Patellar Ligament
Ligaments
Ligaments, Articular
Tendons
Periodontal Ligament
Longitudinal Ligaments
Posterior Cruciate Ligament
Anterior Cruciate Ligament Reconstruction
Ossification of Posterior Longitudinal Ligament
Broad Ligament
Round Ligament
Lateral Ligament, Ankle
Joint Instability
Spiral Ligament of Cochlea
Classification of lesions of the medial patello-femoral ligament in patellar dislocation. (1/199)
The remnants of the medial patello-femoral ligament (MPFL) of 67 knees, 18 with acute patellar dislocation and 49 with chronic patellar dislocation, were studied. The MPFL injuries of the acute cases were categorised into 2 groups: an avulsion tear type and a substantial tear type. The chronic cases were put into 3 groups: those with loose femoral attachment (9 knees), those with scar tissue formation or abnormal scar branch formation (29 knees), and those with no evidence or continuity of the ligament (absent type) (11 knees). It is concluded that incompetence of the medial patello-femoral ligament is a major factor in the occurrence of recurrent patellar dislocation and/or an unstable patella following an acute patellar dislocation. (+info)The effect of the patellar tendon-bearing cast on loading. (2/199)
We assessed the unloading effect of the patellar tendon-bearing (PTB) cast in five healthy volunteers using a new system for analysis of dynamic plantar pressure. We devised a method to improve the unloading effect of the PTB cast, and tested this using the same system. Our findings showed that the conventional PTB cast only achieved unloading of 30% of the body-weight and that the part of the cast on the leg had a more important role in the unloading than that which was in contact with the patellar tendon. When the depth of the free space under the foot inside the PTB cast was 1, 2 and 3 cm, the unloading effect was 60%, 80% and 98%, respectively. The unloading effect of the conventional PTB cast was disappointing at only 30% of body-weight. It was improved by producing a space between the sole of the foot and the cast, and was adjustable by altering the depth of this space. (+info)Endoscopic reconstruction of the anterior cruciate ligament with an ipsilateral patellar tendon autograft. A prospective longitudinal five-year study. (3/199)
A total of 90 patients with an isolated rupture of the anterior cruciate ligament (ACL) had a reconstruction using the ipsilateral patellar tendon secured with round-headed cannulated interference screws. Annual review for five years showed three failures of the graft (two traumatic and one atraumatic); none occurred after two years. Ten patients sustained a rupture of the contralateral ACL. At five years, 69% of those with surviving grafts continued to participate in moderate to strenuous activity. Using the International Knee Documentation Committee assessment, 90% reported their knee as being normal or nearly normal and had a median Lysholm knee score of 96 (64 to 100). Most patients (98%) had a pivot shift of grade 0 with the remaining 2% being grade 1; 90% of the group had a Lachman test of grade 0. The incidence of subsequent meniscectomy was similar in the reconstructed joint to that in the contralateral knee. Radiological examination was normal in 63 of 65 patients. Our study supports the view that reconstruction of the ACL is a reliable technique allowing full rehabilitation of the previously injured knee. In the presence of normal menisci there is a low incidence of osteoarthritic change despite continued participation in sporting activity. (+info)The influence of avascularity on the mechanical properties of human bone-patellar-tendon-bone grafts. (4/199)
Our aim was to analyse the effect of avascularity on the morphology and mechanical properties (tensile strength, viscoelasticity) of human bone-patellar-tendon-bone (BPTB) grafts in vitro. These were harvested at postmortem and stored submerged in denaturated human plasma at a constant pH, pO2, pCO2, temperature and humidity under sterile conditions. Mechanical testing was performed two and four weeks after removal of the graft. The mean ultimate strength was 1085.7 +/- 255.8 N (control), 1009.0 +/- 314.9 N (two weeks cultured) and 1076.8 +/- 414.8 N (four weeks cultured). There was no significant difference in linear stiffness or deformation to failure between the groups. There was a difference in viscoelasticity between the control group and the avascular grafts and the latter had significant lower peak load-to-load ratios after 15 minutes compared with the control group. After two and four weeks the graft contained viable fibroblasts. There was regular cellularity in the superficial layers and decreased cellularity in the midportion. The structure of the collagen including the crimp pattern appeared to be normal in polarised light. We conclude that avascularity does not significantly affect ultimate failure loads or stiffness of BPTB grafts. Slight changes in viscoelasticity were induced, but the significance of the increased stress relaxation is not fully understood. (+info)Increased cell proliferation and associated expression of PDGFRbeta causing hypercellularity in patellar tendinosis. (5/199)
