HIP JOINT

It is a ball-socket type 3-axis synovial joint located between the concave acetabulum and the convex femoral head. It has flexion-extension in the sagittal plane, internal-external rotation in the horizontal plane, and abduction-adduction movements in the frontal plane. These movements are the movements of both the pelvis on the femur and the femur on the pelvis. The main task of the joint is to transfer the weight of the upper extremity and the body to the lower extremity.
Closed package position of the joint = 0-15 degrees of extension, 30 degrees of abduction and internal rotation occurs as a result.
The open package position of the joint / the position where manipulation applications are made is 0-30 degrees of flexion, 30 degrees of abduction and external rotation.

 

BONES

1) Acetabulum

*Creates a socket joint.
* Ilium and ischium participate 75%, pubis 25%.
*The lunate surface is the part that contacts the femur in a semicircular shape. (The main joint is the place) The superior anterior region of this surface has the thickest articular cartilage. Thus, this thickening prevents injuries while transferring the weight to the t extremity!
*The acetabulum does not have a fully rounded shape, and the inferior opening between 60 and 70 degrees is called the acetabular notch.
*The central edge angle is 35 degrees. This angle enables the acetabulum to grasp the femoral head, that is, we can say that the acetabulum can hold the femur in it.
* Decreased central edge angle increases the risk of dislocation and joint pressure during base contact.
*Increased central margin angle; the acetabulum compresses the soft tissues and keeps the femur in the acetabulum too much.
*Acetabular anteversion angle is 20 degrees. It is found by drawing a line from posterior to anterior of the acetabulum. An increase in this angle suggests anterior dislocation, anterior labrum lesions, and excessive external rotation.

CLINICAL= Acetabulum problems occur as a result of maneuvers such as pulling the leg from the baby at birth. As a result, the femur may be placed higher in children. As a result, the risk of developing osteoarthritis in children in the early period increases!

 

2) Labrum

* It is the main place that allows the femoral head to sit on the acetabulum.
* Provides stabilization by creating a negative intra-articular pressure of 30%.
* While the vascularization of the labrum is weak, afferent nerves that provide proprioceptive notification are high.
*Reduces stress during contact and protects articular cartilage.
*The acetabular notch/notch part is covered by the transverse acetabular ligament mentioned above.

 

3) Proximal Femur

*Composed of trochanter major and minor, trochanteric fossa.
*Ligamentum teres attaches to a structure called fovea.
*Except for this fovea region, the entire surface is covered with articular cartilage proximal to the femoral region.
*The angle of inclination is 165-170 degrees in newborns, and it decreases to 125 degrees, which is the adult value, as the load is loaded throughout life. This represents the angle between the femoral neck in the frontal plane and the medial side of the femoral shaft.
*An abnormal increase or decrease in the angle of inclination may change the joint between the femoral head and the acetabulum, thus affecting the biomechanical properties of the hip.
*Increasing the angle of inclination indicates coxae valga, decreasing it indicates coxae vara.

*Femur torsion/declination angle is 40 degrees in newborns and 12-15 degrees in adults.
*As the femoral torsion angle increases, anteversion situation occurs. This situation, which continues in adults, causes hip dislocation, joint incompatibility and an increase in joint contact strength!
*As the torsion angle of the femur decreases, which is common in individuals with cerebral palsy/cp, retroeversion occurs. The femur rotates externally, so the feet step out!

*Compact bone withstands large loads, is very dense and hard. The lower femur and the entire shaft/stem are particularly thick. This helps load transfer to the lower extremity.
* In the proximal of the femur, the cancellous bone is dense, so it helps to absorb the repetitive external forces / become shock absorbent thanks to its elasticity.

 

 

 

LIGAMENTS

1) Intracapsular Ligaments

The iliofemoral, pubofemoral and ischiofemoral ligaments mentioned below surround the hip joint from the outside and provide stabilization. They contribute to the formation of the above-mentioned angle values and do not allow them to increase or decrease. The most elongated and tense position of these 3 ligaments is the extension of the hip.

?Iliofemoral Ligament:
*Also called Bigelow’s Y bond.
* It is the strongest and hardest ligament of the hip.
*Limits hip overextension and external rotation.

?Ischiofemoral Ligament:
* Superficial fibers become tense in internal rotation and extension.
*Superior fibers become tense in adduction.

?Pubofemoral Ligament:
*The hip becomes tense in abduction, extension and external rotation.

 

2) Capsular Ligaments

?Transverse Acetabular Ligament:
* Covers the acetabular notch-notch part.

?Ligamentum Teres:
*Attaches to the fovea of the proximal femur.

 

!!!These ligaments and acetabular labrum, joint capsule are STATIC STABILIZERS of the hip joint.
!!!Soft tissues and muscles are DYNAMIC STABILIZERS of the hip joint.

 

VASCULAR STRUCTURES AND NUTRITION

*Hip joint blood supply is provided by medial and lateral circumflex femoral artery and obturator artery.
CLINICAL = Avascular necrosis of the femoral head occurs if the above-mentioned arteries are present!
*Medial and lateral circumflex femoral vein.

