Materiały źródłowe

• #1 Dislocated Kneecap (Patella Dislocation): Symptoms & Recovery

  https://my.clevelandclinic.org/health/diseases/21633-patellar-dislocations

  A dislocated kneecap (patella dislocation) occurs when your kneecap pops sideways out of its vertical groove at your knee joint. Its usually caused by force, from a collision, a fall or a bad step. […] When your patella dislocates, its forced outside of the trochlear groove and can no longer move up and down. This locks your knee and pulls the ligaments out of place, often tearing them. […] A patella dislocation occurs when your kneecap (patella) slides out of the groove at your knee joint. […] Force either from a direct impact or a bad step that uses your own body weight against you causes acute patellar dislocation. […] Some people have patellar instability, which means that the tendons and ligaments that hold your kneecap in place are already loose and unstable. An unstable kneecap will dislocate more easily. […] People with congenital patellar dislocation (trochlear dysplasia) are born with the condition. […] Researchers dont know what causes congenital patella dislocation, but a higher incidence among biological family members suggests a genetic link.

• #1 Diagnosis and treatment for kneecap patella dislocation

  https://os.clinic/conditions/knee/kneecap-patella-dislocation/

  A dislocated kneecap can be caused by: […] A blow to the knee, for example if the knee joint collides with another person or object with great force. […] A sudden change of direction while the leg is still planted firmly on the ground, such as during sports or dancing. […] Weak leg muscles which puts pressure on the knee joint. […] A misaligned or elevated kneecap. […] Being tall and/or being overweight increases the risk of dislocation and women are also more at risk. […] After a dislocated kneecap, the medial patellofemoral ligament may become torn. This is the ligament that secures the kneecap to the inside (medial) of the knee. Once it is torn it may not heal with the same level of tension as before. This can lead to recurrent dislocation of the kneecap.

• #1 Patellar dislocation – Wikipedia

  https://en.wikipedia.org/wiki/Patellar_dislocation

  Causes Bending the lower leg outwards when the knee is straight, direct blow to the patella when the knee is bent. […] A patellar dislocation typically occurs when the knee is straight and the lower leg is bent outwards when twisting. […] Occasionally, it occurs when the knee is bent and the patella is struck directly. […] A predisposing factor is tightness in the tensor fasciae latae muscle and iliotibial tract in combination with a quadriceps imbalance between the vastus lateralis and vastus medialis muscles can play a large role, found, mainly, in women involved in sports. […] Another cause of patellar symptoms is lateral patellar compression syndrome, which can be caused from lack of balance or inflammation in the joints. […] When there is too much tension on the patella, the ligaments will be susceptible to tearing due to shear force or torsion force, which then displaces the patella from its groove.

• #1 Causes and Risk Factors for Dislocated Kneecaps

  https://www.sports-health.com/sports-injuries/knee-injuries/causes-and-risk-factors-dislocated-kneecaps

  Kneecap dislocation is commonly caused by traumatic injury or by placing an excessive amount of pressure on the knee joint. The injury is more common in women, and is one of the more common injuries sustained by athletes. […] The injury can occur as the result of one or a combination of the following: […] Direct trauma to the knee. When the knee joint collides with another person or object with great force, trauma to the joint can cause the kneecap to dislocate. […] Excessive pressure from movement. When an athlete is moving at high speeds in one direction and has to quickly change direction with his or her leg planted, the knee joint sustains a great deal of pressure. In cases where the pressure is too much, the kneecap may dislocate. […] Female gender. Women have been shown to be at a higher risk for kneecap dislocation than men. It is thought that this risk may may be because women tend to have wider hips, causing the thigh bones slant inward and join the knee at more of an angle.

• #1 Dislocated Kneecaps: What to Do When it Happens

  https://www.parkwayeast.com.sg/health-plus/article/kneecap-dislocation-children

  Kneecap, or patella, dislocation in children happens more often than we think. […] A dislocated kneecap usually happens when a child falls, or takes a hit to the knee. […] Almost 60 80% of kneecap injuries usually occur when performing a cutting/turning action while the foot is firmly planted on the ground. […] Apart from these, inborn deformities of the thighbone, kneecap and ligamentous laxity can make your child more prone to this injury. […] Surgery is required if the patella dislocates multiple times, continues to be unstable despite treatment, or if there’s evidence of bone injury. […] The type of surgery required is guided by the injury sustained as well as the root cause. […] These are important as recurrent dislocations lead to structural damage and subsequent development of arthritis.

• #1 Unstable Kneecap (Patellar Instability) – OrthoInfo – AAOS

  https://orthoinfo.aaos.org/en/diseases–conditions/unstable-kneecap/

  Patellar dislocations often result from a non-contact injury, such as a pivot, twist, or awkward fall. […] A sharp blow to the kneecap could also pop the patella out of place. […] But sometimes, there are issues that make the kneecap more likely to move out of position: Damage to the medial patellofemoral ligament (MPFL), a ligament that prevents the patella from moving too far sideways; A trochlea (groove) that is too flat to keep the patella in its proper position; Abnormal limb alignment, or being knock-kneed; Abnormal rotation in either the femur and/or tibia can cause the patella to shift out of the groove; Attachment site of the patellar tendon on the shin bone if the place where the patellar tendon connects to the shin bone is too far to the lateral side (outside) of the knee, the tendon can pull the kneecap out of the groove.

• #1 Patellar dislocation – Wikipedia

  https://en.wikipedia.org/wiki/Patellar_dislocation

  Patellar dislocation occurs mainly in youths (under age 20) engaged in sports that may involve accidental rotation of the knee while in flexion, a movement clinically called valgus, which is the cause of some 93% of patellar dislocation cases. […] Direct trauma to the knee displacing the patella is rare. […] An angle greater than 25 degrees between the patellar tendon and quadriceps muscle can predispose a person to patellar dislocation. […] In patella alta, the patella sits higher on the knee than normal. […] Decreased VMO function results in instability of the patella. […] Patellar dislocation may also occur when the trochlear groove is shallow, a condition defined as trochlear dysplasia.

• #1 Patellar Dislocation | Orthopedics & Sports Medicine

  https://health.uconn.edu/orthopedics-sports-medicine/conditions-and-treatments/where-does-it-hurt/knee/patellar-dislocation/

  Patellar (kneecap) dislocations occur with significant regularity, especially in younger athletes, with most of the dislocations occurring laterally (outside). […] Patellar dislocations can occur either in contact or non-contact situations. An athlete can dislocate his/her patella when the foot is planted and a rapid change of direction or twisting occurs. Usually a pre-existence ligamentous laxity is required to allow a dislocation to occur in this manner. Direct blows to a knee can cause dislocations as well. The force of these is obviously much greater and usually causes more severe damage especially to restraining ligaments.