OBJECTIVE: This study assessed cellularity in patellar tendinosis with respect to cell proliferation and the expression of platelet-derived growth factor receptor beta (PDGFRbeta). METHODS: Surgical samples were taken from 11 patients fulfilling criteria of patellar tendinosis and from 12 matched controls. Standard immunohistochemistry methods were used to detect expression of PDGFRbeta and proliferation cell nuclear antigen (PCNA). Results were analysed by computer-assisted microscopy. Tendon cells were isolated from nine tendinosis and eight control tissues for cell culture. RESULTS: Increased cellularity (P<0.001) was observed in tendinosis tissues compared with controls, and also a higher proliferative index (P:<0.001). Increased expression of PDGFRbeta was demonstrated (P<0.001). Cultured tendinosis cells showed a higher proliferation rate than controls (P<0.001). This was maintained when the cells were cultured under various conditions of serum supplementation (P<0.01). Tendinosis cells also showed a higher proliferation rate (P<0.01) in medium containing 10 ng/ml PDGF. CONCLUSION: Hypercellularity in patellar tendinosis is caused by increased cell proliferation and is associated with increased expression of PDGFRbeta. (+info)A comparative study of the healing of tendon autograft and tendon-bone autograft using patellar tendon in rabbits. (6/199)
In order to compare the healing of tendon to bone and the healing of bone to bone in a rabbit model, the lateral 4 mm of patellar tendons were detached from their insertion into the tibia either subperiosteally (group I) or with a bone block (group II) and implanted into drill holes in the proximal articular surface of the tibia. The histological and biomechanical features of the graft incorporation were observed at 2, 4, 8 and 12 weeks. Histological patterns similar to normal tendon-bone attachment were seen at the tendon-bone interface in group I by 12 weeks, while direct bony union was seen in group II by 8 weeks. The maximum tensile load and stiffness were significantly greater in group II at 4 and 8 weeks while the difference between the two groups was not significant at 2 and 12 weeks. These findings show that more rapid incorporation of the graft occurs in group II although no significant difference in biomechanical parameters was noted once healing was complete. (+info)The effect of increased stress on the patellar tendon. (7/199)
We performed a biomechanical and histological study to clarify the effect of stress enhancement on the in situ frozen-thawed patellar tendon of the rabbit as a tendon autograft model. We used 48 Japanese White rabbits divided into three groups. In group 1, the patellar tendon underwent in situ freeze-thaw treatment with liquid nitrogen to kill intrinsic fibroblasts. In group 2, after similar treatment, the medial and lateral portions were resected so that the cross-sectional area was reduced by a third. In group 3, after treatment, the cross-sectional area was reduced by a half. In groups 2 and 3, the stress in the tendon was calculated theoretically to be 150% and 200% of the physiological stress during locomotion. Eight rabbits in each group were killed at three and six weeks, respectively. At three weeks, the mean values for the tensile strength of groups 2 and 3 were 113.7% and 75.7% of that of group 1, and at six weeks 101.2% and 57.4%, respectively. The tensile strength in group 3 was significantly lower than that in groups 1 and 2. The histological findings in group 2 were similar to those in group 1, although an acellular area appeared to be wider in the core portion compared with group 1 at each period. In group 3, the collagen bundles of the tendon were less organised than those of groups 1 and 2. Our findings showed that stress enhancement affects the remodelling of the frozen-thawed patellar tendon and that excessively high stress reduces the mechanical properties of the tendon. This indicates that high stress on the patellar tendon autograft should be avoided during ligament reconstruction. (+info)Muscle performance after anterior cruciate ligament reconstruction. (8/199)
We measured muscle strength in 36 patients after anterior cruciate ligament (ACL) reconstruction with autogenous bone-patellar tendon-bone graft. Quadriceps and hamstring isokinetic strength was assessed during concentric contraction at 60 and 180 degrees /s and was measured at 1, 6, 12 and 24 months postoperatively. At 24 months quadriceps muscle strength had recovered to approximately 90% of the level of the uninvolved side, both at 60 and 180 degrees /s. In contrast, hamstring muscle strength had already recovered to approximately 90% at 6 months. Age, gender, activity level, and anterior tibial laxity did not affect the muscle performance. However, the recovery of muscle strength was delayed in patients with anterior knee pain. (+info)The patellar ligament, also known as the patellar tendon, is a strong band of tissue that connects the bottom part of the kneecap (patella) to the top part of the shinbone (tibia). This ligament plays a crucial role in enabling the extension and straightening of the leg during activities such as walking, running, and jumping. Injuries to the patellar ligament, such as tendonitis or tears, can cause pain and difficulty with mobility.
