Plica Syndrome of the Knee

What Is It?

A plica is a normal fold in the thin lining (synovium) of the knee left over from development — most people have several. Plica syndrome occurs when one of these folds, usually along the inner (medial) side of the kneecap, becomes thickened and inflamed and starts snapping over the edge of the femur as the knee bends.

How It Happens

Repetitive bending activity (cycling, running, stairs, squatting), a direct blow to the front of the knee, or a period of joint irritation can inflame the fold. Once thickened, it catches with each bend, which keeps it irritated — a cycle that can persist without treatment.

What It Feels Like

An aching or sharp pain along the inner edge of the kneecap, a snapping or catching sensation as the knee bends around 30–60°, and discomfort with prolonged sitting, stairs, and squatting. Sometimes the thickened band itself can be felt rolling under the fingers.

How Long Recovery Takes

Most plica syndrome settles with 6–12 weeks of conservative care. When surgery is needed, arthroscopic excision of the plica is an outpatient procedure with walking the same day; most patients are back to full activity in 4–6 weeks.

Treatment

First line: activity modification, anti-inflammatory medicine, ice, and physical therapy focused on quadriceps and hip strength and patellar mobility. A corticosteroid injection can calm a stubborn fold.

If symptoms persist despite good conservative care, knee arthroscopy with excision of the inflamed plica (and a check of the rest of the joint) is reliable — the fold does not need to be there, and removing it removes the mechanical irritation.

Returning to Sport

After arthroscopic excision: walking immediately, cycling in 1–2 weeks, jogging around 3–4 weeks, and sport when swelling is gone and strength is symmetric — commonly 4–6 weeks.

Preventing the Next One

Keep the quadriceps and hips strong, progress training loads gradually, and treat flare-ups early with relative rest and ice rather than pushing through snapping pain.

When to Call Us

Call the office at (513) 354-3700 for pain not controlled with medicine, a knee that locks, rapidly increasing swelling, or fever over 101°F.