Review article: Plica syndrome of the knee

Is There a Relationship Between Quadriceps Tendinopathy and Suprapatellar Plica? An Observational Case Series

Purpose

Chronic painful quadriceps tendinopathy is a relatively rare condition known to be difficult to manage. Conservative management is first-line treatment and if that fails open intra-tendinous revision surgery followed by a long rehabilitation period is used. There is sparse research on etiology and new treatment methods. This observational study aimed to evaluate the intra-articular findings in patients with chronic painful quadriceps tendinopathy resistant to conservative management.

Patients and Methods

Seven male athletes (mean age 33 years, range 22–40) suffering from chronic painful quadriceps tendinopathy in altogether 10 tendons, not responding to conservative management including heavy strength training, were included. Clinical examination and ultrasound scanning were used for diagnosis. Arthroscopy was used for evaluation of the inside of the knee.

Results

In all 10 knees, there were obliterating major plica formations in the suprapatellar pouch.

Conclusion

Obliterating plica formations in the suprapatellar pouch may be involved in the aetiology and pathology in quadriceps tendinopathy.

Infrapatellar plica injury: Magnetic resonance imaging review of a neglected cause of anterior knee pain

Synovial plicae are normal remnants of synovial membranes within the knee joint cavity and are usually asymptomatic. Pathological infrapatellar plica, which is mostly due to plica injury, may be a potential cause of anterior knee pain, but is often overlooked and under-reported on magnetic resonance imaging (MRI). This pictorial review illustrates the MRI findings of infrapatellar plica injury and associated knee injuries, with emphasis on its differentiation from the mimics of plica injury.

Magnetic resonance imaging of impingement and friction syndromes around the knee

The knee is a complex joint with its function dependent on a combination of osseous and soft tissue structures. Alteration in the relationship of these tissues, due to either acute or chronic repetitive injury with possible underlying congenital predisposing factors, can result in impingement between the structures resulting in pain, particularly on activity. The purpose of this article is to provide a comprehensive review of the MRI features of various impingement syndromes around the knee.

Magnetic resonance assessment of medial plica syndrome of knee from child to adult with arthroscopic correlation: A single center experience and literature review

Objective:

Synovial plicae are mesenchymal tissue remnants invaginating into the knee joint. Their classification is based on the location as lateral, mediopatellar, suprapatellar, and infrapatellar. Mediopatellar plica is commonly symptomatic. The purpose of this study was to identify magnetic resonance (MR) characteristics of the medial plica and to correlate with arthroscopy for cause confirmation in patients with painful knee.

Materials and Methods:

The current study was undertaken over a 2-year period between July 2017 and June 2019 in the department of radiology at a tertiary care hospital in India. MR examinations of the knee joint were performed using QUADKNEE coil on a 1.5-T scanner (Signa, General Electric Medical Systems, Milwaukee, WI, USA). The criteria studied were: presence of the plica, interposition into the femoropatellar joint, intraarticular effusion, and fenestrated aspect. Twenty-two knees (20 patients) diagnosed with mediopatellar plica syndrome on MR imaging (MRI), and with no other knee pathology, were treated with arthroscopic division of plicae.

Results:

Only two (20.0%) of the ten knees in which the plicae had not been divided have shown improvement and six (85.7%) of the seven knees in which plica had been divided (P < 0.05) have shown improvement. Subsequent division of the plicae resulted in improvement in seven of the eight knees (87.5%) (P < 0.01). Patients presented with crepitus in 9% of cases (2 of 22), instability in 13.6% (3 of 22), pseudo-locking in 45.4% (10 of 22), and quadriceps atrophy in 54.5% (12 of 22). Fourteen knees (63.6%) had Grade 2 plica based on thickness. Twelve knees demonstrated (54.5%) Grade 2 intermediary effusion. Plica was fenestrated in three patients (13.6%). All patients regained full range of motion. Lysholm knee scale scores were compared prior to and postsurgery (preoperative status, 65.22 ± 7.41 vs. postoperative status, 89.43 ± 8.72) which revealed a significant clinical improvement (P < 0.001). Average visual analog scale (VAS) scores (0 – no pain, 10 – excruciating pain) when compared demonstrated a mean improvement was 4 points; from 6 points before surgery and 2 points' postsurgery after a mean follow-up of 3 months. About 68% of patients after arthroscopic resection had an average VAS score of 0 point and were totally pain free.

Conclusion:

Noninvasive capability of MRI can be used as a screening method in the diagnosis of mediopatellar plica syndrome and should be included in the differential diagnosis of internal derangement of the knee.

Management of suprapatellar synovial plica, a common cause of anterior knee pain: a clinical review

BACKGROUND AND AIM OF THE WORK

Suprapatellar synovial plica is caused by a congenital thickening of the synovial membrane and is generally asymptomatic. In the literature, suprapatellar plicae are described as one of the causes of anterior knee pain however, their real role in determining symptoms is controversial. The aim of the current paper is to describe the anatomy, classifications, pathophysiology, symptoms and management of suprapatellar plica syndrome, as well as the differential diagnosis from other causes of anterior knee pain.

