Disorders of the Hip Flashcards
What is osteoarthritis? Which joints are most commonly affected
A degenerative disorder arising from the breakdown of articulations hyaline cartilage
Clinically accompanied by functional limitation and reduced QoL
Most commonly affects; knees, hips, cervical spine, lumbar spine and small joints of the hands
What is primary osteoarthritis and what are the risk factors for developing it?
OA with an unknown cause
Risk factors:
- Age
- Being female
- Ethnicity- increased risk if African American, American Indian or Hispanic women
- Genetics
- Nutrition- diet rich in vitamin C and E offers some level of protection
What is secondary OA and what are the causes?
OA where the cause is known
Some causes;
- Obesity
- Trauma
- Malalignment (developmental dysplasia of the hip)
- Infection
- Inflammatory arthritis
- Metabolic disorder e.g gout
- Haematological disorder e.g haemophilia with haemarthrosis
- Endocrine abnormality
Describe the pathology of osteoarthritis
- Initially, hyaline cartilage becomes swollen due to increased proteoglycan synthesis by Chondrocytes.
- Stage of attempting to repair damage and can last years
- Disease progression; proteoglycan synthesis falls and cartilage loses elasticity
- Over time the cartilage erodes down the the subchondral bone causing loss of bone space
What are the 4 cardinal signs of OA that can been seen on an x-ray?
- Reduced joint space
- Subchondral sclerosis
- Bone cysts
- Osteophytes
In what group of people is OA of the hip most common?
Males over age 40
Describe some of the symptoms experienced in OA of the the hip
- joint stiffness, typically getting out of bed
- hip pain, gluteal and round radiating to the knee
- mechanical pain when weight bearing
- crepitus (grating/ crunching)
- reduced motility
What are the two types of femoral neck fracture and which is the most severe?
Intracapsular & Extracapsular
Intracapsular is most severe as it is more likely to disrupt the ascending bracnhes of the medial circumflex femoral artery blood supply to the femoral head, which is then at high risk of a vascular necrosis
Why are extracapsular fractures at less risk of necrosis?
There are two arteries providing blood supply to the femoral head
In extracapsular fractures the lateral femoral circumflex artery can still supply blood to the femoral head, even if the medial femoral circumflex artery is disrupted
What is the only treatment of intracapsular fractures of the femoral head?
Surgical replacement of the femoral head or total hip replacement
Name some symptoms of a femoral head fracture
- Reduced mobility or inability to bear weight on the limb
- Pain felt in the hip, groin or knee
What does the leg look like in a displaced #NOF
Shorted, abducted and externally rotated
What is the most common way the hip can dislocate?
Posteriorally (90%)
What will a hip that is posteriorally dislocated look like?
Shorted, flexed, adducted and internally rotated
Sciatic nerve palsy is present in 8-20% of cases
What will the hip look like in anterior dislocation ?
The limb will be externally rotated, abducted with a slight flexion
Why is the hip shortened, abducted and externally rotated in a displaced fracture of NOF?
- The NOF allows the shaft of the femur to move independently of the hip joint
- Short lateral rotator of the hip (piriformis, obturator internus, superior and inferior gemilli and quatratus femorus) contract to externally rotate the femoral shaft
- Strong abductors that attach to the greater trochanter (glut medius and minimumus) abduct the femur distal to the fracture site
- Muscles of the thigh distal pull the femur upwards shortening the leg
