Exploring Rafe’s Sciatica: Investigating the Link Between Spondyloarthropathy and Non-discogenic Sciatica

Background and aim Sciatica is commonly attributed to nerve root compression due to disc herniation, foraminal stenosis, or spondylolisthesis, which are well-recognized causes of the condition. However, non-discogenic causes, such as inflammatory disorders, including axial spondyloarthritis, remain underrecognized and contribute significantly to the pathophysiology of sciatica. "Rafe's sciatica," proposing a distinct subtype of sciatica linked to spondyloarthritis (SpA), is one such example. Other types of sciatica share clinical characteristics with this condition, such as piriformis syndrome, which can also involve sacroiliitis and sciatic nerve entrapment. This study aimed to identify and characterize Rafe's sciatica as a novel, non-discogenic sciatica subtype associated with SpA, and to explore its diagnostic and clinical implications. Methods A prospective case series of 41 patients with sciatica and suspected SpA was conducted at the Government Employees' Hospital in Dhaka, Bangladesh, from November 2022 to July 2023. The purposive sampling technique was applied to recruit patients who met the inclusion criteria. No blinding was applied. Data were collected through structured interviews and medical records. The Assessment of Spondyloarthritis International Society (ASAS) and Amor criteria guided SpA diagnosis. Enthesitis was assessed clinically and via ultrasound. Sacroiliitis was diagnosed using X-ray and magnetic resonance imaging findings, including bone marrow edema, synovitis, and subchondral sclerosis. Metabolic causes were excluded biochemically. Ethical approval for the study was obtained from the Institutional Review Board of the Government Employees' Hospital, and informed consent was obtained from all participants prior to inclusion. Results The average age of the patients was 39 years, with a predominance of females (31, 75.6%). Imaging studies revealed that 35 (85.4%) patients had sacroiliitis, a key feature of SpA, and 12 (29.3%) patients tested positive for the human leucocyte antigen (HLA)-B27 genetic marker, which is commonly associated with inflammatory disorders. Clinically, 35 (85.4%) patients reported persistent low back pain and exhibited sacroiliac joint tenderness, while morning stiffness lasting more than 30 minutes was observed in 28 (68.3%) patients. Additionally, dactylitis was present in 21 (51.2%) patients. Almost all patients had positive results from the FAIR (flexion, adduction, and internal rotation), modified FAIR, and piriformis stretch tests, which further indicated a link to SpA. Conclusion Rafe's sciatica appears to represent a novel, non-discogenic sciatica subtype associated with SpA. Recognition of this condition may improve diagnostic accuracy and patient management by emphasizing the role of clinical markers and imaging in identifying inflammatory causes of sciatica. While our findings highlight its potential clinical relevance, further validation through larger, comparative studies is essential to refine diagnostic criteria and develop effective treatment strategies.