Plica Syndrome

Original Editors - Nel Breyne

Top Contributors - Nel Breyne, Andeela Hafeez, Kenneth de Becker, Uchechukwu Chukwuemeka, Kim Jackson, Admin, Simisola Ajeyalemi, Rachael Lowe, Maxime Tuerlinckx, Adam Vallely Farrell, Claire Knott, Jana Beckers, Tarina van der Stockt, Jirka Rossaert, 127.0.0.1, Rucha Gadgil, Wanda van Niekerk and Daphne Jackson  

Definition/Description

A synovial plica is a shelf-like membrane between the synovium of the patella and the tibiofemoral joint.[20 level 3A] Plicae essentially consist of mesenchymal tissue which is formed in the knee during the embryological phase of development. This tissue forms membranes which divide the knee into 3 compartments: the medial and lateral tibiofemoral compartments and the suprapatellar bursa. This tissue usually starts to involute (fold inward) at 8-12 weeks of foetal growth, and is eventually resorbed, leaving a single empty area between the distal femoral and proximal tibial epiphysis: a single knee cavity. Movement of the foetus in the uterus contributes to this resorption. Yet, in many individuals the mesenchymal tissue is not fully resorbed and consequently the cavitation of the knee joint remains incomplete. The result is that in these individuals plicae can be observed, which represent inward folds of the synovial membrane in the knee joint. Various degrees of septation of the cavities are seen in the human knee. It is estimated that plicae are present in about 50% of the population. [7 level 2B][22 level 2A][25 level 4][26 level 4]
The elastic nature of synovial plicae allow normal movement of the bones of the tibiofemoral joint, without restriction. Yet, when repeating the same knee movement too often, such as bending and straightening the knee, or in case of a trauma to the knee, these plicae can become irritated and inflamed. This can result in a disorder called the plica syndrome. It refers to an internal derangement of the knee which prevents normal functioning of the knee joint.
7 (Level 2B)][25 level 4]
It is an interesting problem - particularly seen in children and adolescents -that occurs when an otherwise normal structure in the knee becomes a source of knee pain due to injury or overuse. The diagnosis might sometimes be difficult because the main symptom of non-specific anterior or antero-medial knee pain can point to various knee disorders. But if a plica has been diagnosed beyond any doubt as being the source of knee pain, it can be treated correctly.[23 level 4][25level 4]

Clinically Relevant Anatomy

In the knee, 4 types of plicae can be distinguished, depending on the anatomical location within the knee joint cavities: suprapatellar, mediopatellar, infrapatellar and lateral plicae. The last one is rarely seen and, therefore, there is some controversy regarding its existence or its exact nature. [8 level 2A][13 level 2A] The plicae in the knee joint can vary in both structure and size; they can be fibrous or fatty, longitudinal or crescent-shaped. [22 level 2A][23 level 4]

- Suprapatellar plicae
The suprapatellar plica, also referred to as the plica synovialis suprapatellaris, superior plica, supramedial plica, medial suprapatellar plica [20 level 3A] or septum [25 level 2A] is a domed, crescent shaped septum that generally lies between the suprapatellar bursa and the tibiofemoral joint of the knee. [20 level 3A] It runs downward from the synovium at the anterior side of the femoral metaphysis, to the posterior side of the quadriceps tendon, inserting above the patella.[23 level 4] Its free border appears sharp, thin, wavy or crenated in normal conditions. This type of plica can be present as an arched or peripheral membrane around an opening, called porta. It often blends into the medial plica. As the suprapatellar plica is anteriorly attached to the quadriceps tendon, it changes dimension and orientation when moving the knee. [25 level2A][26 level 4]

Based on arthroscopic investigations the suprapatellar plicae can generally be classified by location and shape into different types. Kim and Choe (1997) have distinguished the following 7 types:
Type Description
Absent No sharp edged fold.
Vestigial Plica with less than 1 mm protrusion. Disappeared with external pressure
Medial Plica lying on the medial side of the suprapatellar pouch
Lateral Plica lying on the lateral side of the suprapatellar pouch
Arch Plica present medially, laterally and anteriorly but not over the anterior femur
Hole Plica extending completely across the suprapatellar pouch but with a central defect.
Complete Plica dividing the suprapatellar pouch into two separate compartments
[3(Level 2A)]

