Liposynovitis prepatellaris in a child (Hoffa’s syndrome): Lessons from MRI

Abstract

BackgroundLiposynovitis prepatellaris (Hoffa’s syndrome) is a rare condition in children and rarely discussed in the literature. Hoffa’s syndrome can lead to an obscure anterior knee pain resulting from impingement and inflammation of the infrapatellar fat pad. Aim of the workThe aim of this case report is to increase awareness among rheumatologists about this condition among children to avoid erroneous diagnosis of juvenile idiopathic arthritis (JIA) and unnecessary treatment with disease-modifying antirheumatic drugs (DMARDs). Case reportIn this report we presented a 12year-old child with this condition who presented with chronic pain and intermittent swelling involving his right knee. The patient was wrongly diagnosed as a case of JIA and wrongly treated with DMARDs for three years duration. The report will shed light on the characteristic MRI features of this condition and the value to order MRI in such atypical presentation. ConclusionHoffa’s syndrome can present with chronic arthropathy in children that can mimic mono-articular JIA presentation and eventually unnecessary treatment with DMARDs. MRI is generally very helpful from the diagnostic point of view, it clearly depicts Hoffa’s infrapatellar fat pad entrapment and its findings may suggest Hoffa’s syndrome.