Diagnosis of acute rupture of the anterior cruciate ligament of the knee by sonography

The Value of Ultrasound Diagnostic Imaging of Anterior Crucial Ligament Tears Verified Using Experimental and Arthroscopic Investigations

This study investigates the potential of the ultrasound imaging technique in the assessment of Anterior Cruciate Ligament (ACL) pathologies by standardizing the examination process. We focused on four key ultrasound parameters: the inclination of the ACL; swelling or scarring at the ACL's proximal attachment to the lateral femoral condyle; swelling or scarring of the ACL/posterior cruciate ligament (PCL) compartment complex with accompanying morphological changes in the posterior joint capsule; and dynamic instability, categorized into three ranges-0-2 mm, 3-4 mm, and ≥5 mm. The study group consisted of 25 patients with an ACL injury and 25 controls. All four tested parameters were found more frequently in the study group compared to the control (p < 0.0001). Our findings suggest that this standardized approach significantly augments the diagnostic capabilities of ultrasound, complementing clinical evaluation and magnetic resonance imaging (MRI) findings. The meticulous assessment of these parameters proved crucial in identifying subtle ACL pathologies, which might otherwise be missed in conventional imaging modalities. Notably, the quantification of dynamic instability and the evaluation of morphological changes were instrumental in early detection of ACL injuries, thereby facilitating more precise and effective treatment planning. This study underscores the importance of a standardized ultrasound protocol in the accurate diagnosis and management of ACL injuries, proposing a more comprehensive diagnostic tool for clinicians in the field of sports medicine and orthopedics.

Evaluation of the knee joint with ultrasound and magnetic resonance imaging

The knee joint relies on a combination of deep and superficial structures for stability and function. Both ultrasound and high-resolution magnetic resonance imaging are extremely useful in evaluating these structures and associated pathology. This article reviews a combination of critical anatomic structures, joint abnormalities, and pathologic conditions at the knee joint, while highlighting the merits, limitations, and pitfalls of the two imaging modalities. A clear appreciation of each method paired with its relative strengths will aid in expediting diagnosis and appropriate treatment for a wide range of knee joint conditions.

EURO-MUSCULUS/USPRM Dynamic Ultrasound Protocols for Knee

ABSTRACT

In this dynamic scanning protocol, ultrasound examination of the knee is described using various maneuvers to assess different conditions. Real-time patient examination and scanning videos are used for better simulation of the daily clinical practice. The protocol is prepared by several/international experts in the field of musculoskeletal ultrasound and within the umbrella of European Musculoskeletal Ultrasound Study Group in Physical and Rehabilitation Medicine/Ultrasound Study Group of the International Society of Physical and Rehabilitation Medicine.

Prone Lachman with Ultrasound: A Literature Review and Description of the Technique

ABSTRACT

Magnetic resonance imaging is the current gold standard imaging modality for diagnosing anterior cruciate ligament (ACL) tears. However, ultrasound has grown in popularity for detecting ACL injuries because of its low cost, portability, and dynamic assessment capabilities. Recent studies demonstrate high sensitivity and specificity for diagnosing isolated ACL tears via ultrasound, but tremendous heterogeneity remains for optimal technique including patient positioning, transducer placement, and dynamic versus static ultrasound usage. As ultrasound becomes ubiquitous in clinics, training rooms, and on the sidelines, identifying objective and sensitive measurements to appropriately screen athletes for significant knee injuries is imperative. This article aims to review the current role of diagnostic ultrasound in ACL injuries and propose a standardized version of the Prone Lachman with Ultrasound test, which is an objective, reliable, and easily reproducible technique to evaluate ACL competency. Developing a standardized protocol will expand the use of point-of-care ultrasound, which may reduce cost and improve efficiency in care.

