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Final Program


Final Program

216 - Lipo-cyst: A New MFAT Complication

Thursday, February 27, 2025
5:00 PM - 6:30 PM MST

    Presenting Author(s)

  • JB

    John Michael Bravo, DO

    Resident
    Walter Reed National Military Medical Center
    Bethesda, Maryland, United States

    • Co-Author(s)

  • JC

    Joseph Adam Chilbert, MD

    Resident physician
    Walter Reed National Military Medical Center
    Baltimore, Maryland, United States

  • AJ

    Aeneas Janze, MD

    Staff physician
    Walter reed national military medical center
    Silver Spring, Maryland, United States

  • ED

    Edward A. Dolomisiewicz, MD

    Program Director
    National Capital Consortium PM&R Residency Program
    Bethesda, Maryland, United States

Case Diagnosis: A Complication of Micro-Fragmented Adipose Tissue (MFAT) Injection for Knee Osteoarthritis: MFAT Extravasation Into a Popliteal Cyst

Case Description: A 49-year-old male patient with symptomatic left knee osteoarthritis (OA) underwent a single left intraarticular knee aspiration and injection of MFAT. A standard MFAT injection protocol was performed without complications. Two months later, the patient presented with posterior left knee pain and swelling. Ultrasound revealed a hyperechoic speckled fluid collection in the expected location for a popliteal cyst. The cyst was aspirated, yielding approximately 15 cc of fluid with the appearance of MFAT. Aspiration resulted in immediate symptomatic relief, with no cyst recurrence and a fifty percent reduction of baseline pain observed at the six-week follow-up. 

Discussions: MFAT has emerged as a novel treatment for knee OA, offering the potential for symptom relief and functional improvement. This case highlights a rare, but significant complication of MFAT intraarticular knee injection. Despite this atypical outcome, the patient’s symptoms improved significantly after aspiration, indicating that such complications can be managed effectively without significant morbidity. Nonetheless, the financial burden remains considerable as U.S. health insurance does not cover MFAT treatments, and the cost per treatment ranges in the thousands of dollars. 

Conclusions: While MFAT injections are generally safe and effective for knee OA, clinicians should be aware of potential complications such as popliteal cyst formation or extravasation. This case underscores the importance of patient selection and close follow-up to minimize complications and ensure optimal treatment outcomes for patients undergoing orthobiologic interventions. Popliteal cysts should be considered a relative contraindication to intraarticular MFAT knee injections. Furthermore, the prevalence of extravasation into cysts as a complication following MFAT knee injections must be established in the current literature, underscoring the necessity for further research.