The joint surface is covered by a smooth articular surface that allows pain-free movement in the joint. Arthritis is a general term covering numerous conditions where the joint surface or cartilage wears out. This surface can wear out for several reasons; often the definite cause is not known. Arthritis often affects the knee joint. When the articular cartilage wears out, the bone ends rub on one another and cause pain. The most common type of arthritis is osteoarthritis. It occurs with aging and use.
Osteoarthritis also called degenerative joint disease, is the most common form of arthritis. It occurs most often in older people. This disease affects the tissue covering the ends of bones in a joint (cartilage).In a person with osteoarthritis, the cartilage becomes damaged and worn out causing pain, swelling, stiffness and restricted movement in the affected joint. This condition most commonly affects the joints in the hips, knees, hands, and spine. Rarely, the disease may affect the shoulders, wrists, and feet.
Knee pain is a common condition affecting individuals of various age groups. It not only affects movement but also impacts your quality of life. An injury or disease of the knee joint or any structure surrounding the knee can result in knee pain. A precise diagnosis of the underlying cause is important to develop an appropriate treatment plan.
A meniscal tear is a common knee injury in athletes, especially those involved in contact sports. A sudden bend or twist in your knee causes the meniscus to tear. Elderly people are more prone to degenerative meniscal tears as the cartilage wears out and weakens with age.
Knee sprain is a common injury that occurs from overstretching of the ligaments that support the knee joint. A knee sprain occurs when the knee ligaments are twisted or turned beyond its normal range, causing the ligaments to tear.
Jumper’s knee, also known as patellar tendinitis, is inflammation of the patellar tendon that connects your kneecap (patella) to your shinbone. This tendon helps in the extension of the lower leg.
The anterior cruciate ligament (ACL) is one of the major ligaments of the knee. It is located in the middle of the knee and runs from the femur (thighbone) to the tibia (shinbone). The ACL prevents the tibia from sliding out in front of the femur. Together with the posterior cruciate ligament (PCL), it provides rotational stability to the knee.
Meniscal tears are one of the most common injuries to the knee joint. It can occur at any age but are more common in athletes involved in contact sports. The meniscus has no direct blood supply and for that reason, when there is an injury to the meniscus, healing is difficult.
Fractures of the Tibia
The lower leg is made up of two long bones called the tibia and fibula that extend between the knee and ankle. The tibia or shinbone is the larger of the two bones. It bears most of the body’s weight and helps form the ankle joint and knee joint.
Osteochondritis Dissecans of the Knee
Osteochondritis dissecans is a joint condition in which a piece of cartilage, along with a thin layer of the bone separates from the end of the bone because of inadequate blood supply. The separated fragments are sometimes called “joint mice”. These fragments may be localized or may detach and fall into the joint space, causing pain and joint instability. Osteochondritis dissecans occurs within the lateral aspect of the medial femoral condyle. The condition can also occur in other joints, including your elbows, ankles, shoulders, and hips.
Shin splints are pain and inflammation of the tendons, muscles and bone tissue along the tibia or shinbone (lower leg). It occurs because of vigorous physical activities such as exercise or sports. The condition is also referred to as medial tibial stress syndrome (MTSS).
Pain, swelling, and stiffness are the common symptoms of any damage or injury to the knee. If care is not taken during the initial phases of injury, it may lead to joint damage, which may end up destroying your knee.
The knee is a complex joint of the body that is vital for movement. The four major ligaments of the knee are anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL) and lateral collateral ligament (LCL). They play an important role in maintaining the stability of the knee. A multiligament injury is a tear in one or more ligaments of the knee, which affects the knee stability.
Any damage to the supporting ligaments may cause the patella to slip out of the groove either partially (subluxation) or completely (dislocation). This misalignment can damage the underlying soft structures such as muscles and ligaments that hold the kneecap in place. Once damaged, these soft structures are unable to keep the patella (kneecap) in position. Repeated subluxation or dislocation makes the knee unstable. This condition is called knee instability. Patellar (kneecap) instability results from one or more complete or partial dislocations (subluxations).
The knee joint is one of the largest joints in the body. This highly complex joint has several tissues supporting and stabilizing its movement:
- Condyles and menisci: Bony protrusions of the thighbone called condyles fit snugly into the depressions of the lateral and medial menisci (spongy cartilage) of the shinbone.
Goosefoot Bursitis of the Knee
A bursa is a small fluid-filled sac found between soft tissues and bones. It lubricates and acts as a cushion, decreasing the friction between bones when they move. Bursitis refers to the inflammation and swelling of the bursa. Goosefoot bursitis or pes anserine bursitis is the inflammation of the bursa present between the tendons of the hamstring muscle and the tibia (shinbone) on the inner side of the knee.
