Articulatio Coxae Anatomisi

• Articulatio coxae is also known as Art. coxofemoralis

Articulatio coxae (Art. coxofemoralis)

• It is located between the acetabulum and the caput femoris
• It is classified as an Art. spheroidea joint
• Not all of the acetabulum participates in the joint
• Only the facies lunata, covered with articular cartilage, participates
• The fossa acetabuli, which does not participate in the joint, is filled with adipose tissue
• The acetabulum has a labrum acetabulare on its edge
• The labrum is a fibrocartilaginous structure that increases the joint surface area
• The incisura acetabuli, on the lower part of the acetabulum, is closed by the lig. transversum acetabuli
• The labrum acetabulare attaches to this ligament

Articulatio coxae ligaments

• Include the Capsula articularis
• Include the Lig. iliofemorale
• Include the Lig. ischiofemorale
• Include the Lig. pubofemorale
• Include the Zona orbicularis
• Include the Lig. capitis femoris
• Include the Lig. transversum acetabuli
• Include the Labrum acetabulare

Capsula articularis

• Tightly surrounds the joint and attaches along the edge of the acetabulum
• Attaches to the lig. transversum acetabuli at the incisura acetabuli below
• Attaches to the linea intertrochanterica on the anterior surface of the femur, and to the crista intertrochanterica on the posterior surface
• A large portion of the femur neck is within the joint cavity
• The weakest part of the joint capsule is the section between the lig. pubofemorale and the lig. ischifemorale
• Hip dislocations are most likely to occur in this area
• The second weakest point is on the front, between the lig. pubofemorale and the lig. iliofemorale
• The m. iliopsoas reinforces this area, preventing dislocations
• The fibrous layer attaches to the rim of the acetabulum to the neck of the femur
• The synovial membrane lines the fibrous layer along with bony surfaces not lined with articular cartilage

Lig. iliofemorale

• It is a strong ligament that can withstand up to 300 kg
• Its apex attaches to the lower part of the spina iliaca anterior inferior
• Its base attaches to the linea intertrochanterica below
• The vertical inner part limits the extension of the thigh or backward movement of the trunk
• The transverse outer part limits adduction of the thigh

Lig. ischiofemorale

• Attaches to the posterior and lower part of the acetabulum
• Runs outward and upward, wrapping around the neck
• Some of its fibers join the zona orbicularis
• Other fibers merge with the lig. iliofemorale and attach to the trochanter major
• This ligament also prevents the femur and trunk from moving backward (extension)
• It also limits internal rotation of the thigh

Lig. pubofemorale

• Originates from the eminentia iliopubica which is on the ramus superior ossis pubis and the crista obturatoria
• Attaches to the linea intertrochanterica
• It also merges with the medial part of the lig. iliofemorale
• Because it is located in front of the joint, it limits extension and supports the femoral head from the front, limiting excessive abduction of the thigh

Zona orbicularis

• The lig. iliofemorale, pubofemorale, and ischiofemorale are tightly attached to the joint capsule
• Some fibers separate from these ligaments, penetrating deep and running close to the membrana synovialis
• These fibers wrap around the femur neck and attach to the joint capsule
• The zona orbicularis prevents the joint from dislocating

Lig. capitis femoris

• Its apex attaches to the fovea capitis femoris
• Its base attaches to the two edges of the incisura acetabuli and the lig. transversum acetabuli
• The lig. capitis femoris contains an artery during development
• This artery is a branch of the a. obturatoria's ramus acetabularis
• The r. acetabularis passes through the inc. acetabuli and the lig. transversum acetabuli
• This artery supplies blood to the epiphyseal plate of the caput femoris
• In adults, this ligament limits adduction or external rotation of the thigh

Lig. transversum acetabuli

• It is the ligament that attaches to the ends of the incisura acetabuli and closes it
• It is like a continuation of the labrum acetabuli
• It transforms the incisura acetabuli into a passage
• Vessels and nerves of the joint pass through here

Labrum acetabulare

• It is attached to the edge of the acetabulum and widens the joint surface
• It is a fibrocartilaginous structure
• It is fused with the lig. transversum acetabuli on the lower side
• By deepening the acetabulum, it ensures a better grip on the femoral head

Movements of the hip joint

• It is an Art. spheroidea joint
• Allows flexion-extension around the transverse axis
• Allows abduction-adduction around the sagittal axis
• Allows internal and external rotation around the vertical axis
• Allows circumduction by using all axes

Arteries of the hip joint

• Include the ramus acetabularis of the A. obturatoria
• Include the r. acetabularis of the A. circumflexae femoris medialis
• Branches of the A. glutea superior and inferior supply blood to the joint