Lateral Inferior Genicular Artery Research Articles

Vascularization of the menisci: a descriptive study of the peri-meniscal archs.

The meniscal vascularization remains poorly documented, particularly its origin. The aim of this cadaveric study was to describe the origin of the arterial vascularization of the menisci. This is an anatomical study on human specimens. Twenty knees were used. The average age of the subjects was 82.7 years old (56-97). Ten knees were injected with latex-neoprene and ten knees were injected with colored gelatin mixed with India ink. The same protocol for dissection was used in all cases. The meniscal vascularization is provided by the genicular arteries of the knee originating from the popliteal artery. The superior medial, superior lateral, inferior medial, inferior lateral, and middle genicular arteries had constant pathways. A second middle genicular artery was found in 55% of cases. The inferior lateral genicular artery ran alongside the meniscal's periphery. The inferior medial genicular artery followed the proximal tibial metaphysis. In all dissections, a previously undocumented small artery originated from under the middle genicular arteries. This artery remained extracapsular and followed the medial meniscal periphery. This artery has been named the "medial capsulo-meniscal artery". The genicular arteries formed an extensive peri-articular anastomotic vascularization for the menisci and thus referred to the "peri-meniscal arterial archs". The lateral peri-meniscal arch was predominantly supplied by the inferior lateral genicular artery, while the medial peri-meniscal arch was mainly supplied by the medial capsulo-meniscal artery. The peri-meniscal arterial archs are a vascular complex formed by the genicular arteries of the knee and an artery not previously described: the "capsulo-meniscal artery". These archs have a constant presence but their formation and distribution is different between the medial and lateral menisci.

Vascularized Fibular Epiphyseal Transfer for Pediatric Limb Salvage: Review of Applications and Outcomes

Summary: Vascularized fibular epiphyseal transfer (VFET) offers a functional advantage in pediatric limb salvage due to the preservation of growth potential and an articular surface for remodeling. This review summarizes the available evidence on the clinical characteristics and outcomes of pediatric reconstruction applying VFET at different recipient sites and with varying techniques. VFET was used to reconstruct the proximal humerus, distal radius or ulna, proximal femur, distal fibula, calcaneus, and mandible. Although most often harvested on the anterior tibial artery, VFET has also been performed using the peroneal artery, the inferior lateral genicular artery, and a dual pedicle. Recipient site flap inset most often involved fixation with plates and/or screws as well as soft tissue reconstruction using a retained slip of biceps femoris tendon. Outcomes included limb growth, range of motion, and strength. The most common reported complications were bone flap fracture and peroneal nerve palsy. The anterior tibial artery was the most applied pedicle with reliable limb growth, but with the added risk of postoperative peroneal palsy. Bone flap fracture most often occurred at the proximal humerus and femur recipient sites. Plate fixation and the combined use of allograft had lower instances of bone flap fracture. This review highlights how the anticipated dynamic growth and remodeling this free flap offers in the long term must be weighed against its complexity and potential complications.

Added Value of Cone-Beam CT to Identify Arterial Supply during Genicular Artery Embolization for Knee Osteoarthritis

