Arthroscopy: The Journal of Arthroscopic & Related Surgery
Technical notesMPP test in the diagnosis of medial patellar plica syndrome
Section snippets
MPP test
The MPP test was conducted with the patient supine and the knee extended. Using the thumb, manual force was applied to press the inferomedial portion of the patellofemoral joint, so as to insert the medial plica between the medial femoral condyle and the patella. While maintaining this force, the knee was flexed at 90°. The MPP test was defined to be positive when the patient experienced pain with the knee in extension and eliminated or markedly diminished pain with the knee in 90° of flexion.
Arthroscopic technique
With the knee extended, plica was located between the patella and trochlea (Fig 1A). At 30° of flexion, the plica began to contact the medial femoral condyle, showing the bowstring phenomenon (Fig 1B). At 60° of flexion, the plica began to slip from the medial femoral condyle, the so-called rolling-over sign. At 90° of flexion, the plica slipped away from the medial femoral condyle (Fig 1C). The MPP test was then repeated while maintaining the superolateral viewing portal to confirm the
Discussion
A pathologic MPP is one of the causes of anterior knee pain. However, clinical diagnosis is frequently difficult.4, 11, 12, 13, 14 Although diagnostic accuracy is improving with the use of magnetic resonance imaging, a carefully documented history and physical examination remain the most important for the diagnosis of MPP syndrome.3, 11, 15
Even for experienced orthopaedic surgeons, correct diagnosis has often proved to be elusive. Some clinical tests have been introduced to improve the
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Cited by (23)
Diagnostic Imaging: Musculoskeletal Trauma
2016, Diagnostic Imaging: Musculoskeletal TraumaDiagnostic test accuracy of clinical and radiological assessments for medial patella plica syndrome: A systematic review and meta-analysis
2014, KneeCitation Excerpt :A normal MPP is a thin, flexible soft-tissue structure, comprised of mainly elastic tissue [3]. Due to the anatomical position of the MPP, it is prone to impingement between the patella and the medial femoral condyle during repetitive flexion activities [4]. Inflammation of the synovial tissue can lead to a thickening of the MPP, and in chronic cases, this can become inelastic [2].
Synovial plicae around the knee
2010, KneeCitation Excerpt :A number of provocative tests for pathological plica have been described. Kim et al. named his the medial patella plica test or MPP test [24]. It is performed by applying a manual force to the infero-medial portion of the patellofemoral joint.
Arthroscopic treatment of patellofemoral soft tissue impingement after posterior stabilized total knee arthroplasty
2008, KneeCitation Excerpt :One patient complained of sustaining mild anterior knee pain even after an arthroscopic debridement, even though there was no evidence of component failure on radiographic evaluation. Before arthroscopic surgery, the patient showed a positive medial patellar plica test [23] as well as a painful crepitus. On arthroscopy, the hypertrophic synovitis was also found at inferomedial side of patella.
The Relationship Between the MPP Test and Arthroscopically Found Medial Patellar Plica Pathology
2007, Arthroscopy - Journal of Arthroscopic and Related SurgeryInferolateral Parapatellar Synovial Fold Causing Patellofemoral Impingement in Both Knee Joints
2007, Arthroscopy - Journal of Arthroscopic and Related SurgeryCitation Excerpt :The pain was aggravated on prolonged walking. There was tenderness with no palpable cord-like structure and a positive mediopatellar plica (MPP) test,4 which is a test of impingement, in the inferolateral parapatellar area of both knee joints. The range of motion was normal with no instability.