• #1 My Knee Popped Out of Place, Then Right Back in Again – Ohio

  https://orthoneuro.com/my-knee-pops-in-out-of-place-patellar-instability/

  Patellar instability is a condition in which your kneecap slides or moves out of its normal position within your trochlear groove, which is the groove on the femur that your kneecap sits on. […] However, if you have patellar instability, the movement will result in an unstable kneecap and can even lead to a dislocated kneecap. The most common cause of a kneecap dislocation is a non-contact twisting injury when the knee joint is almost fully extended. Additionally, a direct blow to the kneecap while playing sports, a fall, or another form of accident can cause a partial or complete dislocation. […] During such injuries, the medial patellofemoral ligament (MPFL) can become damaged. This ligament plays an important role in kneecap stability. […] Kneecap dislocation and subluxation are more common in young women, especially those with loose or hypermobile joints. […] Risk factors include: Shallow Trochlear Groove: A less-defined groove provides less stability, allowing the kneecap to dislocate more easily. […] These anatomical traits make it easier for the kneecap to shift or dislocate, especially during twisting, jumping, or direct impact activities.

• #1 Patella Dislocation – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK538288/

  Acute patellar dislocations typically occur as a result of trauma, usually a non-contact twisting injury to the knee, or from a direct blow to the medial aspect of the knee. A common mechanism is external tibial rotation with the foot fixed on the ground. […] Patellar dislocations can also occur in patients with generalized ligamentous laxity. However, those patients mostly tend to have recurrent subluxations of their patella as opposed to a frank dislocation. […] Anatomic variations such as patella alta and trochlear dysplasia can predispose individuals to patellar dislocation. Ligamentous laxity is more commonly seen in females, or secondary to connective tissue disorders such as Marfan Syndrome or Ehlers-Danlos, increases the risk of dislocation. Muscular imbalance, particularly weakness of the vastus medialis oblique also plays a role in patellar instability.

• #1 Overview: Dislocated kneecap – InformedHealth.org – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK561511/

  Whenever you bend or stretch your leg, the kneecap (patella) moves along a groove on your thigh bone (femur). An awkward twist of the joint or a bump from the side can knock it out of this groove. The kneecap is then dislocated. The medical term for this is patellar dislocation. It happens most often during sports, and is most common in teenagers and young adults. […] The kneecap may become dislocated if the knee joint is slightly bent and turned inward while the foot is flat on the ground. […] Dislocated kneecaps are often caused by a sports-related accident typically while dancing, doing gymnastics, or playing handball or soccer. That type of dislocation is also referred to as an acute or traumatic dislocation. It is the most common type, making up 80% of dislocated kneecaps. […] Partial kneecap dislocation (patellar subluxation) is less common: This happens when the kneecap moves from side to side in the groove, without becoming fully detached. This can result from a previous knee injury or ligaments that have become too loose, for instance.

• #1 Knee Dislocation and Instability in Children – OrthoInfo – AAOS

  https://orthoinfo.aaos.org/en/diseases–conditions/patellar-dislocation-and-instability-in-children-unstable-kneecap/

  Children with cerebral palsy and Down syndrome may have kneecaps that dislocate frequently due to imbalance and muscle weakness. […] Rarely, children are born with unstable kneecaps causing dislocations at a very early age, often without pain. […] Many things can cause patellar dislocation, such as a shallow groove in the femur or direct force on the knee joint. […] In children with normal knee structure, patellar dislocations are often the result of a direct blow or a fall onto the knee. This incidence is more common in high-impact sports, such as football. […] Dislocations can occur without contact, as well. A common example is that of a right-handed baseball player who dislocates the right patella while swinging the bat. When the right foot is planted on the ground and the torso rotates during the swing, the patella lags behind, resulting in dislocation.

• #1 Overview: Dislocated kneecap – InformedHealth.org – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK561511/

  Kneecap dislocation is most common in young people between the ages of 10 and 20. Girls and young women are at greater risk because they typically have more flexible ligaments and less muscle tissue. […] The risk of kneecap dislocation is also higher in people who have joints that stretch farther than normal (hypermobility) or weak ligaments, a kneecap that is higher than normal (patella alta), a deformed trochlear groove (trochlear dysplasia) or other anatomical abnormalities, deformities of the leg bones (such as bow-leggedness), and weak inner thigh muscles. […] A kneecap that has been dislocated is less stable afterwards. After a dislocation, it may feel like the kneecap no longer has enough support. The front of the knee may hurt, especially when more stress is put on the joint. […] In 15 to 45% of people who have a kneecap dislocation, it happens again afterwards. Sometimes this happens after just a few weeks, but it can also happen several months or years later. […] There’s not much good research on the longer-term effects of kneecap dislocation so less is known about them. But it can increase the risk of knee osteoarthritis. That is particularly true if the kneecap has been dislocated several times, which usually damages the cartilage more.

• #1 Patellar Dislocation – SportsMD

  https://www.sportsmd.com/sports-injuries/knee-injuries/patellar-dislocation-instability/

  Patellar dislocation occurs when a twisting injury to the knee joint causes the knee cap to dislocate. It usually occurs in sports when an athlete makes a plant and changes direction or performs a cutting motion. […] Factors related to the knee include poor bony development of the trochlear groove at the end of the thigh bone (femur) in which the patella normally glides. This is termed trochlear dysplasia and when present provides less than normal bony resistance to the patella dislocating. […] Another factor would be if the patella sits too high in the knee (patella alta). In this case the patella is further from the bony support of the trochlear groove and is more reliant on weaker soft-tissue ligaments to keep it centered in the knee. […] Lastly, if the attachment of the patellar tendon to the lower leg bone (tibial tubercle) is rotated too far to the outside, there is an inherent lateral (toward the outside of the knee) pull on the patella. […] Factors not inherent to the knee itself include rotational malalignment to the leg which can involve the femur (femoral anteversion) or the tibia (tibial torsion). Both of these abnormalities align the thigh muscles to pull the patella more lateral than usual.

