MRI Findings Consistent with Peripatellar Fat Pad Impingement: How Much Related to Patellofemoral Maltracking?

Abstract

Peripatellar fat pads are intracapsular extrasynovial adipose cushions that accommodate the changing shape and volume of articular spaces during movement. Variations in bone geometry, passive and active stabilization mechanisms and/or functional demands may lead to peripatellar fat pad abnormalities. While peripatellar fat pads may be affected a variety of conditions such as synovial inflammation, tumor and fibrosis, a mechanical origin should also be considered. Commonly, the clinical term “impingement” is used synonymously in the radiological literature to refer to three distinct entities of structural peripatellar fat pad abnormalities: superolateral the infrapatellar fat pad (Hoffa fat pad) edema, suprapatellar fat pad edema, and prepatellar fat pad edema, implying a mechanical origin of these conditions. The aim of this pictorial review is to describe the normal anatomy of the extensor mechanism of the knee, and discuss the relation of patellofemoral maltracking to the above-mentioned peripatellar fat pad conditions based on current evidence.

The effect of patellofemoral pain syndrome on patellofemoral joint kinematics under upright weight-bearing conditions

“…There were several limitations to this study: (1) factors involved with patellar movement, such as joint morphology, knee muscle activity, and tendon function [ 23 ] were not considered; (2) PFP should be accurately distinguished from other types of anterior knee pain, such as patellar tendinopathy [ 35 ]; (3) other clinical causes of knee pain attributed to rheumatologic or neurologic pathologies should be ruled out [ 35 ]; (4) although patellar maltracking is sometimes related to the condition of the peripatellar fat pads [ 38 ], the effects of the peripatellar fat pads were not considered; and (5) we did not consider the function of the patellofemoral joint with more common causes of PFP such as when walking or using the stairs. However, Bruno et al [ 33 ] reported that it is not always possible to apply more than 25% of the body weight with knee flexion of 90°.…”

Quadriceps Fat Pad Compressıon As the Cause of Anterior Knee Pain

“…Tanıda en önemli yardımcı ileri görüntüleme yöntemleri olmasına rağmen, saptanan bulgular sıkışma sendromu ile uyumlu yapısal patolojiyi göstermekte, tanının klinik bulgularla desteklenmesi gerekmektedir. 7,8 Ancak, henüz net olarak tanımlanmış tanı kriterleri bulunmamaktadır.…”

“…1 Daha sonra diğer yağ yastıklarının sebep olduğu ağrılar üzerine de tanımlamalar yapılmıştır. 7 Diz eklemi içinde tanımlanmış yağ yastıkları eklem kapsülünün içinde, ancak ekstrasinoviyal yerleşimlidir. Dizin ön bölümünde anterior suprapatellar (kuadriseps), posterior suprapatellar (prefemoral) ve infrapatellar (Hoffa) olmak üzere üç yağ yastıkçığı bulunmaktadır (Resim 1).…”

Magnetic Resonance Imaging of Hoffa’s Fat Pad

“…МРТ-картина при болезни Гоффа: а -Т2-взвешенное МР-изображение с жироподавлением в сагиттальной плоскости; определяется значительный диффузный отек жировой клетчатки; b -Т1-взвешенное изображение в корональной плоскости через 6 мес, формирование хаотично расположенных участков фиброза (указано стрелкой); c -протонно-взвешенное изображение с жироподавлением в сагиттальной плоскости через 6 мес, формирование патологической синовиальной пролиферации в центральных отделах (указано стрелкой) определялась, если разрыв жировой ткани был распространен к собственной синовиальной поверхности с формированием узла или распространенного утолщения синовиальной поверхности. Интраструктурный фиброз рассматривался как участок сниженной интенсивности МР-сигнала, не соответствующий нормальному физиологическому каркасу (передняя межменисковая связка, мукозные связки, инфрапателлярная складка) [2,3,14,15,20,21]. Еще три патологических сос-тояния (синдром инфрапателлярной складки, синдром отрыва инфрапателлярной складки, импинджмент-синдром верхнелатерального отдела жировой клетчатки) выделялись отдельно в зависимости от локализации и морфологии изменений.…”