Anterior Cruciate Ligament: A strong ligament of the knee that originates from the posteromedial portion of the lateral condyle of the femur, passes anteriorly and inferiorly between the condyles, and attaches to the depression in front of the intercondylar eminence of the tibia.Anterior Cruciate Ligament Reconstruction: Rebuilding of the ANTERIOR CRUCIATE LIGAMENT to restore functional stability of the knee. AUTOGRAFTING or ALLOGRAFTING of tissues is often used.Knee Injuries: Injuries to the knee or the knee joint.Posterior Cruciate Ligament: A strong ligament of the knee that originates from the anterolateral surface of the medial condyle of the femur, passes posteriorly and inferiorly between the condyles, and attaches to the posterior intercondylar area of the tibia.Ligaments, Articular: Fibrous cords of CONNECTIVE TISSUE that attach bones to each other and hold together the many types of joints in the body. Articular ligaments are strong, elastic, and allow movement in only specific directions, depending on the individual joint.Ligaments: Shiny, flexible bands of fibrous tissue connecting together articular extremities of bones. They are pliant, tough, and inextensile.Rupture: Forcible or traumatic tear or break of an organ or other soft part of the body.Knee Joint: A synovial hinge connection formed between the bones of the FEMUR; TIBIA; and PATELLA.Joint Instability: Lack of stability of a joint or joint prosthesis. Factors involved are intra-articular disease and integrity of extra-articular structures such as joint capsule, ligaments, and muscles.Reconstructive Surgical Procedures: Procedures used to reconstruct, restore, or improve defective, damaged, or missing structures.Arthroscopy: Endoscopic examination, therapy and surgery of the joint.Bone-Patellar Tendon-Bone Grafting: Fixation of the ANTERIOR CRUCIATE LIGAMENT, during surgical reconstruction, by the use of a bone-patellar tendon graft.Tendons: Fibrous bands or cords of CONNECTIVE TISSUE at the ends of SKELETAL MUSCLE FIBERS that serve to attach the MUSCLES to bones and other structures.Patellar Ligament: A band of fibrous tissue that attaches the apex of the PATELLA to the lower part of the tubercle of the TIBIA. The ligament is actually the caudal continuation of the common tendon of the QUADRICEPS FEMORIS. The patella is embedded in that tendon. As such, the patellar ligament can be thought of as connecting the quadriceps femoris tendon to the tibia, and therefore it is sometimes called the patellar tendon.Menisci, Tibial: The interarticular fibrocartilages of the superior surface of the tibia.Biomechanical Phenomena: The properties, processes, and behavior of biological systems under the action of mechanical forces.Athletic Injuries: Injuries incurred during participation in competitive or non-competitive sports.Tibia: The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the FIBULA laterally, the TALUS distally, and the FEMUR proximally.Orthopedic Procedures: Procedures used to treat and correct deformities, diseases, and injuries to the MUSCULOSKELETAL SYSTEM, its articulations, and associated structures.Range of Motion, Articular: The distance and direction to which a bone joint can be extended. Range of motion is a function of the condition of the joints, muscles, and connective tissues involved. Joint flexibility can be improved through appropriate MUSCLE STRETCHING EXERCISES.Ganglion Cysts: Nodular tumor-like lesions or mucoid flesh, arising from tendon sheaths, LIGAMENTS, or JOINT CAPSULE, especially of the hands, wrists, or feet. They are not true cysts as they lack epithelial wall. They are distinguished from SYNOVIAL CYSTS by the lack of communication with a joint cavity or the SYNOVIAL MEMBRANE.Stifle: In horses, cattle, and other quadrupeds, the joint between the femur and the tibia, corresponding to the human knee.Tendon Transfer: Surgical procedure by which a tendon is incised at its insertion and placed at an anatomical site distant from the original insertion. The tendon remains attached at the point of origin and takes over the function of a muscle inactivated by trauma or disease.Femur: The longest and largest bone of the skeleton, it is situated between the hip and the knee.Medial Collateral Ligament, Knee: The ligament that travels from the medial epicondyle of the FEMUR to the medial margin and medial surface of the TIBIA. The medial meniscus is attached to its deep surface.Knee: A region of the lower extremity immediately surrounding and including the KNEE JOINT.Patella: The flat, triangular bone situated at the anterior part of the KNEE.Basketball: A competitive team sport played on a rectangular court having a raised basket at each end.Soccer: A game in which a round inflated ball is advanced by kicking or propelling with any part of the body except the hands or arms. The object of the game is to place the ball in opposite goals.Periodontal Ligament: The fibrous CONNECTIVE TISSUE surrounding the TOOTH ROOT, separating it from and attaching it to the alveolar bone (ALVEOLAR PROCESS).Cadaver: A dead body, usually a human body.Weight-Bearing: The physical state of supporting an applied load. This often refers to the weight-bearing bones or joints that support the body's weight, especially those in the spine, hip, knee, and foot.Longitudinal Ligaments: Two extensive fibrous bands running the length of the vertebral column. The anterior longitudinal ligament (ligamentum longitudinale anterius; lacertus medius) interconnects the anterior surfaces of the vertebral bodies; the posterior longitudinal ligament (ligamentum longitudinale posterius) interconnects the posterior surfaces. The commonest clinical consideration is OSSIFICATION OF POSTERIOR LONGITUDINAL LIGAMENT. (From Stedman, 25th ed)Cartilage, Articular: A protective layer of firm, flexible cartilage over the articulating ends of bones. It provides a smooth surface for joint movement, protecting the ends of long bones from wear at points of contact.Quadriceps Muscle: The quadriceps femoris. A collective name of the four-headed skeletal muscle of the thigh, comprised of the rectus femoris, vastus intermedius, vastus lateralis, and vastus medialis.Osteoarthritis: A progressive, degenerative joint disease, the most common form of arthritis, especially in older persons. The disease is thought to result not from the aging process but from biochemical changes and biomechanical stresses affecting articular cartilage. In the foreign literature it is often called osteoarthrosis deformans.Osteoarthritis, Knee: Noninflammatory degenerative disease of the knee joint consisting of three large categories: conditions that block normal synchronous movement, conditions that produce abnormal pathways of motion, and conditions that cause stress concentration resulting in changes to articular cartilage. (Crenshaw, Campbell's Operative Orthopaedics, 8th ed, p2019)Arthrometry, Articular: Measurements of joint flexibility (RANGE OF MOTION, ARTICULAR), usually by employing an angle-measuring device (arthrometer). Arthrometry is used to measure ligamentous laxity and stability. It is often used to evaluate the outcome of ANTERIOR CRUCIATE LIGAMENT replacement surgery.Thigh: The portion of the leg in humans and other animals found between the HIP and KNEE.Recovery of Function: A partial or complete return to the normal or proper physiologic activity of an organ or part following disease or trauma.Athletes: Individuals who have developed skills, physical stamina and strength or participants in SPORTS or other physical activities.Hemarthrosis: Bleeding into the joints. It may arise from trauma or spontaneously in patients with hemophilia.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Rotation: Motion of an object in which either one or more points on a line are fixed. It is also the motion of a particle about a fixed point. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Muscle Strength: The amount of force generated by MUSCLE CONTRACTION. Muscle strength can be measured during isometric, isotonic, or isokinetic contraction, either manually or using a device such as a MUSCLE STRENGTH DYNAMOMETER.Joint DiseasesStress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Transplantation, Autologous: Transplantation of an individual's own tissue from one site to another site.Torque: The rotational force about an axis that is equal to the product of a force times the distance from the axis where the force is applied.Braces: Orthopedic appliances used to support, align, or hold parts of the body in correct position. (Dorland, 28th ed)Absorbable Implants: Implants constructed of materials designed to be absorbed by the body without producing an immune response. They are usually composed of plastics and are frequently used in orthopedics and orthodontics.Arthralgia: Pain in the joint.Knee Dislocation: Slippage of the FEMUR off the TIBIA.Prostheses and Implants: Artificial substitutes for body parts, and materials inserted into tissue for functional, cosmetic, or therapeutic purposes. Prostheses can be functional, as in the case of artificial arms and legs, or cosmetic, as in the case of an artificial eye. Implants, all surgically inserted or grafted