6 - Disorders of the Hip Flashcards
What is the pathology of osteoarthritis?
- Due to the erosion of cartilage
- Initially hyaline cartilage swells due to increased proteoglycan synthesis by chondrocytes due to more chondrocytes. Attempted repair to cartilage for few years
- Proteoglycan content falls so cartilage softens and loses elasticity
- Flaking and fibrillation along normall smooth articular surface
- Cartilage eroded to subchondral bone resulting in loss of bone space
What would you see on an x-ray of an osteoarthritic joint?
Subchondral Sclerosis: eburnation due to increased vascular invasion and thicker/denser areas at areas of pressure
Subchondral Bone Cysts: osseous necrosis, chronic impaction, intrusion of synovial fluid
Narrowed Joint Space: Erosion of cartilage
Osteophytes: osseous metaplasia of connective tissue so irregular bone growth
What are the causes of osteoarthritis?
Primary: Unknown, risk factors
Secondary:
- Obesity
- Trauma
- Malalignment e.g developmental dysplasia
- Infection
- Inflammatory arthritis e.g ankylosing spondylitis
- Metabolic disorders e.g gout
- Haematological disorders e.g haemophilia
- Endocrine disorders e.g diabetes malalignment charcot joint
What are some risk factors of primary osteoarthritis?
- Age
- Being female
- Ethnicity (increase in hispanic, african and american indian over caucasian american)
- Nutrition
- Genetics (runs in family)
- Nutrition (diet low in Vit C and E)
What are symptoms of osteoarthritis in any joint?
- Deep aching joint pain exacerbated by use
- Reduced range of motion
- Crepitus
- Stiffness during rest (morning stiffness less than hour)
What are then common affected joints of osteoarthritis?
- Hips, Knees, Cervical and Lumbar spine and small joints of hands
- Non-inflammatory disease that comprimises joint pain and limited movement and reduced QoL
What are the symptoms of hip osteoarthritis?
- Joint stiffness (getting out of bed and standing/sitting for long time)
- Pain in hip, glueal and groin regions radiating to knee via obutarator nerve
- Mechanical pain (worse when using or weight bearing)
- Crepitus
- Reduced mobility (getting in and out car, bath,bed, putting sock on)
How is hip osteoarthritis diagnosed?
Clinical presentation of symptoms and x-ray changes
How is osteoarthritic hip treated?
- Activity modification
- Weight reduction
- Stick/Walker
- Physiotherapy/footwear to realign and strengthen muscles
- Analgesia, NSAIDS, COX-2 inhibitors, nutritional supplements (glucosamine)
- Steroid injections to reduce inflammation
- Vicosupplementation (hyularonic acid to promote cartilage growth and lubrication)
ONLY CURE IS HIP REPLACEMENT
What is the definition of a fractured NOF and how is it classified?
- Fracture of the proximal femur, up to 5cm below the lesser trochanter
- 1 in 3 people die in a year after this
Why is there a high risk of avascular necrosis in a intracapsular fracture of the neck of the femur?
Fracture likely to disrupt the ascending cervical (retinacular) arteries of the MFCA.
Inability of the ligamentum teres to supply the femoral head metabolically
Who are extra and intracapsular fractures most likely to affect?
Intra = common in elderly, menopausal women with osteoporotic bone after minor fall
Extra = young and middle aged following traumatic force, e.g car crash
How is a displaced intracapsular fracture treated?
Hemiarthroplasty or total hip replacement because of a high risk of avascular necrosis
What are causes of avascular necrosis?
- Fracture
- Alcoholism
- Thrombosis
- Radiation
- Hypertension
- Decompression sickness
If you have a displaced neck of femur fracture what is the affected leg usually like?
- Shortened: Rectus femoris, adductor magnus and hamstring pull thigh
- Abducted: strong abductors glut medius and minimus
- Externally rotated: short lateral rotators, the iliopsoas
What does idiopathic avascular necrosis of the hip look like?
What is the definition of a hip dislocation?
When the femur is fully displaced from the acetabulum
- Posterior (most common)
- Anterior
- Central (acute)
What is congenital hip displacement?
- Developmental dysplasia of the hip
- Unstable hipjoint due to abnormal formation of the hipjoint so the child is prone to dislocations more often
What is a posterior dislocation presented as?
- Shortened (glut maximus, hamstrings and hip adductors)
- Internally rotated (anterior gluteus med and min)
- Adducted
- Flexed
SCIATIC NERVE PALSY IN 20% PATIENTS
What does an anterior hip dislocation present as?
- External rotation
- Abduction
- Slightly flxed
- Uncommon femoral nerve palsies
What does a central dislocation of the hip present as?
- Fracture dislocation
- Femoral head palpable per rectum
- Intrapelvic haemorrhage due to damage of pelvis venous plexuses
- LIFE THREATENING
How do you locate the correct site for a ventrogluteal intramuscular injection?
Place the palm of one hand over the greater trochanter of the femur, point your thumb towards the inguinal region and your index finger towards the anterior superior iliac crest. Spread the index and middle fingers to make a V and inject between the proximal interphalangeal joints of your fingers into the gluteus medius muscle.
State two typical symptoms experienced by a patient with a fractured neck of femur
Reduced mobility / sudden inability to bear weight on the limb
Pain, which may be felt in the hip, groin and/or knee