• #1 Patella Dislocation – Symptoms, Causes, Treatment and Rehabilitation

  https://www.sportsinjuryclinic.net/acute-knee-injuries/patella-dislocation

  Patella dislocation occurs when the kneecap dislocates outside of its normal position. This is usually around the outside of the knee. It can also partially dislocate, called a subluxation. The patella will sometimes go back to its original position, although this will be very painful. […] A dislocated patella occurs when the patella displaces outside of its normal position. This usually happens laterally (to the outside). […] It is usually a result of an acute blow or twisting action of the knee. In most cases, the patella relocates to the patellofemoral groove when you straighten the knee. However, this is usually extremely painful. […] Patella dislocation is more likely with: […] If you have a weak VMO muscle then patella dislocation is more likely. […] Overpronation of the feet is where the feet roll in or flatten too much when running. This causes the leg to turn inwards which leaves the patella susceptible to moving outwards as the quadriceps contract. […] The Q-angle of the knee relates the angle of the lower leg to the knee. People with an increased Q angle appear knock-kneed. When they straighten their leg, it forces the patella to the outside of the knee, potentially resulting in patella dislocation.

• #1 Common Causes of Knee Dislocation – Mid Atlantic Orthopedic Associates, LLP: Orthopedic Surgery: North & East Brunswick, NJ

  https://www.midatlanticorthonj.com/common-causes-of-knee-dislocation/

  A knee dislocation occurs when one or more of the three bones that make up the structure of the knee move out of place. Causes of knee dislocation range from birth defects (rare) to injuries (most common). […] If your knee collides with another object or person, the impact may cause your kneecap to pop out of place. Moving at high speeds in one direction and then switching directions quickly may also put too much pressure on your knee bones, increasing the risk of dislocation. […] Malnutrition and nutritional deficiencies can raise your risk for dislocations, especially if you’re a woman past the age of 50. Getting enough calcium, vitamin K2, and vitamin D are essential for maintaining bone health as you age and your bones lose their density. […] Weakened muscles around the kneecap put more pressure on the knee, increasing the risk of dislocations. Muscles can weaken due to a sedentary lifestyle, prolonged bed rest, and a diet low in protein.

• #1

  https://www.orthobullets.com/knee-and-sports/3020/patellar-instability

  Patellar instability defines a spectrum from subluxation to dislocation that results from injury, ligamentous laxity, or increased Q angle of the knee. […] Pathophysiology includes a mechanism of noncontact twisting injury with the knee extended and foot externally rotated. […] Direct blow to the medial knee is less common. […] General risk factors include ligamentous laxity (Ehlers-Danlos syndrome) and previous patellar instability event. […] Anatomical factors such as patella alta cause the patella to not articulate with the sulcus, losing its constraint effects. […] Trochlear dysplasia and excessive lateral patellar tilt are also contributing factors. […] Muscle imbalance, particularly vastus medialis oblique (VMO) muscle weakness, can increase the risk of dislocation. […] The recurrence rate of patellar instability is 15-60% following first-time dislocation. […] Younger age, patella alta, and trochlear dysplasia increase the risk of recurrence.

• #1 Patella Dislocation – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK538288/

  Habitual dislocations are characterized by painless dislocations every time the knee flexes, which is usually a result of abnormal tightness of the vastus lateralis muscle and the iliotibial band. […] Congenital dislocations can also occur, most commonly in patients with Down syndrome; this is the result of a small patella in combination with a hypoplastic condyle, and typically requires surgical intervention for reduction.

• #1 Kneecap Dislocation & Treatment – Mayo Clinic Health System

  https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/whats-going-on-with-my-kneecap

  If your kneecap pops or slides to the outside of your knee, you’ll definitely know that something’s going on. Typically, that „something” is a partial or full dislocation, which means the kneecap, also known as the patella, has slipped partly or all the way out of its groove over the knee joint. […] Dislocation can be caused by a sudden blow, such as taking a hard hit playing a contact sport like football or hockey, or by a chronic condition like a stretched ligament. Some people have a particular knee anatomy that makes it more common. In those cases, a dislocation could be caused by something as simple as normal walking or standing up from a chair. […] Acute or chronic dislocation indicates you have a stretched or torn medial patellofemoral ligament, or MPFL, a tough band of tissue that connects to the inside of the kneecap and prevents it from sliding to the outside of the knee.

• #1 Patellar dislocation – Causes and Treatment | OrthoIndy Blog

  https://blog.orthoindy.com/2014/12/05/recurrent-patellar-knee-cap-dislocations/

  After the first patellar (knee cap) dislocation, a percentage of patients will experience another dislocation(s). The probability of this occurring is related to certain risks factors that can be identified with X-rays and MRI. The most commonly cited risk factors are: high riding patella, excessive lateral position of the attachment of the patellar tendon attachment to the tibia, “knock-knees”, residual excessive looseness of the medial patellofemoral ligament or poor trochlear groove shape. […] The medial patellofemoral ligament (MPFL) runs from the inside (medial) aspect of the femur at the knee to the patella. It does not actively pull the patella into the groove, but rather keeps it from exiting or dislocating from the groove. […] The trochlea groove can be thought of as a “V” shape pulley that aids in guiding the patella as the knees flex. If the natural “V” shape is shallow or replaced by a flat or domes trochlea this abnormal shape is termed trochlear dysplasia. Just as a flat pulley would not keep a rope in place, a dysplastic trochlea makes it easier for the patella to escape/dislocate.

• #1 Dislocated kneecap: Symptoms, treatments, recovery, and more

  https://www.medicalnewstoday.com/articles/dislocated-kneecap

  Kneecap dislocation occurs when the patella bone, which sits at the front of the knee, comes out of position. In the process, the connective tissues that hold the bone in place may stretch and tear. […] A dislocated kneecap is a common injury when a person changes direction suddenly with their feet planted on the ground such as during sports or when dancing. […] According to the review, a tear in this ligament occurs in as many as 90% of kneecap dislocations. […] Anyone who has dislocated their kneecap is at risk of the injury happening again. According to a 2020 meta-analysis, people who have received nonsurgical treatment for a first-time kneecap dislocation experience a reoccurrence about 50% of the time. […] The risk of a recurrent dislocation increases if the body has not had enough time to recover fully from the initial injury. […] A 2018 review observes that surgical treatment may be a good option for people with a first-time dislocation who have a high risk of recurrence.

