events in which thoracic VCFs were augmented, 6/7 (or 86%) had developed non-adjacent level pain in areas of the lumbar spine.  The time from vertebral augmentation procedure to subsequent pain procedure ranged from two weeks to five plus years. The average time elapsed was 83 weeks. Only one case required blocks performed within the first six weeks after vertebral augmentation. In this case, the blocks included those at non-adjacent levels. A total of 4/12 cases (33%) had a block within 12 weeks of the original vertebral augmentation procedure. Lumbar spine imaging showed that at least 9/12 patients had pre-existing significant lumbar pathology at the time of fracture treatment. This may have contributed to the later development of pain. CONCLUSION Pain after a successful vertebral augmentation is typically non-acute (i.e., beyond six weeks). Mechanisms other than the primary VCF are usually responsible for non-adjacent level pain, which are present a majority of the time on reviewing the patients' diagnostic studies. These mechanisms usually take many weeks to develop and subsequently elicit pain that requires additional interventional pain procedures. In our study, the pain is usually related to the pre-existing degenerative spondylosis and stenosis rather than the fracture site. This study shows that the facet joints in closely related lumbar degenerative changes are the cause of pain in this patient group. These procedures should be explored with pain after vertebral augmentation, especially in those patients with known or suspected spinal degeneration and/or poor biomechanics.