Abstract
Infrapatellar fat pad impingement represents a source of anterior knee pain that is
often overlooked. Due to the scarcity of reports related to this disorder, we conducted
a systematic review of the literature related to infrapatellar fat pad impingement
in evaluating the following: (1) clinical presentation, (2) imaging, (3) management,
and (4) clinical outcomes. A systematic review was conducted investigating all available
primary literature related to the clinical presentation, imaging, management, and
outcomes of infrapatellar fat pad impingement syndrome. A total of 15 studies (9 case
reports, 1 case series, and 5 retrospective studies) comprising 167 patients met eligibility
criteria for this review. Patients with infrapatellar fat pad impingement were found
to most often present with anterior knee pain that worsened with activity, and was
frequently associated with trauma. Anterior knee pain, tenderness to palpation over
the patellar tendon, loss in terminal extension, and pain with direct pressure on
the medial or lateral side of the patella with the knee extended was often found on
examination. Although patients may have classic imaging findings on magnetic resonance
imaging (localized edema of the infrapatellar fat pad, deep fluid-filled infrapatellar
bursa, nonvisualization of clefts, fibrosis, and calcifications), not all patients
had positive imaging findings, thus making infrapatellar fat pad impingement a clinical
diagnosis. Treatment begins with nonoperative management, but in recalcitrant cases,
patients can be surgically treated with arthroscopic fat pad resection. Most patients
who undergo operative treatment report improvement or complete resolution of symptoms
in terms of pain and range of motion, and are able to return to work. To the best
of our knowledge, this is the first comprehensive review on infrapatellar fat pad
impingement to better aid the orthopaedic surgeons in diagnosing, treating, and managing
patient expectations for this often overlooked knee pathology.
Keywords
knee - fat pad - impingement - infrapatellar fat pad
