Musculoskeletal Sonography for Evaluation of Anatomic Variations of Extensor Tendon Synovial Sheaths in the Wrist.

OBJECTIVES: The purpose of this article is to show the anatomic variations of extensor tendon synovial sheaths in the wrist. METHODS: Videos from 157 patients that were available in the electronic database were reviewed. Sonography showed involvement of 186 tendon sheaths. RESULTS: We describe our center's experience with most tendon variants described in the literature and show the sonographic appearance of the most frequent ones. CONCLUSIONS: Sonography is an accepted, safe, and efficient method for evaluating conditions characterized by effusion into the synovial sheaths of the wrist extensor tendons. Knowledge of anatomy and anatomic abnormalities of these sheaths is essential for diagnosis and for correct ultrasound-guided injection therapy or, less frequently, planning a surgical approach.

Relationship between medial plica and medial femoral condyle--a three-dimensional dynamic finite element model.

BACKGROUND: Many researches reported that the pathologic medial plica impinges on the facing medial femoral condyle during knee motion and leads to erosive changes of the articular cartilage. The purpose of this study was to construct a simplified three-dimensional dynamic finite element human knee model to evaluate the dynamics behaviour between different types of medial plicae with the facing medial femoral condyles during knee motion. METHODS: A three-dimensional dynamic finite element model composed of femur, tibia, covering cartilage and medial plica was developed. The kinematics of this simulation model was verified by previous findings during arthroscopic examination. The validated model was used to investigate and compare the magnitudes of the cyclic pressures acting on the cartilage of the medial femoral condyles by three different types of medial plicae with various Young's moduli. FINDINGS: All types of plicae remained in contact with the medial femoral condyles and shifted medially when the knees moved from extension to flexion. The contact pressures were positively correlated with the Young's moduli of the medial plicae. During the whole range of motion, the maximum contact pressures of all simulation scenarios occurred when the knees moved beyond 50° of flexion. When the Young's moduli of medial plicae were set greater than 60 MPa, all types of medial plicae would elicit contact pressures greater than 10 MPa on the medial femoral condyles. INTERPRETATION: The close relationship and possible high contact pressure between fibrotic medial plica and medial femoral condyle during knee motion might be a cause of cartilage damage on the medial femoral condyle and warrants further investigation.

Intercondylar synovial septum in two patients with nail-patella syndrome.

This case report describes the arthroscopic findings in two patients with nail-patella syndrome (NPS). In both cases, a midline synovial septum was encountered that completely subdivided the knee into medial and lateral compartments. One patient required two subsequent arthroscopic procedures, and the synovial septum was found to have recurred even after it had been resected at the initial surgery. The etiology and clinical significance of this anatomic anomaly are unknown, however, surgeons should be aware of its existence and the potential difficulties it may present during knee arthroscopy in patients with NPS.

Treatment of pathological synovial plicae of the knee.

OBJECTIVE: To analyze the incidence, clinical significance, and clinical manifestations of pathological synovial plicae of the knee. MATERIAL AND METHODS: Between 2002 and 2006, 63 patients with pathological synovial plicae of the knee were studied. Of those 63 patients, 21 had the diagnosis confirmed by previously performed magnetic resonance imaging. All of the patients initially underwent conservative treatment for 90 days that involved strengthening and improving the flexibility of the muscles surrounding the knee as well as modification of their sports activities. RESULTS: A total of 55 patients improved after conservative treatment. Six of these patients eventually experienced a recurrence of symptoms, but the symptoms were not incapacitating in any of these patients. The other eight patients underwent arthroscopic removal of the synovial plica. Of these eight patients, six returned to their pretreatment physical activities, and two had persistent symptoms during physical activity. CONCLUSION: The presence of a synovial plica of the knee should be considered as a potential diagnosis in patients with knee pain, especially those who practice sports inappropriately. Conservative treatment is effective in most cases, and surgical treatment should be reserved for exceptional cases that do not improve with conservative treatment.

Medial plica in patients with knee osteoarthritis: a histomorphological study.