Ultrasound Imaging of the Anterior Cruciate Ligament: A Pictorial Essay and Narrative Review

Ultrasound has been extensively applied to the diagnosis of and guided interventions for knee disorders. However, although it is commonly affected during sports injuries, the anterior cruciate ligament (ACL) is not usually incorporated in the majority of ultrasound scanning protocols. In the past, because of its oblique trajectory and deeper location, the ACL was considered to be a challenging structure for ultrasound imaging. Owing to advances in ultrasound technology and knowledge of knee sono-anatomy, an increasing number of studies are investigating the clinical value of ultrasound in the diagnosis and management of ACL injuries. In this regard, the present review aims to elaborate on the sono-anatomy of the ACL, to summarize the evidence for ultrasound imaging for ACL lesions and to investigate whether it is useful in the pre-operative preparation and post-operative follow-up of ACL reconstruction.

Techniques for In Vivo Measurement of Ligament and Tendon Strain: A Review

The critical clinical and scientific insights achieved through knowledge of in vivo musculoskeletal soft tissue strains has motivated the development of relevant measurement techniques. This review provides a comprehensive summary of the key findings, limitations, and clinical impacts of these techniques to quantify musculoskeletal soft tissue strains during dynamic movements. Current technologies generally leverage three techniques to quantify in vivo strain patterns, including implantable strain sensors, virtual fibre elongation, and ultrasound. (1) Implantable strain sensors enable direct measurements of tissue strains with high accuracy and minimal artefact, but are highly invasive and current designs are not clinically viable. (2) The virtual fibre elongation method tracks the relative displacement of tissue attachments to measure strains in both deep and superficial tissues. However, the associated imaging techniques often require exposure to radiation, limit the activities that can be performed, and only quantify bone-to-bone tissue strains. (3) Ultrasound methods enable safe and non-invasive imaging of soft tissue deformation. However, ultrasound can only image superficial tissues, and measurements are confounded by out-of-plane tissue motion. Finally, all in vivo strain measurement methods are limited in their ability to establish the slack length of musculoskeletal soft tissue structures. Despite the many challenges and limitations of these measurement techniques, knowledge of in vivo soft tissue strain has led to improved clinical treatments for many musculoskeletal pathologies including anterior cruciate ligament reconstruction, Achilles tendon repair, and total knee replacement. This review provides a comprehensive understanding of these measurement techniques and identifies the key features of in vivo strain measurement that can facilitate innovative personalized sports medicine treatment.

Efficiency of knee ultrasound for diagnosing anterior cruciate ligament and posterior cruciate ligament injuries: a systematic review and meta-analysis

OBJECTIVE

To evaluate the diagnostic performance of knee ultrasound for anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries.

MATERIALS AND METHODS

PubMed and EMBASE databases were searched for diagnostic accuracy studies that used ultrasound for diagnosing ACL and PCL injuries. Bivariate and hierarchical summary receiver operating characteristic modeling was used to evaluate diagnostic performance. Subgroup analysis was performed by assessing studies conducted using the ultrasound technique (functional ultrasound versus conventional ultrasound) for diagnosing ACL injury. We performed meta-regression analyses for a potential source of heterogeneity.

RESULTS

Eleven (938 ultrasound/878 patients) and six articles (281 ultrasound/237 patients) were included for ACL and PCL injuries respectively. The summary sensitivity, summary specificity, and area under the hierarchical summary receiver operating characteristic for ACL and PCL injuries were 0.88 (95% confidence interval [CI], 0.81-0.93) and 0.99 (95% CI, 0.49-1.00), 0.96 (95% CI, 0.91-0.98) and 0.99 (95% CI, 0.73-1.00), and 0.97 (95% CI, 0.96-0.98) and 1.00 (95% CI, 0.99-1.00) respectively. In subgroup analysis, there was no significant difference between sensitivity (p = 0.63) and specificity (p = 0.72) of functional and conventional ultrasound. Among the various potential covariates, patient enrollment, patient position, and ultrasound performer were associated with heterogeneity in terms of sensitivity, and proportion of the ACL injury was associated with heterogeneity in terms of specificity.

CONCLUSION

Knee ultrasound demonstrates high diagnostic performance for ACL and PCL injuries, particularly when performed by experienced musculoskeletal radiologists. Future prospective studies to compare the cost- and time-effectiveness between ultrasound and magnetic resonance imaging and to determine the optimal ultrasound parameters are warranted.

