Hip Joint
(Redirected from Hip joint)
Description
Introduction
- The hip joint is a ball and socket synovial joint
- Formed by the articulation of the Acetabulum, a socket found within the Ilium
- And the Femoral Head, the round proximal component of the femur
- This smooth articular surface provides a wide range of motion
Function
- Connection from the lower limb to the pelvic girdle
- Designed for stability and weight bearing (rather than large range of movement)
Articulating Surfaces
- Acetabulum
- Cup like depression located on the inferior lateral aspect of the pelvis
- The socket is deepened by the Acetabular Labrum, a fibrocartilaginous collar
- Head of the Femur
- Proximal, hemispherical component of the femur
- Fits completely within the concavity of the acetabulum
- Both acetabulum and head of femur are covered in articular cartilage
- Hip Joint Capsule[6]
- Originates from near the base of the labrum
- Attaches distally at the base of the trochanters
- Capsule is reinforced by the iliofemoral, ischiofemoral, and pubofemoral ligaments.
Intracapsular Ligaments
- Ligament of the Head of the Femur
- Small structure which runs from the acetabular fossa to the fovea of the femur
- Contains artery to the head of the femur
Extracapsular Ligaments
- Iliofemoral Ligament
- Anterior inferior iliac spine to intertrochanteric line of the femur
- Y-shaped appearance
- Prevents hyperextension of the hip joint
- Strongest of the extracapsular ligaments
- Pubofemoral Ligament
- Spans the superior pubic rami and intertrochanteric line of the femur
- Reinforces the capsule anteriorly and inferiorly
- Triangular shape
- Prevents excessive abduction, extension
- Ischiofemoral Ligament
- Spans the body of the ischium, greater trochanter of the femur
- Reinforces capsule posteriorly
- Spiral orientation
- Prevents hyperextension, holds femoral head in the acetabulum
Stabilizing Factors
- Acetabulum
- Dislocation is rare because the acetabulum is deep, encompassing nearly all of the femoral head
- Acetabular Labrum
- Horseshoe shaped fibrocartilaginous ring around the acetabulum which increases its depth
- Increased depth increases the articular surface, further stabilizing joint
- Iliofemoral, ischiofemoral, and pubofemoral ligaments
- Provide a large degree of stability, especially when combined with the joint capsule
- Have a spiral orientation; they tighten when the joint is extended
Movements/ Muscles
- Flexion: iliopsoas, rectus femoris, sartorius, pectineus
- Extension: gluteus maximus, semimembranosus, semitendinosus, biceps femoris
- Abduction: gluteus medius, gluteus minimus, piriformis, tensor fascia latae
- Adduction: adductors longus, adductor brevis, adductor magnus, pectineus, gracilis
- External Rotation: biceps femoris, gluteus maximus, piriformis, obturators, gemilli, quadratus femoris
- Internal Rotation: gluteus medius, gluteus minimus, tensor fascia latae
Vascular Supply
- Circumflex Femoral Arteries
- Branches of the deep femoral artery (profunda femoris artery)
- Anastomose at the base of the femoral neck to form a ring
- Medial circumflex femoral artery
- Responsible for the majority of vascular supply
- Damage can result in avascular necrosis of the femoral head
- Additional supply
- Artery to the head of the femur
- Superior/inferior gluteal arteries
Innervation
Clinical Significance
See Also
References
- ↑ Image courtesy of muhealth.org
- ↑ Case courtesy of Matthew Lukies, Radiopaedia.org, rID: 51249
- ↑ Mandell, Jacob C., et al. "Traumatic hip dislocation: what the orthopedic surgeon wants to know." Radiographics 37.7 (2017): 2181-2201.
- ↑ Image courtesy of yogaru.ie
- ↑ Image courtesy of orthubllets
- ↑ Keene GS, Villar RN. Arthroscopic anatomy of the hip: an in vivo study. Arthroscopy 1994;10(4):392–399