PurposeTo evaluate if the addition of cone-beam computed tomography (CT) to digital subtraction angiography (DSA) improves the identification of the genicular arteries during genicular artery embolization (GAE) for knee pain secondary to osteoarthritis (OA). Materials and MethodsThis single-center study retrospectively analyzed 222 patients who underwent GAE for painful knee OA between May 2018 and April 2022. Intraprocedural cone-beam CT and DSA images were reviewed independently by 2 sets of interventional radiologists. DSA was performed for all patients. Technically adequate cone-beam CT was available for 205 patients (92.3%). The presence of the genicular arteries identified by cone-beam CT and DSA was compared using Φ coefficients. Embolization targets identified by both cone-beam CT and DSA were evaluated against those identified by DSA alone. ResultsGenicular arteries with the highest concordance between cone-beam CT and DSA were the inferior lateral (196 vs 198; Φ = 0.3530; P < .0001), superior lateral (197 vs 200; Φ = 0.3060; P < .0001), and superior medial genicular (186 vs 161; Φ = 0.2836; P < .0001) arteries. Cone-beam CT demonstrated higher rates of detection of the inferior medial (195 vs 178; Φ = 0.04573; P = .5150) and median genicular arteries (200 vs 192; Φ = 0.04573; P = .5150). Meanwhile, genicular arteries less frequently identified by cone-beam CT were the descending genicular (197 vs 200; Φ = −0.03186; P = .6502), superior patellar (175 vs 184; Φ = 0.1332; P = .0569), and recurrent anterior tibial (156 vs 186; Φ = 0.01809; P = .7969) arteries. Cone-beam CT in combination with DSA identified 13.4% (372 vs 328) more targets compared to DSA alone. ConclusionsBased on the results of the current study, cone-beam CT serves as a valuable adjunct for visualizing the genicular arteries during GAE, and together with DSA, it identifies more potential embolization targets.

Classification of Genicular Artery Anatomic Variants Using Intraoperative Cone-Beam Computed Tomography

PurposeGenicular artery embolization (GAE) is a new treatment option for symptomatic knee osteoarthritis. Genicular arterial anatomy is complex with limited published reports. This study describes the genicular artery anatomy utilizing intraprocedural cone-beam computed tomography (CBCT) during GAE.Materials and MethodsThis retrospective single-center study was approved by the institutional review board. All patients who underwent GAE between May 2018 and April 2022 were reviewed. Patients with a technically adequate CBCT were included in the analysis. CBCTs were analyzed to determine the presence, course, and branching patterns of the genicular arteries.ResultsA total of 222 patients underwent GAE and 205 (92%) were included for analysis. The descending genicular artery was present in 197 (96%) CBCTs with two branches in 152 (77%). The superior medial genicular artery (SMGA) was present in 186 (91%), superior lateral genicular artery (SLGA) in 203 (99%), inferior medial genicular artery (IMGA) in 195 (95%), inferior lateral genicular artery (ILGA) in 196 (95%), and median genicular artery (MGA) in 200 (97%). Four unique branching patterns were identified: common origin of SLGA and MGA (115, 56%), unique origins (45, 22%), trifurcation of SLGA, SMGA, and MGA (32, 15.5%), and common origin of SMGA and MGA (12, 6%). The recurrent ascending tibial was identified in 156 (76%) CBCTs and superior patellar artery in 175 (85%) CBCTs.ConclusionGenicular artery anatomy is complex with numerous common variants. CBCT is a powerful adjunct in GAE to rapidly identify target vessels for embolization and potentially decrease the risk of nontarget embolization.

Artículo traducido] Ligamento anterolateral de la rodilla. Estudio en cadáver en una población caucásica

IntroductionDespite the recognized importance of the anterolateral ligament (ALL) in rotational stability of the knee, some studies still deny its role and even its existence. We studied the prevalence of the ALL in a Caucasian population, as well as its characteristics and anatomical relationships. Materials and methodsThe study was performed on 20 knees from 10 embalmed cadavers. A lateral approach, as described by Steven Claes, was used and the relations of the ALL with the lateral epicondyle, lateral inferior genicular artery, lateral meniscus, Gerdy's tubercle and fibular head were recorded. Its length and its width were also measured. ResultsThe ALL was identified in 16 knees. Its origin was at a distance inferior to 1mm posterior and proximal to the lateral femoral epicondyle and insertion within a mean distance of 2.1±0.6mm from the tibial articular surface, 20.6±1.3mm from the Gerdy's tubercle and 20.3±1.2mm from the fibular head. In all cases ALL presented mutual fibers with the lateral meniscus. The length was 35.8±4.6mm and the width was 4.2±1.3/4.9±1.0/6.5±1.5mm at its proximal, middle and distal third, respectively. No difference was found between gender and the dimensions of the ligament. ConclusionsThe ALL was found in 80% of the knees. Its origin is closely related to the lateral collateral ligament and its insertion is halfway between the fibular head and the Gerdy's tubercle. In all cases, we verified the connection between ALL and the lateral meniscus.