• #1 Dislocated Kneecap: Symptoms, Causes, Risks, Complications & Treatment

  https://resources.healthgrades.com/right-care/knee-and-leg-injury/dislocated-kneecap

  A dislocated kneecap, also called patellar dislocation or dislocated patella, isn’t common; it makes up less than 1% of knee injuries. A dislocated kneecap most often occurs among people who participate in high impact sports. […] There are two common events that can cause a dislocated kneecap: changing direction suddenly with one foot planted firmly on the ground and twisting your knee, or trauma—a direct blow to the knee. Children, especially girls, may experience kneecap dislocations if their knee ligaments are loose. Loose ligaments can’t hold the kneecap in place. […] The people highest at risk of sustaining a kneecap dislocation are those who play high impact or contact sports, such as football. Since these dislocations can also be caused by a sudden pivot to change direction, people who play sports, such as baseball or soccer, are also at risk. If you have previously dislocated your kneecap, you are also at risk for another dislocation. Other risk factors are obesity or being extraordinarily tall.

• #1 Causes and Risk Factors for Dislocated Kneecaps

  https://www.sports-health.com/sports-injuries/knee-injuries/causes-and-risk-factors-dislocated-kneecaps

  Weak leg muscles. Individuals who have weak leg muscles or an imbalance in strength of their respective legs may put unneeded pressure on their knee joint, increasing the risk of patellar dislocation. […] Height. Athletes who are exceptionally tall may have an increased risk of patellar dislocation. […] Misaligned or elevated patella. If an athletes patella is misaligned or sits unnecessarily high on the femoral groove, that individual may have an increased risk of sustaining a dislocated kneecap. […] Prior injury. Having previously suffered a kneecap dislocation or another traumatic injury that has weakened the knee joint may increase the likelihood of sustaining a kneecap dislocation. […] Excess weight. Individuals who are severely overweight or obese are more likely to sustain a kneecap dislocation, and a dislocation can occur even without the presence of traumatic injury or excess force. In what is known as a low-velocity kneecap dislocation, the knee is overwhelmed by the weight of carrying the body and dislocates.

• #1 Patellar Dislocation (Kneecap Dislocation) | Lurie Children’s

  https://www.luriechildrens.org/en/specialties-conditions/patellar-dislocation-kneecap-dislocation/

  With a patellar dislocation, the patella (kneecap) pops out of its usual place in the groove at the end of the femur (thigh bone). […] Many patellar dislocations occur in a non-contact manner when a persons foot is planted on the ground and they twist or quickly change direction. […] Often individuals who sustain this type of injury have a particular structure of the bones such as a shallow or uneven groove for the patella or a patella that sits a little high on the femur (patella alta), which make dislocation more likely. […] Additionally, a kneecap may dislocate after a direct blow to the knee. […] Up to 25 percent of people with this injury have a family history of patellar dislocations.

• #1 Patellar Dislocation | Alexander Orthopaedics

  https://alexanderorthopaedics.com/patellar-dislocation/

  Patellar dislocations must be treated by a medical professional. Attempting to relocate your kneecap by yourself could result in much more damage to both the kneecap and the tendons and ligaments around it. […] Generally speaking, kneecap dislocation is caused by sudden trauma to the knee that forces it out of place. Collision with another object or the ground is a frequent reason these injuries occur. However, patellar dislocations have a number of common causes: Collision with another object or the ground, Sudden change of direction while the leg is firmly planted on the ground, Weak leg muscles that no longer properly support the knee joint, Misalignment in the kneecap. […] Patellar dislocations can happen as a result of blunt force trauma, such as a sudden fall or an accident. However, certain factors can put you at higher risk for a dislocated kneecap. For instance, having a dislocation in the past can raise your risk of it happening again in the future. […] According to the Cleveland Clinic, a number of hereditary conditions may also increase your risk of patellar dislocation, including Larson Syndrome, Arthrogryposis, Diastrophic Dysplasia, Nail-Patella Syndrome, Down Syndrome, and Ellis-Van Creveld Syndrome.

• #1 Recurrent Patella Dislocation Buckinghamshire | Kneecap Dislocation Slough

  https://www.hip2kneeclinic.co.uk/recurrent-patella-dislocation-orthopaedic-trauma-surgeon-wycombe.html

  The risk of further dislocation increases to almost 70% to 80% after two episodes of dislocation. […] There are various causes of recurrent patella dislocation. Some of them include: Certain inherited traits: Kneecap that is seated too high in the groove, Shallow trochlear groove, Tight lateral ligaments, Valgus leg alignment (knock-kneed legs). […] Each dislocation causes stretching of soft tissues and increases the chances of recurrence.

• #1 Why Does My Knee Keep Popping Out of Place? – Heiden Orthopedics

  https://heidenortho.com/patellar-instability/

  There are two types of patellar instability, which is, simply put, when the kneecap moves outside its normal space. One is traumatic patellar dislocation and the other is chronic patellar instability. […] An injury, such as a fall playing sports or a sharp blow during a car accident, can cause patellar instability. It may also be caused by an anatomical issue, like a shallow or uneven trochlear groove that prevents the kneecap from aligning properly. Additionally, some people have loose ligaments that dont hold the kneecap sufficiently during movement, which allows the joint to be overly flexible. […] Certain populations and people with various health conditions are more likely to develop patellar instability. These include: Women, People in their teens and 20s, Individuals with anatomical misalignments of the knee, Overweight individuals, Those with Cerebral palsy, Downs syndrome, or Ehlers-Danlos syndrome. […] Patellar dislocation is often the result of an injury, although chronic patellar instability sometimes also leads to patellar dislocations over time.

• #1 Knee cap dislocation | Orthopaedic knee surgeon Perth

  https://www.shoulderandkneesurgery.com.au/knee-conditions/knee-cap-dislocation-patellar-dislocation-perth/

  Knee cap dislocation, also known as patella dislocation, occurs when the knee cap is completely displaced out of its normal position. […] Patella dislocation is caused by a direct blow to the front of the knee or from a sudden pivoting of the leg, forcing the knee cap to the outside. Some people are more at risk of patella dislocation. Risk factors include: Maltracking or tilt of the patella. Being generally loose jointed. Being knock kneed. Having a high knee cap. Being born with a shallow groove for the knee cap (shallow trochlea). […] Patella maltracking is a very common problem. Even a normal knee cap has a tendency to run towards the outer half of the groove. In some people this can be quite severe, resulting in maltracking and patella tilt. Sometimes the patella does not completely dislocate. It may feel like it is partly slipping out, which is called patella subluxation. […] With a direct blow or a twisting injury, the patella can be dislocated out of its groove onto the outside of the knee joint.

