Anterior cruciate ligament (ACL) injuries are common knee injuries. There are approximately 200,000 ACL injuries in the United States each year. Among these injuries, surgical reconstructions participate in the rehabilitation process of approximately 100,000 people. It is important that healthcare professionals have the ability to confidently and accurately assess these injuries when they occur to enable individuals to begin appropriate treatment as soon as possible. Knowledge of the mechanism of injury, signs and symptoms, and diagnostic tests for ACL injuries are all important assessment tools for a healthcare professional when diagnosing ACL injuries. Current research in these areas is important to ensure that the best examination process is used for accurate diagnosis of ACL injuries. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”?Get the original essayThe ACL, along with the posterior collateral ligament, is one of the two intracapsular cruciate ligaments of the knee. The ACL is composed of collagen – mainly type I – and is arranged in several bundles of fibers. The ACL is innervated by the posterior tibial nerve and receives its blood supply from the middle and inferior genicular arteries. Jarbo et al. (2017) state that the ACL has two distinct parts, “the anteromedial bundle and the posterolateral bundle, named after their respective insertion sites from the tibia to the femur.” One group of researchers argues that these fascicles exhibit less of an anatomical separation, and more of functional differentiation. Markatos et al. (2013) explain: “An anteromedial fasciculus becomes taut at 90 degrees of flexion, and a posterolateral fasciculus becomes taut as it approaches full extension.” This allows the knee to maintain stability at different joint angles that may occur during daily movements. The function of the ACL involves maintaining the stability of the knee joint. Jarbo et al. (2017) describe the role of the ACL as follows: “The ACL is responsible for preventing anterior translation of the tibia relative to the femur and also acts as a secondary constraint to tibial rotation and varus/valgus rotation.” This means that the ACL has more than one responsibility to help maintain knee stability, with the primary function being resistance to anterior movement of the tibia. The importance of the role of the ACL in preventing this movement is described by Markatos et al. (2013) who state that “the ACL…accounts for up to 86% of the total force resisting anterior pulling.” Total stability of the knee, including resistance to rotational movements, is further aided by the surrounding musculature. However, the body is not always able to maintain this stability, especially during athletics. When the ACL is exposed to more load than it is capable of supporting, it causes injuries ranging from small tears to a complete rupture. Athletes of all levels are at increased risk of ACL rupture. The risk for those practicing basketball, handball, football and skiing is even higher than for other sports. ACL injuries can occur through both contact and non-contact injury mechanisms, however, non-contact mechanisms make up the majority of ACL ruptures. Kiapour et al. (2015) state that more than 70% of all ACL injuries originate from a non-contact mechanism. The most common forms of non-contact mechanisms for ACL injuries are related to a change in speed or "the generation of a multidirectional force atacross the knee joint while bearing weight.” According to Wetters et al., the individual's knee is typically in the range "from early flexion to hyperextension at the time of injury." They then explain that when the knee is in this range, the tensile properties of the ACL are higher. An athletic movement when the knee is often in this range is that of deceleration. Therefore, deceleration is described as a frequent mechanism for ACL injury. This can be explained by the fact that in deceleration, "the quadriceps forces necessary to stop the athlete are increased and therefore the contractions can exert significant stress on the ACL". Other mechanics include landing after a jump or performing a side cutting motion. Wetters et al. (2015) add that twisting and pivoting movements can also lead to non-contact ACL injuries. Overall, these injuries tend to be caused by a combination of movements and forces at the knee. One group of researchers describes that “sagittal and coronal loading, in combination with unbalanced muscle contraction forces of the quadriceps and hamstring muscle groups, can result in significant strain. on the ACL”. When the stresses of these forces are too high within the knee, the ACL ruptures. Diagnosis of ACL injuries begins with recognizing the mechanism of injury. Knowing the mechanism of injury can provide clues as to whether or not an ACL injury should be considered a point of suspicion when performing an evaluation. Additionally, it is important to recognize common signs and symptoms of ACL injuries to facilitate a correct diagnosis. One author suggests that it is important to be sure to ask the person involved if they heard any auditory cues, such as a click or pop. Complete ACL tears often create a sound loud enough for the individual or those around them to hear. This can be a good indication of a potential ACL tear. The patient will often describe feeling unstable or that their knee is going to give way. They may be afraid to get up or walk at first after the injury. Upon inspection, ACL tears “usually produce rapid swelling at the joint line.” While it is important to recognize these signs and symptoms of ACL injuries, the most important diagnostic tool is the use of special tests for ACL tears. There are a variety of special tests that can be used to diagnose ACL injuries. According to Jarbo et al. (2017), “The 3 most widely accepted clinical tests for diagnosing an ACL tear include the anterior drawer, Lachman, and pivot shift tests, all of which were initially described in the 1970s.” Recently, a new test was proposed called “Lever Sign”. It is important to review the literature when new tests are published to ensure that the clinical examination tools used in practice are most appropriate for the pathology. Additionally, it is important to consider that in the clinical setting, "the accuracy of these exams may be affected by patient factors such as swelling, pain, protective muscle action, and patient experience." examiner.” Therefore, the selection of a special test for diagnosis should be based on evidence as well as the patient's current presentation. Anterior drawer tests are a simple test to detect ACL injuries. This simplicity makes it one of the most commonly used ACL tests. To perform this test, the practitioner places the patient in a supine position, with the foot flat on the table.assessment, the hip flexed to 45 degrees and the knee flexed to 90 degrees. The foot is stabilized thanks to anterior translation of the tibia. Two different scenarios can result