Anterolateral ligament of the knee—Cadaver study in a Caucasian population

IntroductionDespite the recognized importance of the anterolateral ligament (ALL) in rotational stability of the knee, some studies still deny its role and even its existence. We studied the prevalence of the ALL in a Caucasian population, as well as its characteristics and anatomical relationships. Materials and methodsThe study was performed on 20 knees from 10 embalmed cadavers. A lateral approach, as described by Steven Claes, was used and the relations of the ALL with the lateral epicondyle, lateral inferior genicular artery, lateral meniscus, Gerdy's tubercle and fibular head were recorded. Its length and its width were also measured. ResultsThe ALL was identified in 16 knees. Its origin was at a distance inferior to 1mm posterior and proximal to the lateral femoral epicondyle and insertion within a mean distance of 2.1±0.6mm from de tibial articular surface, 20.6±1.3mm from the Gerdy's tubercle and 20.3±1.2mm from the fibular head. In all cases ALL presented mutual fibers with the lateral meniscus. The length was 35.8±4.6mm and the width was 4.2±1.3/4.9±1.0/6.5±1.5mm at its proximal, middle and distal third, respectively. No difference was found between gender and the dimensions of the ligament. ConclusionsThe ALL was found in 80% of the knees. Its origin is closely related to the lateral collateral ligament and its insertion is halfway between the fibular head and the Gerdy's tubercle. In all cases, we verified the connection between ALL and the lateral meniscus.

Cadaveric Classification of the Genicular Arteries, with Implications for the Interventional Radiologist

PurposeTo document and assess the genicular arterial variation in a large multicenter cadaveric sample and to generate an anatomical classification with implications for genicular artery embolization (GAE). Materials and MethodsA total of 212 dissected donor body lower limbs from 3 medical school institutions were included. The descending genicular artery (DGA), superior lateral genicular artery, superior medial genicular artery, middle genicular artery, inferior lateral genicular artery, inferior medial genicular artery, and anterior tibial recurrent artery were identified for gross anatomical appearance, location of origin, diameter of vessels, and variation in branching patterns. ResultsA total of 198 DGAs, 204 popliteal-origin genicular arteries, and 183 anterior tibial recurrent arteries were adequately preserved and reviewed. Three types (A: 26%, B: 71%, and C: 5%) of DGA branching patterns were proposed along with 6 types (I: 28%, II: 22%, III: 15%, IV: 15%, V: 10%, and VI: 6%) of popliteal-origin genicular artery branching variants. Right versus left comparisons did not reveal clinically significant differences in the vessel distance (P = .30 to .82). ConclusionsDespite the large number of possible anatomical variations of the genicular arteries, 6 main patterns corresponded to >96% of the cases. The description and classification of the genicular arterial anatomy may provide useful information to the interventional radiologist and add to the technical nuances of GAE.

Cadaveric and Angiographic Anatomical Considerations in the Genicular Arterial System: Implications for Genicular Artery Embolisation in Patients with Knee Osteoarthritis.

Genicular artery embolisation (GAE) is a novel treatment for patients with knee osteoarthritis (OA). Cadaveric dissection was undertaken to provide a complete description of the relevant arterial anatomy in order to perform safe and effective GAE. Twenty human lower limb specimens were dissected. The morphology of the genicular arteries and presence of anastomotic connections was recorded and compared with angiographic images from patients having undergone GAE. Vessels were measured to investigate the risk of non-target embolisation (NTE), taking a diameter of 300 microns as the threshold for significance. The descending genicular artery (DGA) is the dominant vessel in medial OA, with 95% of cases revealing vessel division into muscular, saphenous and osteoarticular branches from a single pedicle. The superior medial genicular artery (SMGA) had a shared origin with the middle genicular artery (MGA) in 25% of cases. NTE to the MGA may damage the cruciate ligaments. In 85% of cases, there was an anastomosis between the DGA and SMGA, often encountered at angiography. The mean diameter of the anastomoses was 850 micron, presenting a risk for NTE. An anastomosis between the Inferior Medial Genicular Artery (IMGA) and medial sural artery was found in 5% of cases; the medial sural artery supplies blood to the tibial nerve and should be avoided. The IMGA and inferior lateral genicular artery provided supply to the patellofemoral joint in 69% and 88% of cases, respectively. An in-depth knowledge of genicular artery anatomyis requiredfor interventional radiologists to perform safe and effective GAE in patients with knee osteoarthritis.

