What Is the Fibular Collateral Ligament?

The peroneal collateral ligament is a ligament of the knee joint. This ligament is a cord-like tough fiber located on the outside of the joint. It starts from the outer epicondyle of the femur and stops at the middle of the outer side of the small head of the fibula. There is loose connective tissue between this ligament and the joint capsule, and it is separated from the meniscus by diaphragmatic tendons. The two are not directly connected. When the knee flexes and the calf rotates inward, the tibial and fibula collateral ligaments are relaxed. On the contrary, when the knee is stretched and the calf is out of tension, it is tense, so it has the effect of restricting the excessive extension of the knee joint and the out of rotation.

The peroneal collateral ligament is a ligament of the knee joint. This ligament is a cord-like tough fiber located on the outside of the joint. It starts from the outer epicondyle of the femur and stops at the middle of the outer side of the small head of the fibula. There is loose connective tissue between this ligament and the joint capsule, and it is separated from the meniscus by diaphragmatic tendons. The two are not directly connected. When the knee flexes and the calf rotates inward, the tibial and fibula collateral ligaments are relaxed. On the contrary, when the knee is stretched and the calf is out of tension, it is tense, so it has the effect of restricting the excessive extension of the knee joint and the out of rotation.

Chinese name

Peroneal collateral ligament

Foreign name

ligamentum collaterale fibulare

Department

Anatomy

Physiological significance of peroneal collateral ligament

The fibular collateral ligament and tibial collateral ligament strengthen the knee joint from both sides. When the knee joint is flexed and internally rotated, the fibula collateral ligament relaxes, allowing the calf to perform a small range of maneuvering movements on the knee joint; and when the knee joint is straightened, they are tightened to prevent excessive femoral extension and external rotation.

When the peroneal collateral ligament is loose, the knee joint is subjected to excessive adduction (varus) violence on both sides of the knee joint, which can cause the peroneal collateral ligament to be injured.

The peroneal collateral ligament can be regarded as an upward extension of the peroneus longus. The peroneal collateral ligament is divided into two parts. Generally, the peroneal collateral ligament refers to its superficial part, and its deep external short ligament. In the occurrence, due to the inconsistent growth rate of the tibia and fibula, the upper fibula is lower than the tibial articular surface. The tip of the head will form the extension of the lower part of the original joint capsule, so there is no joint capsule attached to the posterior and outer edges of the upper end of the tibia, and replaced by the patellar tendon. The extended joint capsule is the deep peroneal collateral ligament. Contrary to the tibial collateral ligament, the peroneal collateral ligament is directly connected to the lateral submeniscus. A diaphragmatic tendon surrounds the lateral meniscus and the deep ligament. A synovial sheath forms an oblique groove after the outer edge of the outer meniscus. The position of the tibiofibular collateral ligament is behind the knee joint. When the knee flexes, the collateral ligament is loose. The tibial can be rotated slightly to control abduction, adduction or rotation. When the knee is extended, the lateral collateral ligament is tense, and the knee The joints become stable, which can prevent the knee from over-straightening. When the calf is externally rotated, the peroneal collateral ligament is loosened, sometimes twisted, curled, and protruded.

Clinical anatomy of the peroneal collateral ligament :

The lateral collateral ligament of the knee joint is divided into the medial collateral ligament (MCL) and lateral collateral ligament (LCL). It is the main stabilization device on the inner and outer sides of the knee joint. Included in the knee, lateral space.

Medial collateral ligament

The medial collateral ligament, the hemi-membrane muscle, the goose foot tendon, and the oblique ligament portion of the posterior joint capsule are all included in the medial space. Hughston et al. Divided the medial knee support device into three parts, namely, anterior, medial, and posterior.

The medially spaced support structure ranges from the patellar tendon to the posterior cruciate ligament (PCL) on the medial side. The anterior 1/3 of the medial collateral ligament is relatively loose, and the surface layer is covered by the quadriceps extensor knee support band. The middle 1/3 is a strong structure, which is reinforced by the tibial collateral ligament. The posterior 1/3 of the thickened medial joint capsule ligament is called the posterior oblique ligament. Its function is increased by the dynamic stabilization of the capsule wall of the semitendinal tendon and the zygomatic ligament and aponeurosis, and the medial head of the gastrocnemius muscle provides dynamic support of the medial space.

Because the ligament is composed of tissue layers and loose layers, Warren and Marshall described the concept of the layer of the medial part of the knee joint. The medial knee support structure is divided into 3 levels:

The first layer is the shallowest fascia layer, including deep fascia or superficial fascia and extending from the anterior side of the sacrum and patellar tendon to the posterior midline of the popliteal fossa. The sartorius muscles rest on the fascial fiber network and do not have the obvious cavity structure like the underlying gracilis and semitendinosus muscles. The distal anterior side, the first layer and the sartorius muscle stop at the tibial periosteum. On the posterior side, this layer expands into the fascia of the two heads of the gastrocnemius muscle and the surface layer of the popliteal fossa structure.

