Medial Synovial Plica Irritation

Author: Robert F LaPrade, MD, PhD; Chief Editor: Craig C Young, MD more...

Updated: Feb 28, 2010

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Background
Epidemiology
Functional Anatomy
Sport-Specific Biomechanics
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Background

The medial suprapatellar plica of the knee is an intra-articular synovial fold on the medial aspect of the knee. This plica is one of the most common sources of knee pain in patients; however, a proper rehabilitation program allows most patients to recover from the symptoms associated with irritation of this structure.

Frequency

United States

No exact numbers on the incidence of patients with an irritated synovial plica are available; however, it is estimated that approximately 50% of patients who present with knee pain to a physician's office have some irritation of their patellofemoral joint. In this group of patients, most of them have some amount of suprapatellar plical irritation.

Functional Anatomy

The suprapatellar plica is an intra-articular synovial fold, which has its main component on the medial aspect of the knee. When the knee is in full extension, the suprapatellar plica commonly forms a shelf, which can be palpated by an examiner. Proximally, the plica is attached to the articularis genu muscle. Distally, it is attached to the anterior horn of the medial meniscus and the medial edge of the retropatellar fat pad. In some patients, this plical shelf can become fibrotic and may impinge on the medial edge of the medial femoral condyle.

Sport-Specific Biomechanics

The quadriceps muscles and the articularis genu muscle dynamically control the medial suprapatellar plica. Good quadriceps tone seems to result in normal motion of this plica, whereas patients with poor quadriceps tone or tight hamstring muscles (antagonists of the quadriceps) commonly have irritation of their synovial plica.

Proceed to Clinical Presentation

Contributor Information and Disclosures

Author

Robert F LaPrade, MD, PhD Professor, Department of Orthopedic Surgery, Divisions of Sports Medicine and Shoulder Services, University of Minnesota Medical School; Director, Orthopedic Biomechanics Lab

Robert F LaPrade, MD, PhD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and Arthroscopy Association of North America

Disclosure: Nothing to disclose.

Specialty Editor Board

Anthony J Saglimbeni, MD President, South Bay Sports and Preventive Medicine Associates; Private Practice; Team Internist, San Francisco Giants; Team Internist, West Valley College; Team Physician, Bellarmine College Prep; Team Physician, Presentation High School; Team Physician, Santa Clara University; Consultant, University of San Francisco, Academy of Art University, Skyline College, Foothill College, De Anza College

Anthony J Saglimbeni, MD, is a member of the following medical societies: California Medical Association and Santa Clara County Medical Association

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD Senior Pharmacy Editor, eMedicine

Disclosure: eMedicine Salary Employment

Jon B Whitehurst, MD Clinical Instructor of Surgery, University of Illinois College of Medicine; Partner, Rockford Orthopedic Associates; Orthopedic Chairman, Rockford Memorial Hospital

Jon B Whitehurst, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Orthopaedic Society for Sports Medicine, and Arthroscopy Association of North America

Disclosure: Nothing to disclose.

Chief Editor

Craig C Young, MD Professor, Departments of Orthopedic Surgery and Community and Family Medicine, Medical Director of Sports Medicine, Sports Medicine Fellowship Director, Medical College of Wisconsin

Craig C Young, MD is a member of the following medical societies: American Academy of Family Physicians, American College of Sports Medicine, American Medical Society for Sports Medicine, and Phi Beta Kappa

Disclosure: Nothing to disclose.

References

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Medial plica of left knee.

Patella in a male patient, medial aspect.

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