- Medial patella plica
The medial patellar plica is also known as plica synovialis mediopatellaris, medial synovial shelf, plica alaris elongata, medial parapatellar plica, meniscus of the patella or after its first two descriptors as Iion's band or Aoki’s ledge. It is found along the medial wall of the joint. It attaches to the lower patella and the lower femur and crosses the suprapatellar plica to insert in the synovium surrounding the infrapatellar fat pad. Its free border can have different appearances. As the medial plica is attached to the synovium covering the fat pad and ligamentum patellae, it also changes dimension and orientation during knee movement. The medial plica is known to be the most commonly injured plica due to its anatomical location and it is usually this plica which is implicated when describing the plica syndrome. [18 level 5][20 level 3A][23 level 4][25 level 4][26 level 4]
Similar to the suprapatellar plicae, the medial plicae has also can be classified by appearance. Kim and Choe (1997) (24 level 3B) have defined the following 6 types:

Type Description

• Absent No synovial shelf on the medial wall
• Vestigial Less than 1 mm of synovial elevation which disappears with external pressure
• Shelf A complete fold with a sharp free margin.
• Reduplicated Two or more sheves running parallel. They may be of differing sizes.
• Fenestra The shelf contains a central defect

High-Riding A shelf like structure running anterior to the posterior aspect of the patella, in a position where I could not touch the femur.
Each type is subdivided according to size and relation to femoral condyle with flexion and extension of the knee into: A—Narrow non touch (never makes contact with the femoral condyle). B—Medium touch (touches condyle with knee movement). C—Wide covering (covers the femoral condyle).
[3(Level 2A)]

- Infrapatellar plica

The infrapatellar plica is also called as ligamentum mucosum, plica synovialis infrapatellaris, inferior plica or anterior plica. It is a fold of synovium which originates from a narrow base in the intercondylar notch, extends distally in front of the anterior cruciate ligament (ACL) and inserts into the inferior of the infrapatellar fat pad. It is often difficult to differentiate the infrapatellar plica from the ACL. Mostly it appears as a thin, cord-like, fibrous band. The infrapatellar plica is considered to be the most common plica in the human knee. Discussion is on-going whether this plica is structurally important to regular knee movement or whether it is redundant. [23 level 4][25 level 4]

A classification for infrapatellar plicae can be as follows:

Type Description

• Absent No synovial fold between the condyles of the femur.
• Separated A complete synovial fold that was separate from the anterior cruciate ligament (ACL).
• Split Synovial fold that is separate from the ACL but is also divided into two or more cords.
• Vertical septum A complete synovial fold tht is attached to the ACL and divided the joint into medial and lateral compartments.
• Fenestra A vertical septum pattern that contains a hole or defect.

[3(Level 2A)]

- Lateral plica
The lateral plica is also known as plica synovialis lateralis or lateral para-patellar plica. It is longitudinal, thin and is located 1-2 cm lateral to the patella. It is formed as a synovial fold along the lateral wall above the popliteus hiatus, extending inferiorly and inserting into the synovium of the infrapatellar fat pad. [22 level 2A][23 level 4][25 level 2A] Some authors doubt whether it is a true septal remnant from the embryological phase of development or whether it is derived from the parapatellar adipose synovial fringe. [8 level 2A]
This type of plica is only seen on rare occasions; its incidence being well below 1%. [25 level 4]

 

Epidemiology /Etiology

Pain starts most of the time after exercising for a long time. A plica causes pain when it’s irritated. It can be irritated by overuse, due to exercises where you bend and straight the knee all the time. For example cycling and running. Pain on the medial side of the knee, along the border of the patella, is usually due to overuse of the plica synovialis medialis. Most of the time there’s a intern hydrops and a string palpable. For the other plica’s the complaints are the same but less frequent. It’s more common in adolescent athletes.