• #1 Dislocated kneecap | informedhealth.org

  https://www.informedhealth.org/dislocated-kneecap.html

  Kneecap dislocation is most common in young people between the ages of 10 and 20. Girls and young women are at greater risk because they typically have more flexible ligaments and less muscle tissue. […] The risk of kneecap dislocation is also higher in people who have joints that stretch farther than normal (hypermobility) or weak ligaments, a kneecap that is higher than normal (patella alta), a deformed trochlear groove (trochlear dysplasia) or other anatomical abnormalities, deformities of the leg bones (such as bow-leggedness), and weak inner thigh muscles. […] A kneecap that has been dislocated is less stable afterwards. After a dislocation, it may feel like the kneecap no longer has enough support. […] Surgery is usually considered if this is already the second time your kneecap has been dislocated. It may also be considered if the kneecap is likely to be dislocated again or if there are major cartilage or bone injuries.

• #1 Patellofemoral Instability| Kneecap & Knee Joint Problems

  https://www.hss.edu/conditions_patellofemoral-kneecap-instability.asp

  Although injured ligaments do fill in and heal during recovery, these structures are generally stretched from the injury and are less able to control the patella – further contributing to the risk of another instability episode. […] Statistics show that this risk of having another dislocation or subluxation after a first time dislocation is somewhere between 20-40%; and that after the second dislocation the risk of recurrence goes up to greater than 50%. […] Surgery to stabilize the kneecap is recommended for individuals who have experienced more than one dislocation. […] Depending on the underlying risk factors for instability, the orthopedic surgeon may perform either a soft tissue or a bony procedure. […] Bony procedures or realignment surgery is advised when the patient has an anatomical abnormality in which the patella tendon attaches to the tibia in such a way that there is a severe pull on the patella sideways or laterally. […] Osteotomy also helps to compensate for the risk associated with a high patella (patella alta).

• #1 Kneecap Dislocations – Injuries and Poisoning – Merck Manual Consumer Version

  https://www.merckmanuals.com/home/injuries-and-poisoning/dislocations/kneecap-dislocations

  Kneecap dislocations occur when the kneecap and the ligaments that hold it in place slide sideways and to the outside of the knee. […] Kneecap dislocations are common. They often occur in adolescent girls who have an anatomic abnormality of the knee joint, such as loose ligaments or slightly misaligned bones. […] Usually, the kneecap slides out of place when people suddenly try to change direction. Kneecap dislocations may occur in sports that involve sudden twisting of the knee and/or impact (such as soccer, gymnastics, baseball when swinging a bat, and ice hockey). They can also occur when people trip or slip. […] Sometimes the force that caused the dislocation fractures the cartilage on the back of the kneecap or causes a small piece of the end of the thighbone to break off.

• #2 Kneecap dislocation Information | Mount Sinai – New York

  https://www.mountsinai.org/health-library/injury/kneecap-dislocation

  Kneecap dislocation occurs when the round-shaped bone covering the knee (patella) moves or slides out of place. The dislocation often occurs toward the outside of the leg. […] Kneecap dislocation often occurs after a sudden change in direction when your leg is planted. This puts your kneecap under stress. This can occur when playing certain sports, such as basketball. […] Dislocation may also occur as result of direct trauma. When the kneecap is dislocated, it can slip sideways to the outside of the knee. […] Some cases of knee dislocation may not be preventable, especially if physical factors make you more likely to dislocate your knee.

• #2 Patella Dislocation – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK538288/

  Acute patellar dislocations typically occur as a result of trauma, usually a non-contact twisting injury to the knee, or from a direct blow to the medial aspect of the knee. A common mechanism is external tibial rotation with the foot fixed on the ground. […] Patellar dislocations can also occur in patients with generalized ligamentous laxity. However, those patients mostly tend to have recurrent subluxations of their patella as opposed to a frank dislocation. […] Anatomic variations such as patella alta and trochlear dysplasia can predispose individuals to patellar dislocation. Ligamentous laxity is more commonly seen in females, or secondary to connective tissue disorders such as Marfan Syndrome or Ehlers-Danlos, increases the risk of dislocation. Muscular imbalance, particularly weakness of the vastus medialis oblique also plays a role in patellar instability.

• #2 Kneecap Dislocation & Treatment – Mayo Clinic Health System

  https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/whats-going-on-with-my-kneecap

  If your kneecap pops or slides to the outside of your knee, you’ll definitely know that something’s going on. Typically, that „something” is a partial or full dislocation, which means the kneecap, also known as the patella, has slipped partly or all the way out of its groove over the knee joint. […] Dislocation can be caused by a sudden blow, such as taking a hard hit playing a contact sport like football or hockey, or by a chronic condition like a stretched ligament. Some people have a particular knee anatomy that makes it more common. In those cases, a dislocation could be caused by something as simple as normal walking or standing up from a chair. […] Acute or chronic dislocation indicates you have a stretched or torn medial patellofemoral ligament, or MPFL, a tough band of tissue that connects to the inside of the kneecap and prevents it from sliding to the outside of the knee.

• #2 Patellar dislocation: causes, symptoms, and treatment

  https://gesund.bund.de/en/dislocated-kneecap-patellar-dislocation

  The kneecap can pop out of its groove as a result of an unfortunate twisting motion or a bump. […] An unfortunate twisting motion or a bump from the side can knock it out of its groove (dislocation). This often happens during sports, especially in adolescents and young adults. […] The kneecap can pop out when the knee joint is turned inwards in a slightly bent position, while the foot lies flat on the ground. This often happens during sports and is called acute or traumatic dislocation. Typical types of sport where this injury is particularly likely to happen include football, handball, dancing and gymnastics. […] At 80 percent, acute patellar dislocation is the most common form. Patellar subluxation can also occur, but this is less common. With subluxation, the kneecap moves sideways in the groove back and forth, without popping out completely. This can be as a result of a previous knee injury or ligaments that are too loose, for example.

• #2 Patellar dislocation – Causes and Treatment | OrthoIndy Blog

  https://blog.orthoindy.com/2014/12/05/recurrent-patellar-knee-cap-dislocations/

  After the first patellar (knee cap) dislocation, a percentage of patients will experience another dislocation(s). The probability of this occurring is related to certain risks factors that can be identified with X-rays and MRI. The most commonly cited risk factors are: high riding patella, excessive lateral position of the attachment of the patellar tendon attachment to the tibia, “knock-knees”, residual excessive looseness of the medial patellofemoral ligament or poor trochlear groove shape. […] The medial patellofemoral ligament (MPFL) runs from the inside (medial) aspect of the femur at the knee to the patella. It does not actively pull the patella into the groove, but rather keeps it from exiting or dislocating from the groove. […] The trochlea groove can be thought of as a “V” shape pulley that aids in guiding the patella as the knees flex. If the natural “V” shape is shallow or replaced by a flat or domes trochlea this abnormal shape is termed trochlear dysplasia. Just as a flat pulley would not keep a rope in place, a dysplastic trochlea makes it easier for the patella to escape/dislocate.