The second layer is a parallel layer of shallow medial collateral ligament. Brantigan and Voshell described this ligament as having a vertical portion and an oblique portion, which act differently when the knee flexes. The vertical and oblique sections stop at 5 cm below the joint level, on the back side of the goose feet. The shallow anterior part of the medial ligament is parallel to the fibers, which are distributed around the flexion of the knee joint to maintain continuous tension in the range of motion. On the posterior side, the oblique fibers of the superficial ligament are mixed with the deep layer at the posterior inner corner, thereby forming a posterior oblique ligament that relaxes during flexion. On the front side, layers 1 and 2 form a connecting structure and extend to the edge of the medial femoral muscle. Located between the posterior inner corners of layers 1 and 2 are the semitendinosus and gracilis tendons.

The posterior internal articular capsule is the posterior oblique ligament, and its dynamic stabilization effect is increased by the semitendinal muscle tendon, the joint capsule wall, and the oblique ligament aponeurosis. The semimembranous muscle sends out two extensions to the distal end. The first is the zygomatic oblique ligament that penetrates from the dead center located at the postero-medial part of the tibia to the dead center of the lateral head of the gastrocnemius muscle. When the zygomatic oblique ligament contracts, its posterior medial tightens the posterior part of the joint capsule. The second is the posterior angle of the posterior articular capsule and the medial meniscus. This part can also tighten the medial part and make the medial meniscus pull back to the knee when the knee flexes. The anterior medial tendon extends along the medial side of the tibia and stops below the superficial layer of the medial collateral ligament. This straight head is attached to the posterior medial tibia below the joint level. The distal portion of the hemiperitoneal muscle continues to the distal end to form a fibrous portion of the diaphragm surface and integrates into the periosteum of the medial tibial bone. The hemimenus flexes and rotates the tibia, contracts the posterior horn of the medial meniscus, and tightens the posterior joint capsule through the zygomatic ligament.

The third layer is the actual knee joint capsule, located deep in the superficial layer of the medial ligament. The third layer thickens to form a short fiber bundle in the vertical direction, that is, the deep layer of the medial collateral ligament, or the medial joint capsule ligament. This deep ligament extends from the femur to the middle of the meniscus and tibia margins. The meniscal femur of the deep ligament merges into the head at the point of attachment of the superficial ligament. Anatomy has shown that there is another separate attachment point for this ligament in some joints. The joint capsule enters the tibial meniscus and is relatively loose and short, preventing the medial meniscus from over-mobilizing. Coronary ligament is usually a structure separated from the superficial ligament. The other parts of the third layer follow the synovial cavity and extend proximally to the supracondylar dimple and distally to the meniscus tibial ligament. Layers 2 and 3 are mixed on the posterior side to form a loose structure like oblique fibers of the posterior internal joint capsule.

Hughton et al. Believe that the posterior oblique ligament is the main medial support structure to resist knee valgus pressure. Although the posterior oblique ligament is more relaxed when flexed under the action of the semitendinal muscle tendon, the posterior oblique ligament plays a significant role in stabilizing at the first 60 ° of flexion. Muller also believes that when the knee is extended, the posterior oblique ligament has the greatest effect against valgus relaxation. At the same time, the posterior oblique ligament and the tibial collateral ligament are functionally independent, but both are dynamic. The former is the hemimen tendon and the latter is the medial femoral muscle. At the same time, he believes that the tibial collateral ligament can prevent the external rotation of the tibia on the femur during knee flexion. However, the prevention of external rotation is mainly the posterior oblique ligament.

Warren et al. Believe that the main stable structure of the medial knee joint is the long tibial collateral ligament, especially the anterior fiber. The front 5mm stays tight during flexion and counteracts valgus pressure when turning out in this position. The superficial tibial collateral ligament is slightly loosened 2/3 of the time after knee flexion, which serves as the posterior force to counter valgus and external rotation. The shallow oblique or posterior part of the tibial collateral ligament, which Hughton believes is the posterior oblique ligament, is the thickened part of the posterior side of the knee capsule, where it firmly contacts and attaches to the medial meniscus.

Goose foot is the common termination point of the semitendinosus muscle, the sartorius muscle, and the gracilis muscle. The semitendinosus muscle starts from the ischial tuberosity, crosses the thigh, and stops at the upper tibia by fusing ligaments. The semitendinosus muscle is dominated by the sciatic nerve and supplied by the deep femoral artery and the iliac artery, but the semitendinosus muscle is slightly outside the starting point of the sciatic tuberosity and slightly shallower and posterior in the tibial condyle. The gracilis muscles originate from the pubic symphysis, are parallel to the semimembranosus and semitendinosus muscles in the thighs, and stop at the goose feet on the medial part of the tibia. Dominated by the anterior branch of the obturator nerve, its blood supply comes from three main sources: the deep femoral artery, the obturator artery, and the internal femoral artery. The sartorius muscle starts at the proximal end of all the medial muscles, starting from the anterior superior iliac spine and ends at the medial part of the tibia in the form of a goose foot. Its blood supply and innervation come from the femoral artery and the femoral nerve, respectively.