MRI Evaluation of Anterolateral Ligament of the Knee: A Cross-Sectional Study in Malaysia.

IntroductionAfter detailed anatomical delineation of the anterolateral ligament (ALL) of the knee, there is a surge in research on this anatomical structure. Owing to the anatomical variation and lack of experience in the identification of this structure, magnetic resonance (MR) evaluation of the ALL produces mixed results. It was aimed to evaluate the ALL using the routinely performed MR imaging of the knee and to determine any associated factors with ALL injuries.Materials and methodsThirty-six MR images of the knee from 31 patients from January 1, 2017, to June 30, 2017, are evaluated. MR sequences performed include T1-weighted, T2-weighted, proton density (PD), and PD fat saturation (FS). All MR images were double-read by two authors and approved by a consultant radiologist with more than 20 years of radiological experience. The ALL was divided into three portions: femoral, meniscal, and tibial, and the ALL was considered fully visualized when all three portions were seen on MR images.ResultsAt least a portion of the ALL was visualized in 27 scans (75%), and it was fully visualized in 20 scans (55.6%). The femoral portion was the most commonly identified (75%), followed by the meniscal portion (69.4%) and the tibial portion (58.3%). ALLs were best visualized on coronal view in PD FS with the lateral inferior genicular artery as a guide to locate the bifurcation of the meniscal and tibial components.ConclusionThe ALL can be visualized in routine 1.5-T MR imaging, either full delineation (55.6%) or partially visualized (75%). It is best characterized via a PD-weighted sequence with fat saturation on the coronal plane. The ALL injury was associated with an anterior cruciate ligament (ACL) injury.

Angiographic Analysis of the Anatomical Variants in Genicular Artery Embolization

Abstract Purpose Genicular artery embolization (GAE) has been proposed as a novel technique to treat painful synovitis related to osteoarthritis. An in-depth understanding of the genicular arterial anatomy is crucial to achieve technical success and avoid nontarget-related complications. Given the lack of previous angiographic description, the present study analyzes genicular arterial anatomy and proposes an angiographic classification system. Materials and Methods Angiographic findings from 41 GAEs performed during two US clinical trials from January 2017 to July 2019 were reviewed to analyze the anatomical details of the following vessels: descending genicular artery (DGA), medial superior genicular artery (MSGA), medial inferior genicular artery (MIGA), lateral superior genicular artery (LSGA), lateral inferior genicular artery (LIGA), and anterior tibial recurrent artery (ATRA). The diameter, angle of origin, and anastomotic pathways were recorded for each vessel. The branching patterns were classified as: medially, M1 (3/3 arteries present) vs M2 (2/3 arteries present); and laterally, L1 (3/3 arteries present) vs L2 (2/3 arteries present). Results A total of 91 genicular arteries were embolized: DGA (26.4%), MIGA (23.1%), MSGA (22.0%), LIGA (14.3%), and LSGA/ATRA (14.3%). The branching patterns were: medially = M1, 74.4% (n = 29), M2, 25.6% (n = 10); and laterally = L1, 94.9% (n = 37), L2, 5.1% (n = 2). A common origin for MSGA and LSGA was noted in 11 patients (28.2%). A direct DGA origin from the popliteal artery was reported in three patients (7.7%, n = 3). Conclusions A thorough understanding of the geniculate arterial anatomy is important for maximizing postprocedural pain reduction while minimizing complications, procedure time, and radiation exposure during GAE.

