Anterior Intermeniscal Ligament Research Articles

Is osteophyte located in the inferior of the intermeniscal ligament an indication for the surgical treatment of degenerative meniscal tear?

Objectives: Our study aimed to determine how often the osteophyte located underneath the anterior intermeniscal ligament is observed in patients who underwent arthroscopic surgery due to degenerative meniscal tears, how often this osteophyte can be diagnosed by magnetic resonance imaging, and whether this osteophyte could be an indication for the surgery to be performed for degenerative meniscopathy. Methods: Our retrospective study included 47 patients operated for degenerative meniscus tears between 2017 and 2018, with a minimum follow-up of 2 years. Visual analog scale (VAS), Lysholm knee, and Western Ontario Meniscal Evaluation Tool (WOMET) scores were applied to all patients included in the study preoperatively and at the postoperative 3rd, 6th, 12th, and 24th months. The operated patients were grouped into two groups with and without osteophytes beneath the anterior intermeniscal ligament in magnetic resonance imaging (Group A and B). Preoperative and postoperative values of the patients were compared among themselves. Results: The average age of the patients included in our study was 57 (range: 42 to 72) years. Forty (85%) participants were female. Osteophyte was detected in 36.1% (n = 17) of the patients in preoperative magnetic resonance imagings (Group-A). There was a statistically significant difference between preoperative VAS, Lysholm, and WOMET scores and postoperative 3rd, 6th, 12th, and 24th months (p < 0.05). Mean follow-up time was 32 (range: 24 to 60) months. Conclusions: We believe that arthroscopic control of the inferior intermeniscal ligament for the presence of any osteophytes in patients treated surgically for degenerative meniscal tears is one of the main steps of this surgery.

Meniscal Allograft Transplantation With Soft-Tissue Fixation Including the Anterior Intermeniscal Ligament

Meniscal allograft transplantation has been introduced as a treatment for symptomatic meniscus-deficient patients to improve clinical outcomes. We describe an arthroscopic technique for meniscal allograft with soft-tissue fixation including the anterior intermeniscal ligament (AIML): arthroscopic double soft-tissue fixation technique. The AIML and anterior and posterior roots are detached and sutured using running locked Krackow stitches. After preparation of the meniscal bed, the meniscus is passed into the knee and the posterior meniscal horn is fixed with sutures through bone tunnels. The body of the meniscus is fixed with all-inside sutures. Then, the anterior meniscal suture is fixed on the anatomic point of the anterior root with an anchor. The AIML suture is fixed with an anchor to the bare area of the proximal tibia, anterior to the anterior cruciate ligament insertion. This reliable and reproducible technique is less complex than bone plug methods; it is less invasive but still provides stable and secure graft fixation. It will help surgeons to improve clinical results and to limit early secondary extrusion of the graft.

The insertion of the anterior horn of the medial meniscus: an anatomic study

The purpose of this study was to identify the various patterns of insertion of the anterior horn of the medial meniscus in Ghanaian subjects. The study involved 35 cadaveric knees (26 males and 9 females). Berlet and Fowler classification was used to classify the insertion of the anterior horn of the medila meniscus. The distribution of the insertion pattern was as follows; 42.9% (15) had type I insertion, 45.7% (16) had type II, type III and IV insertions were each found in 5.7% (2) of the dissected knees. Type II insertion had the highest incidence which was a deviation from what has been reported in literature. The incidence of the anterior intermeniscal ligament (AIML) was 34.3%, which was much lower that most studies have reported. The findings of the study may suggest that the pattern of insertion of the anterior horn of the medial meniscus may be different in the Ghanaian population; further research is needed in this area.

Importance of Mechanoreceptors and Other Neural Structures Within the Anterior Intermeniscal Ligament in the Etiology of Anterior Knee Pain After Tibial Nailing.

Anterior knee pain is the most common complication after intramedullary tibial nailing. The cause is often multifactorial and varies among individuals. Violation of the anterior intermeniscal ligament (AIL) during intramedullary tibial nailing might be a possible source of postsurgical anterior knee pain. Although there is a certain ambiguity regarding the importance and function of the AIL, neural structures in the AIL tissue might play a significant role with respect to functional purposes and pain perception. We subjected 6 AIL specimens to histologic examination to identify the neural structures that are a mandatory requirement as a source of anterior knee pain. Specifically, we performed three-dimensional immunohistochemical investigation of subtyping, orientation, and detailed characterization of neural structures within the AIL tissue. Histologic and three-dimensional immunohistochemical examinations confirmed the presence of neural structures in all 6 AIL specimens. We identified myelinated and unmyelinated nerve fibers, as well as all types of mechanoreceptors. Free nerve endings are a mandatory requirement for pain perception as a result of AIL violation during tibial nailing. Our verification of all different types of mechanoreceptors in the AIL tissue makes a role of the ligament in knee joint function and proprioception highly probable. Further investigations are necessary to clarify possible correlations between neural supply and function of the AIL. Violation of the ligament during operative procedures should be avoided, although the significance of the AIL is still debated.

