P-082 - (Poster #82) Epidural Steroid Injection as a Treatment Alternative for Ankylosing Spondylitis Complicated by Andersson Lesions: A Case Report

Andersson lesions are rare destructive discovertebral lesions found in patients with ankylosing spondylitis, characterized by areas of bone destruction and sclerosis at the vertebral endplates and intervertebral discs. These lesions cause chronic pain, resulting in significant reductions in quality of life. Management for Andersson lesions ranges from conservative measures, including physiotherapy and pharmacological interventions, to surgical solutions such as spinal instrumentation and fusion. There is a notable gap in the literature addressing alternative therapeutic options for patients with symptomatic Andersson lesions who fail conservative treatment but are not candidates for surgery. 

Purpose/Objectives:

The primary objective of this clinical work is to present the case of a patient with a 20-year history of ankylosing spondylitis complicated by Andersson lesions, and over 10 years of worsening thoracic back who achieved 60-80% pain relief with an erector spinae plane block until his biologics were titrated to therapeutic dosages. After a thoracic spine MRI revealed a T7 Andersson Lesion that was undiagnosed in prior imaging, periodic repeat injections and eventually an epidural steroid injection effectively managed the patient’s pain.

Methods:

No extraneous methods were utilized in assessing the patient outside of standard management of care and interventions provided as this is a case report. Thorough review of EMR records filed over 20 years, in addition to standard lab results and imaging were used to build this case report and examine the challenges associated with treating patients with Andersson lesions outside of conservative or surgical interventions.

Results:

We present a 59-year-old male with a history of hypertension, anxiety, depression, peripheral axonal neuropathy, and longstanding ankylosing spondylitis who presented to the pain clinic with significant mid-thoracic, lumbar, and sacral pain worsening for the past 10 years. Despite initiating anti-tumor necrosis factor (TNF) therapy with etanercept for ankylosing spondylitis one year prior and conservative management with physiotherapy and opioids, he continued to experience persistent but controlled thoracic pain, managed electively only with celecoxib. Sacral and lumbar pain were treated with sacroiliac joint injections and medial branch blocks, respectively, with good result. Concurrently, patient biologics were up titrated to include etanercept, methotrexate, and leflunomide. Initial bone scan showed increased signaling at the anterior superior corner of the T8 vertebral body with degenerative changes and Schmorl’s nodes.

Five years after initial presentation, the patient developed atypical tuberculosis cellulitis requiring incision & drainage with 6 day hospitalization and discontinuation of biologics. This led to worsening thoracic pain, requiring pain psychology consultation, strong opioids, and frequent emergency room visits. Repeat bone scan suggested that that persistent T8-T9 edema could represent a spinal hemangioma. In 15 months, bilateral US-guided T7 erector spinae blocks were performed with ropivacaine and dexamethasone, resulting in 60–80% pain relief. He resumed Enbrel at a reduced dose but experienced uncontrolled thoracic pain requiring repeated emergency department visits. In one and a half year, fluoroscopy-guided erector spinae blocks at T7-T8 with ropivacaine and Kenalog provided 60% relief. The following year, CT thoracic spine performed showed a focal lucency/erosion within the inferior endplate of T7, with concern of an acute inflammatory lesion. The patient was switched to adalimumab, and a left paramedian T6-7 epidural steroid injection provided 90% pain relief. In follow up MRI, resolution of T7 edema was noted with chronic Schmorl’s node formation. Given that spinal hemangiomas do not usually resolve and typically present on MRI as "honeycomb" or "polka-dot" pattern. It was likely that the patient had been experiencing pain secondary to an undiagnosed Andersson lesion. At most recent follow-up, the patient reported gross resolution of thoracic pain.
 

Conclusions/Implications for future research and/or clinical care:

In patients with ankylosing spondylitis complicated by Andersson lesions, timely diagnosis and appropriate management are crucial to improving outcomes and quality of life. This case highlights the potential role of epidural steroid injections as a bridge for acute pain relief when conservative measures fail, and surgical interventions are not feasible. Further research is needed to validate the efficacy of epidural steroid injections and refine pain management guidelines for this challenging condition.