Validity of Indirect Ultrasound Findings in Acute Anterior Cruciate Ligament Ruptures

OBJECTIVES

Ultrasound (US) is increasingly being used as an extension of the physical examination on the sidelines, in training rooms, and in clinics. Anterior cruciate ligament (ACL) injury in sport is common, but the literature on US findings after acute ACL rupture is limited. Three indirect US findings of ACL rupture have been described, and this study assessed the validity of these indirect signs.

METHODS

Patients with an acute knee injury (<6 weeks) underwent US examinations to determine whether there was evidence of a femoral notch sign, posterior cruciate ligament wave sign, or capsular protrusion sign. Ultrasound findings were compared to magnetic resonance imaging.

RESULTS

Sixty-nine patients were included (53 with ACL tears and 16 control patients). The posterior cruciate ligament sign had the highest sensitivity (84.9%), and the notch sign had the highest specificity (93.8%). If 2 or 3 of the signs were positive, the sensitivity was 86.8%, and the specificity was 87.5%.

CONCLUSIONS

A US examination is an easy-to-perform and noninvasive test, and the 3 indirect signs of an acute ACL tear had high positive predictive values ranging from 91.8% to 96.8%.

Feasibility of point-of-care knee ultrasonography for diagnosing anterior cruciate and posterior cruciate ligament tears in the ED

OBJECTIVE

To evaluate the feasibility of point-of-care knee ultrasonography (POCUS) compared with knee magnetic resonance imaging (MRI) for diagnosing anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears in patients with acute knee trauma.

MATERIAL AND METHODS

A prospective study was conducted in a tertiary hospital emergency department; acute (within 1-week) knee trauma patients with suspected ACL or PCL tear were recruited. Two POCUS performers (a board-certified emergency physician and a musculoskeletal radiologist) independently evaluated the ACL and PCL using POCUS. Findings were classified as normal appearance or ligament tear. Final radiology reports of knee MRI were used as the reference standard. We calculated the diagnostic values (sensitivity, specificity, and accuracy) for POCUS obtained by both POCUS performers. Kappa values (k) were calculated for inter-observer agreement between the two POCUS performers.

RESULTS

Sixty-two patients were enrolled. Compared with the reference standard, POCUS showed acceptable sensitivity (90.6-100%), specificity (90.0-97.7%), and accuracy (91.9-96.8%). Inter-observer agreement between the two POCUS performers was excellent (k = 0.853-0.903).

CONCLUSION

POCUS demonstrates excellent precision as compared to MRI in the diagnosis of ACL and PCL tears. The findings of POCUS could be used for immediate diagnosis and further pre-operative imaging in patients with acute knee trauma.

Ultrasonography as a Diagnostic, Therapeutic, and Research Tool in Orthopaedic Surgery

Ultrasonography is an imaging modality that facilitates the diagnosis of pathology and injection therapy without exposing the patient to radiation. In addition, ultrasonography has become popular because of its portability, low cost, and production of real-time tomographic images that provide a cross-sectional view of anatomic structures. Despite its benefits and widespread adoption in general medicine and other specialties, however, ultrasonography is not as well adapted as a diagnostic and research tool in orthopaedic surgery. An understanding of the basic principles of ultrasonography and the evidence supporting its use can aid the orthopaedic surgeon in applying this modality appropriately in clinical practice.

The role of ultrasonography in the diagnosis of anterior cruciate ligament injury: A systematic review and meta-analysis