Anterior intermeniscal ligament: frequency in MRI studies and spatial relationship to the entry point for intramedullary tibial nailing related to the risk of iatrogenic violation.

Anterior knee pain is the most common complication after intramedullary tibial nailing. Often, the cause is multifactorial and individually different. Violation of the anterior intermeniscal ligament (AIL) during intramedullary tibial nailing might be a possible origin of postsurgical anterior knee pain. Both the importance and function of the AIL remain somewhat ambivalent, and even the figures quoted in the literature for its existence in the population vary drastically. Our aim was to verify the estimated frequency of the AIL in the literature by retrospectively analysing the data of MRI studies conducted at our hospital. In addition, we attempted to assess the potential risk of AIL violation during intramedullary tibial nailing, based on the spatial arrangement. Two independent examiners analysed the images generated in 351 MRI studies conducted at our hospital between June 2013 and May 2014. All cases who did not reveal any previous knee-joint injury or osteoarthritis of the knee were allocated to group I. All other cases were included in group II. To estimate the potential risk of AIL injury during the nailing procedure, the distance between the AIL and the theoretical entry point for intramedullary nailing was measured. We identified the AIL on the images of nearly all patients (96.5%) in group I. In group II, the presence of the AIL was confirmed in only 51.4% of cases (p < 0.001). The average distance between the AIL and theoretical entry point for intramedullary tibial nailing was 10.1mm (range 3.48-18.88mm). Because we were able to confirm the presence of the AIL in nearly all patients without a history of knee joint injuries or osteoarthrosis, we presume that the AIL may play a role in knee joint function. Violation of the AIL during intramedullary nailing appears likely due to the close position of the AIL in relation to the entry point for the inserted nail. As a result and due to its rich sensory innervation, a connection between AIL violation during tibial nailing and postoperative onset of anterior knee pain seems likely. To eliminate one risk factor of anterior knee pain development and in view of the unresolved issues of AIL function, violation of the ligament during any operative procedure should be avoided.

Sectioning of the Anterior Intermeniscal Ligament Changes Knee Loading Mechanics

The purpose of this cadaver research project was to describe the biomechanical consequences of anterior intermeniscal ligament (AIML) resection on menisci function under load conditions in full extension and 60° of flexion. Ten unpaired fresh frozen cadaveric knees were dissected leaving the knee joint intact with its capsular and ligamentous attachments. The femur and tibia were sectioned 15cm from the joint line and mounted onto the loading platform. A linear motion x-y table allows the tibial part of the joint to freely translate in the anterior-posterior direction. K-scan sensors were used to define contact area, contact pressure, and position of pressure center of application (PCOA). Two series of analysis were planned: before and after AIML resection, mechanical testing was performed with specimens in full extension (1,400N load) and in 60° of flexion (700N load) to approximate heel strike and foot impulsion during the gait. Sectioning of the AIML produced mechanical variations below the 2 menisci when specimens were at full extension and loaded to 1,400N: increasing the mean contact pressure (delta 0.4 ± 0.2MPa,+15% variation P= .008) and maximum contact pressure (delta 1.50 ± 0.8MPa, 15% variation P < .0001) and decreasing of tibiofemoral contact area (delta 71 ± 51mm2, -15% variation P < .0001) and PCOA (delta 2.1 ± 0.8mm). At 60° flexion, significant differences regarding lateral meniscus mechanical parameters were observed before and after AIML resection: mean contact pressure increasing (delta 0.06 ± 0.1MPa,+21% variation P= .001), maximal contact-pressure increasing (delta 0.17 ± 0.9MPa,+28% variation P= .001), mean contact area decreasing (delta 1.84 ± 8mm2, 4% variation P= .3), and PCOA displacement to the joint center (mean displacement 0.6 ± 0.5mm). The section of the intermeniscal ligament leads to substantial changes in knee biomechanics, increasing femorotibial contact pressures, decreasing contact areas, and finally moving force center of application, which becomes more central inside the joint. AIML resection performed exvivo in this study, might potentially be deleterious invivo. Clinical studies focusing on preserving or even repairing the AIML are needed to evaluate those exvivo elements.

