NEW findings suggest that clinically significant inflammatory arthritis can develop months to years after bariatric surgery, even in the context of substantial postoperative weight loss. The report provides a detailed clinical and imaging overview of patients who developed spondyloarthritis-like disease following bariatric procedures.
A Rare but Under-Recognised Complication
Bariatric surgery is widely associated with metabolic and inflammatory benefits, including improvements in musculoskeletal pain and inflammatory markers. However, sporadic reports have suggested that inflammatory arthritis may emerge after surgery in a small subset of patients. Until now, systematic descriptions of clinical presentation and MRI findings have been limited.
To address this gap, researchers conducted a retrospective case series of patients evaluated at a tertiary rheumatology centre between 2010 and 2025 who developed new-onset inflammatory arthritis following bariatric surgery.
Clinical and Imaging Patterns
The case series included 14 patients with a mean age of 48 years. The average interval between bariatric surgery and symptom onset was nearly five years, highlighting a delayed presentation rather than an acute postoperative phenomenon. Despite significant reductions in body mass index after surgery, patients developed persistent inflammatory symptoms.
Inflammatory low back pain was the most common presenting feature, reported in nearly 80% of cases. Enthesitis and dactylitis were also frequently observed. Based on clinical assessment and imaging, six patients were classified as having axial spondyloarthritis, all with MRI-confirmed sacroiliitis. Seven patients met criteria for peripheral spondyloarthritis, including cases with MRI-proven peripheral inflammation, HLA-B27–associated disease, and reactive arthritis following infection. One patient was categorised as having undifferentiated inflammatory arthritis.
Treatment Burden Despite Weight Loss
All patients had been treated with non-steroidal anti-inflammatory drugs, but nearly half ultimately required biologic or targeted synthetic therapies to control disease activity. Laboratory findings were variable, and many patients were seronegative, underscoring the importance of imaging in diagnosis.
The authors note that the emergence of inflammatory arthritis in this context challenges assumptions that weight loss alone is protective against immune-mediated joint disease. Alterations in immune regulation, gut microbiota, or metabolic signalling after bariatric surgery may contribute, though mechanisms remain speculative.
Implications for Clinical Practice
While the authors stress that this descriptive study is hypothesis-generating, the findings highlight the need for clinician awareness of inflammatory arthritis as a potential long-term complication after bariatric surgery. Persistent inflammatory musculoskeletal symptoms in postoperative patients should prompt rheumatological evaluation rather than being attributed solely to mechanical or degenerative causes.
Larger, controlled studies will be needed to clarify incidence, risk factors, and underlying mechanisms. For now, the case series provides an important signal that inflammatory arthritis can emerge after bariatric surgery and may require advanced immunomodulatory treatment.
Reference
Kiliç J et al. Post-bariatric surgery–associated inflammatory arthritis: a case series describing clinical and MRI features. BMC Rheumatol. 2026;DOI: 10.1186/s41927-026-00619-x.