• #2 Patellar Dislocation (Kneecap Dislocation) | Lurie Children’s

  https://www.luriechildrens.org/en/specialties-conditions/patellar-dislocation-kneecap-dislocation/

  With a patellar dislocation, the patella (kneecap) pops out of its usual place in the groove at the end of the femur (thigh bone). […] Many patellar dislocations occur in a non-contact manner when a persons foot is planted on the ground and they twist or quickly change direction. […] Often individuals who sustain this type of injury have a particular structure of the bones such as a shallow or uneven groove for the patella or a patella that sits a little high on the femur (patella alta), which make dislocation more likely. […] Additionally, a kneecap may dislocate after a direct blow to the knee. […] Up to 25 percent of people with this injury have a family history of patellar dislocations.

• #2 Recurrent Patellar Dislocation

  https://uvahealth.com/services/orthopedics/recurrent-patellar-dislocation

  Recurrent Patellar Dislocation occurs when the kneecap slides out of place. […] When the medial patellofemoral ligament on the inside of the knee tears as a result of patellar dislocation, you might need reconstructive surgery. These tears are caused by anatomic variables like: Knock knees knees angled inward and touching when the legs are straight, Rotation of thigh or leg bone. […] Factors that may increase your chance of patellar dislocation include: Weak thigh muscles, A patella that sits too high on the thigh bone, Excess pronation of the feet inward roll of the feet when walking or running, Weak and stretched ligaments from previous patellar dislocations.

• #2 Patellar Dislocation – SportsMD

  https://www.sportsmd.com/sports-injuries/knee-injuries/patellar-dislocation-instability/

  Patellar dislocation occurs when a twisting injury to the knee joint causes the knee cap to dislocate. It usually occurs in sports when an athlete makes a plant and changes direction or performs a cutting motion. […] Factors related to the knee include poor bony development of the trochlear groove at the end of the thigh bone (femur) in which the patella normally glides. This is termed trochlear dysplasia and when present provides less than normal bony resistance to the patella dislocating. […] Another factor would be if the patella sits too high in the knee (patella alta). In this case the patella is further from the bony support of the trochlear groove and is more reliant on weaker soft-tissue ligaments to keep it centered in the knee. […] Lastly, if the attachment of the patellar tendon to the lower leg bone (tibial tubercle) is rotated too far to the outside, there is an inherent lateral (toward the outside of the knee) pull on the patella. […] Factors not inherent to the knee itself include rotational malalignment to the leg which can involve the femur (femoral anteversion) or the tibia (tibial torsion). Both of these abnormalities align the thigh muscles to pull the patella more lateral than usual.

• #2 My Knee Popped Out of Place, Then Right Back in Again – Ohio

  https://orthoneuro.com/my-knee-pops-in-out-of-place-patellar-instability/

  Patellar instability is a condition in which your kneecap slides or moves out of its normal position within your trochlear groove, which is the groove on the femur that your kneecap sits on. […] However, if you have patellar instability, the movement will result in an unstable kneecap and can even lead to a dislocated kneecap. The most common cause of a kneecap dislocation is a non-contact twisting injury when the knee joint is almost fully extended. Additionally, a direct blow to the kneecap while playing sports, a fall, or another form of accident can cause a partial or complete dislocation. […] During such injuries, the medial patellofemoral ligament (MPFL) can become damaged. This ligament plays an important role in kneecap stability. […] Kneecap dislocation and subluxation are more common in young women, especially those with loose or hypermobile joints. […] Risk factors include: Shallow Trochlear Groove: A less-defined groove provides less stability, allowing the kneecap to dislocate more easily. […] These anatomical traits make it easier for the kneecap to shift or dislocate, especially during twisting, jumping, or direct impact activities.

• #2 Patellar dislocation – Wikipedia

  https://en.wikipedia.org/wiki/Patellar_dislocation

  Causes Bending the lower leg outwards when the knee is straight, direct blow to the patella when the knee is bent. […] A patellar dislocation typically occurs when the knee is straight and the lower leg is bent outwards when twisting. […] Occasionally, it occurs when the knee is bent and the patella is struck directly. […] A predisposing factor is tightness in the tensor fasciae latae muscle and iliotibial tract in combination with a quadriceps imbalance between the vastus lateralis and vastus medialis muscles can play a large role, found, mainly, in women involved in sports. […] Another cause of patellar symptoms is lateral patellar compression syndrome, which can be caused from lack of balance or inflammation in the joints. […] When there is too much tension on the patella, the ligaments will be susceptible to tearing due to shear force or torsion force, which then displaces the patella from its groove.

• #2 Patellar Dislocation – Causes, Treatment & Exercises

  https://physioadvisor.com.au/injuries/knee/patellar-dislocation

  Patellar dislocation typically occurs when the forces pushing the knee cap out of its normal position are greater than the quadriceps muscle and patella retinaculum can resist. This typically occurs traumatically due to excessive twisting or jumping forces or due to a direct blow (usually to the inner aspect of the patella). […] There are several factors which can predispose patients to developing this condition. These need to be assessed and, where possible, corrected with direction from a physiotherapist. Some of these factors include: muscle weakness (especially the quadriceps (VMO), gluteals or hamstrings), tight lateral (outer) structures, such as the lateral patella retinaculum or iliotibial band (ITB), loose medial (inner) patella retinaculum, general hypermobility (ligament laxity), a shallow femoral groove (i.e. the groove that the knee cap sits within), genu valgum (knock knees), femoral anteversion (where the thigh bones turn inward), patella alta (abnormally high patella in relation to the thigh bone), poor lower limb biomechanics (flat feet, increased Q angle), muscle tightness (e.g. vastus lateralis, ITB, hip internal rotators, calfs), poor balance, poor pelvic or core stability, poor landing strategies, poor coordination, gender (i.e. greater likelihood in females), certain stages of the menstrual cycle (e.g. at mid-cycle (ovulation) when oestrogen peaks and ligament laxity increases), fatigue.