into the body, tend to be used therapeutically. IMPLANTS, EXPERIMENTAL is available for those used experimentally.Tensile Strength: The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)Bone Transplantation: The grafting of bone from a donor site to a recipient site.Ossification of Posterior Longitudinal Ligament: A calcification of the posterior longitudinal ligament of the spinal column, usually at the level of the cervical spine. It is often associated with anterior ankylosing hyperostosis.Gait: Manner or style of walking.Broad Ligament: A broad fold of peritoneum that extends from the side of the uterus to the wall of the pelvis.Injury Severity Score: An anatomic severity scale based on the Abbreviated Injury Scale (AIS) and developed specifically to score multiple traumatic injuries. It has been used as a predictor of mortality.Cartilage Diseases: Pathological processes involving the chondral tissue (CARTILAGE).Proprioception: Sensory functions that transduce stimuli received by proprioceptive receptors in joints, tendons, muscles, and the INNER EAR into neural impulses to be transmitted to the CENTRAL NERVOUS SYSTEM. Proprioception provides sense of stationary positions and movements of one's body parts, and is important in maintaining KINESTHESIA and POSTURAL BALANCE.Injections, Intra-Articular: Methods of delivering drugs into a joint space.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Platelet-Rich Plasma: A preparation consisting of PLATELETS concentrated in a limited volume of PLASMA. This is used in various surgical tissue regeneration procedures where the GROWTH FACTORS in the platelets enhance wound healing and regeneration.Athletic Performance: Carrying out of specific physical routines or procedures by one who is trained or skilled in physical activity. Performance is influenced by a combination of physiological, psychological, and socio-cultural factors.Wound Healing: Restoration of integrity to traumatized tissue.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Allografts: Tissues, cells, or organs transplanted between genetically different individuals of the same species.Synovial Fluid: The clear, viscous fluid secreted by the SYNOVIAL MEMBRANE. It contains mucin, albumin, fat, and mineral salts and serves to lubricate joints.Transplants: Organs, tissues, or cells taken from the body for grafting into another area of the same body or into another individual.Femoral Nerve: A nerve originating in the lumbar spinal cord (usually L2 to L4) and traveling through the lumbar plexus to provide motor innervation to extensors of the thigh and sensory innervation to parts of the thigh, lower leg, and foot, and to the hip and knee joints.Joint Loose Bodies: Fibrous, bony, cartilaginous and osteocartilaginous fragments in a synovial joint. Major causes are osteochondritis dissecans, synovial chondromatosis, osteophytes, fractured articular surfaces and damaged menisci.Movement: The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.Electrosurgery: Division of tissues by a high-frequency current applied locally with a metal instrument or needle. (Stedman, 25th ed)Bone Screws: Specialized devices used in ORTHOPEDIC SURGERY to repair bone fractures.Casts, Surgical: Dressings made of fiberglass, plastic, or bandage impregnated with plaster of paris used for immobilization of various parts of the body in cases of fractures, dislocations, and infected wounds. In comparison with plaster casts, casts made of fiberglass or plastic are lightweight, radiolucent, able to withstand moisture, and less rigid.Fluoroscopy: Production of an image when x-rays strike a fluorescent screen.Postoperative Period: The period following a surgical operation.Sprains and Strains: A collective term for muscle and ligament injuries without dislocation or fracture. A sprain is a joint injury in which some of the fibers of a supporting ligament are ruptured but the continuity of the ligament remains intact. A strain is an overstretching or overexertion of some part of the musculature.Knee Prosthesis: Replacement for a knee joint.Arthroplasty: Surgical reconstruction of a joint to relieve pain or restore motion.