Evaluation of anterior intermeniscal ligament in discoid lateral meniscus cases and presenting the accompanying meniscal pathologies with MRI.

Although several studies were conducted to put forth the biomechanical function of anterior intermeniscal ligament (AIML) on the stability of meniscal structures, there are few data on the etiology of the early degeneration of discoid type compared to the normal shaped ones. To determine the AIML subtypes and accompanying meniscal pathologies in discoid lateral menisci (DLM) on knee MRI exams. Knee MRI exams of 171 individuals with DLM were reviewed. DLMs and AIMLs were typed according to Watanabe's classification and Nelson-Laprade classification, respectively. Medial and lateral menisci were evaluated for tear and menisco-capsular pathology. Pearson's correlation test was used for statistical analysis. DLM was type I in 83 (48.5%) individuals and type II in 88 (51.5%) individuals. AIML was absent in 90 (52.6%) participants; type I AIML was seen in 38 out 81 (22.2%), type II in 31 out of 81(18.1%), and type III in 12 out of 81 (7%). Meniscal pathology was observed in 56 (32.7%) individuals as follows: menisco-capsular strain/separation in 25 (14.6%); medial meniscal tear in 22 (12.8%); and lateral meniscal tear in nine (5.2%); Of these 56 cases, 26 (46%) had no AIML, 15 cases (27%) had type I, nine cases (16%) had type II, and six cases (11%) had type III AIML. No statistically significant correlation was found between the type of DLM and type of AIML ( P = 0.855), between the type of DLM and meniscal pathology ( P = 0.791), or between the type of AIML and meniscal pathology ( P = 0.282).

Variations in the attachments of the medial meniscal anterior horn: a descriptive cadaveric study.

Meniscal tears are common in Kenya, with prevalence rates ranging from 45 to 78% of intracapsular knee pathology. Diagnosis of these injuries relies on the use of both clinical signs and symptoms as well as radiological investigations. In a few instances, radiological detection could be difficult, partly because of variant attachment patterns of the medial meniscal anterior horn. Some of these unusual attachments of the anterior horn of the medial meniscus could even be mistaken for meniscal tears. There is also evidence that these variations differ from population to population. This study, therefore, aimed to determine the variant bony and ligamentous attachments of the medial meniscal anterior horn in a sample Kenyan population. The study was conducted at the Department of Human Anatomy, University of Nairobi. Thirty-one male and female unpaired medial menisci were obtained from cadaveric specimen. The bony and ligamentous attachments were identified and recorded and photomacrographs taken. The bony attachments different from the classical textbook attachment accounted for 54.8% of the medial meniscal anterior horns. The anterior intermeniscal ligament was present in 62.3% while 16.2% showed attachment to the anterior cruciate ligament. Twenty-nine percent (29%) of the medial menisci studied did not have any ligamentous attachments. The bony and ligamentous attachments of the medial meniscal anterior horn are highly variable presenting unique diagnostic and therapeutic challenges. A new classification of ligamentous attachments is thus proposed.

Function of the Anterior Intermeniscal Ligament.

The function and importance of the anterior intermeniscal ligament (AIML) of the knee are not fully known. The purpose of this study was to evaluate the biomechanical and sensorimotor function of the AIML. Computational analysis was used to assess AIML and tibiomeniscofemoral biomechanics under combined translational and rotational loading applied during dynamic knee flexion-extension. Histologic and immunohistochemical examination was used to identify and characterize neural elements in the tissue. The computational models were created from anatomy and passive motion of two female subjects and histologic examinations were conducted on AIMLs retrieved from 10 fresh-frozen cadaveric knees. It was found that AIML strain increased with compressive knee loading and that external rotation of the tibia unloads the AIML, suppressing the relationship between AIML strain and compressive knee loads. Extensive neural elements were located throughout the AIML tissue and these elements were distributed across the three AIML anatomical types. The AIMLs have a beneficial influence on knee biomechanics with decreased meniscal load sharing with AIML loss. The AIML plays a significant biomechanical and neurologic role in the sensorimotor functions of the knee. The major role for the AIML may primarily involve its neurologic function.

MR imaging of the anatomy of the anterior horn of the medial meniscus.