Lateral collateral ligament

The sacral tibia, lateral collateral ligament, iliac tendon, and biceps femoris are included in the lateral septum. Hugh-ton et al. Divided the lateral support structure of the knee joint into 3 parts: anterior, middle, and posterior 1/3. The lateral extent of the structure includes the patellar tendon to the posterior cruciate ligament (PCL). The anterior 1/3 is relatively thin and loose, and its surface is covered by the quadriceps extensor support band. The anterior 1/3 includes the joint capsule ligament that expands backwards, ranging from the lateral border of the patellar tendon and the iliac bone to the front of the sacroiliac tibia. edge. There is no connection between the anterior third of the lateral joint capsule ligament and the femur. The middle third of the lateral ligament is composed of the sacro-tibial tract and its deep joint capsule ligament, which extends backward to the lateral collateral ligament. The zygomatic tibia bundle can provide dynamic / static stability, enhancing the middle 1/3 area. The middle 1/3 of the lateral joint capsule ligament attaches proximally to the femoral epicondyle and distally to the edge of the tibial joint. The posterior 1/3 includes the articular capsule and non-articular capsule ligaments, forming a single functional unit called the "arched complex". This unit consists of the peroneal collateral ligament, arcuate ligament, and diaphragm. The posterior third is enhanced by the power from the lateral head of the gastrocnemius, diaphragm, and biceps femoris (Figure 16-37).

Seebacher believes that, similar to the medial knee, there is a three-layer structure on the lateral knee.

The first layer is the shallowest layer, which is composed of the superficial layer of the iliotibial bundle and its anterior expansion part of the biceps femoris and its backward expansion part. The zygomatic tibial tract provides dynamic / static support. This structure extends from the superior iliac capsule to the popliteal fossa. Terry et al. Studied the effect of the iliotibial bundle as a lateral knee static / dynamic stabilization dynamic. The iliotibial bundle is anatomically divided into the aponeurotic layer, superficial, middle, and deep, and the synovial layer of the joint capsule. The aponeurosis layer is located on the surface of the sacrum and the patellar tendon, with a superficial layer below it, consisting of the lateral femoral muscle, the iliotibial bundle, the lateral patellar tendon, and the biceps femoris. The middle layer forms a wavy cross, which strengthens the iliotibial bundle. Deep thickening strengthens the superficial layer of the iliotibial bundle.

The second layer is formed by the support band of the quadriceps, and the posterior side is formed by 2 patellofemoral ligaments. The posterior ligament joins the terminal fibers of the lateral muscle space, and the distal end stops at the gastrocnemius bean (seed fibrocartilage in the gastrocnemius muscle) or the posterior lateral joint capsule and the lateral head of the gastrocnemius on the femoral condyle. The metatarsal ligament of the sacrum attaches to the lateral meniscus and stops at the Gerdy tubercle (anterior tibial tubercle). There is an LCL (lateral collateral ligament) between the quadriceps support band and the patellofemoral ligament.

The third layer is the deepest layer and is attached to the edges of the tibia and femur. The joint capsule attaches to the lateral meniscus like a coronary ligament. The patellar tendon is attached to the femur through a slit in the coronary ligament. On the posterior side, the arcuate ligaments span the diaphragm and originate from the junction between the femoral and fibula tendons. The posterolateral articular capsule is composed of the knee collateral ligament, arched ligament, and plantar tendon. The support function of the arcuate complex is enhanced by the dynamic effects of the biceps femoris, diaphragm and gastrocnemius lateral head.

Although the LCL relaxes during flexion, it may be the major valgus stabilization force when the knee is straightened. The arcuate ligament is the posterolateral part of the knee joint, which lies immediately behind the LCL and is located between the two layers of the joint capsule. The arcuate ligament is usually separated by blood vessels on the medial knee. Fibers of the oblique ligament are added to the inner foot of the arcuate ligament. The posterolateral part of the knee joint is often called the zygomatic oblique ligament. Hughton and Eller's description of the arcuate complex includes LCL, the plantar tendon, and the medial and lateral heads of the gastrocnemius muscle. The diaphragm is the last part of this quadrangular complex, and it has a composition that reverses the starting and ending points. The proximal attachment (starting point) is its tendon part, and its muscular abdomen is located at the distal end. The basic function is to make the knee rotate internally. By virtue of the wavy articular surface of the joint, the posterior portion of the lateral meniscus is contracted to complete the "unbuttoning" of the knee joint.