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.
Patellofemoral arthritis is an inflammatory condition characterized by loss of the smooth cartilage between the kneecap (patella) and the underlying femoral (thigh) bone in the knee joint. When the articular cartilage wears out, the underlying bones rub against each other, causing pain, swelling, stiffness, and restricted movement.
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.
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.
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.
Fractures of the Tibia
A crack or break in the tibia is referred to as a tibial fracture. The tibia is the most frequently fractured long bone of the body. It normally takes a great amount of force for a fracture of the tibia to occur.
Fractures of the tibia vary depending on the force involved and are classified based on the location of the fracture, the pattern of the fracture, and exposure of the fracture site.
Distal Femur Fracture
A femur fracture is a break in the femur. The distal femur refers to the lower part of the thigh bone which flares out like an upside-down funnel and its lower end is covered by a smooth, slippery articular cartilage that protects and cushions the bone during movement. Fracture of the distal femur may involve the cartilaginous surface of the knee as well and result in arthritis. A distal femur fracture is a break in the thighbone that occurs just above your knee joint.
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.
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.
The patella may break into two pieces or several pieces depending on the nature of the injury. Any part of the patella may be involved.
Tibial Shaft Fracture
A tibial shaft fracture is a crack or break in the middle section of the tibia bone due to severe trauma.
The lower leg is made up of two long bones called the tibia and fibula that extend between the knee and ankle and help form the ankle joint and knee joint. The tibia or shinbone is the larger of the two bones and is one of the major bones of the lower leg.
Knee Stress Fractures
Stress fractures of the patella or knee are very rare. Approximately two out of 10,000 athletes may experience a patella stress fracture. Initial symptoms include activity-related pain and then a fatigue stress fracture after minor trauma. The term insufficiency stress fracture is used for cases where the patella is weakened previously such as after patella resurfacing surgery.
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.
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.
A tibial eminence fracture is break or crack in the bony attachment of the ACL to the tibia. The fracture can be a contact or non-contact injury and occurs at the base of the tibial eminence.
Stress Fracture of the Tibia
A stress fracture of the tibia or shinbone is a thin fracture, also called a hairline fracture that occurs in the tibia due to excess stress or overuse. The tibia is a weight-bearing bone in which stresses can accumulate from activities such as running and jumping.
Chondromalacia patella is a common condition characterized by softening, weakening and damage of the cartilage. The condition is most often seen in young athletes and older adults who have arthritis of the knee. It especially occurs in women.
A bursa is a small fluid-filled sac found between soft tissues and bones. It lubricates and acts as a cushion to decrease friction between bones when they move.
Bursitis refers to the inflammation and swelling of the bursa. Inflammation of the bursa in front of the kneecap (patella) is known as kneecap bursitis or prepatellar bursitis.
The knee consists of a fluid called synovial fluid, which reduces the friction between the bones of the knee joint while you move your leg. Sometimes this fluid is produced in excess, resulting in its accumulation in the back of your knee. A Baker’s cyst or popliteal cyst is a fluid-filled swelling that develops into a lump behind the knee. This causes stiffness, tightness, and pain behind your 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.
Bone Marrow Edema in the Knee
Bone marrow edema, also known as bone marrow lesion, in the knee is a condition characterized by the accumulation of fluid in the bone marrow of the knee that may result in pressure and pain within the knee. This condition is visible on an MRI, but not on regular X-ray findings.
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).
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.
Recurrent Patella Dislocation
Patellar dislocation occurs when the kneecap slides out of the trochlea. When dislocation of the patella occurs on more than one occasion, it is referred to as recurrent patellar dislocation. The risk of further dislocation increases to almost 70% to 80% after two episodes of 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.
Patellar Tendon Rupture
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.
Pigmented Villonodular Synovitis (PVNS) of the Knee
Pigmented villonodular synovitis (PVNS) of the knee is a rare condition characterized by overgrowth and thickening or swelling of the synovium (a thin layer of tissue that lines the joints and tendons), resulting in a growth called a tumor. The tumor or mass that occurs from this overgrowth is benign (noncancerous) and does not metastasize (spread) to other regions of the body.
Osteomyelitis of the Knee
Osteomyelitis of the knee also known as a knee infection is a condition characterized by swelling, pain, and tenderness in the joint. This infection is mainly caused due to the invasion of bacteria or fungi into the bone through the bloodstream.
Osteogenesis imperfecta, also called brittle bone disease, is a bone disorder that results in imperfectly formed bones which are fragile and break easily. It is a hereditary disease that usually runs in the family and affects young children.
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.
Children under 2 years of age may present with bowed legs (physiologic), which usually corrects itself by the age of 3 to 4.
Patellar Tracking Disorder/Patellar Maltracking
Patellar tracking disorder, also known as patellar maltracking, is a condition in which the kneecap (patella) moves sideways from its groove when the leg is bent or straightened.
Spontaneous Osteonecrosis of the Knee (SONK)
Spontaneous osteonecrosis of the knee (SONK) is a painful knee condition of idiopathic or unknown cause that occurs spontaneously. It is a distinct clinical entity with no consensus regarding the etiology of the condition. SONK is the most common form of osteonecrosis of the knee.
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.
Patellar tendinitis usually results from repetitive trauma or overuse, particularly from sports activities involving jumping such as basketball or volleyball.
Periprosthetic Knee Infection
A very small percentage of patients (less than 1%) who undergo knee replacement may develop an infection around the knee joint. This infection is called a periprosthetic knee infection.
A periprosthetic knee infection may occur immediately after the surgery or even many years later.
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.
Pes Anserine Bursitis
Pes anserine bursitis is the inflammation of the pes anserine bursa present between the tendons of the hamstring muscle and the tibia or shinbone on the inner side of the knee. The condition occurs when the pes anserine bursa becomes inflamed and produces excess fluid causing the bursa to swell which places pressure on the adjacent sections of the knee.
Pseudogout is a type of arthritis that is characterized by the development of a painful swelling that occurs suddenly in one or more joints. It is also known as calcium pyrophosphate deposition disease (CPPD) because of the type of crystals that are deposited on the joint during the disease process.
Knee Joint Bursa Infection
Knee joint bursa infection, also known as septic knee bursitis, is a condition characterized by inflammation of the small fluid-filled sacs (bursa) near the knee joint due to an infection caused by bacteria or other microorganisms. This occurs either on the kneecap, below the joint, or the inner side of the knee.
Quadriceps Tendon Rupture and Repair
A quadriceps tendon rupture is defined as a tear of the quadriceps tendon as a result of a traumatic incident.
A quadriceps tendon rupture can be either partial or complete. A partial rupture does not completely damage the soft tissue. A complete rupture cuts the soft tissue into 2 pieces with the quadriceps muscles no longer attached to the kneecap.
Knee effusion also known as water on the knee or swollen knee is a condition characterized by swelling in the knee joint due to the excess accumulation of synovial fluid(the fluid which surrounds the joint)or leakage of lymph fluid or blood into the joint space.