in a positive test result: if there is no extremity sensation or if there is increased tibial translation compared to the uninjured side, this is considered positive for a ACL injury. For this test to be performed correctly, the practitioner must ensure that the tibia is aligned with the medial condyle of the femur before starting the test. Rossi et al. (2011) explain that failure to do so could cause a false positive in cases of damaged PCL, as this can cause a more posterior tibial starting position, giving the impression that there is increased anterior translation relative to the other side. Another point to consider is that pain and inflammation can make it uncomfortable, or even impossible, for the patient to obtain 90 degree knee flexion to properly perform this test. The Lachman test is proposed to be the most valid ACL examination test because it generally has high sensitivity and specificity. This test is also performed with the patient supine, but it only requires 20 to 30 degrees of knee flexion. For this test, “the examiner stabilizes the patient's femur with one hand while translating the tibia in an anterior direction with the other hand. As with the anterior drawer test, it is important to consider the final sensation when this test is performed. Rossi et al. (2011) explain that a soft extremity sensation indicates a complete ACL tear, whereas a firm extremity sensation would be a negative test. The pivot shift test does not require the examiner to take into account an ending sensation. This test is performed with the patient in a supine position and with 40 degrees of hip flexion and slight hip adduction. The examiner slightly flexes the patient's knee and applies gentle valgus and internal rotation forces. The knee is then passively flexed by the practitioner while maintaining these forces. Lichtenberg et al. (2018) describe a positive test as follows: “there is anterior subluxation of the lateral tibial plateau which spontaneously reduces beyond 30 degrees of knee flexion”. The most recent ACL diagnostic test is the Lever sign test. This test is also performed with the patient in a supine position, but with the knee fully extended. The examiner “then places a closed fist under the proximal third of the calf [which] causes a slight flexion of the knee.” This will serve as the fulcrum for the lever in this test. Next, the examiner exerts an anteroposterior force on the patient's quadriceps, approximately one third anterior to the knee. This test looks for an “ACL discontinuity.” A negative test would be if the knee joint goes into full extension and the heel of the affected leg rises off the table. This would mean that an uninjured ACL creates intact leverage at the knee, allowing the heel to lift off the table under the force applied to the quadriceps. Conversely, a positive test would have a missing piece of the lever system; this means that a damaged ACL will not be able to help lift the heel off the table. Therefore, a positive Lever Sign test is one in which the knee does not move into flexion and the heel remains on the table. Various studies have been carried out to compare the effectiveness of this new Lever Sign test against the other three, more traditional, ACL diagnostic tests. Measures of effectiveness of special tests include sensitivity and specificity. Sensitivity is defined by Fritz & Wainner (2001) as “the ability of the test to recognize the condition when it is present. A very sensitive testgives relatively few false negative results. Conversely, “specificity is the ability of the test to identify the absence of disease.” This means that “a very specific test gives relatively few false positive results.” Ideally, a test should have both high sensitivity and specificity. However, Fritz and Wainner (2001) argue that few tests fall into this category. Ideally, a test should have both high sensitivity and specificity. However, Fritz and Wainner (2001) argue that few tests fall into this category. In their study, Lelli et al. (2016) carried out a prospective study over a period of 8 months. They evaluated a total of 400 patients in 4 different categories. These categories were based on their stage of post-injury healing – acute or chronic – and their MRI findings – complete or partial ACL tear. In this study, the acute phase was defined as “less than 20 days after injury.” The patients in this study were 29.8% women and 70.2% men with a mean age of 26.4 years. All patients were tested by the same examiner who was blinded to the MRI results. Each participant was assessed using the “Lachman test, Anterior Drawer test, Pivot Shift test, and Lever Sign test.” The uninjured leg of each participant was used as a control for this study, but only for the Lever Sign test. This test showed that the sensitivity and specificity of the Lever Sign test were both 1.0, meaning that the test was still correct compared to the MRI results. The average sensitivity of the other three tests was 62% for the Lachman test, 72% for the Anterior Drawer test, and 47% for the Pivot Shift test. As these tests were not compared to the uninjured side, specificity was not calculated. A study conducted by Jarbo et al. (2017) also examined the new Lever Sign test and its effectiveness as a diagnostic test. Their study included 102 patients with acute knee injuries. Acute injuries were defined as less than or equal to 4 weeks old. There were 44 women included in the study, 28 in the surgical group and 16 in the non-surgical group, and 58 men in the study, 26 in the surgical group and 32 in the non-surgical group. The people included in the study were 23 years old on average. All patients were evaluated in the clinic for ACL integrity using the 4 diagnostic tests: the Lachman test, the Anterior Drawer test, the Pict Shift, and the Lever Sign test. Patients in the surgical group were also tested with all 4 tests under anesthesia. ACL integrity, or lack thereof, was confirmed by MRI and arthroscopic surgery in the surgical group, while the ACL injury status of the non-surgical group was confirmed by MRI only; however, the results were only compared to MRI results to calculate sensitivity and specificity. Having the test results in clinical and surgical settings allowed researchers to compare the accuracy of the tests in awake patients and those under anesthesia. Under anesthesia, the Anterior Drawer, Lachman, and Pivot Shift tests were all more accurate, but the difference in Lever Sign test results was not statistically significant. In addition, compared to MRI, the sensitivity values ​​for the 4 tests were as follows: 88% for the anterior drawer test, 90% for the Lachman test, 59% for the Pivot Shift and 63% for the Raise Sign. Additionally, test sensitivity was 94% for the Anterior Drawer test, 96% for the Lachman test, 98% for the Pivot Shift test, and 90% for the Lever Sign test. The authors add that the overall accuracy of the Lachman test was the highest of the 4 tests, at 93%, and that.