METHOD

Via a search within the MEDLINE/PubMed database, a current review was conducted, and the results summarized.

RESULTS

Due to idiopathic, traumatic or inflammatory conditions, plicae can become pathological, causing anterior knee pain with possible knee clicking, swelling, giving way and locking after prolonged flexion of the knee. The diagnosis should be formulated based on an accurate medical history and clinical examination, followed by an appropriate imaging study. However, arthroscopy remains the "golden standard" for detecting all synovial plica.

CONCLUSIONS

In patients with anterior knee pain, where doubt is present in the imaging investigation for intraarticular or periarticular lesions, pathological suprapatellar synovial plica must be suspected. The treatment should initially be conservative, but in cases where symptoms persist, patients should undergo arthroscopy to confirm diagnosis and to determine a suitable treatment. In the presence of pathological plica associated with cartilage damage of the femoral condyle or patella at the time of diagnostic arthroscopy, plicae excision leads to favourable results in a high number of cases.

Suprapatellar plica classification and suprapatellar plica syndrome

Background

Plicae around the knee are anatomically normal structures that are remnants of embryonic membranes and are generally asymptomatic. Synovial plica syndrome is known to cause knee symptoms; however, its pathological contribution has been rarely reported. This study aimed to investigate the clinical significance of suprapatellar plicae as well as the morphological characteristics of suprapatellar plicae in patients with knee symptoms who required arthroscopic treatment.

Methods

Of 223 arthroscopic knee surgeries, 125 patients undergoing primary arthroscopy for various diseases were eligible for inclusion in this study. All affected knees were preoperatively examined by two skilled physicians in a routine manner. Each patient was diagnosed with one primary disease entity based on clinical examinations and arthroscopic findings. At least two skilled orthopedic physicians watched the surgical videos together and defined the type of plicae based on the Dandy classification (Dandy DJ. 1990) as follows: (A) absent, (B) the plica was up to one-quarter of the width of the suprapatellar pouch, (C) the plica was between one-quarter and one-third of the width of the suprapatellar pouch, (D) the plica was between one-third and two-thirds of the width of the suprapatellar pouch, (E) the plica was more than two-thirds of the width of the suprapatellar pouch, (F) the plica had a complete membrane, (G) the plica was perforated, (H) arch, (I) pillar, or (J) lateral. Suprapatellar plica syndrome was considered when (1) the patient complained of anterior knee pain and had localized tenderness above the suprapatellar pouch, (2) magnetic resonance imaging revealed suprapatellar plica structures, and (3) other suspicious pathologies accounting for knee symptoms were excluded. We investigated primary disease type, type of plica, and the relationships between them.

Results

The results revealed that meniscus injuries and anterior cruciate ligament injuries caused the majority of primary diseases (approximately 80%). Regarding plica forms, 23 knees were classified as having absent (type A) plicae, 14 knees as having a complete septum (type F), and 88 knees were classified as “other.” There were no significant relationships between disease type and the morphological characteristics of the plicae (chi-squared test, p = 0.35). Suprapatellar pain was observed in five cases, of which two patients were diagnosed with intra-articular free body, one patient with synovitis combined osteoarthritis, and two patients with suprapatellar plica syndrome with a complete septum. The latter two cases experienced knee symptom resolution soon after arthroscopic resection of the plica.

Conclusions

Although the results did not show any relationship between forms of plica remnants and primary disease type, all patients diagnosed with suprapatellar plica syndrome showed complete septum type suprapatellar plicae. A large population study is required in the future.

The infrapatellar fat pad and the synovial membrane: an anatomo-functional unit

The infrapatellar pad, a fibro-adipose tissue with peculiar microscopic and mechanical features, is gaining wide attention in the field of rheumatological research. The purpose of this descriptive review is to summarize the most recent published evidence on the anatomic, physiologic and biomechanical inter-relationship between the infrapatellar fat pad and the knee synovial membrane. As an extrasynovial tissue, the infrapatellar fat pad does not directly interact with the articular cartilage; based on its location in close contact with the synovial membrane, and due to the metabolic properties of adipose tissue, it may influence the behavior of the synovial membrane. In fact, considering evidence of macroscopic and microscopic anatomy, the infrapatellar fat pad is the site of insertion of the infrapatellar and medial synovial plicae. Also biochemically, there is much evidence highlighting the interaction among these two structures; in the case of inflammation, the mutual interplay is ascribable to the release of pro-inflammatory mediators stimulating the proliferation of inflammatory cells and promoting tissue modifications in both. All these assumptions could support the emerging idea that the infrapatellar fat pad and the synovial membrane may be considered a morpho-functional unit.

Synovial Plica Syndrome of the Knee: A Commonly Overlooked Cause of Anterior Knee Pain

Synovial plica syndrome (SPS) occurs in the knee, when an otherwise normal structure becomes a source of pain due to injury or overuse. Patients may present to general practitioners, physiotherapists, or surgeons with anterior knee pain with or without mechanical symptoms, and the diagnosis can sometimes be difficult. Several studies have examined the epidemiology, diagnosis, and treatment of SPS. We review these resources to provide an evidence-based guide to the diagnosis and treatment of SPS of the knee.

