The ligamentum mucosum's potential as a preventative structure in the development of knee osteoarthritis.

PURPOSE: This paper aimed to identify whether the presence, type, and/or morphology of the ligamentum mucosum could play a role in the development of knee osteoarthritis. Since its microscopic structure is alike that of other knee ligaments, it was hypothesized that its presence could facilitate knee motion and stability, thus preventing or reducing the extent of knee osteoarthritis. METHODS: Thirty three cadavers (a total of 51 knees) were dissected. The ligamentum mucosum, if present, was measured with a digital caliber and a measuring tape in terms of length, width, and thickness. Knee osteoarthritis was assessed in six regions of the knee. The OuterBridge Classification System (Grades 0-4) was used to visually assess the extent, in addition to probing the area. Osteoarthritis was deemed present if the grade was 2 or greater. RESULTS: The presence of the ligament was associated with a lower mean osteoarthritis level in the trochlear groove and lateral tibial plateau regions (p < 0.001 and p = 0.013, respectively). Overall osteoarthritis of the knee was also present at varying levels for each type of the ligamentum mucosum (p < 0.001). The patella and the medial condyle had the greatest levels of osteoarthritis, while the medial and lateral tibial plateaus had the lowest levels. CONCLUSION: The presence of the ligamentum mucosum is linked with decreased osteoarthritis in the trochlear groove region. In addition, both the absent ligament and its classification as a vertical septum are associated with increased knee osteoarthritis. LEVEL OF EVIDENCE: Five.

The infrapatellar plica of the knee: analysis of relationship with femoral trochlear chondrosis using radiographs and 3.0-T MRI.

OBJECTIVE: To assess the relationship of the infrapatellar plica (IPP) with femoral trochlear chondrosis (FTC) using radiographs and 3.0-T MRI. MATERIALS AND METHODS: Four hundred eighty-three knees of 476 patients undergoing radiography and MRI were reviewed, and 280 knees of 276 patients were included. We performed a comparison of the frequency of the IPP between men and women, and that of FTC and chondromalacia patella between knees with and without the IPP. In knees with the IPP, we analyzed the correlation between FTC and sex, age, laterality, Insall-Salvati ratio (ISR), femoral sulcus angle, tilting angle, height of insertion of the IPP to Hoffa's fat pad, and width of the IPP. RESULTS: The IPP was found in 192 of 280 knees (68.6%) overall and was more common in men than in women (100 of 132 [75.8%], 92 of 148 [62.2%], p = 0.01). FTC was observed in 26 of 280 (9.3%) and was only in knees with the IPP (knees with the IPP: 26 of 192 [13.5%], knees without the IPP: 0 of 88 [0%], p < 0.001). In knees with the IPP, ISR was significantly greater in knees with FTC (p = 0.002). ISR was the only significant factor associated with FTC (odds ratio: 2.87, 95% confidence interval: 1.14, 7.22, p = 0.03), and the cutoff value of ISR for FTC was > 1.00 with sensitivity of 69.2% and specificity of 63.9%. CONCLUSION: Presence of the IPP combined with ISR > 1.00 was correlated with FTC.

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.

Medical imaging and diagnosis of subpatellar vertebrae based on improved Laplacian image enhancement algorithm.

OBJECTIVE: Nowadays, arthroscopy is widely applied to the treatment of joint diseases. The experimental trials were designed to determine whether the infrapatellar plica was symptomatic or not, and to appraise the medical effects of these patients who underwent arthroscopic treatment. An improved Laplacian image enhancement algorithm is added to the experiment. The medical image of the Subpatellar vertebral body under arthroscope is processed by the algorithm. The processed image is compared with the original image, and the advantages and disadvantages of the improved Laplacian image enhancement algorithm are analyzed. METHODS: Retrospective Medical trial design was executed in our study. In addition, X-ray film and magnetic resonance imaging (MRI) were included in the study. Visual Analogue Scale (VAS) and Lysholm Score were carried out. Arthroscopy results, MRI findings, and Medical features were researched and analyzed carefully. Then we use the improved Laplacian image enhancement algorithm to process the image, which makes the image more convenient for analysis and improves the diagnostic accuracy. RESULTS: Some of the experimental protomedical images are not clear enough, and the details and textures are difficult to judge, which hinders the diagnosis. After the improved Laplacian algorithm processing, the image effect has been significantly improved. From the image we get the result, although the wound healed after surgery, some patients have existence of transient swelling in recovery process but no effusion. The pain of all patients knee was sharply relieved and the function was improved. All patients' conditions were most satisfactory. CONCLUSION: The findings in this study demonstrate a significant reduction in knee pain and improvement in function by releasing and removal of the symptomatic infrapatellar plica under arthroscopic surgery. The image processed by the improved Laplacian image enhancement algorithm can effectively retain the image details, which is conducive to diagnosis and improve the diagnostic accuracy.

Imaging appearance and prevalence of the anteromedial meniscofemoral ligament: A potential pitfall to anterior cruciate ligament analysis on MRI.