To evaluate the value of ultrasonography in the diagnosis of anterior cruciate ligament injury (ACL injury) by conducting a systematic review and meta-analysis. A literature search was carried out in the Cochrane Library, Embase, Pubmed databases and included studies prior to April 2017. Based on inclusion and exclusion criteria, studies evaluating ultrasound to diagnose ACL injury were selected. MRI, arthroscopy and clinical-follow were considered the reference standards. The diagnostic accuracy of ultrasound was assessed using a combination of sensitivity, specificity, likelihood ratio (LR), post-test probability, diagnostic odds ratio (DOR) and by summarizing the area under the receiver operating characteristic (SROC) curve. A total of 4 studies involving 246 patients were eventually included in the analysis. In these four studies, the combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, post-test probability and DOR were 90.0% (95% CI: 77-96), 97% (95% CI: 90-99), 31.08 (95% CI: 8.75-110.41), 0.11 (95% CI: 0.05-0.24), 89% (3%) and 288.81 (95% CI: 78.51-1062.48), respectively. The area under the SROC curve was 0.98 (95% CI: 0.97-0.99). Our meta-analysis showed that ultrasound can play an important role in the diagnosis of ACL injury. Because of its high sensitivity, high specificity and high diagnostic ability, ultrasound should be a part of the standard diagnostic work-up of an ACL injury.

US of the Knee: Scanning Techniques, Pitfalls, and Pathologic Conditions

Pain and other disorders of the knee are a common presenting complaint in the ambulatory setting. Although the cornerstones of imaging evaluation of the knee are radiographs and magnetic resonance (MR) imaging, ultrasonography (US) is less expensive than MR imaging, easily available, and of comparable accuracy in the evaluation of certain pathologic conditions of the knee. The benefits of US include portability, low cost, high spatial resolution, dynamic imaging, and ability to guide percutaneous interventions when indicated. US also allows direct patient contact, facilitating immediate clinical correlation and the ability to compare with the contralateral knee. US evaluation of the knee can be targeted to a specific region on the basis of the complaint or be a comprehensive review. For comprehensive evaluation, the knee is divided into anterior, medial, lateral, and posterior compartments for structured evaluation of the tendons, ligaments, joint space, osseous structures, as well as peripheral nerves and vasculature. US is particularly well suited for evaluating injuries of the quadriceps and patellar tendons, injuries of the medial and lateral collateral ligaments, joint effusions, and fluid collections around the knee. There is additional utility in evaluation of the distal hamstrings tendons, the iliotibial tract, the superficial patellar cortex, the common peroneal nerve, the popliteal vessels, and juxta-articular cystic collections including Baker cyst. In-depth appreciation of relevant sonographic anatomy, common pathologic conditions, knowledge of important pitfalls, and mastery of US technique will allow one to effectively use this powerful bedside tool for the evaluation of a wide variety of knee disorders. ^©RSNA, 2016.

A review of ultrasonographic methods for the assessment of the anterior cruciate ligament in patients with knee instability - diagnostics using a posterior approach

Aim

The purpose of the study was to improve the ultrasonographic assessment of the anterior cruciate ligament by an inclusion of a dynamic element. The proposed functional modification aims to restore normal posterior cruciate ligament tension, which is associated with a visible change in the ligament shape. This method reduces the risk of an error resulting from subjectively assessing the shape of the posterior cruciate ligament. It should be also emphasized that the method combined with other ultrasound anterior cruciate ligament assessment techniques helps increase diagnostic accuracy.

Methods

Ultrasonography is used as an adjunctive technique in the diagnosis of anterior cruciate ligament injury. The paper presents a sonographic technique for the assessment of suspected anterior cruciate ligament insufficiency supplemented by the use of a dynamic examination. This technique can be recommended as an additional procedure in routine ultrasound diagnostics of anterior cruciate ligament injuries.

Results

Supplementing routine ultrasonography with the dynamic assessment of posterior cruciate ligament shape changes in patients with suspected anterior cruciate ligament injury reduces the risk of subjective errors and increases diagnostic accuracy. This is important especially in cases of minor anterior knee instability and bilateral anterior knee instability.

Conclusions

An assessment of changes in posterior cruciate ligament using a dynamic ultrasound examination effectively complements routine sonographic diagnostic techniques for anterior cruciate ligament insufficiency.