 

MUSCLES

1) M. Iliopsoas

*The psoas major muscle starts from the lumbar vertebrae, and the iliacus muscle starts from the fossa iliaca and ends in the trochantor minor. It is innervated by the N.femoralis(L2-4). The primary mover task is to make the art.coxae flexion. It also makes the thigh flexion and externally rotate.

2) M.Pectineus

*The pubic beak and pectineus start from the fascia and end in the linea pectinea of the femur. It is innervated by the N.femoralis(L2-4). It makes the thigh adduct and flexion.

3)M.Quadriceps Femoris

?Rectus femoris=Spina iliaca anterior inferior
?Vastus lateralis=Linea aspera and trochantor major
?Vastus intermedius=Anterior aspect of the femur
?Vastus medialis=Linea aspera and crista supraepicondylus start from medialis and end in tuberositas tibia via ligamentum patella. N.femoralis(L2-4) innervation of these four muscles forming quadriceps.

 

4)M.Tensor Fascia Lata/TFL

*Starting from the sias and ending in the lateral condyle of the tibia. It is innervated by the N. Gluteus superior (L4-S1). It makes abduction when the thigh is in flexion. At the same time, it makes the thigh flexion and the leg extends.

5) M. Sartorius

*Starting from the sias and ending on the inner side of the tibia. It is innervated by the N. femoralis (L2-4). It makes the thigh; flexion, abduction and external rotation. At the same time, it is responsible for making the leg flexion and internal rotation.

 

 

6) Hamstrings

?Biceps Femoris= Caput longum tuber ischiadicum, starting lateral to the caput breve linea aspera and ending in the lateral condyle of the caput fibula and tibia. The caput longum is innervated by the N. Tibialis(L4-5 and S1-3). Caput breve part is innervated by N.Peroneus Communis(L4-5). While extending the thigh, it makes the leg flexion and external rotation.
?Semimebranosus= It starts from the tuber ischiadicum and ends in the medial condyle of the tibia. It is innervated by the N.tibialis(L4-5,S1-3). It makes the leg flexion and internal rotation while extending the thigh.
?Semitendinosus= It starts from the tuber ischiadicum and ends on the proximal inner side of the tibia. It is innervated by the N.tibialis. It makes the leg flexion and internal rotation while extending the thigh.

 

7) M. Gluteus Maximus

*Starting from os ilium, os sacrum and ligament sacrotuberale and ending in tub.glutea and lig.iliotibiale. It is innervated by N. Gluteus Inferior(L5-S2). The primary mover task is to extend the thigh to the thigh. In addition, it makes the thigh externally rotate.

8) M. Gluteus Medius

*Starts on the outer surface of the Iium and ends at the trochantor major. It is innervated by the N. Gluteus Superior (L4-S1). The primary mover task is to abduct the thigh. In addition, it makes the thigh internally rotate.
CLINIC = It is the strongest abductor of the thigh. The abductor muscles need to create a force of about 3 times the body weight because this muscle balances the incoming body weight and provides our balance while walking. If this event cannot be achieved due to muscle weakness, TRANDELENBURG WALK, which is a gait pathology, occurs.

9) M. Gluteus Minimus

*Linea starts from the area between the glutea superior and inferior and ends in the trochantor major. It is innervated by the N. Gluteus Superior (L4-S1). The primary mover function is internal rotation of the thigh. It helps thigh abduction.

 

 

10) Adductors

?M.Adductor Magnus = It is the strongest adductor of the thigh. The part in the hamstring starts from the tub.ischiadicum, while the remaining part starts from the ramus ossis ischii and ends in the distal part of the linea aspera. N. Tibialis innervates, that is, it has double nerve innervation. The primary mover task is to adduct the thigh. In addition, it takes part in thigh flexion.

?M.Adduktor Longus=Starting from the pubis and ending in the middle 1/3 of the linea aspera. It is innervated by N. Obturatorius (L2-4). The primary mover task is to adduct the thigh. In addition, it makes the thigh flexion and internal rotation.

?M.Adduktor Brevis=Starts from the pubis and ends in the proximal part of the linea aspera. It is innervated by N. Obturatorius (L2-4). The primary mover task adducts the thigh. In addition, it makes the thigh flexion.

 

11) M. Gracilis

*Starts from the pubis and ends on the proximal inner side of the tibia. It is innervated by N.Obturatorius. It makes the leg flexion and internal rotation while adduction of the thigh.

12) Hip External Rotators

?Piriformis = Innervated by nerve branches coming from the sacral plexus.
?Gemellus superior = Innervated by branches from the sacral plexus.
?Gemellus inferior = Innervated by branches from the sacral plexus.
?Obturatorius internus = Innervated by branches from the sacral plexus.
?Obturatorius externus = Innervated by N.Obturatorius.
?Quadratus femoris = It is the strongest external rotator of the hip. It is innervated by branches from the sacral plexus.