Ligaments are bands of dense, fibrous connective tissue that surround joints and provide support, stability, and limits the range of motion. They are made up primarily of collagen fibers arranged in a parallel pattern to withstand tension and stress. Ligaments attach bone to bone, and their function is to prevent excessive movement that could cause injury or dislocation.
There are two main types of ligaments: extracapsular and intracapsular. Extracapsular ligaments are located outside the joint capsule and provide stability to the joint by limiting its range of motion. Intracapsular ligaments, on the other hand, are found inside the joint capsule and help maintain the alignment of the joint surfaces.
Examples of common ligaments in the body include the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) in the knee, the medial collateral ligament (MCL) and lateral collateral ligament (LCL) in the elbow, and the coracoacromial ligament in the shoulder.
Injuries to ligaments can occur due to sudden trauma or overuse, leading to sprains, strains, or tears. These injuries can cause pain, swelling, bruising, and limited mobility, and may require medical treatment such as immobilization, physical therapy, or surgery.
Articular ligaments, also known as fibrous ligaments, are bands of dense, fibrous connective tissue that connect and stabilize bones to each other at joints. They help to limit the range of motion of a joint and provide support, preventing excessive movement that could cause injury. Articular ligaments are composed mainly of collagen fibers arranged in a parallel pattern, making them strong and flexible. They have limited blood supply and few nerve endings, which makes them less prone to injury but also slower to heal if damaged. Examples of articular ligaments include the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) in the knee joint, and the medial collateral ligament (MCL) and lateral collateral ligament (LCL) in the elbow joint.
The patella, also known as the kneecap, is a sesamoid bone located at the front of the knee joint. It is embedded in the tendon of the quadriceps muscle and serves to protect the knee joint and increase the leverage of the extensor mechanism, allowing for greater extension force of the lower leg. The patella moves within a groove on the femur called the trochlea during flexion and extension of the knee.
A tendon is the strong, flexible band of tissue that connects muscle to bone. It helps transfer the force produced by the muscle to allow various movements of our body parts. Tendons are made up of collagen fibers arranged in parallel bundles and have a poor blood supply, making them prone to injuries and slow to heal. Examples include the Achilles tendon, which connects the calf muscle to the heel bone, and the patellar tendon, which connects the kneecap to the shinbone.
The knee joint, also known as the tibiofemoral joint, is the largest and one of the most complex joints in the human body. It is a synovial joint that connects the thighbone (femur) to the shinbone (tibia). The patella (kneecap), which is a sesamoid bone, is located in front of the knee joint and helps in the extension of the leg.
The knee joint is made up of three articulations: the femorotibial joint between the femur and tibia, the femoropatellar joint between the femur and patella, and the tibiofibular joint between the tibia and fibula. These articulations are surrounded by a fibrous capsule that encloses the synovial membrane, which secretes synovial fluid to lubricate the joint.
The knee joint is stabilized by several ligaments, including the medial and lateral collateral ligaments, which provide stability to the sides of the joint, and the anterior and posterior cruciate ligaments, which prevent excessive forward and backward movement of the tibia relative to the femur. The menisci, which are C-shaped fibrocartilaginous structures located between the femoral condyles and tibial plateaus, also help to stabilize the joint by absorbing shock and distributing weight evenly across the articular surfaces.
The knee joint allows for flexion, extension, and a small amount of rotation, making it essential for activities such as walking, running, jumping, and sitting.
The periodontal ligament, also known as the "PDL," is the soft tissue that connects the tooth root to the alveolar bone within the dental alveolus (socket). It consists of collagen fibers organized into groups called principal fibers and accessory fibers. These fibers are embedded into both the cementum of the tooth root and the alveolar bone, providing shock absorption during biting and chewing forces, allowing for slight tooth movement, and maintaining the tooth in its position within the socket.
