613 - Acute Pseudogout Flare Following Intra-Articular Platelet-Rich Plasma Injection: A Case Report

Calcium pyrophosphate deposition disease (CPPD) post platelet rich plasma injection (PRP)

Case Description:

A 43-year-old female with no prior history of CPPD underwent intra-articular PRP injection to the knee for discomfort related to degenerative joint disease and degenerative meniscal tears seen on MRI. Within one hour, she developed knee swelling, joint stiffness, and bruising at the injection site. Symptoms worsened over the next 24 hours, prompting a return visit the following day.

Examination revealed moderate joint effusion with joint stiffness, pain and warmth without erythema. A popliteal cyst was aspirated and found to contain cloudy synovial fluid which was sent for culture, cell count, and gram staining. She was referred to the ED to rule out a septic joint. Synovial fluid analysis revealed crystals consistent with calcium pyrophosphate, confirming acute pseudogout. Gram stain and culture were negative for infection.

She was managed conservatively with elevation, alternating heat and ice, compression, NSAIDs as needed, and knee mobility exercises. Her symptoms resolved within two weeks.

Discussions:

This is a unique case of a rare complication of PRP therapy in which an episode of pseudogout was precipitated in a 43-year-old female with no prior history of CPPD. To our knowledge, three other cases of pseudogout triggered by PRP injections have been reported in the literature. These prior cases were all in older patients, and only two of them without history of pseudogout.

Conclusions:

As PRP therapy becomes more widespread in musculoskeletal rehabilitation, awareness of this rare complication is essential, particularly in individuals with subclinical crystal deposition. Further research is needed to explore the role of subclinical pseudogout in osteoarthritis development and to better understand the inflammatory pathways involved in PRP-related flares.