Diagnosis
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| Patellar subluxation syndrome | |
|---|---|
| Other names | Patellar instability, Unstable kneecap |
Patellar subluxation syndrome, is an injury that is concerned with the kneecap. Patellar subluxation is more common than patellar dislocation and is just as disabling. [1]
In this condition, the patella repetitively subluxates and places strain on the medial restraints and excessive stress/tension on the patellofemoral joint. Patellar subluxation can be caused by osseous abnormalities, such as incorrect articulation of the femoral groove with the patella, trochlear dysplasia, or patella alta, which is a distance of greater than 20 mm between the tibial tubercle and the trochlear groove. It can also result from soft-tissue abnormalities, such as a torn medial patellofemoral ligament, or a weakened vastus medialis obliquus. [2] Symptoms are regulated by the amount of activity. Such pain is commonly caused by running and jumping sports and activities that place large forces on the patellofemoral joint. [1]
Symptoms usually include: [3]
Patellar subluxation was once thought to occur mainly in women, [1] due to the frequency of genu valgum and lax ligaments. However, now the frequency of this condition in any athletic person, man or woman, is apparent.[ citation needed ]
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Conservative treatment in primary acute LPD (lateral patellar dislocation) is the therapy of choice. It includes a multimodal approach with behavioural education of the patient, physical therapy, braces, weight reduction and pain medication. [4]
Physical therapy especially focuses on muscle strengthening and proprioceptive exercises. The vastus medialis oblique muscle is described to have an important role in functional stabilization of the patella against lateral vector force. [5] Proprioceptive exercises and strengthening of the hip abductors and positioning of the foot are crucial, especially indicated in patient with miserable malalignment syndrome or medial collapse. [6]
Several patellar braces or taping methods exist to improve return to sport. They may however not alter medial or lateral displacement, but can be helpful as a diagnostic tool for occult patellofemoral instability. [7]
Increasing age is associated with decreased physical activity after surgical stabilization, and therefore in growing and very active athletes early surgical treatment intervention needs to be considered. Reconstruction of the MPFL (medial patellofemoral ligament) in patients with minor trochlear dysplasia is technically possible without interfering with distal growth plate of the femur, [8] however, large studies are missing. Osseous articular correction before epiphyseal closure is contraindicated. [9]
In adult patients with recurrent LPD and without trochlear dysplasia or type A or C according to Dejour classification, MPFL reconstruction alone might be beneficial, in which unchanged osseous or dynamic instability will be compensated. [10] Patients with an important supra-trochlear spur as in type B and D trochlear dysplasia and chronic instability are more reluctant to conservative and soft-tissue surgical treatment options. [11] In such cases sulcus-deepening trochleoplasty should be performed. [10] Typically, post-surgical results are more favourable when instability was the main symptom. Hence, in such patients low-pivoting physical activity may be re-achieved.[ citation needed ]
In humans and other primates, the knee joins the thigh with the leg and consists of two joints: one between the femur and tibia, and one between the femur and patella. It is the largest joint in the human body. The knee is a modified hinge joint, which permits flexion and extension as well as slight internal and external rotation. The knee is vulnerable to injury and to the development of osteoarthritis.
The patella, also known as the kneecap, is a flat, rounded triangular bone which articulates with the femur and covers and protects the anterior articular surface of the knee joint. The patella is found in many tetrapods, such as mice, cats, birds and dogs, but not in whales, or most reptiles.
The quadriceps femoris muscle is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large fleshy mass which covers the front and sides of the femur. The name derives from Latin four-headed muscle of the femur.
A luxating patella, sometimes called a trick knee, is a condition in which the patella, or kneecap, dislocates or moves out of its normal location. It can be associated with damage to the anterior cruciate ligament.
A joint dislocation, also called luxation, occurs when there is an abnormal separation in the joint, where two or more bones meet. A partial dislocation is referred to as a subluxation. Dislocations are often caused by sudden trauma on the joint like an impact or fall. A joint dislocation can cause damage to the surrounding ligaments, tendons, muscles, and nerves. Dislocations can occur in any major joint or minor joint. The most common joint dislocation is a shoulder dislocation.
