Medial patellar plica syndrome are symptoms that can be associated with the presence of synovial plicae of the knee (most commonly the medial plica). It can be a common source of anterior knee pain.
On this page:
Epidemiology
While it can affect those of any age, it typically involves the young patients (1st-3rd decades) of both sexes 10 involved in repetitive athletic activity ref.
Clinical presentation
Patients may present with pain over the anteromedial aspect of the knees (mostly above the joint line 8) and this may be accompanied by episodes of crepitation, snapping, catching, popping 11, stiffness, and locking sensations 10. Localized tenderness +/- palpable band may be present along with a knee joint effusion 10.
Pathology
Knee plicae are synovial invaginations which are thought to be remnants of embryological development. Plicae ≥1 mm may be present in over 70% of individuals and are mostly asymptomatic 8,9. Under certain circumstances, they carry the potential to become inflamed and symptomatic. The medial plica is the most common to be symptomatic 10. There can be fibrosis of a plica rendering it inflexible 8.
Radiographic features
Plain radiograph
Plicae are occult on plain radiograph.
MRI
Useful for identifying the presence of a plica and if it is thickened (typically appears like a shelf-like band). Signal characteristics of plicae are:
- T1: low signal
- T2/PD: low signal
In symptomatic patients, thickening of the medial plica and associated chondral defect of the medial patellar facet can be seen ref.
Treatment and prognosis
Management options range from the conservative end of rest - physiotherapy to corticosteroid injections to arthroscopic surgery.