Arteriography and Embolization of Lateral Inferior Genicular Artery of Recurrent Spontaneous Hemarthrosis after Total Knee Arthroplasty

Arteriography and Embolization of Lateral Inferior Genicular Artery of Recurrent Spontaneous Hemarthrosis after Total Knee Arthroplasty

MRI Evaluation of Anterolateral Ligament of the Knee: A CrossSectional Study in Malaysia

Introduction: Anterolateral ligament (ALL) of the knee has been demonstrated to be an important secondary restrainer in providing rotational stability to the knee. ALL stabilizes the internal tibial rotation with increasing knee flexion. ALL injuries with concomitant anterior cruciate ligament (ACL) injuries have a higher grade of pivot shift. Magnetic resonant (MR) studies on ALL have been performed but there is no such data among the Malaysian population. We aim to investigate the reproducibility of ALL identification on 1.5T MRI and the association with other ligamentous injuries. Materials and method: Magnetic resonant imaging of the knees with suspected ligamentous injuries from 1st January 2017 to 30th June 2017 were reviewed for suitability of this study. Post-operative MRI and MRI of patients with suspected tumour at the knee region were excluded. 1.5T MRI (Siemens Medical Solution) was used for assessment of all the knees. All MRIs were double read and approved by a consultant radiologist. Results: A total of 36 knee MR images were obtained from 31 patients during the study period. 5 patients were excluded (3 for suspected tumour and 2 for post-operative). Mean age of the patients was 29.44. All three components of ALL were identified in 20 MRIs (55.6%): femoral component (75%); meniscal (69.4%) and tibial (58.3%). There were 11 knees identified to have ALL injury, which was associated with ACL injury. Discussion: ALLs are best visualized on coronal views (PD, PD FS and T2) with lateral inferior genicular artery as a guide to locate the bifurcation of meniscal and tibial components. Delineation of ALLs from other surrounding structures such as lateral collateral ligaments, iliotibial band and popliteus tendon was done in both coronal and axial views. Conclusion: ALLs of the knees are delineated in more than half of the MR images. There is an association between ALL injuries and ACL injuries.

Vascular coverage of the anterior knee region - an anatomical study.

Descriptions of vessel angiosomes or perforasomes throughout the human body are quite frequent, and led to the development of flaps nowadays commonly used to surgically cover skin and soft tissue defects. In these procedures, the surgeon requires a profound anatomical knowledge of the respective blood vessels and the extent of the perfused area to define the size of the graft. In the region of the knee joint, descriptions of flaps based on the superior lateral genicular artery and descending genicular artery are quite frequent. In contrast, information regarding other popliteal branches is scarce or non‐existent. The aim of this study was to provide a concise and complete overview on the extent and variability of the perforator angiosomes of the femoral and popliteal arteries in the anterior knee region. Twenty lower extremities were dissected, the respective perforators identified and perfused with dye. All resulting angiosomes were marked and documented. A total of 84 angiosomes were identified in all specimens, with an average of 4.2 (3–6) angiosomes per specimen. The average size of the angiosomes was 97.04 ± 72.30 cm2 (8.61–360.41 cm2), their source vessels had an average diameter of 1.42 ± 0.54 mm (0.60–3.25 mm). The complex and highly variable distribution of perforator angiosomes of the anterior knee region and especially of its less frequently investigated distal part was demonstrated. Based on these results, the planning of existing perforator flaps in this region and the development of flaps including the inferior medial or inferior lateral genicular arteries may be facilitated.

Vascularity of the Proximal Fibula and Its Implications in Vascularized Epiphyseal Transfer: An Anatomical and High-Resolution Computed Tomographic Angiography Study.