The periodontal ligament plays a crucial role in the health and maintenance of the periodontium, which includes the gingiva (gums), cementum, alveolar bone, and the periodontal ligament itself. Inflammation or infection of the periodontal ligament can lead to periodontal disease, potentially causing tooth loss if not treated promptly and appropriately.
Longitudinal ligaments, in the context of anatomy, refer to the fibrous bands that run lengthwise along the spine. They are named as such because they extend in the same direction as the long axis of the body. The main function of these ligaments is to provide stability and limit excessive movement in the spinal column.
There are three layers of longitudinal ligaments in the spine:
1. Anterior Longitudinal Ligament (ALL): This ligament runs down the front of the vertebral bodies, attached to their anterior aspects. It helps to prevent hyperextension of the spine.
2. Posterior Longitudinal Ligament (PLL): The PLL is located on the posterior side of the vertebral bodies and extends from the axis (C2) to the sacrum. Its primary function is to limit hyperflexion of the spine.
3. Ligamentum Flavum: Although not strictly a 'longitudinal' ligament, it is often grouped with them due to its longitudinal orientation. The ligamentum flavum is a pair of elastic bands that connect adjacent laminae (posterior bony parts) of the vertebral arch in the spine. Its main function is to maintain tension and stability while allowing slight movement between the vertebrae.
These longitudinal ligaments play an essential role in maintaining spinal alignment, protecting the spinal cord, and facilitating controlled movements within the spine.
The Posterior Cruciate Ligament (PCL) is one of the major ligaments in the knee, providing stability to the joint. It is a strong band of tissue located in the back of the knee, connecting the thighbone (femur) to the shinbone (tibia). The PCL limits the backward motion of the tibia relative to the femur and provides resistance to forces that tend to push the tibia backwards. It also assists in maintaining the overall alignment and function of the knee joint during various movements and activities. Injuries to the PCL are less common compared to injuries to the Anterior Cruciate Ligament (ACL) but can still occur due to high-energy trauma, such as motor vehicle accidents or sports incidents involving direct impact to the front of the knee.
Anterior cruciate ligament (ACL) reconstruction is a surgical procedure in which the damaged or torn ACL, a major stabilizing ligament in the knee, is replaced with a graft. The ACL is responsible for preventing excessive motion of the knee joint, and when it is injured, the knee may become unstable and prone to further damage.
During the procedure, the surgeon makes an incision in the knee to access the damaged ligament. The torn ends of the ACL are then removed, and a graft is taken from another part of the body (such as the patellar tendon or hamstring tendons) or from a donor. This graft is then positioned in the same location as the original ACL and fixed in place with screws or other devices.
The goal of ACL reconstruction is to restore stability and function to the knee joint, allowing the patient to return to their normal activities, including sports and exercise. Physical therapy is typically required after surgery to help strengthen the knee and improve range of motion.
Ossification of the Posterior Longitudinal Ligament (OPLL) is a medical condition where there is abnormal growth and hardening (ossification) of the posterior longitudinal ligament in the spine. The posterior longitudinal ligament runs down the length of the spine, along the back of the vertebral bodies, and helps to maintain the stability and alignment of the spinal column.
In OPLL, the ossification of this ligament can cause narrowing of the spinal canal (spinal stenosis) and compression of the spinal cord or nerve roots. This condition is more commonly found in the cervical spine (neck), but it can also occur in the thoracic (chest) and lumbar (lower back) regions of the spine.
The symptoms of OPLL may include neck pain, stiffness, numbness, tingling, or weakness in the arms and/or legs, depending on the location and severity of the compression. In severe cases, it can lead to serious neurological deficits such as paralysis. The exact cause of OPLL is not fully understood, but it is believed to be related to genetic factors, aging, and mechanical stress on the spine.
The broad ligament is a wide, flat fold of peritoneum (the serous membrane that lines the abdominal cavity) that supports and suspends the uterus within the pelvic cavity. It consists of two layers - the anterior leaf and the posterior leaf - which enclose and protect various reproductive structures such as the fallopian tubes, ovaries, and blood vessels.
The broad ligament plays a crucial role in maintaining the position and stability of the uterus, allowing for proper functioning of the female reproductive system. It also serves as a conduit for nerves, blood vessels, and lymphatics that supply and drain the uterus and other pelvic organs.
