Anterior interval release
Encyclopedia
Anterior interval release (AIR) is a type of arthroscopic
knee surgery performed to alleviate pain and associated symptoms caused by scar tissue (or fibrosis)
accumulation in the anterior region of the knee
, behind and under the knee cap (or patella), in a condition called arthrofibrosis
. In normal, asymptomatic knee
s, this anterior compartment of the knee comprises mobile, scar-free tissues such as the infrapatellar (Hoffa's) fat pad. With progression, scar tissue (or fibrosis)
leads to closure of the anterior interval, tethering the patella tendon and causing pain, loss of range of motion
, damage to knee
cartilage
, and/or pain, among other symptoms.
Diagnosis of arthrofibrosis
or scar tissue
in the anterior interval can comprise of clinical signs such as a positive Hoffa test, loss in knee
flexion
, and/or diminished superoinferior patella mobility
, with supplementation by magnetic resonance imaging (or MRI)
Post-surgical rehabilitation should be conservative in nature, focusing on maintaining joint mobility via early motion to avoid reformation of scar tissue
. Early motion may be promoted by specific mobility exercises
and use of continuous passive motion
. Restoration of joint range of motion
may be augmented by specialized bracing
devices. Weight bearing
is delayed appropriately post-surgically to promote control of swelling, pain, and joint irritation. Strengthening is delayed to a minimum of 6 weeks, oftentimes several months, post-operatively.
The origins leading to arthrofibrosis
are unclear. They frequently have involved previous knee injury or trauma
, such as anterior cruciate ligament
reconstruction surgery. More subtle origins of fibrotic
contracture in the anterior interval have also been attributed to plica (or naturally occurring folds in the knee joint lining
that become stiff and restrictive.
Arthroscopy
Arthroscopy is a minimally invasive surgical procedure in which an examination and sometimes treatment of damage of the interior of a joint is performed using an arthroscope, a type of endoscope that is inserted into the joint through a small incision...
knee surgery performed to alleviate pain and associated symptoms caused by scar tissue (or fibrosis)
Fibrosis
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...
accumulation in the anterior region of the knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
, behind and under the knee cap (or patella), in a condition called arthrofibrosis
Arthrofibrosis
Arthrofibrosis is a complication of injury or trauma where an excessive scar tissue response leads to painful restriction of joint motion, with scar tissue forming within the joint and surrounding soft tissue spaces and persisting despite rehabilitation exercises and stretches...
. In normal, asymptomatic knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
s, this anterior compartment of the knee comprises mobile, scar-free tissues such as the infrapatellar (Hoffa's) fat pad. With progression, scar tissue (or fibrosis)
Fibrosis
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...
leads to closure of the anterior interval, tethering the patella tendon and causing pain, loss of range of motion
Range of motion
Range of motion , is the distance that a movable object may normally travel while properly attached to another object. It is also called range of travel, particularly when talking about mechanical devices and in mechanical engineering fields...
, damage to knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
cartilage
Cartilage
Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...
, and/or pain, among other symptoms.
Diagnosis of arthrofibrosis
Arthrofibrosis
Arthrofibrosis is a complication of injury or trauma where an excessive scar tissue response leads to painful restriction of joint motion, with scar tissue forming within the joint and surrounding soft tissue spaces and persisting despite rehabilitation exercises and stretches...
or scar tissue
Fibrosis
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...
in the anterior interval can comprise of clinical signs such as a positive Hoffa test, loss in knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
flexion
Flexion
In anatomy, flexion is a position that is made possible by the joint angle decreasing. The skeletal and muscular systems work together to move the joint into a "flexed" position. For example the elbow is flexed when the hand is brought closer to the shoulder...
, and/or diminished superoinferior patella mobility
Mobility
Mobility may refer to:* Mobility * "Mobiliy" , a song by Moby* Mobility * Mobility , the ability of military units or weapon systems to move to an objective-See also:* Academic mobility* Apprentices mobility...
, with supplementation by magnetic resonance imaging (or MRI)
Magnetic resonance imaging
Magnetic resonance imaging , nuclear magnetic resonance imaging , or magnetic resonance tomography is a medical imaging technique used in radiology to visualize detailed internal structures...
Post-surgical rehabilitation should be conservative in nature, focusing on maintaining joint mobility via early motion to avoid reformation of scar tissue
Fibrosis
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...
. Early motion may be promoted by specific mobility exercises
Exercises
- 30th Anniversary Bonus Tracks:-Band members:*Dan McCafferty - vocals*Darrell Sweet - drums, backing vocals*Pete Agnew - bass guitar, acoustic guitar, backing vocals*Manny Charlton - guitar, 12-string guitar, backing vocals-Additional musicians:...
and use of continuous passive motion
Continuous passive motion
Continuous passive motion devices are used during the first phase of rehabilitation following a soft tissue surgical procedure or trauma. The goals of phase 1 rehabilitation are Control post-operative pain, Reduce inflammation, Provide passive motion in a specific plane of movement , and Protect...
. Restoration of joint range of motion
Range of motion
Range of motion , is the distance that a movable object may normally travel while properly attached to another object. It is also called range of travel, particularly when talking about mechanical devices and in mechanical engineering fields...
may be augmented by specialized bracing
Orthotics
Orthotics is a specialty within the medical field concerned with the design, manufacture and application of orthoses. An orthosis is an orthopedic device that supports or corrects the function of a limb or the torso...
devices. Weight bearing
Weight bearing
In orthopedics, weight-bearing is the amount of weight a patient puts on the leg on which surgery has been performed. In general, it is described as a percentage of the body weight, because each leg of a healthy person carries the full body weight when walking, in an alternating fashion.After...
is delayed appropriately post-surgically to promote control of swelling, pain, and joint irritation. Strengthening is delayed to a minimum of 6 weeks, oftentimes several months, post-operatively.
The origins leading to arthrofibrosis
Arthrofibrosis
Arthrofibrosis is a complication of injury or trauma where an excessive scar tissue response leads to painful restriction of joint motion, with scar tissue forming within the joint and surrounding soft tissue spaces and persisting despite rehabilitation exercises and stretches...
are unclear. They frequently have involved previous knee injury or trauma
Trauma (medicine)
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
, such as anterior cruciate ligament
Anterior cruciate ligament
The anterior cruciate ligament is a cruciate ligament which is one of the four major ligaments of the human knee. In the quadruped stifle , based on its anatomical position, it is referred to as the cranial cruciate ligament.The ACL originates from deep within the notch of the distal femur...
reconstruction surgery. More subtle origins of fibrotic
Fibrosis
Fibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...
contracture in the anterior interval have also been attributed to plica (or naturally occurring folds in the knee joint lining
Plica Syndrome
Plica Syndrome occurs when the plica becomes irritated or inflamed.-Presentation and pathophysiology:...
that become stiff and restrictive.