The Lachman test is a clinical test used to diagnose injury of the anterior cruciate ligament (ACL). It is recognized as reliable, sensitive, and usually superior to the anterior drawer test. [1]
The Lachman test is a clinical test used to diagnose injury of the anterior cruciate ligament (ACL). It is recognized as reliable, sensitive, and usually superior to the anterior drawer test. [1]
The knee is flexed at 15 degrees with the patient supine. [2] The examiner should place one hand behind the tibia and the other grasping the patient's thigh. It is important that the examiner's thumb be on the tibial tuberosity. [3] The tibia is pulled forward to assess the amount of anterior motion of the tibia in comparison to the femur. An intact ACL should prevent forward translational movement ("firm endpoint") while an ACL-deficient knee will demonstrate increased forward translation without a decisive endpoint - a soft or mushy endpoint indicative of a positive test. More than about 2 mm of anterior translation compared to the uninvolved knee suggests a torn ACL ("soft endpoint"), as does 10 mm of total anterior translation. An instrument called a "KT-1000" can be used to determine the magnitude of movement in millimetres. This test can be done in either an on-field evaluation in acute injury, or in a clinical setting when a patient presents for follow-up with knee pain.
The test may be negative in chronic ruptures as the ACL stump can scar to the PCL. [4]
The test is named after orthopaedic surgeon John Lachman, late Chairman of the Department of Orthopaedic Surgery and Sports Medicine at Temple University School of Medicine in Philadelphia, Pennsylvania. The original description was submitted by one of his colleagues, JS Torg. [5]
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia, and one between the femur and patella. It is the largest joint in the human body. The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. The knee is vulnerable to injury and to the development of osteoarthritis.
The posterior cruciate ligament (PCL) is a ligament in each knee of humans and various other animals. It works as a counterpart to the anterior cruciate ligament (ACL). It connects the posterior intercondylar area of the tibia to the medial condyle of the femur. This configuration allows the PCL to resist forces pushing the tibia posteriorly relative to the femur.
The anterior cruciate ligament (ACL) is one of a pair of cruciate ligaments in the human knee. The two ligaments are also called "cruciform" ligaments, as they are arranged in a crossed formation. In the quadruped stifle joint, based on its anatomical position, it is also referred to as the cranial cruciate ligament. The term cruciate translates to cross. This name is fitting because the ACL crosses the posterior cruciate ligament to form an “X”. It is composed of strong, fibrous material and assists in controlling excessive motion. This is done by limiting mobility of the joint. The anterior cruciate ligament is one of the four main ligaments of the knee, providing 85% of the restraining force to anterior tibial displacement at 30 and 90° of knee flexion. The ACL is the most injured ligament of the four located in the knee.
The Segond fracture is a type of avulsion fracture from the lateral tibial plateau of the knee, immediately below the articular surface of the tibia.
The drawer test is used in the initial clinical assessment of suspected rupture of the cruciate ligaments in the knee. The patient should be supine with the hips flexed to 45 degrees, the knees flexed to 90 degrees and the feet flat on table. The examiner positions himself by sitting on the examination table in front of the involved knee and grasping the tibia just below the joint line of the knee. The thumbs are placed along the joint line on either side of the patellar tendon. The tibia is then drawn forward anteriorly. An increased amount of anterior tibial translation compared with the opposite limb or lack of a firm end-point may indicate either a sprain of the anteromedial bundle or complete tear of the ACL. If the tibia pulls forward or backward more than normal, the test is considered positive. Excessive displacement of the tibia anteriorly suggests that the anterior cruciate ligament is injured, whereas excessive posterior displacement of the tibia may indicate injury of the posterior cruciate ligament.
Anterior cruciate ligament reconstruction is a surgical tissue graft replacement of the anterior cruciate ligament, located in the knee, to restore its function after an injury. The torn ligament can either be removed from the knee, or preserved before reconstruction through an arthroscopic procedure. ACL repair is also a surgical option. This involves repairing the ACL by re-attaching it, instead of performing a reconstruction. Theoretical advantages of repair include faster recovery and a lack of donor site morbidity, but randomised controlled trials and long-term data regarding re-rupture rates using contemporary surgical techniques are lacking.
The knee examination, in medicine and physiotherapy, is performed as part of a physical examination, or when a patient presents with knee pain or a history that suggests a pathology of the knee joint.
Cruciate ligaments are pairs of ligaments arranged like a letter X. They occur in several joints of the body, such as the knee joint, wrist joint and the atlanto-axial joint. In a fashion similar to the cords in a toy Jacob's ladder, the crossed ligaments stabilize the joint while allowing a very large range of motion.