The accuracy of diagnostic ultrasound imaging for musculoskeletal soft tissue pathology of the extremities: a comprehensive review of the literature

Musculoskeletal diagnostic ultrasound imaging (MSK-DUSI) has been growing outside the traditional radiology speciality. Increased use of this technology has been reported in several healthcare settings, however an apparent gap in the knowledge of the accuracy of this diagnostic technology indicated a review was warranted. We undertook a structured review of the literature to assess the accuracy of MSK-DUSI for the diagnosis of musculoskeletal soft tissue pathology of the extremities. An electronic search of the National Library of Medicine’s PubMed database (1972 to mid-2014) was conducted. All relevant systematic reviews of diagnostic studies, all diagnostic studies published after the date of the latest systematic reviews and relevant diagnostic studies outside the scope the systematic reviews that directly compared the accuracy of MSK-DUSI (the index test) to an appropriate reference standard for the target condition were included. A fundamental appraisal of the methodological quality of studies was completed. The individual sensitivity, specificity and likelihood ratio data were extracted and entered into diagnostic accuracy tables. A total of 207 individual studies were included. The results show that MSK-DUSI has acceptable diagnostic accuracy for a wide spectrum of musculoskeletal conditions of the extremities. However, there is a lack of high quality prospective experimental studies in this area and as such clinicians should interpret the results with some caution due to the potential for overestimation of diagnostic accuracy.

Sonographically Guided Posterior Cruciate Ligament Injections: Technique and Validation

OBJECTIVE

To describe and validate a technique for sonographically guided posterior cruciate ligament (PCL) injections.

DESIGN

Prospective, cadaveric laboratory investigation.

SETTING

Procedural skills laboratory.

SUBJECTS

Eight unembalmed, cadaveric, mid-thigh-knee specimens (4 left knees and 4 right knees) obtained from 4 male and 4 female donors aged 57 to 64 years (mean 60.8 years) with body mass indices of 27.7 to 36.5 kg/m(2) (mean 32 kg/m(2)).

METHODS

A 5-2-MHz curvilinear probe and a 22-gauge, 78-mm stainless steel needle was used to inject 2 mL of diluted blue latex into the PCL of each specimen using an in-plane, caudad-to-cephalad approach. At a minimum of 24 hours postinjection, each specimen was dissected to assess the presence and distribution of latex within the PCL.

MAIN OUTCOME

Presence and distribution of latex within the PCL.

RESULTS

All 8 injections accurately delivered latex throughout the PCL, including the tibial and femoral footprints. In 2 of 8 specimens (25%), a small amount of latex was noted to extend beyond the PCL and into the joint space. No specimens exhibited evidence of needle injury of latex infiltration with respect to the popliteal neurovascular bundle, menisci, hyaline cartilage, or anterior cruciate ligament.

CONCLUSIONS

Sonographically guided intraligamentous PCL injections are technically feasible and can be performed with a high degree of accuracy. Sonographically guided PCL injections should be considered for research and clinical purposes to deliver therapeutic agents into the PCL postinjury or postreconstruction.

Evaluation and management of traumatic knee injuries in the emergency department

Posttraumatic knee pain is a common presentation in the emergency department (ED). The use of clinical decision rules can rule out reliably fractures of the knee and reduce the unnecessary cost and radiation exposure associated with plain radiographs. If ligamentous or meniscal injury to the knee is suspected, the ED physician should arrange for expedited follow- up with the patient's primary care physician or an orthopedic specialist for consideration of an MRI and further management. Patients presenting after high-energy mechanisms are at risk for occult fracture and vascular injuries. ED providers must consider these injuries in the proper clinical setting.

Smaller anterior cruciate ligament diameter is a predictor of subjects prone to ligament injuries: an ultrasound study

Purpose. To test if diameter of normal anterior cruciate ligament (ACL) can be measured by ultrasound (US), to see if there is a relationship between smaller ACL diameter and ACL injury, and to assess agreement between radiologists in measuring ACL diameter in cases and matched controls. Materials and Methods. In this ethics committee-approved study, maximum diameter of ACL near tibial insertion site was measured by static and dynamic US study in 25 normal contralateral knees of subjects who suffered noncontact ACL injury and in 25 matched control subjects. Results. ACL was visualized as a thick linear hypoechoic band inserted approximately 11 mm caudal to the tibial plateau and the intercondylar eminence. Maximum diameter of contralateral ACL near tibial insertion site among injured subjects was significantly smaller than in noninjured subjects (0.62 ± 0.07 cm versus 0.81 ± 0.06 cm; P < 0.0001). In the regression analysis, the diameter of ACL near tibial insertion site was found significantly proportional to body weight and not significantly associated to height, gender, and age. Conclusion. Diameter of normal ACL near tibial insertion site can be measured by US and the maximum diameter is significantly smaller among subjects with noncontact ACL injury. US is a promising modality that can be used as an excellent screening test to detect subjects especially aspiring athletes prone to ACL injury. Very strong agreement was observed between radiologists in measuring ACL diameter.