Knee infection is a serious medical condition that needs immediate treatment. Infection may occur followed by a knee replacement surgery or trauma and is usually caused by bacteria. Infection may spread to the space of the knee joint or deep layers of your knee causing serious complications.
The medial collateral ligament (MCL) is the ligament located on the inner part of the knee joint. It runs from the femur (thighbone) to the top of the tibia (shinbone) and helps in stabilizing the knee.
Your MCL may get sprained or injured while twisting, bending or quickly changing direction. The sprain is classified into three degrees:
- Your MCL may get sprained or injured while twisting, bending or quickly changing direction. The sprain is classified into three degrees:
Fractures of the Patella
The patella or kneecap is a small bone present in the front of your knee where the thigh bone meets the shinbone. It provides protection to your knee and attachment to muscles in the front of the thigh. An injury to the knee can result in a break or fracture of the patella.
Knee Ligament Injuries
Knee problems may arise if any of these structures get injured by overuse or suddenly during sports activities. Pain, swelling, and stiffness are the common symptoms of any damage or injury to the knee. The common causes of knee injury include:
- Fracture of the femur (thighbone) or tibia and fibula (leg bones)
Patellar Dislocation/Patellofemoral Dislocation
Patellar dislocation occurs when the patella moves out of the patellofemoral groove, (trochlea) onto the bony head of the femur. If the kneecap partially comes out of the groove, it is called subluxation; if the kneecap completely comes out, it is called dislocation (luxation).
Posterior cruciate ligament (PCL), one of the four major ligaments of the knee, is situated at the back of the knee. It connects the thighbone (femur) to the shinbone (tibia). The PCL limits the backward motion of the shinbone.
Chondral or Articular Cartilage Defects
The articular or hyaline cartilage is the tissue lining the surface of the two bones in the knee joint. Cartilage helps the bones move smoothly against each other and can withstand the weight of your body during activities such as running and jumping. Articular cartilage does not have a direct blood supply to it, so has less capacity to repair itself. Once the cartilage is torn it will not heal easily and can lead to degeneration of the articular surface, leading to the development of osteoarthritis.
Patellofemoral instability means that the patella (kneecap) moves out of its normal pattern of alignment. This malalignment can damage the underlying soft structures such as muscles and ligaments that hold the knee in place.
The kneecap or patella forms a part of the knee joint. It is present at the front of the knee, protecting the knee and providing attachment to various muscle groups of the thigh and leg. The undersurface of the kneecap and the lower end of the femur are coated with articular cartilage, which helps in smooth movement of the knee joint. A fracture in the kneecap is rare but common in adult males.
Recurrent Patella Dislocation
The patella (kneecap) is a small bone that shields your knee joint. It is present in front of your knee, on a groove called the trochlear groove that sits at the junction of the femur (thighbone) and tibia (shinbone). Articular cartilage presents below the patella and end of the femur cushion and helps the bones glide smoothly over each other when the legs move. This joint is stabilized and supported by a network of soft tissues. The medial patellofemoral ligament (MPFL) connects to the inner side of the patella and helps to keep it from slipping away from the knee. Damage to this ligament leads to patellar dislocation.
Quadriceps Tendon Rupture
The quadriceps can rupture after a fall, direct blow to the leg and when you land on your leg awkwardly from a jump. Quadriceps tendon rupture most commonly occurs in middle-aged people who participate in sports that involve jumping and running. Other causes include tendonitis (inflammation of quadriceps tendon), diseases such as rheumatoid arthritis, diabetes mellitus, infection and chronic renal failure, which weaken the quadriceps tendon. Use of medications such as steroids and some antibiotics also weakens the quadriceps tendon.
Patellar Tendon Rupture
The patellar tendon works together with the quadriceps muscle and the quadriceps tendon to allow your knee to straighten out. Patella tendon rupture is the rupture of the tendon that connects the patella (kneecap) to the top portion of the tibia (shinbone).
Posterolateral instability, also known as posterolateral rotatory instability (PLRI), is a common pattern of knee instability that results from injuries to the structures that support the outside of the knee joint, the posterolateral corner. When individuals injure the knee ligaments, they are most likely to injure the structures of the posterolateral corner. These structures include the popliteus tendon, lateral collateral ligament, and the knee joint capsule. The knee instability mostly occurs along with other ligamentous injuries, in particular, damage to either the ACL (anterior cruciate ligament), the PCL (posterior cruciate ligament), or both.
Osteonecrosis of the Knee
Osteonecrosis is a condition in which the death of a section of bone occurs because of lack of blood supply to it. It is one of the most common causes of knee pain in older women. Women over 60 years of age are commonly affected, three times more often than men.