• #2 Dislocated kneecap: Symptoms, treatments, recovery, and more

  https://www.medicalnewstoday.com/articles/dislocated-kneecap

  Kneecap dislocation occurs when the patella bone, which sits at the front of the knee, comes out of position. In the process, the connective tissues that hold the bone in place may stretch and tear. […] A dislocated kneecap is a common injury when a person changes direction suddenly with their feet planted on the ground such as during sports or when dancing. […] According to the review, a tear in this ligament occurs in as many as 90% of kneecap dislocations. […] Anyone who has dislocated their kneecap is at risk of the injury happening again. According to a 2020 meta-analysis, people who have received nonsurgical treatment for a first-time kneecap dislocation experience a reoccurrence about 50% of the time. […] The risk of a recurrent dislocation increases if the body has not had enough time to recover fully from the initial injury. […] A 2018 review observes that surgical treatment may be a good option for people with a first-time dislocation who have a high risk of recurrence.

• #2 What Are the Signs of Kneecap Dislocation?

  https://www.verywellhealth.com/kneecap-dislocation-2549592

  A dislocation of the kneecap occurs when the patella comes completely out of its groove on the end of the thigh bone (femur), and comes to rest on the outside of the knee joint. […] When the kneecap comes out of joint the first time, ligaments that were holding the kneecap in position are torn. The most important torn structure is called the medial patellofemoral ligament, or MPFL. This ligament secures the patella to the inside (medial) part of the knee. When a kneecap dislocation occurs, the MPFL can be torn or stretched. […] Once the MPFL is torn, it often does not heal with proper tension, and the kneecap can subsequently dislocate more easily. That is why recurrent dislocations of the kneecap can continue to occur in some patients who have this injury.

• #2

  https://www.orthobullets.com/knee-and-sports/3020/patellar-instability

  Patellar instability defines a spectrum from subluxation to dislocation that results from injury, ligamentous laxity, or increased Q angle of the knee. […] Pathophysiology includes a mechanism of noncontact twisting injury with the knee extended and foot externally rotated. […] Direct blow to the medial knee is less common. […] General risk factors include ligamentous laxity (Ehlers-Danlos syndrome) and previous patellar instability event. […] Anatomical factors such as patella alta cause the patella to not articulate with the sulcus, losing its constraint effects. […] Trochlear dysplasia and excessive lateral patellar tilt are also contributing factors. […] Muscle imbalance, particularly vastus medialis oblique (VMO) muscle weakness, can increase the risk of dislocation. […] The recurrence rate of patellar instability is 15-60% following first-time dislocation. […] Younger age, patella alta, and trochlear dysplasia increase the risk of recurrence.

• #2 Dislocated kneecap | nidirect

  https://www.nidirect.gov.uk/conditions/dislocated-kneecap

  A dislocated kneecap is a common injury that normally takes about six weeks to heal. It’s often caused by a blow or a sudden change in direction when the leg is planted on the ground, such as during sports or dancing. […] This often occurs if the tissues that support the kneecap are weak or loose, such as in people with hypermobile joints, or because the groove in the bone beneath the kneecap is too shallow or uneven. […] Surgery may occasionally be needed if the kneecap keeps dislocating. This involves operating on the connective tissue (ligament) that helps hold the kneecap in place, repairing and strengthening it.

• #2 Patellar dislocation: causes, symptoms, and treatment

  https://gesund.bund.de/en/dislocated-kneecap-patellar-dislocation

  There are a few factors that increase the risk of the kneecap dislocating. These include: malformations of the legs such as knock knees, a deformed groove or other anatomical abnormalities, a higher kneecap, a weak inner thigh muscle, hypermobile joints or weak ligaments. […] Dislocation of the knee mainly occurs in young people between 10 and 20 years of age. Girls and young women are more commonly affected because they usually have more flexible ligaments and weaker muscles than boys. […] In 15 to 45 percent of people, the kneecap pops out again after it is dislocated the first time. This can happen after a few weeks or only after months or even years. […] But there is evidence that patellar dislocation can increase the risk of arthritis of the knee.

• #2 Causes and Risk Factors for Dislocated Kneecaps

  https://www.sports-health.com/sports-injuries/knee-injuries/causes-and-risk-factors-dislocated-kneecaps

  Kneecap dislocation is commonly caused by traumatic injury or by placing an excessive amount of pressure on the knee joint. The injury is more common in women, and is one of the more common injuries sustained by athletes. […] The injury can occur as the result of one or a combination of the following: […] Direct trauma to the knee. When the knee joint collides with another person or object with great force, trauma to the joint can cause the kneecap to dislocate. […] Excessive pressure from movement. When an athlete is moving at high speeds in one direction and has to quickly change direction with his or her leg planted, the knee joint sustains a great deal of pressure. In cases where the pressure is too much, the kneecap may dislocate. […] Female gender. Women have been shown to be at a higher risk for kneecap dislocation than men. It is thought that this risk may may be because women tend to have wider hips, causing the thigh bones slant inward and join the knee at more of an angle.

• #2 Patella dislocation | University of Iowa Health Care

  https://uihc.org/health-topics/patella-dislocation

  Playing a sport that requires you to change directions quickly, like tennis or basketball, can put you at risk for a kneecap dislocation. […] Causes include: […] A sudden change in direction while your leg is planted. […] A direct hit to your knee by the ground or by another person.

• #2 Common Causes of Knee Dislocation – Mid Atlantic Orthopedic Associates, LLP: Orthopedic Surgery: North & East Brunswick, NJ

  https://www.midatlanticorthonj.com/common-causes-of-knee-dislocation/

  Being overweight or obese significantly increases the amount of pressure on the knees, making even simple movements such as climbing stairs demanding. Obesity is associated with more severe dislocations that cause damage to the veins near the knee. […] Studies suggest that participating in sports that involve moving at high speeds and engaging in high-risk movements (e.g., snowboarding, skateboarding, and skiing) may increase your risk for hip and knee dislocations.

• #2 Patellar Dislocation in Children | The Noyes Knee Institute

  https://noyeskneeinstitute.com/patellar-dislocation-in-children-what-parents-need-to-know/

  When the knee functions as intended, the kneecap sits securely in a groove at the end of the thighbone. Problems arise when the kneecap moves too far to the left or the right, which creates a misplacement. […] Knee dislocations in children are often due to abnormalities in the structure of the knee, which makes it easy for the kneecap to slip out of place. If a child’s ligaments are loose, this causes the joints to be more flexible, which can result in a higher likelihood of patellar dislocation. […] Children with Down Syndrome and cerebral palsy may be more susceptible to knee dislocations due to issues with imbalance and muscle weakness. Though rare, some children are born with unstable kneecaps and may suffer painless dislocations at a very early age.