The prevalence of suprapatellar plica syndrome is ranging from 11% to 87% and for mediapatellar plica syndrome, it varies from 18% to 60%. Infrapatellar plica syndrome has a mean of prevalence of 65% of patients.
Plica syndrome is most common in patients who undergo repetitive knee movements. It also occurse more in females than in males.[8(Level 2A)]

Characteristics/Clinical Presentation

The pain can be located at different places like the supra- patellar and the mid-patellar region when extending the knee. You can also hear cracking noises when flexing of extending the knee.
The combination of contracting the quadriceps and the compression of the supra-patellar pouch can also be the cause of pain.
What occurs frequently in patients with plica syndrome is that they often have a sense of instability when walking upstairs, downstairs or slopes[7(Level 2B)]

Differential Diagnosis

- patellar femoral syndrome
- patella bipartite
- patellar maltracking
- degenerative joint disease
- hoffa syndrome
- sinding-Larsen-Johansson disease
- medial collateral ligament sprain
- osteochondritis dissecans
- pes anserinus bursitis
- meniscal tears
- patellar maltracking
[8(Level 2A)] [9][10][11(level 2A)][13(level 2A)][14(level 2A)]

Diagnostic Procedures

Radiography isn’t helpful to see if there is a plica syndrome, the radiograph will be negative. Radiography can be helpful to rule out other syndromes where the symptoms are common with a plica syndrome (see differential diagnosis). If there is symptomatic plicae, it will demonstrate hypertrophy and inflammation. This will lead to thickening and eventually fibrosis. If the fibrosis is significant, changes in the articular surface and the subchondral bone may occur.
Arthroscopy can be used because plica syndrome is often confused with chondromalacia or a medial meniscal tear.[12][10]
Most cases of plica syndrome do not require MRI but it can help to rule out other pathologies that can cause knee pain. MRI can detect a pathologic plica, but only if an effusion is present. An MRI also shows excludes bone bruises, meniscus tears, ligament injuries, cartilage defects, OCD lesions,… that may masquerade as plica syndrome.[9]

Outcome Measures

add links to outcome measures here (also see Outcome Measures Database)

Examination

One of the most important points in diagnosing medial synovial plica pathology is obtaining an appropriate history from the patient. The pain is often described as a dull pain in the proximomedial aspect of the knee which increases with activity and is practically bothersome at night. Most patients have complains when doing stairs, squads and standing up from a chair because these movements create a stress on the patellofemorale joint. The patient may also complain of pain following prolonged periods of sitting. About 50% of the patients let us know that they have been doing exercises with repetitive flexion and extension.[15(Level 2A)]

Medical Management

The treatment of a plica syndrome consists of physiotherapy and rest. If this doesn’t have a big influence, you can start with corticosteroid injections and anti-inflammatory medicines. This way of handling has a success rate of less than 20% and appears to have more influence on young people with short-term symptoms. If this therapy fails, you can always perform surgery. This surgery involves an arthroscopy where preferably the whole plica should be removed.[14(Level 2A)]

Physical Therapy Management

Conservative treatment consists of limiting aggravating activities, correcting biomechanical abnormalities (tight hamstrings, weak quads), pain relief with NSAIDS/ cryotherapy and physical therapy aimed at decreasing compressive forces (increasing quadriceps strength and increasing hamstring flexibility).[9]
First you need to reduce the inflammation. You can do this with ice and by resting. If this doesn’t work you can try ice massage, ultrasound and/or friction massage. Friction massage is also used in this therapy to break down scar tissue.[10] Once the inflammation is reduced you can start with the conservative treatment.This treatment is usually recommended for the first 6-8 weeks after initial examination.[11(level 2A)]
It consists of strengthening and flexibility of muscles around the knee, such as the Quadriceps, Hamstrings, adductors, abductors, M Gastrocnemius and M Soleus. [8(level 2A)][9][11(level 2A)][12][13(level 2A)]

The most important part of the quadriceps to train is the m. vastus mediale. Full range of quadriceps is not recommended because these create excessive patellar compression at 90°. Instead straight leg raises and short-arc quadriceps exercises at 5°-10°, also hip adductor strengthening should be performed. Other exercises to be performed are squad, go up and down the stairs and lunging forward. [10] Other important components of this treatment are a stretching program for these muscles (quadriceps, hamstrings and gastrocnemius) and knee extension exercises.[8(level 2A)][11(level 2A)] The goal of this knee extension exercises is the strengthening of the tensor musculature of the joint capsule. But if the patient has too much pain when reaching terminal extension, then this should be avoided.[12] This conservative treatment is effective in most cases, but in some patients a surgery is necessary. The surgical therapy includes arthroscopic removal of the synovial plica. In this case a post-operative therapy is necessary. The post-operative treatment is identical to the conservative treatment and is usually started 15 days after the surgery. The main goal of physiotherapy in plica syndrome is to reduce pain, maximize the ROM and increase the strength of the muscles. (1)