Ultrasonographic test for complete anterior cruciate ligament injury

BACKGROUND

Although ultrasound (US) has a wide range of applications in orthopedic diagnostics, sonographic evaluation of traumatic anterior cruciate ligament (ACL) insufficiency is still inadequate. There is a growing need for diagnostic tests that allow for simple and reliable assessment of ACL instability. This investigation aims to evaluate feasibility of sonographic technique for diagnosing complete ACL insufficiency.

MATERIALS AND METHODS

Eighty three consecutive patients suspected of ACL injury were examined with sonographic, dynamic test of anterior instability. The translation of the intercondylar eminence against the patellar tendon was measured in the injured and opposite (injured) knee. Subsequent magnetic resonance imaging was performed on all patients. Forty-seven of them underwent a further arthroscopy. Five patients have been examined for the 2(nd) time to evaluate interclass and intraclass agreement and bias.

RESULTS

Complete ACL insufficiency has been confirmed in 37 patients. In those individuals, the total anterior knee translation and the difference between two joints (side-to-side difference) were significantly increased (8.67 mm standard deviation [SD] 2.65 mm in the affected knee versus 2.88 mm SD 1.26 mm in uninjured joint; P < 0.001). Based on a threshold of 2.0 mm for the side-to-side difference and 5.0 mm for the absolute translation, the sonographic test was found to have a sensitivity and specificity of 91.9% and 95.6%, respectively.

CONCLUSIONS

The present technique supports the clinician with additional fast and noninvasive diagnostic procedure that can facilitate the evaluation of anterior knee instability.

New sonographically-guided test for anterior knee instability - preliminary report

Aim of the study

Ultrasound examination is widely used in orthopedic diagnostics, however sonographic evaluation of traumatic anterior cruciate ligament insufficiency is still inadequate. Aim of this study is to evaluate diagnostic capability of a new sonographically-guided test for diagnosing complete anterior cruciate ligament insufficiency.

Material and methods

In 47 patients, with suspicion of unilateral anterior cruciate ligament injury (based on magnetic resonance imaging), the sonographically-guided test for anterior instability was performed. The translation of the intercondylar eminence against the patellar tendon was measured in both knees. Afterwards all patients underwent arthroscopy.

Results

In 37 patients, with arthroscopically confirmed complete anterior cruciate ligament insufficiency, the mean anterior knee translation was 8.3 mm (SD = 2.8) in affected knee vs. 3 mm (SD = 1.1) in uninjured knee (p < 0.001). In 10 patients with no anterior cruciate ligament insufficiency the difference between body sides was not significant (2.6 mm, SD = 1.4 in injured knee vs. 2.5 mm, SD = 1.1 in uninjured joint; p < 0.7753).

Conclusions

The proposed test supports the clinician with fast and non-invasive examination that can facilitate evaluation of anterior knee instability.

Role of high-resolution ultrasonography without and with real-time spatial compound imaging in evaluating the injured posterior cruciate ligament: preliminary study

PURPOSE

This study sought to compare high-resolution ultrasonography (HRUS) without and with compound imaging in evaluating the injured posterior cruciate ligament (PCL).

MATERIALS AND METHODS

Thirteen patients with a magnetic resonance imaging (MRI) diagnosis of PCL lesions (ten acute and three chronic) and 20 healthy controls underwent conventional and compound HRUS performed by the same radiologist who was blinded to the subjects' case-control status. The PCL was scanned in a longitudinal direction in all cases. HRUS images were assessed for PCL thickness by two other radiologists blinded to the number and type of PCL injury. PCLs were classified as normal or injured, and the latter as having acute or chronic injuries. Inter-method reproducibility of measuring PCL thickness was assessed on conventional and compound HRUS images.