Background In cadaveric and arthroscopic studies different insertion locations of the anterior horn of the medial meniscus (AHMM) have been described. Purpose To investigate if the different insertion locations of the AHMM, as described in cadaveric studies, can be determined on magnetic resonance imaging (MRI). Material and Methods MR images of 100 patients without meniscal tears on MRI were retrospectively evaluated. Two observers classified the AHMM insertion based on its position relative to the anterior tibial edge and the medial tibial spine. The association between AHMM insertion and tibial plateau slope, meniscal radial displacement, and anterior intermeniscal ligament (AIL) presence was investigated. Results The AHMM inserted posterior to the anterior tibial edge in 93 knees and anterior to the tibial edge in seven knees (= type III). Of the 93 knees with AHMM insertion posterior to the anterior tibial edge, 63 inserted lateral to the medial tibial spine (= type I) and 30 medial (= type II). The AHMMs inserting anterior to the tibial edge had a significantly ( P < 0.05) steeper anterior tibial plateau slope and a significantly ( P < 0.05) higher presence of the AIL. No significant difference in radial displacement was observed between the three insertion types ( P > 0.05). A strong inter- and intra-observer agreement was observed. Conclusion Three different bony insertion locations of the AHMM, as described in cadaveric studies, could be identified on MRI. All AHMMs inserting anterior to the tibial edge displayed an AIL. Whether there is a clinical correlation with these insertion patterns remains unclear.

Arthroscopic Repair of Separation of Anterior Intermeniscal Ligament

Objectives:Aim of this article is to present and discuss a patient with separation of anterior intermeniscal ligament which was repaired arthroscopically.Methods:Anterior intermeniscal ligament (AIML) (transverse geniculate ligament or anterior transvers ligament) is an intraarticular structure connecting anterior convex edge of lateral meniscle to anterior tip of medial meniscle; limits anterior movement of menisci during extension and prevents pressure application of condylar surfaces onto menisci; and also limits anterior-posterior separation of anterior horn of medial meniscus during low degrees of flexion. AIML was found in 69 to 94 percent in different studies.Results:A thirty-eight year-old female patient referred our clinic with complaints of pain in right knee for a year that responds to pain killers, increasing with climbing stairs and decreasing with rest. Synovium origined mass was seen on MRI with contrast applied after an intraarticular mass seen on MRI. She undervent surgery and the mass in the medial of joint space considered as pigmented villonodular sinovitis was resected arthroscopically. During arthroscopy, separation of anterior marge of AIML and elevation of anterior horns of both medial and lateral were noticed. Using no 1 PDS suture AIML was pulled downwards from anterior marge and fixed. After fixation AIML and anterior horns of menisci replaced on tibial plateu again.Conclusion:As injuries of AIML which has an important role at stabilization of menisci during knee motions are seen very rarely, freuquency of AIML was reported 9.75 percent in a cadaver study and 75 percent of them was accompanied by medial meniscal tear. We could not find any other clinical study reporting AIML injury in the literature. As we apply arthroscopical intervention in order to resect intraarticular mass considered as pigmented villonodular synovitis, anterior separation of AIML and elevation of anterior horn of both menisci were noticed coincidentally and then were repaired. As the arthroscopical evaluation due to injuries of intraarticular structures is performed, AIML should also be evaluated, if necessary, repair should be performed in order to obtain stabilization of anterior horns of menisci.

Anterior intermeniscal ligament: an anatomic study of its insertion pattern in Ghanaians

The purpose of this study was to identify the various patterns of attachment of the anterior intermeniscal ligament that is predominate in the Ghanaian as there is no known publication on this subject.The study was conducted in the Department of Anatomy of the School of Medical Sciences, University of Cape Coast and involved 42 paired cadaveric knees, from 16 males and 5 females. The incidence of the AIML was 40.5%. The mean length of the AIML was 28.95mm; the mean width was 1.94mm, while the mean distance from mid-portion of the AIML to the insertion of the anterior cruciate ligament was 4.32mm. Type I pattern of attachment was the most common pattern of insertion observed (64.7%), followed by type II (29.4%) and then type III (5.9%). The incidence of the AIML may be lower in the Ghanaian populace than most reported studies.

