Journal of Life Science and Biomedicine  
J Life Sci Biomed, 9 (3): 74-81, 2019  
License: CC BY 4.0  
ISSN 2251-9939  
Diagnostic criteria for the synovial plica  
syndrome of the knee, a review  
Murodjon Ergashevich IRISMETOV1, Murod Bakhodirovich TADJINAZAROV1  
Alisher  
Mukhammadjonovich KHOLIKOV1, Dilshod Fayzakhmatovich SHAMSHIMETOV1, Farrukh  
Makhamadjonovich USMONOV1 and Qurbon Nurmamatovich RAJABOV1  
Department of Sports Traumatology, Republican Specialized Scientific and Practical Medical Center of Traumatology and  
Orthopedics, Tashkent, Uzbekistan  
Corresponding author’s Email: tadjinazarov.murod88@gmail.com  
ABSTRACT  
Review Article  
Aim. Based on literature review, the article highlights the current diagnostic criteria for  
the synovial plicae syndrome (SPS) of the knee.  
Introduction. The syndrome diagnosis algorithm includes a carefully collected clinical  
history and clinical examination using specific functional tests, non-invasive research  
methods (ultrasound, magnetic resonance imaging) and arthroscopy.  
PII: S225199391900012-9  
Rec. 25 February 2019  
Rev. 24 April  
Pub. 10 May  
2019  
2019  
Discussion. It should be noted that the principles of early diagnosis by clinical and  
radiological methods are still not well understood. Due to non-specific clinical symptoms,  
this syndrome in most cases is detected by arthroscopic intervention.  
Conclusion. We try to provide an evidence-based guide to the diagnosis criteria of the  
knee SPS, based on the analysis of the literature and our own experience.  
Keywords  
Knee joint,  
Pain syndrome of the knee,  
Synovial plicae syndrome,  
Diagnostic  
INTRODUCTION  
The synovial plicae syndrome (SPS) of the knee develops as a functional disorder in response to chronic  
inflammation, injury or other pathological conditions of the knee, in which there is a change in the structure of  
the synovial plicae (violation of elasticity, fibrous restructuring).  
Patients often mention anterior knee pain, clicking, clunking, and a popping sensation on patellofemoral  
loading activity such as squatting [1, 2]. There is wide variation in reported prevalence of SPS, ranging from 3 to  
30% in European population studies; most studies cite a figure of approximately 10% [3, 4, 5]. According to their  
location, the synovial plicae are classified as suprapatellar, mediopatellar, infrapatellar, or lateral; the medial  
plica is the most commonly symptomatic one [6, 7, 8].  
Most cases of knee SPS are  
idiopathic, and symptoms have been  
estimated to be bilateral in up to 60% of  
cases, although they may not manifest  
concurrently [8]. Other causes or  
associations have been identified  
associated with trauma, overuse injuries,  
hematoma, diabetes, and inflammatory  
arthropathy.  
In adolescence, symptoms can  
occur during a period of growth spurt.  
Any primary disorder of the knee capable  
of producing transient or chronic  
synovitis may therefore be implicated in  
the development of a pathological plica.  
Figure 1. The topical anatomy of the pathological plicae of the knee  
To cite this paper: Irismetov M E, Tadjinazarov M B, Kholikov A M, Shamshimetov D F, Usmonov F M and Rajabov Q N. 2019. Diagnostic criteria for the synovial  
plica syndrome of the knee, a review. J. Life Sci. Biomed. 9(3): 74-81; www.jlsb.science-line.com  
74  
The article outlines the main points of the examination of patients with the SPS. Based on the analysis of  
the literature and our own experience, diagnostic criteria for this pathology are presented.  
HISTORY AND METHODS  
Undoubtedly, one of the most important stages in the diagnosis of knee pathology is obtaining an appropriate  
history of the disease in a patient. Patients may report an aggravation of symptoms on excessive or severe  
traumatic effects associated with flexion and extension of the knee. Intense painful sensations are more  
common in athletes with poor quadricep tone or significant muscular imbalance around the knee, because  
synovial folds are directly related to the articular surfaces of the knee and are indirectly attached to the muscles  
of the quadriceps, while the folds change dynamically during knee activity [4].  