Key Research

add links and reviews of high quality evidence here (case studies should be added on new pages using the case study template)

Resources

1. Gilberto Luis Camanho. (20 october 2009). Treatment of Pathological Synovial Plicae of the Knee  http://www.ncbi.nlm.nih.gov/pubmed/20360913 (A)

(n.d.). Retrieved 12 21, 2010, from Physiothearpy in banff for the knee: http://www.activemotionphysio.ca/article.php?aid=347

Irha, & Vrdoljak. (2003). Medial synovial plica syndrome of the knee: a diagnostic pitfall in adolescent athletes. JOURNAL OF PEDIATRIC ORTHOPAEDICS-PART B , 44-48.

Kenta, & Khanduja. (2009). Synovial plicae around the knee. The Knee , 97-102.

Lipton, & Roofeh. (2008, Juli). The medical plica syndrome can mimic recurring acute haemarthroses. HAEMOPHILIA , pp. 862-862.

Tindel, & Nisonson. (1992). The plica syndrome. ORTHOPEDIC CLINICS OF NORTH AMERICA , 613-618.

Yilmaz, Golpinar, Vurucu, Ozturk, & Eskandari. (2005, Oktober). Retinacular band excision improves outcome in treatment of plica syndrome. INTERNATIONAL ORTHOPAEDICS , pp. 291-295.

Clinical Bottom Line

add text here

Recent Related Research (from Pubmed)

see tutorial on Adding PubMed Feed

References

1. ↑ 1.0 1.1 1.2 Lipton, & Roofeh. (2008, Juli). The medical plica syndrome can mimic recurring acute haemarthroses. HAEMOPHILIA , pp. 862-862.
2. ↑ Tindel, & Nisonson. (1992). The plica syndrome. ORTHOPEDIC CLINICS OF NORTH AMERICA , 613-618.
3. ↑ M. Kent et al.; Synovial plicae around the knee; The Knee; Volume 17, Issue 2, Pages 97-102,2010; (Level 2A)
4. ↑ (n.d.) Retrieved 12 21, 2010, from Physiotherapy in banff for the knee: http://www/activemotionphysio.ca/article.php?aid=347.
5. ↑ Ihra, &Vrdoljak. (2003). Medial synovial plica syndrome of the knee: a diagnostic pitfall in adolescent athletes. Journal of pediatric ortopaedics-Part B, 44-48.
6. ↑ Yilmaz, Golpinar, Vurucu, Ozturk,& Eskandari. (2005, October). Retinacular band excision improves outcome in treatment of plica syndrome. International Orthopaedics, 291-295.
7. Camanho GL ; Treatment of pathological synovial plicae of the knee. Clinics. 2010;65(3):247-50; (Level 2B)
8. Nawfal Al-Hadithy et al.; Review article - Plica syndrome of the knee, Journal of Orthopaedic Surgery 2011;19(3):354-8; (Level 2A)
9. V.Morelli et al.; Sports medicine – an issue of primary care clinics in office practice; Elsevier Health Sciences; 28 June 2013; chapter 7 plica syndrome
10. W.I.Hammer; Functional soft-tissue examination and treatment by manuel methods; Jones and Bartlett publishers; 2007; p.375-376
11. Tal Sznajderman MSc et al.; review – medial plica syndrome; Dept. of Orthopedic Surgery; Assaf Harofeh Medical Center Zerifin 70300, Israel; 2008;11:54–57 (level 2A)
12. R.T.Morrissy et al.; Lovell and Winter’s Pediatric Orthopaedics; Lippincott Williams & Wilkins; 2006; p.1413
13. Sharath S.Bellary et al.; Medial plica syndrome – a review of the literature, department of anatomical sciences; st. George’s university, school of medicine; Grenada; West indies; Clinical Anatomy 25:423–428 (2012)(level 2A)
14. Tal Sznajderman et al. ;Medial Plica Syndrome ; januari 2009; Israel Medical Association Journal Vol 11; (Level 2A)
15. Chad J. Griffith et al. ; Medial plica irritation: diagnosis and treatment; 2008; Curr Rev Musculoskelet Med; (Level 2A)
16. Arthroscopic Classification of Suprapatellar Plica and Medial Synovial Plica; Mitsuru Hanada et. al.; Scientific research; Surgical Science, 2012, 3, 425-429 (Level 3A)