An anterior cruciate ligament injury occurs when the anterior cruciate ligament (ACL) is either stretched, partially torn, or completely torn. The most common injury is a complete tear. Symptoms include pain, an audible cracking sound during injury, instability of the knee, and joint swelling. Swelling generally appears within a couple of hours. In approximately 50% of cases, other structures of the knee such as surrounding ligaments, cartilage, or meniscus are damaged.
The patellar tendon is the distal portion of the common tendon of the quadriceps femoris, which is continued from the patella to the tibial tuberosity. It is also sometimes called the patellar ligament as it forms a bone to bone connection when the patella is fully ossified.
The unhappy triad, also known as a blown knee among other names, is an injury to the anterior cruciate ligament, medial collateral ligament, and meniscus. Analysis during the 1990s indicated that this 'classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries. Some authors mistakenly believe that in this type of injury, "combined anterior cruciate and medial collateral ligament disruptions that were incurred during athletic endeavors" always present with concomitant medial meniscus injury. However, the 1990 analysis showed that lateral meniscus tears are more common than medial meniscus tears in conjunction with sprains of the ACL.
A tear of a meniscus is a rupturing of one or more of the fibrocartilage strips in the knee called menisci. When doctors and patients refer to "torn cartilage" in the knee, they actually may be referring to an injury to a meniscus at the top of one of the tibiae. Menisci can be torn during innocuous activities such as walking or squatting. They can also be torn by traumatic force encountered in sports or other forms of physical exertion. The traumatic action is most often a twisting movement at the knee while the leg is bent. In older adults, the meniscus can be damaged following prolonged 'wear and tear'. Especially acute injuries can lead to displaced tears which can cause mechanical symptoms such as clicking, catching, or locking during motion of the joint. The joint will be in pain when in use, but when there is no load, the pain goes away.
The pivot-shift test is one of the three major tests for assessing anterior cruciate injury or laxity, the other two being the anterior drawer and Lachman test. However, unlike the other two, it tests for instability, an important determinant as to how the knee will function. In fact, it is instability, not simply the injury to the anterior cruciate ligament itself, that places the menisci at future risk, and gives rise to the feeling that the "knee is not secure" or "may give out".
Posterolateral corner injuries of the knee are injuries to a complex area formed by the interaction of multiple structures. Injuries to the posterolateral corner can be debilitating to the person and require recognition and treatment to avoid long term consequences. Injuries to the PLC often occur in combination with other ligamentous injuries to the knee; most commonly the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL). As with any injury, an understanding of the anatomy and functional interactions of the posterolateral corner is important to diagnosing and treating the injury.
Medial knee injuries are the most common type of knee injury. The medial ligament complex of the knee consists of:
The function of the posterior cruciate ligament (PCL) is to prevent the femur from sliding off the anterior edge of the tibia and to prevent the tibia from displacing posterior to the femur. Common causes of PCL injuries are direct blows to the flexed knee, such as the knee hitting the dashboard in a car accident or falling hard on the knee, both instances displacing the tibia posterior to the femur.
Movement assessment is the practice of analysing movement performance during functional tasks to determine the kinematics of individual joints and their effect on the kinetic chain. Three-dimensional or two-dimensional analysis of the biomechanics involved in sporting tasks can assist in prevention of injury and enhancing athletic performance. Identification of abnormal movement mechanics provides physical therapists and Athletic trainers the ability to prescribe more accurate corrective exercise programs to prevent injury and improve exercise rehabilitation and progression following injury and assist in determining readiness to return to sport.
Simitri Stable in Stride is a three part modular surgical implant used during surgery performed on dogs to stabilize the stifle joint (knee) after rupture of the cranial cruciate ligament (CrCL) which is analogous to the anterior cruciate ligament (ACL) in humans.
A knee dislocation is an injury in which there is disruption of the knee joint between the tibia and the femur. Symptoms include pain and instability of the knee. Complications may include injury to an artery, most commonly the popliteal artery behind the knee, or compartment syndrome.
Artificial ligaments are devices used to replace damaged ligaments. Today, the most common use of artificial ligaments is in anterior cruciate ligament reconstruction. Although autotransplantation remains the most common method of ligament reconstruction, numerous materials and structures were developed to optimize the artificial ligament since its creation in the World War I era. Many modern artificial ligaments are made of synthetic polymers, such as polyethylene terephthalate. Various coatings have been added to improve the biocompatibility of the synthetic polymers. Early artificial ligaments developed in the 1980s were ineffective due to material deterioration. Currently, the Ligament Advanced Reinforcement System (LARS) artificial ligament has been utilized extensively in clinical applications. Tissue engineering is a growing area of research which aims to regenerate and restore ligament function.