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Ligament Reconstruction with Reference to the Anterior Cruciate Ligament of the Knee
Published in Verna Wright, Eric L. Radin, Mechanics of Human Joints, 2020
The ACL is the major constraint on the anterior movement of the tibia with respect to the femur. When it is ruptured this constraint is lost, and the anterior laxity of the joint is increased above the normal. In the clinical situation, the surgeon determines whether the ACL is ruptured or intact using three manual examinations. These are the Lachman test, the anterior draw test, and the pivot shift test. The first two are carried out with the patient lying supine. The examiner applies a forward force on each of the tibiae of both knees and compares the anterior movement of the tibia in the injured knee with that of the contralateral joint. In the Lachman test this examination is carried out at 20–30° of knee flexion and in the anterior draw test at 90°. Grades are assigned to the difference in laxities of the two joints. Thus grade 0 is assigned to the injured knee should its laxity “feel” identical to that of the contralateral joint, in which case it is deemed normal. Grade 1 is assigned if there is a slight difference and grade 2 if the difference is moderate, and so on. Clearly this method is not objective, regardless of the grading system adopted. The examiner cannot apply manually, on every occasion, the same forceon both joints for every patient. This precludes any objective comparison of different examiners’ gradings of the same group of patients and hence monitoring the results of any type of treatment, since there would be no basis for pooling results from different centers.
Kicking
Published in Paul Grimshaw, Michael Cole, Adrian Burden, Neil Fowler, Instant Notes in Sport and Exercise Biomechanics, 2019
Like most sporting activities, injuries in kicking-related sports are generally caused by deficits in a player’s fitness, training errors, environmental factors or mechanisms related to sport-specific equipment. Under controlled conditions, the forces that are transmitted across the knee joint while performing the kicking action are considerable; however, in competition, players are frequently required to perform the task while being challenged by an opponent. For example, in soccer, a tackle made by an opposing player has the potential to place the knee in a vulnerable position and can lead to the ligaments of this joint being easily injured. Under these situations, a rupture of the anterior cruciate ligament (ACL), with or without a concomitant tear of the medial collateral ligament (MCL), can be quite common. The ACL is one of the main supporting ligaments of the knee (Figure F5.3) and is responsible for supporting the knee in a movement known as anterior tibial translation, where the tibia is moved anteriorly (forward) with respect to the femur. In addition, the ligament also contributes to the stability of the joint during rotation of the tibia on the femur. The ligaments, together with the muscles, provide joint support and stability, and injury to these ligaments of the knee can seriously affect an athlete’s career.
Regenerative Engineering of the Human Using Convergence
Published in Yusuf Khan, Cato T. Laurencin, Regenerative Engineering, 2018
Cato T. Laurencin, Naveen Nagiah
We have examined the use of regenerative engineering technologies for the regeneration of the anterior cruciate ligament (ACL). The ACL is the major intraarticular ligament of the knee, which is responsible for angular motion stability and acts as an overall stabilizer of the knee. Injuries or tears to the ligament lead to excessive joint mobility and instability of the knee. Due to its intricate structure and functionality, regeneration of a completely healed and functioning ligament after injury is a major challenge mandating the need for surgical intervention. Figure 8.4 shows the fibrous hierarchical design of the ACL (7). The ACL consists predominantly of fiber bundles. Collagen fibrils form fiber bundles which are further grouped into fascicles with a specific orientation. The arrangement of the fascicles within the ligament vary from being thick and dense to small and loosely embedded. Similarly, the orientation of the fascicles is helical in the sides and parallel in the center. This results in varying load bearing capacity of the fascicles according to the varying knee motion (7). The scaffold designed for ACL regeneration must mimic the fibrous structure of the ACL at the microstructural level with a comparable load bearing capacity to the native ACL.