Anomalies or pathologies of the broad ligament, such as cysts, tumors, or inflammation, can potentially lead to various gynecological conditions and symptoms, requiring medical evaluation and intervention if necessary.
The round ligament is a cord-like structure in the female pelvis that extends from the uterus to the labia majora. It is one of the major ligaments that support the uterus and helps to maintain its position within the pelvis. The round ligament is composed of fibrous tissue and smooth muscle, and it plays a role in maintaining the tone and shape of the uterus.
During pregnancy, the round ligament can become stretched and thickened as the uterus grows and expands. This can sometimes cause discomfort or pain, particularly on one side of the pelvis. In some cases, the round ligament may also contribute to the development of certain gynecological conditions, such as uterine prolapse or urinary incontinence.
It is important for healthcare providers to consider the round ligament when evaluating and treating female reproductive health issues, as it can have a significant impact on the function and positioning of the uterus and other pelvic organs.
The lateral ligaments of the ankle are a group of three major ligaments located on the outside (lateral) aspect of the ankle joint. They play a crucial role in maintaining the stability and integrity of the ankle joint by preventing excessive side-to-side movement or eversion of the foot. The three lateral ligaments are:
1. Anterior talofibular ligament (ATFL): This is the most commonly injured ligament among the three, as it is the weakest and thinnest. It connects the anterior aspect of the fibula (the lateral malleolus) to the talus bone in the ankle joint. The primary function of the ATFL is to prevent excessive anterior displacement or tilting of the talus bone.
2. Calcaneofibular ligament (CFL): This ligament connects the lateral aspect of the calcaneus (heel bone) to the fibula, preventing excessive inversion and rotation of the ankle joint. The CFL plays a significant role in maintaining the stability of the subtalar joint, which is located just below the ankle joint.
3. Posterior talofibular ligament (PTFL): This is the strongest and thickest of the lateral ligaments. It connects the posterior aspect of the fibula to the talus bone, preventing excessive posterior displacement or tilting of the talus. The PTFL also helps to stabilize the ankle joint during plantarflexion (pointing the foot downward) movements.
Injuries to these lateral ligaments can occur due to sudden twisting motions, falls, or direct blows to the ankle, leading to conditions such as sprains or tears. Proper diagnosis and appropriate treatment are essential for ensuring optimal recovery and preventing long-term complications like chronic ankle instability.
Joint instability is a condition characterized by the loss of normal joint function and increased risk of joint injury due to impaired integrity of the supporting structures, such as ligaments, muscles, or cartilage. This can result in excessive movement or laxity within the joint, leading to decreased stability and increased susceptibility to dislocations or subluxations. Joint instability may cause pain, swelling, and limited range of motion, and it can significantly impact a person's mobility and quality of life. It is often caused by trauma, degenerative conditions, or congenital abnormalities and may require medical intervention, such as physical therapy, bracing, or surgery, to restore joint stability.
The spiral ligament of the cochlea is a fibrous structure located in the inner ear, more specifically in the cochlea. It is part of the membranous labyrinth and helps to maintain the shape and tension of the cochlear duct, which is essential for hearing.
The spiral ligament is attached to the bony wall of the cochlea and runs along the entire length of the cochlear duct, spiraling around it in a snail-like fashion. It consists of an outer, highly vascularized fibrous layer (the fibrous cap) and an inner, more cellular layer (the avascular zone).
The spiral ligament plays a crucial role in sound transmission and perception by helping to maintain the mechanical properties of the cochlear duct. The tension on the basilar membrane, where the sensory hair cells are located, is regulated by the spiral ligament's stiffness and elasticity. This tension affects the vibration amplitude and frequency selectivity of the basilar membrane, which in turn influences how we perceive different sounds and pitches.
Damage to the spiral ligament can result in hearing loss or impairment due to disrupted sound transmission and perception.
A rupture, in medical terms, refers to the breaking or tearing of an organ, tissue, or structure in the body. This can occur due to various reasons such as trauma, injury, increased pressure, or degeneration. A ruptured organ or structure can lead to serious complications, including internal bleeding, infection, and even death, if not treated promptly and appropriately. Examples of ruptures include a ruptured appendix, ruptured eardrum, or a ruptured disc in the spine.