A plica or synovial plica is a band of synovial tissue found in the knee joint. Plica syndrome, also known as medial plica syndrome, usually affects the medial plica (on the inner side of the knee). There are also other plicae at the knee such as lateral plica, medial suprapatellar plica, lateral suprapatellar plica, suprapatellar septum, and ligamentum mucosum. Plica syndrome occurs when the plica becomes irritated and inflamed from repetitive friction.
The severity of plica syndrome can be categorised as follows:
Mild: intermittent discomfort or a clicking sensation in the knee during certain movements. The pain and discomfort may be mild and may not significantly impair daily activities or mobility.
Moderate: frequent or persistent pain and discomfort, as well as swelling or stiffness in the knee joint. The condition may impair mobility and hinder an individual’s participation in certain activities.
Severe: significant pain and disability, including persistent pain, swelling, stiffness, and difficulty with knee movements. The condition may significantly impair an individual’s daily activities and require medical intervention, such as physiotherapy or surgery.
What causes plica syndrome?
Some potential causes of plica syndrome include:
Overuse: repetitive movements such as bending and extending the knee joint.
Injury: high-impact trauma such as a car accident or a blow to the knee.
A “pop” or “snap” sensation in the knee during certain movements
Pain and discomfort in front of the knee
Swelling and stiffness in the affected knee joint
Impaired range of motion
Tenderness and sensitivity in the affected area
Instability and weakness in the affected knee
If you notice any of the symptoms, make an appointment with an orthopaedic specialist to get an accurate diagnosis and treatment.
Dr Puah KL is our Senior Consultant Orthopaedic Surgeon at Artisan Sports & Orthopaedic Surgery. He used to serve the sports service of Singapore General Hospital - the highest volume trauma centre for orthopaedics in Singapore.
Yes. Plica syndrome can cause pain in the knee, specifically felt in the front of the affected knee.
Pain levels vary depending on the severity of the condition. Pain levels can be aggravated through repetitive knee-related activities such as squatting or walking up the stairs causing the plica to rub against other structures in the knee joint causing further discomfort.
Who is at risk of plica syndrome in Singapore?
Plica syndrome can occur in anyone, but the following factors increase your risk:
Athletes: cyclists and runners who execute repetitive knee movements are more prone to developing plica syndrome.
Congenital factors: individuals born with larger or more prominent plicas are at higher risk to develop plica syndrome.
Health conditions: individuals with hemarthrosis secondary to haemophilia, intra-articular lesions, loose foreign bodies, and rheumatoid arthritis are at an increased risk of developing plica syndrome.
How is plica syndrome diagnosed?
Plica syndrome is one of the trickier knee injuries to diagnose as it tends to show similar symptoms to other knee conditions, hence proper diagnosis with an orthopaedist is necessary.
Diagnosis of plica syndrome occurs in the following ways:
Physical examination and medical history: inform your orthopaedist of the potential activities that may have led to an injury such as trauma, exercise, or sports and underlying health conditions that are plausible causes of plica syndrome. The knee will be particularly investigated for a palpable taut band in the middle of the knee. Physical tests such as the Stutter test and the Hughston test would be administered to confirm the diagnosis.