Associations of patient characteristics, rate of torque development, voluntary activation of quadriceps with quadriceps strength, and knee function before anterior cruciate ligament reconstruction
Published in Research in Sports Medicine, 2022
Jihong Qiu, Michael Tim-Yun Ong, Chi-Yin Choi, Xin He, Lawrence Chun-Man Lau, Sai-Chuen Fu, Daniel T.P. Fong, Patrick Shu-Hang Yung
This study was approved by the ethical review board of our institution (No.). Informed consent was obtained from all the patients, and all the procedures were conducted in accordance with the Declaration of Helsinki. The patients were consecutively screened and recruited at the Orthopaedics and Traumatology Clinic in ***** hospital from March 2021 to April 2022. Inclusion criteria of our study were 1) 18 to 45 years old patients with, 2) a primary, unilateral ACL rupture, 3) pre-injury Tegner Activity Scale of 6 or above, 4) had finished their routine preoperative rehabilitation in our institution and were waiting for an ACLR procedure in our institution. The ACL injury status was diagnosed by clinical examinations performed by specialized surgeons and magnetic resonance imaging (MRI). The concomitant meniscus injury was recorded if they needed extra repair or meniscectomy during the ACLR. Exclusion criteria included 1) previous traumatic lower limb injuries, 2) cardiovascular disorders, metabolic disorders, neurological disorders, 3) multi-ligamentous ruptures, and 4) concomitant bone fractures. All the patients in this study were prescribed two sessions of PreRehab per week for five weeks in our institution. Our PreRehab followed the protocol reported in another previous study (Eitzen et al., 2010). In addition, all the patients were not allowed to participate in any strenuous sports within 24 hours prior to the measurements in this study.
Knee wobbling during the single-leg-squat-and-hold test reflects dynamic knee instability in patients with anterior cruciate ligament injury
Published in Research in Sports Medicine, 2022
Xin He, Matthew Chun Sing Chow, Jihong Qiu, Sai-Chuen Fu, Kam-Ming Mok, Michael Tim-Yun Ong, Daniel T.P. Fong, Patrick Shu-Hang Yung
Injuries to the anterior cruciate ligament (ACL) are common in pivoting sports such as football, handball, basketball and rugby (Beynnon et al., 2005). Noncontact ACL injuries are typically associated with sports which involve movements such as cutting, landing, and deceleration. The injury and resulting loss of knee stability leads to a significantly lowered activity level in many patients (Ardern et al., 2011). Patients with ACL injuries often experience symptoms such as knee instability and feelings of “giving way” during activities (Lewek et al., 2003). Biomechanically, dynamic knee stability is considered as the ability to control the relative tibiofemoral displacements during loading. Dynamic knee stability is determined by both passive restraints (bone, meniscus, ligament, capsules), and active restraints (muscles). Loss of these restraints including laxity due to ACL rupture, muscle strength deficits and poor neuromuscular control contribute to dynamic knee instability (Tagesson, 2008).
Greater explosive quadriceps strength is associated with greater knee flexion at initial contact during landing in females
Published in Sports Biomechanics, 2021
Marc F. Norcross, Roy Almog, Yu-Lun Huang, Eunwook Chang, Kimberly S. Hannigan, Samuel T. Johnson
Anterior cruciate ligament (ACL) injuries of the knee are common among individuals engaging in sports requiring rapid deceleration and change of direction with approximately 70% of these injuries occurring as a result of a non-contact mechanism of injury (Boden et al., 2010; Kobayashi et al., 2010). Though ACL injuries are problematic for both sexes, females have a significantly higher risk of ACL injury than males when participating in similar sports (Agel et al., 2005; Boden et al., 2010). ACL injuries are especially devastating for athletes because many of those injured will not return to pre-injury levels of competition (Ardern et al., 2011), and those that do are at an increased risk of sustaining a second ACL injury event (Paterno et al., 2014). Moreover, despite advances in surgical reconstructive techniques, it is overwhelmingly likely that ACL-injured athletes will experience numerous long-term consequences including early-onset knee osteoarthritis, pain, and functional limitation (Lohmander et al., 2004). Therefore, identifying modifiable risk factors associated with ACL injury remains an important step for informing primary and secondary ACL injury prevention initiatives.