Non-classical Celiac Disease as an Unrecognized Cause for Post-operative Knee Swelling following Patellofemoral Arthroplasty: A Case Report.

Introduction: Non-classical Celiac disease is a previously undescribed cause of debilitating post-operative cutaneous complications following an orthopedic procedure. Non-specific symptoms and rarity of the disease pose a diagnostic challenge; however, given underdiagnosis and significant morbidity, after ruling out of acute pathology, Celiac disease should be included in differential diagnosis for refractory cutaneous complications following an operative procedure. Case Report: A 34-year-old woman who underwent patellofemoral arthroplasty and medial patellofemoral ligament reconstruction experienced over 5 months of post-operative knee swelling, erythema, and pain unresponsive to antihistamines and negative infectious, vascular, and implant allergy testing workups. After careful dietary monitoring by an allergy specialist, she was tested and confirmed to have Celiac disease. Following cessation of her oral contraceptive pill and dietary gluten, her knee swelling, erythema, and debilitating pain resolved. Conclusion: Skin erythema, swelling, and pain are known complications after any operative treatment, but after ruling out of acute infectious and thromboembolic processes, diagnosis and management of refractory complications pose a challenging scenario. In this rare phenomenon, previously undescribed, a patient presented with months of post-operative knee erythema, swelling, stiffness, and extreme pain on activity along with non-specific symptoms of headache and fatigue before diagnosis with Celiac disease. On cessation of her birth control and dietary gluten, her symptoms and knee function improved dramatically.