PURPOSE: To describe the aspect of the anteromedial meniscofemoral ligament on MRI and to assess its prevalence. METHOD: One thousand five hundred sixty knee MRI studies were retrospectively evaluated for the presence of an anteromedial meniscofemoral ligament. In addition to these studies, nine full MRI studies from our department's image archive were also analysed. The anteromedial meniscofemoral ligament length, thickness, and angle with respect to the tibial plateau were evaluated independently by two radiologists. For comparison purposes, the anterior cruciate ligament was assessed in the same manner. RESULTS: There was a 0.77% prevalence of the anteromedial meniscofemoral ligament in the study population. Compared to the anterior cruciate ligament, the anteromedial meniscofemoral ligament was 80.6%-83.8% thinner according to both observers (P =  0.0002), with a mean thickness of 1.53 ±â€¯0.47 mm and 1.80 ±â€¯0.66 mm determined by observers 1 and 2, respectively. The anteromedial meniscofemoral ligament angles were 15%-17.7% lower than the anterior cruciate ligament angles (P <  0.003). Interobserver reproducibility was considered excellent for the length and angle measurements (ICCs varying from 0.85-0.97) and good for the thickness measurements (ICCs 0.66-0.77). CONCLUSIONS: The anteromedial meniscofemoral ligament is a rare structure that can be differentiated from the anterior cruciate ligament based on morphologic criteria.

The biomechanical and morphological characteristics of the ligamentum mucosum and its potential role in anterior knee pain.

BACKGROUND: The ligamentum mucosum is composed of dense regular connective tissue and traverses from the distal femur to the infrapatellar fat pad. While the gross and histologic morphology has been studied, there is currently no evidence concerning the biomechanical properties of the ligamentum mucosum and the potential of anterior knee pain. The purpose of this study was to determine the anatomical, mechanical and histological properties of the ligamentum mucosum. METHODS: Dissections were performed on cadaveric knee specimens (N = 18) and histological analysis (n = 6) was performed to define the anatomical characteristics of the ligamentum mucosum using standard hematoxylin and eosin (H&E), Masson's trichrome, and immunohistochemical methods. Biomechanical testing (n = 5) was conducted to determine the tensile properties of the ligamentum mucosum. The peak load at failure, stiffness, and strain were analyzed. RESULTS: Sixty-four percent of the knees had a ligamentum mucosum and the histological analysis confirmed it to be composed of dense regular connective tissue. Small peripheral nerves were identified in the junction between the ligamentum mucosum and the fat pad. The average (SD) peak force of failure, stiffness, and strain were 31.9 N (19.0), 5.1 N/mm (3.59), and 0.83 (0.14), respectively. CONCLUSIONS: The tensile strength and stiffness of the ligamentum mucosum is considerably less than the primary stabilizers of the knee joint. Based on these findings, it is improbable that the ligamentum mucosum has a meaningful effect on the kinematics of the extensor mechanism; perturbations of the tissue and the connected infrapatellar fat pad could potentially play a role in the pathogenesis of anterior knee pain.

Posterior Hoffa's fat pad impingement secondary to a thickened infrapatellar plica: a case report and review of the literature.

We report a case of posterior hoffitis in a middle-aged woman with no prior history of significant major trauma. Her symptoms of anterior knee pain and limited extension failed conservative measures. Preoperative magnetic resonance imaging demonstrated a significantly thickened infrapatellar plica tethering Hoffa's fat pad in the anterior interval of the knee. Arthroscopic resection of the infrapatellar plica resulted in complete resolution of symptoms within six months following the surgery.

Loss of a condyle of the femur or tibia following septic arthritis in infancy: problems of management and testing of a hypothesis of pathogenesis.

PURPOSE: The study was undertaken to: (1) describe the characteristic radiological features and problems of management of the loss of one condyle of the femur or tibia following septic arthritis of the knee in infancy and (2) test a hypothesis of the cause of the loss of a single condyle. METHODS: Radiographs of eight children with the loss of one condyle of the femur or the tibia following septic arthritis in infancy were reviewed. The course and outcome in two of these children who underwent reconstructive operations were studied. The knees of 35 stillborn foetuses were dissected to determine if the presence of synovial septae could account for the isolated loss of one condyle following infection. RESULTS: All eight cases showed characteristic features of loss of half the epiphysis, the underlying physis and part of the adjacent metaphysis; the other condyle was totally spared. The two children who underwent elaborate reconstructive procedures had poor outcomes at skeletal maturity, despite a series of additional operations. The foetal cadaveric study showed that complete infrapatellar synovial septae are present in some foetuses approaching 40 weeks of gestation. CONCLUSIONS: The pattern of loss of a femoral or tibial condyle following septic arthritis is consistent with total preservation of the other condyle. The outcome of surgical reconstruction of the missing condyle is poor. The presence of a complete synovial septum could result in the localisation of infection to one half of the joint, with the destruction of one condyle.