Anterior intermeniscal ligament: an anatomic study of its insertion pattern in Ghanaians

Anterior intermeniscal ligament: an anatomic study of its insertion pattern in Ghanaians

Relation of discoid lateral meniscus and cord-like anterior intermeniscal ligament: morphological and clinical study

Discoid lateral meniscus is a rare disorder and its association with other variations in the knee joint has been reported. The anterior intermeniscal ligament has also been described as connecting the anterior convex margin of the lateral meniscus to the anterior horn of the medial meniscus. In the normal population, it was observed at 53-94%. Although the functional properties of the anterior intermeniscal ligament are not yet clarified, two distinct types of the ligament have been described according to their morphological characteristics as cord-like and membranous types. The purpose of this study was to evaluate any possible association between morphologic types of anterior intermeniscal ligament and discoid lateral meniscus. A retrospective study was designed; 20 discoid lateral menisci were operated using routine arthroscopic examination. Upon arthroscopic examination the thickness of the ligament and associated morphological changes were recorded systematically. The cord-like anterior intermeniscal ligament was an associated structure in 15 of the 20 knees with discoid lateral meniscus (75%). Patients with discoid lateral meniscus apparently have cord-like type anterior intermeniscal ligament, thus we conclude that cord-like type of anterior intermeniscal ligament is a frequent accompanying structure to discoid lateral meniscus and may have a potential stabilizing effect on its anterior stability.

Role of the anterior intermeniscal ligament in tibiofemoral contact mechanics during axial joint loading

The anterior intermeniscal ligament (AIML) is an anatomically distinct structure that connects the anterior horns of the medial and lateral menisci. We hypothesized that both menisci work together as a unit in converting axial joint loading into circumferential hoop stresses, due to intermeniscal attachments. Therefore, loss of the AIML could lead to increased tibiofemoral contact stress and predispose to arthritic change. In this cadaveric study, we compared tibiofemoral contact pressures on axial loading, before and after sectioning of the AIML. Five fresh frozen human cadaveric knees were mounted on a linear x–y motion table and loaded in extension under axial compression of 1800N (about 2.5 times body weight for a 70kg individual), using a materials testing machine. Tibiofemoral contact pressures before and after sectioning of the AIML were measured using resistive pressure sensors. Contrary to our hypothesis, sectioning of the AIML produced no statistically significant increase in mean contact pressure, peak contact pressure or change in contact area, in either the medial or lateral compartment of the knees. This implies that the menisci work independently in converting axial loads into circumferential hoop stresses, and is probably due to their individual root attachments to the tibia. Based on this study, inadvertent sectioning of the AIML during knee surgery, e.g., arthroscopy, anterograde tibia nailing, anterior cruciate ligament reconstruction, meniscus transplantation and unicondylar knee replacement, is functionally insignificant.

Knee Medial Compartment Contact Pressure Increases with Release of the Type I Anterior Intermeniscal Ligament

Background The anterior intermeniscal ligament of the knee is at risk during knee arthroscopy, anterior cruciate ligament reconstruction, and tibial nail insertion. Hypothesis Release of the anterior intermeniscal ligament, in knees with type I ligaments, will result in altered contact pressures in the medial compartment. Study Design Controlled laboratory study. Methods Five fresh-frozen human cadaveric knees with intact type I anterior intermeniscal ligaments were chosen for testing in a modified MTS machine from 0° to 60° of flexion under 2 conditions: (1) intact and (2) after sharp sectioning of the anterior intermeniscal ligament. Measurements were made using inframeniscal contact pressure sensors covering the medial compartment. Poststudy analysis was done in 10° increments between 0° and 60° of flexion, looking at peak contact pressure and the amount of contact area seeing pressure. Results Sectioning of the anterior intermeniscal ligament caused a statistically significant increase in the peak pressure at 20°, 30°, 40°, and 50° of knee flexion. The largest change occurred at 40° of knee flexion, when the peak pressure increased by 27.5% (3.68 MPa to 4.69 MPa). Contact area decreased, although this difference was not statistically significant. Conclusion Release of the anterior intermeniscal ligament results in increased peak contact pressures in the medial compartment of the knee. Clinical Relevance Care should be taken to avoid sacrifice of this ligament during surgery.