Various vascular pedicles have been used to supply the proximal fibula for vascularized epiphyseal transfer. The optimal pedicle has, however, not been agreed on. This study aimed to describe the detailed vascular anatomy of the proximal fibula to assist the surgeon in choosing the optimal pedicle. Twenty-eight lower extremities were injected with latex or a mixture of latex and barium sulfate. Vessels supplying the proximal fibula were identified and dissected, and the course, diameter, anatomical relations, length, and branches were documented. In the barium group, high-resolution computed tomographic scanning was conducted before dissection. In seven specimens, branches of the deep peroneal nerve to the tibialis anterior muscle were carefully preserved, and their relation to the proximal fibular vascularity was noted. An anastomotic vascular network supplied the proximal fibula. This was formed superiorly by branches of the inferior lateral genicular artery, and inferiorly by branches of the anterior tibial artery, the most important of which were the first and second recurrent epiphyseal arteries. One or more deep peroneal nerve branches passed deep to the first recurrent epiphyseal artery in all specimens examined. In five specimens, all of the branches were superficial to the second recurrent epiphyseal artery, whereas two had branches deep to it. The proximal fibula can be transferred using the inferior lateral genicular or anterior tibial artery because of the existing anastomosis. Factors including length of pedicle, potential for nerve injury, and diaphyseal portion to be harvested should be considered in the pedicle choice.

Quantitative analysis of the perimeniscal position of the inferior lateral genicular artery (ILGA): magnetic resonance imaging study.

The inferior lateral genicular artery (ILGA) passes around the lateral knee joint, adjacent to the lateral meniscus (LM). ILGA injuries in total knee arthroplasty or arthroscopic surgery can result in recurrent hemarthrosis or painful pseudoaneurysms. Detailed information about the perimeniscal position of the ILGA relative to the LM is necessary to avoid these complications. 3-T MR images of 100 knees (mean age 36.3 ± 11.2years) were retrospectively reviewed. The perimeniscal area was divided into four regions: the anterior, middle, popliteal hiatus, and posterior zones. In each zone, the ILGA diameter, superoinferior position (assessed as the height of the ILGA from the LM base), and distance between the meniscocapsular junction and the ILGA were measured. The distance between the ILGA and meniscocapsular junction was significantly smaller in the middle zone than in the other three zones (anterior 5.3 ± 0.8mm, middle 1.4 ± 0.4mm, popliteal hiatus 6.1 ± 1.0mm, and posterior 5.6 ± 1.5mm, p < 0.05). In the superoinferior position, the height of the ILGA was 3.4 ± 0.9mm in the anterior zone, 0.4 ± 1.3mm in the middle zone, - 1.9 ± 1.8mm in the popliteal hiatus zone, and - 1.3 ± 4.3mm in the posterior zone. When the LM bottom is the base, the ILGA was located superiorly in the anterior zone, close to the base in the middle zone, and inferiorly in the popliteal hiatus zone. To avoid ILGA injury, close attention is necessary during surgical procedures involving the meniscocapsular junction of the LM, especially at the meniscal base in the middle zone.

Unusually located inferior lateral genicular artery in two cadavers and an abnormally attached soleus with the absence of plantaris

Two cadavers (ages of 54 and 68, male) were presented with the variative inferior lateral genicular artery which was passing superficial to the plantaris instead of deep to it. Soleus attached to popliteus tendon with the absence of plantaris was encountered in the other extremity of one of those cases. The cases were evaluated regarding clinical and developmental aspects. This case is the first to our knowledge to describe inferior lateral genicular artery passing superficial to the plantaris. Positional variations of the artery could be taken into account related with during radiological assessments regarding misdiagnosis. The case that soleus attached to the popliteus tendon in the absence of plantaris has not been mentioned in the literature.

How to Test the Anterolateral Ligament With Ultrasound

Ultrasonography (US) is a nonirradiating, low-cost, real-time imaging modality that has very good spatial resolution. US can be used to view the anterolateral ligament (ALL) and injuries to the ALL. Several authors have sought to analyze the anterolateral aspect of the knee using US with varying luck. All of them analyzed the ALL statically only. The goal of this Technical Note is to describe in detail the technique that we use to analyze the anterolateral aspect of the knee in patients with an anterior cruciate ligament tear. We use a simple technique that starts by locating the tibial end of the ALL. The lateral inferior genicular artery is a reliable landmark in this context. The analysis is dynamic in addition to being static. To determine if the ALL is injured, we look for a lack of tension on the ALL when the knee is internally rotated and for a Segond fracture. We believe that it is essential to start evaluating the ALL by its tibial end. US analysis of the ALL forms the basis for developing an appropriate “à la carte” treatment for the patient's injury.