The diagnosis should be suspected in patients of any age. Also, it should be noted that aggravation of  
symptoms is not a mandatory clinical course of the disease and for this reason the problem of identifying  
patients with a long asymptomatic syndrome is still relevant. Some patients report blunt trauma or twisting  
trauma, which usually lead to the development of effusion. Prolonged pain in the projection of the medial  
articular surface of the knee is usually associated with the development of fibrosis [9].  
Pain syndrome sometimes occurs after intense passive or active physical exertion (repeated flexion and  
extension of the knee), when climbing or descending stairs, squatting, getting up after prolonged sitting [5]. In  
addition, patients may note pain in the knee during the sitting itself [1, 10]. Patients commonly report  
intermittent nonspecific anterior knee pain, snapping, clicking, catching, clunking, grinding, “giving way,” or a  
popping sensation along the inside of the knee during flexion and extension. The knee may be tender to the  
touch, swollen, and stiff (Table 1) [11].  
Thus, the pain that occurs on the anterior articular surface of the knee is a cardinal symptom and is  
present in almost all patients with this pathology.  
Table 1. Symptoms and signs of knee synovial plica syndrome  
Anterior knee pain  
• Snapping sensation along the inside of the knee as the knee is bent  
• Clicking, catching, clunking, grinding, popping  
• Tender to the touch  
• Felt as a tender band underneath the skin  
• Knee effusion, swelling  
• Pain on squatting  
• Locking, stiffness, giving way  
CLINICAL EXAMINATION  
In a clinical examination, the surface of the knee may be soft to the touch, swollen or hard. Symptoms are often  
clinically indistinguishable from other intra-articular pathologies of the knee, such as damage to the meniscus  
and articular cartilage, making it difficult to diagnose [2]. Therefore, physical methods are insufficient.  
In turn, clinical diagnosis is supported by special functional tests and instrumental imaging methods.  
When examining the knee, it is important to make sure that the patient is relaxed, which is usually achieved by  
taking a supine position on the back while supporting both legs.  
The abnormal medial plicae is palpated in the form of a cord located 1 cm medially from the superior of the  
patella. Some patients may experience a feeling of moderate pain when palpating the location of the synovial  
fold. In this case, an important point is to conduct a comparative study with the second knee to see if there is a  
difference in the intensity of pain.  
As with any other physical examination, it is important to simultaneously determine whether there are  
other possible pathologies in the structures of the knee, which are located close to the synovial folds. In case of  
acute injuries, other common pathologies of the knee soft tissues, such as meniscal and cruciate ligament  
injuries, should be excluded.  
The Hughston’s plica test (Figure 2) and Stutter test (Figure 3) are provocative tests commonly used to  
support a diagnosis of SPS [5, 9, 10]. These tests are considered to be more supportive of the diagnosis when  
To cite this paper: Irismetov M E, Tadjinazarov M B, Kholikov A M, Shamshimetov D F, Usmonov F M and Rajabov Q N. 2019. Diagnostic criteria for the synovial  
plica syndrome of the knee, a review. J. Life Sci. Biomed. 9(3): 74-81; www.jlsb.science-line.com  
75  
both tests are positive, but are less reliable when used individually, with wide variationnin their reported  
sensitivity and specificity.  
Figure 2. Hughston’s plica test  
Hughston's plica test  
Patient positioning: supine with the knee fully extended and relaxed. The examiner stands on the affected  
side, placing one hand around the heel and the palm of the other hand over the lateral border of the patella with  
the fingers over the medial femoral condyle. Action: the examiner flexes and extends the patient’s knee while  
internally rotating the tibia and pushing the patella medially. Positive finding: pain and/or popping in the knee  
is indicative of an abnormal plica. It is typically in the range of 30 to 60 degrees toward extension.  
To cite this paper: Irismetov M E, Tadjinazarov M B, Kholikov A M, Shamshimetov D F, Usmonov F M and Rajabov Q N. 2019. Diagnostic criteria for the synovial  
plica syndrome of the knee, a review. J. Life Sci. Biomed. 9(3): 74-81; www.jlsb.science-line.com  
76  
Figure 3. Statter test (description in the text)  
Stutter test. Patient positioning: sitting on the side of the bed with knee flex to 90 degrees. The examiner  
crouches down to knee level placing the index and middle fingers on the center of the patella. Action: the  
examiner asks the patient to extend the knee slowly while keeping the fingers on the patella and watches its  
movement. Positive finding: if the patella stutters or jumps during the course of movement, it is indicative of a  
plica. It is typically in the range of 45 to 70 degrees toward extension. Crepitus of the patella may also be felt.  
