The Medial Plica is a thin wall of fibrous tissue that are extensions of the synovial capsule of the knee.
During fetal development, the knee is divided into three separate compartments. As the fetus develops, these compartments develop into one large protective cavity (synovial membrane).
The majority of people have remnants of these three cavities referred to as a plica. Most often the plica is on the medial (inside) of the knee at the level of the medial femoral condyle. Most individuals are not adversely affected by the presence of plicas.
The plica only becomes a problem when the knee is irritated, causing an inflammation in the synovial sack. When the synovium is inflamed, the area of the plica becomes thicker. This thickened area then begins to catch on the femur as the knee moves. This in turn keeps the plica inflamed resulting in a vicious cycle.
Patients usually complain of anterior and medial-sided knee pain. They may have associated flat feet as well.
Diagnosis is mainly physical examination of the knee showing tenderness at the medial plica during palpation (pressed). There may be associated patellar lateral maltracking in many patients.
Decrease the inflammation by oral anti-inflammatory drugs.
Physiotherapy modalities e.g. iontophoresis (low intensity electric currents), phonophoresis (ultrasound) and ICE treatment may help.
Therapeutic exercises – on increasing overall quadriceps, hamstring, and calf strength, as well as increasing overall muscular flexibility.
Keyhole arthroscopic excision of the medial plica may sometimes be necessary if conservative treatment fails.
This is how an inflamed medial plica looks like on arthroscopy:
The inflamed medial plica can be removed using arthroscopy resulting in resolution of the knee pain.