MR imaging of anterior knee pain: a pictorial essay

Abstract

Anterior knee pathology is a frequent cause of joint pain and limitation of function and mobility among patients presenting to an orthopaedic department. Proper recognition and treatment of pathologic conditions depend on the knowledge of normal anatomy and of the various abnormalities, which affect this area of the knee and may present with anterior knee pain. A broad array of benign and malignant processes may be manifested as anterior knee discomfort, and this common clinical entity is among the most frequent indications for MR imaging of the lower extremities. Clinical history and physical examination are also of paramount importance. The disorders can be categorized and differentiated primarily according to their location. Traumatic or non-traumatic disorders of the patella, patellar retinacula, quadriceps and patellar tendons and supra or infrapatellar fat pad can be the source of symptoms. This article includes a comprehensive pictorial essay of the characteristic MR features of common and uncommon disorders causing anterior knee pain. For accurate assessment of the aforementioned clinical problem, a radiologist should be able to identify typical MR imaging patterns that contribute in establishing the correct diagnosis and thus tailoring the appropriate therapy. Level of evidence IV.

Magnetic Resonance Imaging of the Extensor Mechanism

“…Chronic cases of patellar tendinosis may show thickening and abnormal signal involving the entire tendon with abnormal signal intensity on both T1-weighted and T2-weighted sequences. 1,26,27 Other described chronic imaging findings include periosteal reaction along the anterior margin of the patella, calcification within the patellar tendon, and elongation of the inferior patellar pole. 25 …”

“…1 Types of quadriceps and patellar tendon injury include acute traumatic rupture, chronic repetitive/overuse injury, and tendon degeneration. Patellofemoral instability, patellar dislocation, and tracking abnormalities are common disorders.…”

Unusual Symptomatic Multipartite Patella Associated with Quadriceps Fat Pad Edema

“…Bipartite/multipartite patella is a developmental variation which is commonly detected incidentally. Although most patients are asymptomatic, partite patella can also be one of the primary causes of anterior knee pain [ 1 6 ] (Table 1 ). The bipartite patella was categorized by Saupe into three subgroups based on the location of the fragments in 1921: Type I involving the inferior pole, Type II the lateral margin, and Type III the superolateral quadrant of the patella [ 1 7 8 ].…”

MR Imaging of Extrasynovial Inflammation and Impingement About the Knee

“…8 At the end stage of disease, scarring, fibrosis, and calcification may occur. [8][9][10][11][12][13][14] Ogilvie-Harris and Giddens 13 found Hoffa disease present in 1% of patients undergoing knee At the anterior portion of the knee, the capsule is thin (thin blue line) abutting the quadriceps and patellar tendons (black); no synovial layer is seen. Close to the patella, the capsule is quite thin (dashed blue lines).…”