UNLABELLED: The gross appearance and histological features of the medial plicae removed from 48 consecutive patients who had received total knee replacement for severe medial compartment osteoarthritis of their knees were investigated prospectively. The prevalence of the medial plica was 100%. A small branch of skeletal muscle originating from articularis genu inserting into the proximal synovial stroma of the medial plica was found in all knees. The synovial fold of the distal part of the medial plica was disclosed to have a close relationship with the gracilis tendon sheath. Histologically, the majority of advanced pathologic presentation was found at the middle and distal portion of the medial plica that might abrade on the articular cartilage of the medial femoral condyle. Noticeable cartilaginous lesion was found on the facing medial femoral condyle in all knees. The histomorphological findings of the medial plica imply the close interplay between this structure and the medial femoral condyle that might play a role in the pathogenesis of medial compartment osteoarthritis of the knee. CLINICAL RELEVANCE: The findings of this study support the beneficial effect of some surgical procedure that would remove the pathologic medial plica for the treatment of medial compartment OA knee.

Treatment of pathological synovial plicae of the knee

OBJECTIVE: To analyze the incidence, clinical significance, and clinical manifestations of pathological synovial plicae of the knee. MATERIAL AND METHODS: Between 2002 and 2006, 63 patients with pathological synovial plicae of the knee were studied. Of those 63 patients, 21 had the diagnosis confirmed by previously performed magnetic resonance imaging. All of the patients initially underwent conservative treatment for 90 days that involved strengthening and improving the flexibility of the muscles surrounding the knee as well as modification of their sports activities. RESULTS: A total of 55 patients improved after conservative treatment. Six of these patients eventually experienced a recurrence of symptoms, but the symptoms were not incapacitating in any of these patients. The other eight patients underwent arthroscopic removal of the synovial plica. Of these eight patients, six returned to their pretreatment physical activities, and two had persistent symptoms during physical activity. CONCLUSION: The presence of a synovial plica of the knee should be considered as a potential diagnosis in patients with knee pain, especially those who practice sports inappropriately. Conservative treatment is effective in most cases, and surgical treatment should be reserved for exceptional cases that do not improve with conservative treatment.

Patellar impingement by synovial cord following anterior cruciate ligament reconstruction.

We found a cordlike structure (synovial cord) in the patellofemoral joint causing patellar impingement in a 45-year-old man after anterior cruciate ligament (ACL) reconstruction. Arthroscopic examination revealed that a cylindrical cordlike soft tissue with a smooth surface extended between the medial and lateral capsule of the patellofemoral joint. The tissue histologically consisted of dense collagen fibers in parallel bundles covered with thin layers of synovial tissue; in addition, there was a proliferation of small vessel patches surrounded by hemosiderin-laden macrophages, which indicated bleeding episodes due to impingement in the patellofemoral joint. To our knowledge, this is the first case report of a synovial cord in the patellofemoral joint causing patellar impingement following ACL reconstruction.

Medial plica syndrome of the knee: diagnosis with dynamic sonography.

PURPOSE: To perform a feasibility study of dynamic sonography for the diagnosis of medial plica syndrome of the knee. MATERIALS AND METHODS: The study design was approved by the university bioethics board, and all the participants gave informed consent. Inclusion criteria were a palpable medial band, history of painful aching, and giving way or locking, which limited the subject's activity for at least 6 months. Exclusion criteria were a history of trauma with hemarthrosis, previous knee surgery, and arthrosis detectable on radiographs. A prospective evaluation in 88 subjects (56 female subjects, 32 male subjects; mean age, 20 years; range, 7-47 years) who were suspected of having a medial plica and 91 knees was performed. Three sonographic criteria were assessed during patellar movement by using a 12-MHz 38-mm linear transducer: (a) continuous echo sliding over the medial femoral condyle during medial and lateral movement of the patella, (b) entry of the echo under the patella during medial movement of the patella, and (c) pain or discomfort during dynamic sonography. Arthroscopy was the reference standard. An asymptomatic control group consisting of 32 volunteers (mean age, 28 years; range, 10-52 years) and 60 knees was also assessed. RESULTS: Arthroscopy revealed 68 plicae with pathologic findings, 61 of which met all three sonographic criteria. Medial plicae with pathologic findings were absent in 23 knees; 19 plicae were correctly diagnosed by using sonography. Diagnostic accuracy was 88%, sensitivity was 90%, and specificity was 83%. In the asymptomatic control group, there were 37 knees without a plica echo, 16 knees with a plica echo that met one criterion, and seven knees that met two criteria. CONCLUSION: Dynamic sonography allows detection of abnormalities of medial plicae in the knee, with good sensitivity and specificity.

[The labral plicae entrapment syndrome of hip in children: an ultrasonography study].