Chondromalacia patellae is an inflammation of the underside of the patella and softening of the cartilage.
Knee replacement, also known as knee arthroplasty, is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve pain and disability, most commonly offered when joint pain is not diminished by conservative sources. It may also be performed for other knee diseases, such as rheumatoid arthritis. In patients with severe deformity from advanced rheumatoid arthritis, trauma, or long-standing osteoarthritis, the surgery may be more complicated and carry higher risk. Osteoporosis does not typically cause knee pain, deformity, or inflammation, and is not a reason to perform knee replacement.
The vastus medialis is an extensor muscle located medially in the thigh that extends the knee. The vastus medialis is part of the quadriceps muscle group.
The knee examination, in medicine and physiotherapy, is performed as part of a physical examination, or when a patient presents with knee pain or a history that suggests a pathology of the knee joint.
The unhappy triad, also known as a blown knee among other names, is an injury to the anterior cruciate ligament, medial collateral ligament, and meniscus. Analysis during the 1990s indicated that this 'classic' O'Donoghue triad is actually an unusual clinical entity among athletes with knee injuries. Some authors mistakenly believe that in this type of injury, "combined anterior cruciate and medial collateral ligament disruptions that were incurred during athletic endeavors" always present with concomitant medial meniscus injury. However, the 1990 analysis showed that lateral meniscus tears are more common than medial meniscus tears in conjunction with sprains of the ACL.
In human anatomy, the quadriceps tendon works with the quadriceps muscle to extend the leg. All four parts of the quadriceps muscle attach to the shin via the patella, where the quadriceps tendon becomes the patellar ligament. It attaches the quadriceps to the top of the patella, which in turn is connected to the shin from its bottom by the patellar ligament. A tendon connects muscle to bone, while a ligament connects bone to bone.
Patellofemoral pain syndrome is knee pain as a result of problems between the kneecap and the femur. The pain is generally in the front of the knee and comes on gradually. Pain may worsen with sitting, excessive use, or climbing and descending stairs.
A lateral release is a surgical procedure to release tight capsular structures on the outer aspect of the kneecap (patella). This is usually performed because of knee pain related to the kneecap being pulled over to the outer (lateral) side and not being able to run properly in the centre of the groove of the femur bone as the knee bends and straightens. The procedure is also known as a 'lateral retinacular release'.
The intercondylar fossa of femur is a deep notch between the rear surfaces of the medial and lateral epicondyle of the femur, two protrusions on the distal end of the femur that joins the knee. On the front of the femur, the condyles are but much less prominent and are separated from one another by a smooth shallow articular depression called the patellar surface because it articulates with the posterior surface of the patella (kneecap).
The pivot-shift test is one of the three major tests for assessing anterior cruciate injury or laxity, the other two being the anterior drawer and Lachman test. However, unlike the other two, it tests for instability, an important determinant as to how the knee will function. In fact, it is instability, not simply the injury to the anterior cruciate ligament itself, that places the menisci at future risk, and gives rise to the feeling that the "knee is not secure" or "may give out".
A patellar dislocation is a knee injury in which the patella (kneecap) slips out of its normal position. Often the knee is partly bent, painful and swollen. The patella is also often felt and seen out of place. Complications may include a patella fracture or arthritis.
The medial patellofemoral ligament is one of the several ligaments on the medial aspect of the knee. It originates on the superomedial aspect of the patella and inserts in the space between the adductor tubercle and the medial femoral epicondyle. Its main function is to prevent lateral displacement of the patella.
Knee pain is pain in or around the knee.
Medial knee injuries are the most common type of knee injury. The medial ligament complex of the knee consists of:
The anterolateral ligament (ALL) is a ligament on the lateral aspect of the human knee, anterior to the fibular collateral ligament.