• #2 Kneecap (Patellar) Dislocation | Cedars-Sinai

  https://www.cedars-sinai.org/health-library/diseases-and-conditions/k/kneecap-patellar-dislocation.html

  It is common for a kneecap dislocation to occur after a high-impact injury. After the first time, the kneecap is more likely to dislocate again. Young people, such as adolescents who are more active, are at a greater risk of having a dislocated kneecap. […] A common problem comes from having too much sideways pull which moves the kneecap out of its groove. This can place increased pressure on cartilage and lead to dislocation.

• #2 Patellofemoral Instability| Kneecap & Knee Joint Problems

  https://www.hss.edu/conditions_patellofemoral-kneecap-instability.asp

  Although injured ligaments do fill in and heal during recovery, these structures are generally stretched from the injury and are less able to control the patella – further contributing to the risk of another instability episode. […] Statistics show that this risk of having another dislocation or subluxation after a first time dislocation is somewhere between 20-40%; and that after the second dislocation the risk of recurrence goes up to greater than 50%. […] Surgery to stabilize the kneecap is recommended for individuals who have experienced more than one dislocation. […] Depending on the underlying risk factors for instability, the orthopedic surgeon may perform either a soft tissue or a bony procedure. […] Bony procedures or realignment surgery is advised when the patient has an anatomical abnormality in which the patella tendon attaches to the tibia in such a way that there is a severe pull on the patella sideways or laterally. […] Osteotomy also helps to compensate for the risk associated with a high patella (patella alta).

• #2 Recurrent Patella Dislocation Parker, CO | Knee Instability Parker, CO

  https://www.karimmeijermd.com/recurrent-patella-dislocation-orthopaedic-surgeon-parker-co/

  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. […] There are various causes of recurrent patella dislocation. Some of them include: Certain inherited traits: Kneecap that is seated too high in the groove, Shallow trochlear groove, Tight lateral ligaments, Valgus leg alignment (knock-kneed legs), Trauma (sudden twisting and bending of the leg), Skeletal immaturity, Each dislocation causes stretching of soft tissues and increases the chances of recurrence.

• #2 Knee Dislocation and Instability in Children – OrthoInfo – AAOS

  https://orthoinfo.aaos.org/en/diseases–conditions/patellar-dislocation-and-instability-in-children-unstable-kneecap/

  Because a dislocation often damages knee tissue, the patella often remains looser, or more unstable, than it was before the injury. As a result, the patella may dislocate again. […] Recurrences also are common if the dislocation was caused by an irregularity in the knee structure. […] If your child’s patella dislocates multiple times, or continues to be unstable despite therapy and bracing, surgery may be recommended to correct the problem. The type of surgery will depend on the cause of the unstable kneecap.

• #2 Dislocated Kneecaps: What to Do When it Happens

  https://www.parkwayeast.com.sg/health-plus/article/kneecap-dislocation-children

  Kneecap, or patella, dislocation in children happens more often than we think. […] A dislocated kneecap usually happens when a child falls, or takes a hit to the knee. […] Almost 60 80% of kneecap injuries usually occur when performing a cutting/turning action while the foot is firmly planted on the ground. […] Apart from these, inborn deformities of the thighbone, kneecap and ligamentous laxity can make your child more prone to this injury. […] Surgery is required if the patella dislocates multiple times, continues to be unstable despite treatment, or if there’s evidence of bone injury. […] The type of surgery required is guided by the injury sustained as well as the root cause. […] These are important as recurrent dislocations lead to structural damage and subsequent development of arthritis.

• #2 Dislocated kneecap | informedhealth.org

  https://www.informedhealth.org/dislocated-kneecap.html

  Kneecap dislocation is most common in young people between the ages of 10 and 20. Girls and young women are at greater risk because they typically have more flexible ligaments and less muscle tissue. […] The risk of kneecap dislocation is also higher in people who have joints that stretch farther than normal (hypermobility) or weak ligaments, a kneecap that is higher than normal (patella alta), a deformed trochlear groove (trochlear dysplasia) or other anatomical abnormalities, deformities of the leg bones (such as bow-leggedness), and weak inner thigh muscles. […] A kneecap that has been dislocated is less stable afterwards. After a dislocation, it may feel like the kneecap no longer has enough support. […] Surgery is usually considered if this is already the second time your kneecap has been dislocated. It may also be considered if the kneecap is likely to be dislocated again or if there are major cartilage or bone injuries.

• #2 Overview: Dislocated kneecap – InformedHealth.org – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK561511/

  Kneecap dislocation is most common in young people between the ages of 10 and 20. Girls and young women are at greater risk because they typically have more flexible ligaments and less muscle tissue. […] The risk of kneecap dislocation is also higher in people who have joints that stretch farther than normal (hypermobility) or weak ligaments, a kneecap that is higher than normal (patella alta), a deformed trochlear groove (trochlear dysplasia) or other anatomical abnormalities, deformities of the leg bones (such as bow-leggedness), and weak inner thigh muscles. […] A kneecap that has been dislocated is less stable afterwards. After a dislocation, it may feel like the kneecap no longer has enough support. The front of the knee may hurt, especially when more stress is put on the joint. […] In 15 to 45% of people who have a kneecap dislocation, it happens again afterwards. Sometimes this happens after just a few weeks, but it can also happen several months or years later. […] There’s not much good research on the longer-term effects of kneecap dislocation so less is known about them. But it can increase the risk of knee osteoarthritis. That is particularly true if the kneecap has been dislocated several times, which usually damages the cartilage more.

• #3 Dislocated Kneecaps: What to Do When it Happens

  https://www.parkwayeast.com.sg/health-plus/article/kneecap-dislocation-children

  Kneecap, or patella, dislocation in children happens more often than we think. […] A dislocated kneecap usually happens when a child falls, or takes a hit to the knee. […] Almost 60 80% of kneecap injuries usually occur when performing a cutting/turning action while the foot is firmly planted on the ground. […] Apart from these, inborn deformities of the thighbone, kneecap and ligamentous laxity can make your child more prone to this injury. […] Surgery is required if the patella dislocates multiple times, continues to be unstable despite treatment, or if there’s evidence of bone injury. […] The type of surgery required is guided by the injury sustained as well as the root cause. […] These are important as recurrent dislocations lead to structural damage and subsequent development of arthritis.

Zobacz więcej