Session 8 - The hip joint Flashcards
What is the function of the hip joint?
- Support the body weight on standing
- Joins the lower limb to the pelvic girdle
What are the articulations of the hip joint?
-Acetablum with head of femur
Which parts of the hip joint are covered in articular cartilage?
-Both head of femur and acetabulum
At what point do the pubis, ischium and ilium fuse?
-15 to 25 years
What stabilises the three hip bones before fusion?
-Triradiate cartilage
Where is the acetabular notch?
-The inferior margin of the acetabulum which is incomplete
What is the acetabular labrum and what is its function?
- Fibrocartilaginous rim attached to the margin of acetabulum
- Increased articular contact which increases stability
What is the transverse acetabular ligament and what is its function?
-fibrous continuation of the labrum which crosses the acetabular notch (leaves a small gap for vessels) to strengthen the joint inferiorly
What is the joint capsule?
-Fibrous coating lined with synovium surrounding the joint which attaches anteriorly at the intertrochanteric line and finishes proximally to intertrochanteric crest
What is the function og the joint capsule and he ligaments of the hip?
-Increase strength and stability
What are the two groups of ligaments of the hip joint?
-Intracapsular and extracapsular
Name the intracapsular ligament and its anatomical location
- Ligament of head of femur
- Runs from acetabular fossa to fovea capitis
How does ligament of head of femur effect movement?
-Limits abduction
What is significant about the ligament of head of femur?
-Encloses a small branch of the obturator artery (small portion of bloodflow)
Name the extracapsular ligaments
- Iliofemoral
- Pubofemoral
- Ischiofemoral
Describe the anatomical location of the iliofemoral ligament
- Located anteriorly
- Runs from ilium, inferior to ASIS, to intertrochanteric line
What is the function of iliofemoral ligament?
- Strongest ligament
- Protects hip joint anteriorly and superiorly
- Prevents hyperextension
Describe the anatomical location of the pubofemoral ligament
- Located anterioinferiorly
- Attached atiliopubic eminence and blends with capsule
What is the function of pubofemoral ligament?
- Protects anteriorly and inferiorly
- Prevents excessive aBduction and extension
Describe the anatomical location of the ischiofemoral ligament
- Located posteriorly
- Originates from ischium and attaches to greater trochanter
What is the function of the ischiofemoral ligament?
- Protects posteriorly
- Prevents excessive extension of the hip
Which is the weakest of the 3 extracapsular hip joint ligaments?
-Ischiofemoral
Which muscles are responsible for flexion of the hip?
-Iliopsoas
-Rectus femoris
-Sartorius
(-Pectineus
-Adductor magnus)
What nerve serves the hip flexors?
-Femoral nerve
Which muscle makes the lateral border of the femoral triangle?
-Sartorius
What artery serves the hip flexors?
-Medial and Lateral circumflex
What type of joint is the hip joint?
-Synovial ball and socket joint
Which muscles are responsible for hip aDduction?
- Adductor brevis
- Adductor longus
- Adductor magnus
- Pectineus
- Obturator externus
- Gracilis
Whst nerve supplies the hip ADductors?
-Obturator nerve
What artery predominantly serves the hip aDductors? What is the exception?
- Obturator artery
- Pectineus (medial circumflex)
Which muscles are responsible for hip extension?
- Gluteus maximus
- Long head biceps femoris
- Semimembranosus
- Semitendinosus
What arteries serve the hip extensors?
- Glut. max. = superior and inferior gluteal artery
- Biceps, semimembranosus and semitendinosus = perforating arteries
What nerve serves glut max?
-Inferior gluteal nerve
What nerve innervates the hamstrings?
-Tibial
Which muscles are responsible for hip ABduction?
-Gluteus medius
-Gluteus minimus
-Tensor fascia lata
(Deep Gluteal muscles except quadratus femoris)
What nerve/artery serves glut med and glut min?
-Superior gluteal nerve/artery
What muscles are responsible for lateral rotation of the hip?
- Piriformis
- Gemelli superior
- Obturator Internus
- Gemelli inferior
- Obturator externus
- Quadratur femoris
What does nerve of quadratus femoris innervate?
- Quadratus femoris
- Gemelli inferior
What does nerve of obturator internus innervate?
- Obturator internus
- Gemelli superior
What innervates piriformis?
-Sacral plexus
What is the main arterial supply to the hip?
-Lateral and medial femoral circumflex arteries from deep femoral artery
What is the minor blood supply to the hip?
-Branch of obturator artery in ligament head of femur
Is the obturator blood supply to the hip enough to supply the hip if the circumflex arteries are damaged?
-No, avascular necrosis would occur
How is the circumflex artery located in the hip joint?
-Anastomose around the femoral neck to form a ring, with smaller branches arising to supply the joint
What is hip dysplasia?
- Abnormal growth causing in-exact articulations with head of femur, predisposing to dislocations due to abnormal pressures running through the hip
- Spectrum of severity
What is a slipped upper femoral epiphysis?
-Fracture through epiphyseal growth plate, causing the remaining femur to ride up and forward in relation to epiphysis
Are hip diclocations common?
-No, the joint is highly stable
What is the most frequent cause of a hip dislocation and in which direction does it occur and why?
- RTA
- Posteriorly ->Head of femur tears through inferior and posterior part of joint capsule as this is the weakest point
If a hip id posteriorly dislocated, how will it look anatomically?
-Shortened and medially rotated
Damage to what major nerve can occur during hip dislocations? What would be the consequence of this?
- Sciatic nerve
- Paralysis of hamstrings and muscles distal to the knee
Where does the femur most commonly fracture?
-Neck
Who do intracapsular neck of femur fractures commonly occur in?
-The elderly
What are the two types of neck of femur fracture?
- Intracapsular
- Extracapsular
Who do extracapsular neck of femur fractures most commonly effect?
-Young/middle-aged
Which type of neck of femur fracture has a higher risk of avascular necrosis?
-Intracapsular
What is the main cause of intracapsular neck of femur fractures?
-Minor trip/stumble
What blood supply is disrupted in an intracapsular neck of femur fracture?
-Lateral and medial circumflex arteries
In a extracapsular neck of femur fracture, how does the limb look anatomically?
- Shortened
- Externally rotated
What determines treatment in neck of femur fracture?
-Age and health of the patient determines whether a replacement is needed
How are extracapsulr neck of femur fractures usually treated?
-With a dynamic hip screw
What is arthritis?
- Inflammation in the synovium of joint resulting in damage to cartilage
- Pain from inflammation
-What is osteoarthritis?
- Wear of the articular cartilage which leads to secondary changes in the underlying bone
- Pain from mechanical grinding
What is rheumatoid arthritis?
- Autoimmune condition where the joint cartilage is destroyed
- Inflammatory pain then mechanical pain
What are the bursa of the hip?
- Iliopsoas
- Trochanteric
- Gluteus medius
- Ischiogluteal
What is the largest bursa of the hip and where is it?
-Trochanteric bursa between the greater trochanter and gluteus maximus
Why is bursitis of the iliopsoas bursa significant?
-It may present as a swelling below the iguinal ligament and thus is a differential diagnosis of a femoral hernia
What is a common cause of inflammation of the ischiogluteal bursa?
-Prolonged sitting eg biking
When does bursitis cause pain?
-On movement and application of direct pressure