RESULTS

Complete agreement in classifying normal or injured PCL and acute or chronic PCL injuries was achieved. PCL thickness in volunteers was 4.5+/-0.7 mm on conventional images and 4.6+/-0.7 mm on compound images. On conventional and compound HRUS images, the thickness of acutely injured PCL was 9.1+/-1.5 mm and 9.2+/-1.7 mm, respectively, and that of chronically injured PCL was 7+/-0.9 mm and 7+/-0.8 mm. Inter-method reproducibility of PCL thickness measurements on conventional vs. compound HRUS images was 98.6%.

CONCLUSIONS

HRUS is a reliable technique for studying the PCL and detecting PCL injuries.

Role of Sonographic Examination in Traumatic Knee Internal Derangement

OBJECTIVES

To define the accuracy (compared with magnetic resonance imaging [MRI]) of sonographic examination in detecting knee effusion and to determine whether the presence of knee effusions in patients with traumatic knee injury can predict knee internal derangement as assessed by MRI.

DESIGN

Prospective study.

SETTING

Hospital rehabilitation department.

PARTICIPANTS

Thirty patients (19 men, 11 women) with traumatic knee injury were recruited. Subjects received sonographic examination and MRI on the same day.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

The presence or absence of knee effusion was assessed by sonographic examination. MRI was used as criterion standard to evaluate whether the presence of knee effusion and internal derangement, which included tear of anterior and posterior cruciate ligaments, as well as meniscus tear.

RESULTS

The sensitivity of sonographic examination for detecting knee effusion was 79.1%, and specificity was 50%. The positive-predictive value (PPV) was 86.3% and negative-predictive value (NPV) was 37.5%. The PPV of sonographic effusion to internal derangement was 90.9%, and the NPV was 37.5%.

CONCLUSIONS

Sonographic examination can accurately detect effusion of the knee. The detection of knee effusion in patients with traumatic knee injury by sonographic examination is highly indicative of internal knee derangement.

High-resolution ultrasonography (HRUS) of the meniscal cyst of the knee: our experience

PURPOSE

This study was undertaken to assess the diagnostic accuracy of high-resolution ultrasonography (HRUS) in the detection of meniscal cysts.

MATERIALS AND METHODS

Over a 2-year period, 1,857 patients underwent magnetic resonance imaging (MRI) of the knee for traumatic or degenerative disorders. All patients with MRI evidence of a meniscal cyst were studied by HRUS. HRUS was also performed on an equal number of patients without MRI evidence of meniscal cyst who were used as a control group. All HRUS examinations were conducted by a radiologist blinded to the MRI findings. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of HRUS were assessed with reference to MRI. All patients underwent surgery, and the resected masses were studied by histological examination.

RESULTS

MRI allowed identification of a meniscal cyst in 52 patients. HRUS enabled correct detection of the meniscal cyst in 49/52 cases. In the control group, HRUS excluded the presence of meniscal cysts in all cases. HRUS had a sensitivity, specificity, PPV and NPV of 94.23%, 100%, 100% and 94.54%, respectively, for the detection of meniscal cysts.

CONCLUSIONS

HRUS is a fairly reliable technique in the detection, characterisation and differentiation of the different forms of meniscal cyst.

