Plica Syndrome

A plica is a fold of synovial tissue inside the knee. Most people have these folds without symptoms. Plica syndrome develops when a fold becomes irritated, thickened or repeatedly rubbed as the knee bends and straightens, often near the inner side of the kneecap.

Plica syndrome is irritation of a fold in the knee lining that can cause pain, clicking or catching during movement.

The irritation can resemble other causes of front or inner knee pain. It may affect runners, cyclists, athletes and people returning to activity after a period of inflammation or reduced movement.

Plica syndrome commonly presents with pain at the front or inner side of the knee, especially during stairs, squats, cycling or repeated bending. A person may feel a tender band or snapping sensation beside the kneecap. Knee clicking and grinding can occur, and some people report catching or brief knee locking.

Symptoms may increase after activity or after sitting with the knee bent. Swelling is often mild when present. A knee that becomes truly stuck, gives way repeatedly, becomes hot and swollen, or cannot bear weight needs prompt assessment because other knee problems can produce similar signs.

Repeated knee bending can rub an irritated plica against nearby structures. A sudden increase in running, cycling, stairs or squatting may overload the fold. Injury, inflammation or a change in movement after another knee problem can also make the tissue more sensitive.

Muscle weakness or poor control around the hip and knee may alter kneecap tracking and increase rubbing. Plica syndrome is diagnosed by combining the history and examination with consideration of other causes, rather than by treating every knee click as a plica problem.

Symptoms may begin gradually or follow a change in activity. They can settle when irritation is reduced, then return if demanding movement is resumed too quickly. Improvement is usually judged by better tolerance of stairs, squats and daily walking rather than by the complete absence of every knee sound.

Potential contributors include repetitive sport, a rapid training change, prolonged kneeling, reduced hip or thigh strength and limited flexibility. Previous knee inflammation or injury may also alter movement. These factors do not confirm plica syndrome; they help a clinician understand how the symptoms started and what loads need adjusting.

A clinician will ask where the pain is, when clicking or catching occurs, and how activity affects it. They may press along the inner knee, move the kneecap, assess range of motion and test hip, thigh and knee strength. Walking and single-leg movement can show contributing control changes.

Scans may be used when the diagnosis is uncertain or symptoms suggest cartilage, ligament, tendon or bone involvement. Plica syndrome can be difficult to distinguish from other knee conditions, so examination and the full symptom pattern matter.

Initial care commonly combines a temporary reduction in provoking activity with ice or other comfort measures, when suitable, and a gradual rehabilitation plan. Physiotherapy can address hip and thigh strength, knee control, flexibility and a staged return to sport.

If symptoms continue despite appropriate non-surgical care, an orthopaedic clinician may discuss knee arthroscopy. During this procedure, the surgeon can inspect the joint and treat an irritated plica when it is judged to be the pain source. The decision depends on examination findings and alternative diagnoses.

Keep daily movement within a tolerable range and avoid repeatedly testing the painful click. Adjust training volume, use lower-impact alternatives for a period and return to deep bending gradually. Recording which movements trigger symptoms can help your clinician tailor rehabilitation.

Persistent pain may lead to reduced activity, thigh weakness and compensatory movement. Repeatedly working through sharp catching can prolong irritation or hide another knee problem. Seek review if the knee locks, swells substantially, becomes unstable or stops supporting your weight.

Build training volume progressively, vary repetitive activities and include recovery days. Maintain hip, thigh and calf strength, and address changes in running or cycling technique with a professional when needed. Warm up before demanding sessions and respond early to recurring inner-knee pain.

See a physiotherapist or orthopaedic clinician when knee pain, catching or clicking limits sport, stairs or work, or when symptoms do not settle after activity adjustment. Prompt assessment is appropriate for a locked knee, major swelling after injury, fever, redness or inability to bear weight.