The correlation between medial plica and trochlear dysplasis: An MRI study

Background:

Trochlear dysplasia is the most commonly encountered congenital etiologic factor of anterior knee pain.

Aims:

The purpose of this study was to evaluate the relationship between trochlear dysplasia with medial patellar plica as well as to investigate the distribution of plica types according to types of dysplasia.

Settings and Design:

This is a retrospective case-control study.

Materials and Methods:

This study was conducted among 138 knee magnetic resonance imaging (MRI) scans. The presence of medial plica and its types were compared among 69 patients in whom trochlear dysplasia had been detected and 69 individuals with normal trochlear who were of the same age and gender as the patient group.

Statistical Analysis:

Trochlear dysplasia and medial plica was compared by Chi-square with Yates correction and Fisher's exact probability tests (P < 0.001). The data were presented as mean, standard deviation, minimum–maximum, frequency, and percentage.

Results:

Of all the patients (n = 138), the number of patients in whom plica was observed was n = 104 (75.3%), and the distribution of plica type was as follows: n = 70 (67.3%) Type 1, n = 25 (24%) Type 2, and n = 9 (8.6%) Type 3. Medial plica was more frequently observed in patients with trochlear dysplasia (P < 0.001). Type 2 and Type 3 medial plica were more frequently encountered in trochlear dysplasia (P < 0.001). Type 3 plica was not seen in patients with normal trochlea.

Conclusion:

Medial patellar plica is more frequently seen in trochlear dysplasia. As the type of trochlear dysplasia progresses, the prevalence of thicker and shelf-shaped plica increases.

The effects of medial synovial plica excision with and without lateral retinacular release on adolescents with anterior knee pain

OBJECTIVES

To describe the functional outcomes in patients aged ≤18 years with anterior knee pain treated with medial plica excision with or without lateral release.

METHODS

We identified 135 patients including 30 bilateral cases (165 knees) with a mean ± SD age of 15.1 ± 2.0 years. Patient and surgical information was recorded and a follow-up athletic questionnaire and an International Knee Documentation Committee (IKDC) Subjective Knee Evaluation form were sent out. Statistical analysis evaluated predictors of residual pain, reoperation, return to sports, IKDC score and satisfaction with surgery.

RESULTS

At a final mean follow-up of 4.4 years (range 2-7.5), 36 % of patients were pain free, 46 % had mild residual pain and 18 % had pain not improved from surgery. Reoperation was more likely following isolated plica excision (7/41; 17 %) versus plica excision with lateral release (8/124; 6 %), although not statistically significant, P = 0.06. Mean IKDC score (107 knees) was 76.9 ± 17.8 (range 31-100). Most patients (86/99; 87 %) were satisfied with surgery and were able to return to sports (104/120; 87 %).

CONCLUSIONS

While most patients were satisfied and able to return to sports following plica excision with or without lateral release, residual symptoms were common.

Synovial plicae of the knee joint: the role of advanced MRI

Synovial plicae are normal anatomical structures of the knee that may become symptomatic. MRI is an established technique for evaluating the anatomy of the knee, and it is a valuable tool for detecting plicae because of its high resolution resulting in increased tissue characterisation. At MRI, knee plicae appear as low-signal-intensity structures of variable size and thickness, and they are better visualised at fluid-sensitive sequences with or without fat suppression. The combined use of clinical examination and MRI may also facilitate the diagnosis of fibrotic or inflamed plicae that may be symptomatic. Arthroscopy remains the gold standard for recognition and repair of knee plicae in cases of knee dysfunction.

Intra-articular plica causing ankle impingement in a young handball player: a case report

Ankle sprains are common injuries that respond well to rehabilitation. In the case of persisting symptoms, the differential diagnosis should include osteochondral defects, tendon injury, mechanical instability, and ankle impingement. In the present case report, we describe a 16-year-old male handball player who presented with persisting pain and locking in the right ankle 3 years after having sustained multiple minor inversion trauma. The clinical examination and conventional radiography showed no abnormalities. On magnetic resonance imaging, a flake fracture at the anteromedial talar dome and/or loose body was assumed. Arthroscopic examination revealed an intra-articular plica originating from an osteochondral fossa at the anteromedial tibial plafond. The plica was debrided. Retrospectively, the arthroscopic findings matched the radiographs and magnetic resonance images. The postoperative protocol consisted of early mobilization. At 6 weeks of follow-up, the patient had no pain and had returned to his sports activities. The present case report illustrates, to the best of our knowledge, the first case of ankle impingement due to a, most likely congenital, intra-articular plica arising from an osteochondral fossa at the anteromedial tibial plafond. This rare clinical condition can be diagnosed with magnetic resonance imaging. Arthroscopic debridement will effectively relieve the symptoms.