Knee Angular Deformities
Angular deformities of the knee are variations in the normal growth pattern during early childhood and are common during childhood. Physiologic angular deformities vary with age as:
- During the first year: Lateral bowing of tibia
Articular Cartilage Injury
Articular or hyaline cartilage is the tissue lining the surface of the two bones in the knee joint. Cartilage helps the bones move smoothly against each other and can withstand the weight of the body during activities such as running and jumping. Articular cartilage does not have a direct blood supply to it so has little capacity to repair itself. Once the cartilage is torn it will not heal easily and can lead to degeneration of the articular surface, leading to the development of osteoarthritis.
Patellofemoral pain syndrome also called runner’s knee refers to pain under and around your kneecap. Patellofemoral pain is associated with a number of medical conditions such as anterior knee pain syndrome, patellofemoral malalignment, and chondromalacia patella. Patellofemoral pain is a common complaint among runners, jumpers, and other athletes such as skiers, cyclists, and soccer players; thus the common name, runner’s knee.
A fracture is a condition in which there is a break in the continuity of the bone. In younger individuals, these fractures are caused by high energy injuries, as from a motor vehicle accident. In older people, the most common cause is a weak and fragile bone.
Knee Sports Injuries
Trauma is any injury caused during physical activity, motor vehicle accidents, electric shock, or other activities. Sports trauma or sports injuries refer to injuries caused while playing indoor or outdoor sports and exercising. Sports trauma can result from accidents, inadequate training, improper use of protective devices, or insufficient stretching or warm-up exercises. The most common sports injuries are sprains and strains, fractures, and dislocations.
Patellar tendinitis, also known as "jumper's knee", is an inflammation of the patellar tendon that connects your kneecap (patella) to your shinbone. This tendon helps in extension of the lower leg.
Multiligament Knee Injuries
Injury to more than one knee ligament is called a multiligament knee injury and may occur during sports or other physical activities.
Anterior Knee Pain
Anterior knee pain is characterized by chronic pain over the front and center of the knee joint. It is common in athletes, active adolescents (especially girls) and overweight individuals. Anterior knee pain refers to various conditions, which include runner's knee or patellar tendinitis, and chondromalacia of the patella. There is an inter-individual variation in the duration and presentation of pain.
Bowed leg is a bony deformity resulting in outward curvature of one or both knees of the lower legs. It is commonly seen in toddlers and overweight adolescents.
Tibial Shaft Fracture
A tibial shaft fracture is a crack or break in the middle section of the tibia bone due to severe trauma.
Periprosthetic Knee Fractures
Knee replacement, also called knee arthroplasty, is a surgical procedure in which the worn-out or damaged surfaces of the knee joint are removed and replaced with artificial implants. Any resulting fractures or breaks in the bone around the implant are called periprosthetic knee fractures. These fractures may occur during surgery (intraoperative) or after surgery (postoperative), and usually involve the patella, tibia or the femur (kneecap, shinbone, and thighbone). Women are at higher risk than men.
Tibial Plateau Fracture
A tibial plateau fracture is a crack or break on the top surface of the tibia or shinbone in the knee joint. The fracture most often occurs following a high-intensity trauma or injury from the impaction of the femoral condyles over the tibial plateau. Fractures of the tibial plateau are serious injuries that are more commonly seen in athletes involved in high-impact sports such as basketball, rugby, and football and can put athletes out of action for a long period of time.
Women and ACL Injuries
The anterior cruciate ligament is one of the four major ligaments of the knee that connects the femur (thigh bone) to the tibia (shin bone) and helps stabilize the knee joint. Anterior cruciate ligament (ACL) injury is one of the common injuries of the knee. An injury to the ACL commonly occurs during sports or activities that involve twisting, overextension, landing from a jump incorrectly and abrupt change in direction or speed of movements.
Medial Meniscus Syndrome
Of the menisci within the knee, it is the medial that is more easily injured. Differences in the anatomical attachments of the medial meniscus compared to the lateral, mean that the medial meniscus becomes distorted during combined flexion and rotation movements in a manner not experienced on the lateral side.
Tibial Eminence Fractures
The tibial eminence, also called the tibial spine, is a bony protuberance of the tibia (shin bone) that attaches to the anterior cruciate ligament (ACL) of the knee joint.
Osgood Schlatter Disease
Osgood-Schlatter disease refers to a condition in older children and teenagers caused by excessive stress to the patellar tendon (located below the kneecap). Participants in sports such as soccer, gymnastics, basketball, and distance running are at higher risk for this disease.