Intra-articular lipoma arborescence of the knee - A rare clinical entity

Background: Intra-articular lipoma arborescence (LA) is a rare entity that presents with swelling and with recurrent effusion of the joints lined by synovium, especially the large joints like knee and others. Pathologically, it is characterised by replacement of subsynovial tissue by fat cells. Magnetic resonance imaging can clinch the diagnosis. Method: We describe four cases of LA, who presented with chronic intermittent pain and swelling of the knee joint. Arthroscopic synovectomy and further biopsy helped establishing the diagnosis. Result: Arthroscopic resection of lesion and management of concomitant lesion help in managing the symptoms. Conclusions: LA should be included in the differential diagnosis of cases with persistent, refractory, chronic knee joint swelling and pain.