The anterior intermeniscal ligament of the knee: an anatomic and MR study

The purposes of this study were to identify the presence of the anterior intermeniscal ligament of the knee (AIL), to study its attachment patterns and relationships to other anatomic structures within the knee and to evaluate the potential association of its rupture with other pathology of the knee. Ten human cadaver knees were dissected excluding knees with surgical scars. Fifty-one MR examinations were performed in symptomatic patients. Arthroscopic observations were carried out on ten patients. AIL was found in nine dissected knees with type I insertion in six cases, type II insertion in three cases. The average length was 31.2 mm (25-45 mm). The average distance between AIL and insertion of the anterior cruciate ligament was 12 mm (11-15 mm). Concerning MR study, AIL was found in 34 cases (82.9%). Four (9.75%) ruptures of the AIL were encountered. Where AIL was intact, 14 patients presented meniscal lesions (46.6%). Where AIL was ruptured, three patients presented meniscal lesions (75%). The present study demonstrates through anatomical and MR studies that AIL is present in more than 80% of the cases with predominant type I insertion. The association of meniscal and AIL lesions was highlighted demonstrating that AIL is not only an anatomical point of interest but also a clinical and surgical reality.

Biomechanics of the meniscus-meniscal ligament construct of the knee

The menisci of the knee act primarily to redistribute contact force across the tibio-femoral articulation. This meniscal function is achieved through a combination of the material, geometry and attachments of the menisci. The main ligaments that attach the menisci to the tibia (insertional ligaments, deep medial collateral ligament), the femur (meniscofemoral ligaments, deep medial collateral ligament) and each other (the anterior intermeniscal ligament) are the means by which the contact force between tibia and femur is distributed into hoop stresses in the menisci to reduce contact pressure at the joint. This means that the functional biomechanics of the menisci cannot be considered in isolation and should be considered as the functional biomechanics of the meniscus-meniscal ligament construct. This article presents the current knowledge on the anatomy and functional biomechanics of the meniscus and its associated ligaments. Much is known about the function of the meniscus-meniscal ligament construct; however, there still remain significant gaps in the literature in terms of the properties of the anterior intermeniscal ligament and its function, the properties of the insertional ligaments, and the most appropriate ways to reconstruct meniscal function surgically.

An arthroscopic study on the anterior intermeniscal ligament

An arthroscopic study was made on the presence and anatomic features of the anterior intermeniscal ligament with regard to its thickness and attachment patterns to the anterior horn of the menisci, together with its relationship with associated non-traumatic intraarticular disorders of the knee. This multicenter study included 136 consecutive patients (80 males, 56 females; mean age 40 years; range 15 to 74 years) in whom the presence of anterior intermeniscal ligament was sought during arthroscopic examination of the knee. Arthroscopic features of the ligament was evaluated by probe. The anterior intermeniscal ligament was detected in 80 knees (58.8%). Its presence did not differ significantly with respect to sex (33 females, 58.9%; 47 males, 58.8%; p>0.05). A cord-like appearance was observed in 19 cases (14%), whereas a membranous-like structure was identified in 61 cases (44.9%), 34 (55.7%) of which could only be detected following synovial abrasion. Attachment patterns according to the Nelson and LaPrade's description showed type A in 47 cases (58.8%), type B in 23 cases (28.8%), and type C in 10 cases (12.5%). Type A was more common among cord-like intermeniscal ligaments, although this did not reach significance (p>0.05). No significant association was found between the presence of the ligament and intraarticular disorders. The detection of discoid lateral meniscus was significantly associated with the presence of a cord-like intermeniscal ligament (p<0.05). Of eight cases with discoid lateral meniscus (5 complete, 3 incomplete), five patients exhibited a cord-like anterior intermeniscal ligament. This is the first arthroscopic study to define the anatomy and the incidence of the anterior intermeniscal ligament. Functional features of the ligament should be more clearly demonstrated biomechanically.

The reference point to measure the anterior intermeniscal ligament's thickness: an MRI study.

The purpose of this study was to identify a reliable reference point for measuring anterior intermeniscal ligament thickness and to investigate the morphological characteristics of the ligament at its attachment site to anterior horns of both menisci by MRI. MRI was performed in 98 knees of randomly chosen patients. The anterior intermeniscal ligament was detected in 61 knees (62.2%). The average ligament length was 29.8 mm. Men had significantly longer anterior intermeniscal ligament than women patients (32.5 vs. 27.8 mm). The thickness of anterior intermeniscal ligaments at their attachment sites to menisci was usually less than 3 mm; a thickness of 3 mm or more at the attachment site to anterior horns of the meniscus was defined as "cordlike." It is suggested that the "cordlike" pattern is a variation of the anterior intermeniscal ligament's attachment characteristics, and that this might have a significant role in meniscal translations during knee motion, and also that the "cordlike" pattern could be clinically important with respect to its relationship to the anterior horn of medial meniscus. The attachment site of the ligament is a reliable reference point for measuring its thickness.