OBJECTIVE: To study the ultrasonographic (US) features of labral plicae entrapment syndrome of hip (LPEH) in children and to evaluate the value of US in diagnosing LPEH. METHODS: (1) Twenty six LPEH models and 38 sham LPEH hips were established surgically from 32 children cadavers [15 male and 17 female, age from 2 to 8 years, mean age of (6.12 +/- 2.13) years]. US was performed on these hips double-blindly. The sensitivity, specificity, positive and negative predictive values were calculated. (2) A total of 21 children (17 male and 4 female, mean age (5.95 +/- 2.67) years) with unilateral LPEH and 21 age and gender matched children with normal hips were consecutively recruited. The 21 symptomatic hips, 21 asymptomatic hips and 42 normal hips were examined by the US (ATL 5000) using the high-frequency (7.5-12 MHz) linear array transducer. RESULTS: (1) The sensitivity, specificity, positive and negative predictive values of the US for the LPEH model were 88%, 84%, 79%, and 91%, respectively. (2) Fluids in hip joints were detected in all of the 21 symptomatic hips. No fluid was detected in the asymptomatic and normal hips (less than 2mm); The mean width of the inferomedial recess was significantly larger than that of the anterior recess (12.50 mm vs. 4.35 mm, P < 0.05) in the 21 symptomatic hip joints; The echogenic entrapped labral plicaes were demonstrated in the inferomedial recess of the 21 symptomatic hip joints, with a length ranging from 5.3 to 25.0 mm [mean(15.63 +/- 5.57) mm) and a width ranging from 4.0 to 17.0 mm [mean (8.90 +/- 7.81) mm], respectively; No color signal of blood flow was demonstrated in 90% of the 21 entrapped labral plicaes; With regard to the mean thickness of cartilage of femora head, anterior layer and posterior layer of the anterior capsule, there were no statistical significant differences between the three groups (P > 0.05). After manual reduction and conservative treatment, all of the entrapped labral plicae and fluids disappeared in the US follow-up examinations. CONCLUSION: The entrapped labral plicae in the inferomedial recess of hip joints could be visualized by the US. The US provides a useful diagnostic clue to LPEH in children.

The synovial plicae in the knee joint.

OBJECTIVE: To investigate and evaluate the prevalence of 4 kinds of synovial plicae named according to patella, which are inferior, medial, lateral and superior. METHODS: We evaluated plicae in 318 knee arthroscopies through video records, obtained from January 1994 to December 2002 in the Arthroscopy Unit, Department of Orthopedic Surgery, Faculty of Medicine, Trakya University, Edirne, Turkey. In addition, we also investigated plicae in 7 bilateral knee cadavers. RESULTS: In the arthroscopic evaluation, the prevalence of infrapatellar synovial plica was 194 (61%), mediopatellar plica was 302 (95%), lateral patellar plica was 66 (20.7%) and suprapatellar plica was 184 (57.8%). We found that there were 8 (57%) infrapatellar synovial plicae, 13 (92%) mediopatellar plicae, 7 (50%) lateral patellar plicae and 6 (42%) suprapatellar plicae in 14 cadaveric knees. CONCLUSION: We observed a high prevalence of lateral plicae and mediopatellar plicae on the cadavers and the people with arthroscopic diagnosis, and believe our results can contribute to knee anatomy and surgery.

A complete supra-patellar plica with an unusual presentation.

A suprapatellar plica is a persistent remnant of the embryologic synovial membrane between the suprapatellar pouch and the knee joint. Pathologic synovial plica is not a common entity, however, when present, it can mimic a variety of clinical situations. We describe here a case of pathologic suprapatellar plica that has a check-valve mechanism, which results in a clinical presentation as knee joint swelling.

Symptomatic infrapatellar plica.