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Round Ligament: A fibromuscular band that attaches to the UTERUS and then passes along the BROAD LIGAMENT, out through the INGUINAL RING, and into the labium majus.Physical Examination: Systematic and thorough inspection of the patient for physical signs of disease or abnormality.Pain Measurement: Scales, questionnaires, tests, and other methods used to assess pain severity and duration in patients or experimental animals to aid in diagnosis, therapy, and physiological studies.Robotics: The application of electronic, computerized control systems to mechanical devices designed to perform human functions. Formerly restricted to industry, but nowadays applied to artificial organs controlled by bionic (bioelectronic) devices, like automated insulin pumps and other prostheses.Tendon Injuries: Injuries to the fibrous cords of connective tissue which attach muscles to bones or other structures.Contusions: Injuries resulting in hemorrhage, usually manifested in the skin.Arthroscopes: Endoscopes for visualizing the interior of a joint.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Polyethylene Terephthalates: Polyester polymers formed from terephthalic acid or its esters and ethylene glycol. They can be formed into tapes, films or pulled into fibers that are pressed into meshes or woven into fabrics.Postoperative Care: The period of care beginning when the patient is removed from surgery and aimed at meeting the patient's psychological and physical needs directly after surgery. (From Dictionary of Health Services Management, 2d ed)Hypesthesia: Absent or reduced sensitivity to cutaneous stimulation.Arthroplasty, Replacement, Knee: Replacement of the knee joint.Tenodesis: Fixation of the end of a tendon to a bone, often by suturing.Volleyball: A team sport in which two teams hit an inflated ball back and forth over a high net using their hands.Reoperation: A repeat operation for the same condition in the same patient due to disease progression or recurrence, or as followup to failed previous surgery.Lateral Ligament, Ankle: LATERAL LIGAMENTS of the ANKLE JOINT. It includes inferior tibiofibular ligaments.Sports: Activities or games, usually involving physical effort or skill. Reasons for engagement in sports include pleasure, competition, and/or financial reward.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Debridement: The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. (Dorland, 27th ed)Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Muscle, Skeletal: A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.Second-Look Surgery: A followup operation to examine the outcome of the previous surgery and other treatments, such as chemotherapy or radiation therapy.Football: A competitive team sport played on a rectangular field. This is the American or Canadian version of the game and also includes the form known as rugby. It does not include non-North American football (= SOCCER).Epiphyses: The head of a long bone that is separated from the shaft by the epiphyseal plate until bone growth stops. At that time, the plate disappears and the head and shaft are united.Collagen: A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).Time Factors: Elements of limited time intervals, contributing to particular results or situations.Physical Conditioning, Human: Diet modification and physical exercise to improve the ability to carry out daily tasks and perform physical activities.Osteophyte: Bony outgrowth usually found around joints and often seen in conditions such as ARTHRITIS.Hindlimb: Either of two extremities of four-footed non-primate land animals. It usually consists of a FEMUR; TIBIA; and FIBULA; tarsals; METATARSALS; and TOES. (From Storer et al., General Zoology, 6th ed, p73)Spiral Ligament of Cochlea: A spiral thickening of the fibrous lining of the cochlear wall. Spiral ligament secures the membranous COCHLEAR DUCT to the bony spiral canal of the COCHLEA. Its spiral ligament fibrocytes function in conjunction with the STRIA VASCULARIS to mediate cochlear ion homeostasis.Suture Techniques: Techniques for securing together the edges of a wound, with loops of thread or similar materials (SUTURES).Synovitis: Inflammation of a synovial membrane. It is usually painful, particularly on motion, and is characterized by a fluctuating swelling due to effusion within a synovial sac. (Dorland, 27th ed)Musculoskeletal Physiological Phenomena: Processes and properties of the MUSCULOSKELETAL SYSTEM.Polydioxanone: An absorbable suture material used also as ligating clips, as pins for internal fixation of broken bones, and as ligament reinforcement for surgically managed ligament injuries. Its promising characteristics are elasticity, complete biodegradability, and lack of side effects such as infections.Physical Therapy Modalities: Therapeutic modalities frequently used in PHYSICAL THERAPY SPECIALTY by PHYSICAL THERAPISTS or physiotherapists to promote, maintain, or restore the physical and physiological well-being of an individual.