To cite this paper: Irismetov M E, Tadjinazarov M B, Kholikov A M, Shamshimetov D F, Usmonov F M and Rajabov Q N. 2019. Diagnostic criteria for the synovial  
plica syndrome of the knee, a review. J. Life Sci. Biomed. 9(3): 74-81; www.jlsb.science-line.com  
77  
Figure 4. X-ray examination of the medial plicae syndrome of the knee  
In order to exclude another pathology of the knee, it is recommended to conduct an X-ray of the knee to  
exclude bone traumatic pathology (Figure 4). Also, this method determines the ratio of bones in the joint,  
standing of the patella, the presence of dysplasia, etc. However, in many patients with SPS, radiography does  
not reliably indicate the presence of the syndrome.  
Ultrasound and magnetic resonance imaging (MRI) can reveal the presence of a patellar fold, but they are  
unreliable in verifying the pathological fold. These visualization methods are useful and their use is better in  
specialized centers for the assessment of complex cases, the recurrence of symptoms and for the evaluation of  
indications for surgery.  
Figure 5. Ultrasound photo showing reveal the presence of a patellar plicae  
To cite this paper: Irismetov M E, Tadjinazarov M B, Kholikov A M, Shamshimetov D F, Usmonov F M and Rajabov Q N. 2019. Diagnostic criteria for the synovial  
plica syndrome of the knee, a review. J. Life Sci. Biomed. 9(3): 74-81; www.jlsb.science-line.com  
78  
The average arithmetic indicators of MRI are: accuracy-86.8%, the predictive value of a positive test is  
78%, the predictive value of a negative test is 91.6%. On MRI, the synovial membrane looks like a dark line on T1  
and T2-weighted images. It is extremely difficult to visualize an unchanged synovial sac, in both adults and  
children, especially since there is no contrast enhancement of the unchanged synovial membrane. Basically  
folds are visualized in axial sections, as they are located in the horizontal plane. Have a lower characteristic of  
the signal T1- and T2 VI. The physiological separation of the joint is due to synovial folds, which can also be seen  
on the MRI tomogram series [2, 3, 12].  
Indirect signs can be chondral and osteochondral damage to articular surfaces, i.e. identification on a  
series of tomograms of chondromalacia of the patella or indentation zones on the internal condyle of the thigh  
from contact with the fibrous patellar plicae.  
Figure 6. Synovial plica syndrome of the knee. MRI.  
Figure 7. Suprapatellar plicae of the knee. A 45-year-old patient with pain syndrome  
To cite this paper: Irismetov M E, Tadjinazarov M B, Kholikov A M, Shamshimetov D F, Usmonov F M and Rajabov Q N. 2019. Diagnostic criteria for the synovial  
plica syndrome of the knee, a review. J. Life Sci. Biomed. 9(3): 74-81; www.jlsb.science-line.com  
79  
Figure 8. Arthroscopic photo showing the cartilage surface of the medial femoral compartment being eroded  
by the synovial plica  
Arthroscopy is the most reliable method for the diagnosis of the SPS. Due to the emergence and  
development of the method of arthroscopy, it is possible to most accurately diagnose intra-articular pathology,  
to study the synovial membrane of the knee in more detail. Today, arthroscopy has become the best method for  
this pathology, which allows with 100% certainty to verify certain injuries in the knee, including the SPS, as well  
as to carry out adequate operational measures.  
CONCLUSION  
The SPS of the knee is common and is seen in both community and hospital practice. A diagnosis of SPS should  
be suspected in patients with intermittent pain, swelling, and snapping sensation affecting the knees, which is  
associated with activity that involves increased loading of the patellofemoral joint.  
DECLARATIONS  
Authors’ Contributions  
All authors contributed equally to this work.  
Acknowledgements  
This work was supported by Republican Specialized Scientific and Practical Medical Center of  
Traumatology and Orthopedics, Tashkent, Uzbekistan.  
Competing interests  
The authors declare that they have no competing interests.  
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