To assess the clinical outcomes of a group of patients who underwent arthroscopic infrapatellar plica (IPP) excision and to determine, whether the IPP was symptomatic or not, to identify the symptoms or signs in the patient's clinical presentation and to study the correlations between arthroscopic findings and patient's clinical presentation. A retrospective clinical study. We studied all the patients undergoing arthroscopic resection of symptomatic infrapatellar plica without other intraarticular abnormality at our department from February 1996 to April 2001. Fourteen patients with isolated IPP and with regular follow-up intervals were included in the study. Arthroscopy findings, preoperative magnetic resonance imaging (MRI) findings, and clinical presentation were correlated. The mean duration of follow-up was 36 months with a range of 24-60 months. The IPP was found to be in fenestra pattern in seven patients, separate (cordlike) pattern in five patients and vertical septum pattern in two patients. IPP in all patients was excised with a powered instrument. Two patients were rated as excellent, ten patients as good and two patients as poor results. All the patients were documented with pain, popping or snapping with flexion and extension, giving way and swelling. There was no correlation between IPP type and MRI findings with being symptomatic (P>0.05). It was found that IPP type was not a prognostic factor. Infrapatellar plica should be considered as a potential cause of knee pain with probable MRI imaging and no other evidence of internal derangement. We recommend close correlation with the clinical symptoms and exclusion of other internal derangement before suggesting infrapatellar plica as a sole cause for knee symptoms.

Non perforated septum supra-patellaris mimicking a soft tissue tumour.

Plicae synoviales of the knee are well known to present as anterior knee pain but can also cause blocking, clicking, and swelling of the knee mimicking pathology such as meniscal tears or other internal derangements, and even mono-arthritis. Embryologically, the knee is divided into a medial and lateral compartment and a supra-patellar pouch by thin membranes of synovium. Incomplete involution of these membranes gives rise to a plica. When there is no involution at all, the membrane is called a septum. There are three frequent types of plicae/septa: a suprapatellar, a medial-patellar, and an infra-patellar type. We discuss on a patient with a non perforated septum supra-patellaris which resulted in a swelling above the knee, mistaken for a soft tissue tumour.

Variant attachments of the anterior horn of the medial meniscus.

The purpose of this study was to analyse the occurrence of variants of anomalous insertions of the anterior horn of the medial meniscus in human knee joints. The study was carried out on 78 human lower limbs of both sexes (42 males and 36 females). Out of 78 knee joints, 10 knee joints (12.82%) presented atypical attachments of the anterior horn of the medial meniscus. In 9 cases we found that the anterior horn of the medial meniscus was attached to the transverse ligament of the knee and in 1 case it was attached to the coronary ligament. In the remaining cases the anterior horn of the medial meniscus was attached to the anterior intercondylar area of the tibia.

Does the meniscus exist in the elbow joint in children?

The authors report a case of meniscus at the elbow joint in a 15-month-old infant causing a limitation of elbow extension. Histological examination demonstrated that this tissue was not a synovial fold or a chondroid metaplasia of the synovial fold. As a meniscus does not appear at any stage of the embryological evolution of the elbow joint, it has been concluded that the presence of the meniscus can be considered as an abnormal condition.

United unresorbed medial and lateral plicae as anterior mesenchymal synovial septal remnant.

Mesenchymal tissue that forms compartments in the knee joint begins to be resorbed in the 8th week of embryologic life. Unless these mesenchymal tissues are totally resorbed, they remain as septal remnants, and are termed mediopatellar, infrapatellar, suprapatellar, and lateral plicae. We report a case of united anterior plica; the inferior part of the anterior mesenchymal septum at the back of the patellar tendon was unseparated and unresorbed, and one-half of the superior part of the septum beginning from the inferior pole of the patella formed the V-shaped medial and lateral plicae such that their opening looked upwards.

Arch type pathologic suprapatellar plica.

The authors encountered a case of arch type pathologic suprapatellar plica that was excised using an arthroscopic technique. It is reported with a review of the literature.

Direct MR arthrography of plica synovialis mediopatellaris.

OBJECTIVE: To evaluate the efficacy of direct MR arthrography for diagnosing plica synovialis mediopatellaris (PSM). MATERIAL AND METHODS: Twenty-two knees of 19 patients were examined by direct MR arthrography. In 19 of those knees, field-echo T2*-weighted transaxial images were obtained with intra-articular administration of 40 ml of saline ("direct MR arthrography"). In the other 3 knees, T1-weighted transaxial images were obtained with intra-articular administration of 40 ml of gadopentetate dimeglumine. Conventional MR images were evaluated prior to direct MR arthrography in 12 of the 22 knees. The results of direct MR arthrography and conventional MR imaging were compared with the arthroscopic findings. RESULTS: Direct MR arthrography demonstrated 17 of 19 PSMs proved on arthroscopy. The features of 16 PSMs on direct MR arthrography corresponded accurately with the arthroscopic classification. Conventional MR demonstrated only 3 plicae. CONCLUSION: Direct MR arthrography enabled accurate diagnosis of PSMs and could replace diagnostic arthroscopy.