SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Lateral meniscus

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A controversial discussion is held on using stabilizing knee braces after anterior cruciate ligament (ACL) surgery. The current study investigated the influence of a stabilizing knee brace on results after ACL reconstruction using patellar tendon autografts.

Concepts: Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Anterior cruciate ligament reconstruction, Cruciate ligament, Hamstring, Lateral meniscus

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In 1879, the French surgeon Segond described the existence of a ‘pearly, resistant, fibrous band’ at the anterolateral aspect of the human knee, attached to the eponymous Segond fracture. To date, the enigma surrounding this anatomical structure is reflected in confusing names such as ‘(mid-third) lateral capsular ligament’, ‘capsulo-osseous layer of the iliotibial band’ or ‘anterolateral ligament’, and no clear anatomical description has yet been provided. In this study, the presence and characteristics of Segond’s ‘pearly band’, hereafter termed anterolateral ligament (ALL), was investigated in 41 unpaired, human cadaveric knees. The femoral and tibial attachment of the ALL, its course and its relationship with nearby anatomical structures were studied both qualitatively and quantitatively. In all but one of 41 cadaveric knees (97%), the ALL was found as a well-defined ligamentous structure, clearly distinguishable from the anterolateral joint capsule. The origin of the ALL was situated at the prominence of the lateral femoral epicondyle, slightly anterior to the origin of the lateral collateral ligament, although connecting fibers between the two structures were observed. The ALL showed an oblique course to the anterolateral aspect of the proximal tibia, with firm attachments to the lateral meniscus, thus enveloping the inferior lateral geniculate artery and vein. Its insertion on the anterolateral tibia was grossly located midway between Gerdy’s tubercle and the tip of the fibular head, definitely separate from the iliotibial band (ITB). The ALL was found to be a distinct ligamentous structure at the anterolateral aspect of the human knee with consistent origin and insertion site features. By providing a detailed anatomical characterization of the ALL, this study clarifies the long-standing enigma surrounding the existence of a ligamentous structure connecting the femur with the anterolateral tibia. Given its structure and anatomic location, the ALL is hypothesized to control internal tibial rotation and thus to affect the pivot shift phenomenon, although further studies are needed to investigate its biomechanical function.

Concepts: Knee, Anterior cruciate ligament, Joint, Anatomy, Human anatomy, Anatomical terms of location, Tibia, Lateral meniscus

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Rehabilitation after anterior cruciate ligament (ACL) reconstruction should consider control of postoperative pain and swelling, protection of the healing graft, restoration of full range of motion symmetric to the contralateral knee, strengthening of the muscles that stabilize the knee, hip, and trunk, enhancing neuromuscular control, and a gradual progression to functional activities that are required for return to sports. The effects of concomitant injuries and surgical procedures must also be considered in planning an individualized rehabilitation program. This article provides an overview, discusses our experience, and makes recommendations for rehabilitation after anatomic ACL reconstruction rehabilitation.

Concepts: Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Anterior cruciate ligament reconstruction, Cruciate ligament, Hamstring, Lateral meniscus

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BACKGROUND:Debate exists on the proper relation of the anterior cruciate ligament (ACL) footprint with the intercondylar notch in anatomic ACL reconstructions. Patient-specific graft placement based on the inclination of the intercondylar roof has been proposed. The relationship between the intercondylar roof and native ACL footprint on the tibia has not previously been quantified. HYPOTHESIS:No statistical relationship exists between the intercondylar roof angle and the location of the native footprint of the ACL on the tibia. STUDY DESIGN:Case series; Level of evidence, 4. METHODS:Knees from 138 patients with both lateral radiographs and MRI, without a history of ligamentous injury or fracture, were reviewed to measure the intercondylar roof angle of the femur. Roof angles were measured on lateral radiographs. The MRI data of the same knees were analyzed to measure the position of the central tibial footprint of the ACL (cACL). The roof angle and tibial footprint were evaluated to determine if statistical relationships existed. RESULTS:Patients had a mean ± SD age of 40 ± 16 years. Average roof angle was 34.7° ± 5.2° (range, 23°-48°; 95% CI, 33.9°-35.5°), and it differed by sex but not by side (right/left). The cACL was 44.1% ± 3.4% (range, 36.1%-51.9%; 95% CI, 43.2%-45.0%) of the anteroposterior length of the tibia. There was only a weak correlation between the intercondylar roof angle and the cACL (R = 0.106). No significant differences arose between subpopulations of sex or side. CONCLUSION:The tibial footprint of the ACL is located in a position on the tibia that is consistent and does not vary according to intercondylar roof angle. The cACL is consistently located between 43.2% and 45.0% of the anteroposterior length of the tibia. Intercondylar roof-based guidance may not predictably place a tibial tunnel in the native ACL footprint. Use of a generic ACL footprint to place a tibial tunnel during ACL reconstruction may be reliable in up to 95% of patients.