Vascular supply at risk during lateral release of the patella during total knee arthroplasty: A cadaveric study

IntroductionLateral release to improve patellar tracking is commonly performed during total knee arthroplasty. Blood is supplied to the lateral patella by two main arteries: the superior and inferior lateral genicular arteries. The transverse infrapatellar artery also branches off the lateral inferior genicular artery to supply the inferior half of the patella. Severance of any of these arteries during lateral release can lead to avascular necrosis of the patella. This cadaveric study investigates the lateral vasculature to the patella and whether it can be visualized and preserved during lateral release of the patella. Materials and methodsThis study involved ten cadavers, each of which underwent lateral release of the patella. One senior joint surgeon performed and supervised the incisions and attempted to locate and preserve these vessels. We then quantified the number of cadavers with visualized blood vessels and analysed their location and course to determine whether they could be preserved during lateral release of the patella. ResultsIn our study, three of the ten cadavers had an artery that was visible within the incisional plane and preserved. Two were the inferior lateral genicular artery, and one was the superior lateral genicular artery. In the other seven cadavers, no vessels were visualized during the lateral dissection. ConclusionsThese results demonstrate that it is difficult to visualize blood supply to the patella during lateral release. Every attempt should be made to preserve these blood vessels to avoid devascularization to patella in the setting of an already severed medial vascularity due to standard approach to knee replacement.

Ultrasonography imaging of the anterolateral ligament using real-time virtual sonography

BackgroundThe anterolateral ligament (ALL) functions as a stabilizer in the internal rotation of the knee. Previous studies have reported the ALL can be identified using magnetic resonance imaging (MRI); however, there are no reports on using ultrasonography (US) for this purpose. Real-time virtual sonography (RVS) uses magnetic navigation and computer software for the synchronized display of real-time US and multiplanar reconstruction MRI images. This study investigated the ability of using US with RVS to evaluate the ALL. MethodsNine healthy subjects were enrolled. The Digital Imaging Communications in Medicine MRI dataset was loaded into the Hitachi Aloka Preirus, and US images were displayed on the same monitor. When the ALL was identified using MRI, the monitor was frozen to evaluate the ALL. The ALL was divided into the femoral, meniscal, and tibial portions. The portions and thickness of the ALLs and the lateral inferior genicular artery (LIGA), a landmark for the ALL, were evaluated. ResultsAll portions of the ALL could be identified using MRI. Using US, the tibial portion of the ALL was detected in all subjects and the femoral portion was detected in seven subjects; however, the meniscal portions could not be identified. The average ALL thickness as measured by US was 1.3±0.1mm and the LIGA was identified in all cases. ConclusionsMost portions of the ALL can be identified using US. As most ALL injuries occur at the femoral or tibial portion, US may be useful as a diagnostic tool for ALL injury.Level of Evidence: 4

Spontaneous Recurrent Hemarthrosis of the Knee: A Report of Two Cases with a Source of Bleeding Detected during Arthroscopic Surgery of the Knee Joint.

We report two cases of the spontaneous recurrent hemarthrosis of the knee. In these cases lateral meniscus was severely torn and a small tubular soft tissue with pulsation was identified on the synovium in the posterolateral corner during arthroscopic surgery of the knee joint. Gentle grasping of this tissue by forceps led to pulsating bleeding, which stopped by electrocoagulation. This soft tissue was considered a source of bleeding, since no recurrence of hemarthrosis was observed for more than four years after surgery. It was highly probable that this soft tissue was the ruptured end of the lateral inferior genicular artery or its branch. This case report strongly supports the theory that the bleeding from the peripheral arteries of the posterior portion of the lateral meniscus is the cause of spontaneous recurrent hemarthrosis of the knee.