Elastographic imaging of strain distribution in the anterior cruciate ligament and at the ligament-bone insertions

The anterior cruciate ligament (ACL) functions as a mechanical stabilizer in the tibiofemoral joint, and is the most commonly injured knee ligament. To improve the clinical outcome of tendon grafts used for ACL reconstructions, our long-term goal is to promote graft-bone integration via the regeneration of the native ligament-bone interface. An understanding of strain distribution at this interface is crucial for functional scaffold design and clinical evaluation. Experimental determination, however, has been difficult due to the small length scale of the insertion sites. This study utilizes ultrasound elastography to characterize the response of the ACL and ACL-bone interface under tension. Specifically, bovine tibiofemoral joints were mounted on a material testing system and loaded in tension while radiofrequency (RF) data were acquired at 5 MHz. Axial strain elastograms between RF frames and a reference frame were generated using crosscorrelation and recorrelation techniques. Elastographic analyses revealed that when the joint was loaded in tension, complex strains with both compressive and tensile components occurred at the tibial insertion, with higher strains found at the insertion sites. In addition, the displacement was greatest at the ACL proper and decreased in value gradually from ligament to bone, likely a reflection of the matrix organization at the ligament-bone interface. Our results indicate that elastography is a novel method that can be readily used to characterize the mechanical properties of the ACL and its insertions into bone.

[Validity of clinical and ultrasound findings in relation to arthroscopic findings of new injuries of the anterior cruciate ligament of the knee]

Injuries of anterior cruciate ligament are constantly present in sports, but also in common life activities. Diagnostic procedures which are available today in diagnosis and estimation of severity of intraarticular knee structures, are numerous, but they are not available, plausibile and valid in the same manner. Aim of this study was to compare diagnostic validity of clinic and ultrasound examination related to arthroscopy in "fresh trauma: of anterior cruciate ligament This prospective study contains analysis 205 hospitalised patients treated from 2004 to 2006 at IOS "Banjica" Beograd and SOSH "Decedra" Beograd in matter of arthroscopy. Before the arthroscopy, clinical and ultrasound examination was performed. Values of sensitivity(87.1%), specificity(97.7%), positive (98.2%) and negative predictive value (84.3%) of ultrasound examination are affirmative in high reliability of this diagnostic procedure in a diagnosis of fresh lesions of anterior cruciate ligament.

Ultrasonographic evaluation of cranial cruciate ligament rupture via dynamic intra-articular saline injection

Ultrasonographic examination of both stifle joints of five clinically and radiographically normal adult dogs was performed before and after surgical transection of the cranial cruciate ligament (CrCL). At pre- and postsurgery, the hyperechoic patellar ligament and the infrapatellar fat interfered with sonographic visualization of the CrCL. When the stifle joint, however, was imaged via dynamic intra-articular saline injection, the hyperechoic ligament was visualized because of the separation of the infrapatellar fat and the CrCL and the contrasting effect of anechoic saline. When the stifle joint was imaged by real-time scanning after the transection of the CrCL, flutter of the ligament and an anechoic area between the bone and the CrCL were identified. The increased diameter of the ligament and the increased thickness of the joint space were identified as well. Ultrasonographic examination via dynamic saline injection into the joint space has potential as a diagnostic tool for assessing CrCL rupture.

Anterior and posterior cruciate ligament injuries

Knee pain is a common complaint in the primary care setting, and ACL and PCL injuries are common causes of knee pain. Therefore, it is important for the primary care physician to be skilled in the diagnosis and initial management of these injuries and to be aware of potential associated knee injuries. By understanding the history, mechanism of injury, physical examination maneuvers, and imaging modalities related to ACL and PCL injuries, primary care physicians can prepare themselves to make an accurate diagnosis. Then they can counsel the patients on the available treatments, initiate conservative treatment if appropriate, and facilitate an effective referral to a primary care sports medicine physician or orthopedic surgeon.

Performance characteristics of ultrasound of the knee in a general radiological setting

Ultrasound of the musculoskeletal system is an attractive imaging modality due to the lack of ionising radiation, cost and ease of availability. A role has been established in the shoulder and pediatric hip but not in the knee. Ultrasound studies of the knee performed at six general radiological practices without established musculoskeletal expertise were compared with clinical examination in 56 patients. Final diagnoses were established by arthroscopy and/or MRI. The sensitivity and specificity for detection of superficial lesions in the knee were 88 and 41% for clinical examination and 32 and 59% for ultrasound. For deep lesions sensitivity and specificity were 61 and 64% for clinical examination and 13 and 100% for ultrasound. Ultrasound studies of the knee in a general radiological practice do not offer significant information above clinical examination.