Concepts: Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Anterior cruciate ligament reconstruction, Cruciate ligament, Hamstring, Lateral meniscus

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There is an increased risk of developing knee osteoarthritis (OA) following anterior cruciate ligament (ACL) injury. Biomarkers may provide diagnostic, prognostic, or burden of disease indicators of OA before radiographic changes become apparent. Unfortunately, there has been no systematic review to clarify which biomarkers may be most informative following injury. Therefore, this review critically investigated existing studies of OA-related biomarkers in ACL-deficient (ACL-D) and reconstructed (ACL-R) patients to summarize the current evidence and identify knowledge gaps.

Concepts: Osteoarthritis, Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Anterior cruciate ligament reconstruction, Cruciate ligament, Lateral meniscus

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An avulsion of the posterior root attachment of the lateral meniscus or a radial tear close to the root attachment can lead to degenerative knee arthritis. Although the biomechanical effects of comparable injuries involving the medial meniscus have been studied, we are aware of no such study involving the lateral meniscus. We hypothesized that in situ pull-out suture repair of lateral meniscus root avulsions and of complete radial tears 3 and 6 mm from the root attachment would increase the contact area and decrease mean and peak tibiofemoral contact pressures, at all knee flexion angles, relative to the corresponding avulsion or tear condition.

Concepts: Knee, Hertzian contact stress, Cornea, Tears, Lateral meniscus, Medial meniscus, Meniscal cartilage replacement therapy, Contact mechanics

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Acute athletic knee injuries are often caused by a combination of valgus impact with external rotation of the tibia leading to a triad of injuries involving medial collateral and anterior cruciate ligament disruption with associated meniscal damage. This injury pattern has been greatly discussed in the literature with conflicts of opinion and evidence as to whether medial or lateral meniscal pathology has a higher incidence. This case report introduces a 17-year-old male athlete with this unhappy triad It will evaluate the clinical assessment which suggested a medial meniscal lesion follow the patient through arthroscopy revealing a lateral meniscal tear in addition to complete anterior cruciate ligament rupture and grade 2 medial collateral ligament tear. It will go on to look at the evidence base for the relative incidence of lateral and medial meniscal injuries and will evaluate the role of MRI in assessing acute athletic knee injuries.

Concepts: Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Cruciate ligament, Arthroscopy, Lateral meniscus, Medial collateral ligament

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To explore patients' knowledge and beliefs about osteoarthritis (OA) and OA risk following anterior cruciate ligament (ACL) injury, to explore the extent to which information about these risks is provided by health professionals, and to examine associations among participant characteristics, knowledge, and risk beliefs and health professional advice.

Concepts: Health care provider, Patient, Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament injury, Cruciate ligament, Lateral meniscus

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An anterior cruciate ligament (ACL) rupture has major consequences at midterm follow-up, with an increasing chance of developing an old knee in a young patient. The long-term (≥20 years) effects of the operative and nonoperative treatment of ACL ruptures are still unclear.

Concepts: Knee, Anterior cruciate ligament, Ligament, Anterior cruciate ligament reconstruction, Cruciate ligament, Ligaments, Lateral meniscus, Rupture of membranes