Research Day
BILATERAL LIPOMA ARBORESCENS IN A PEDIATRIC PATIENT WITH OBLIGATE PATELLAR INSTABILITY AND JUVENILE IDIOPATHIC ARTHRITIS: A CASE REPORT
Document Type
Abstract
Date
2021
Abstract
Introduction: Lipoma arborescens is characterized by benign proliferation of synovium and replacement of the subsynovial connective tissue with adipocytes. Typical presentation consists of an adult patient with painless unilateral joint swelling with progression to painful effusion. Though the exact etiology remains elusive, lipoma arborescens has been linked to both post-traumatic and chronic inflammatory disease processes, suggesting a possible genetic component. Here, we report an unusual case of bilateral lipoma arborescens in a pediatric patient with concurrent obligate patellar instability and juvenile idiopathic arthritis (JIA).
Case Description: A 14-year-old female with history of autosomal recessive congenital ichthyosis presented with four months of right knee pain and edema. On exam, she had bilateral obligate patellar instability and large effusions. MRI without contrast revealed diffuse synovial thickening of both knees, lateral patellar subluxation, and chondral loss of the patella and trochlea. Pediatric Rheumatology consultation diagnosed JIA given the disproportionally advanced degree of inflammation compared to what would be expected from mechanical stress related to patellar instability alone. She underwent right knee arthroscopic synovectomy, open patellar realignment and stabilization, and osteochondral drilling. Postoperative course was complicated by arthrofibrosis that responded well to manipulation under anesthesia. Patient reports significantly improved pain, minimal effusion, and maintained patellar stability postoperatively.
Conclusions: Lipoma arborescens associated with JIA and obligate patellar instability was successfully treated with arthroscopic synovectomy, patellar realignment, and medial patellofemoral ligament reconstruction in a 14-year-old girl. With future genetic testing planned, a unifying diagnosis may provide valuable insight into the etiology of this uncommon entity.