Knee Gout Flare Following a Viscosupplementation Injection: A Rare Occurrence in Osteoarthritis Management

Case Diagnosis: Right Knee Gout exacerbation after a Viscosupplementation Injection

Case Description or Program Description: A 63-year-old patient with bilateral knee pain associated with degenerative joint disease developed knee gout exacerbation after receiving a viscosupplementation injection for osteoarthritis management. Three weeks after the injection, patient presented to the emergency room with severe pain at the right knee, associated with swelling and discomfort, without history of trauma.

Setting: Secondary Care

Assessment/Results: A comprehensive physical examination was performed with findings of tenderness upon right knee palpation, swelling, and limited range of motion due to pain. MRI revealed a moderate-sized joint effusion and high-grade chondromalacia at the medial femorotibial compartment. To completely rule out knee joint infection, an arthrocentesis was performed and found no bacteria, however demonstrated yellow needle-shaped uric acid crystals under parallel polarized light, indicative of inflammatory arthritis.

Discussion (relevance): Gout is a form of inflammatory arthritis caused by the deposition of uric acid crystals in the joints. This case is specifically notable as the patient developed gout after receiving a viscosupplementation injection, a hyaluronic acid-based treatment for knee osteoarthritis with goals to improve joint lubrication and reduce pain. Viscosupplementation injections are not typically the cause of a gout flare, with trauma, alcohol consumption, and high meat intake being the most common. This case highlights a rare yet significant complication of gout exacerbation following a viscosupplementation injection in a patient with pre-existing degenerative joint disease, a situation rarely reported in current literature.

Conclusions: This case emphasizes the importance of considering a full differential diagnosis, including gout, when managing patients with knee pain and swelling after viscosupplementation. Clinicians should be aware of this potential complication and rule out other causes, such as joint infection, post-injection inflammatory response, pseudogout, among others, before determining definitive treatment. Early identification and treatment of gout flares can prevent long-term joint damage and improve patient outcomes.