Lecture 6 Clinical correlates of hip Flashcards
How would you test to see if your patient had a superior gluteal nerve injury?
-the superior gluteal nerve supplies the abductors of the hip (gluteus medius/minimus)
-ask them to stand on their injured lower limb
-if pelvis on unsupported side descends= positive Trendelenburg sign
(usually the gluteus minimus/medius contract, preventing tilting of pelvis on unsupported side)
How do pulled hamstrings occur?
- Sudden muscular exertion resulting in stretching of posterior thigh muscles (jumping, sprinting, lunging)
- common in footballers/athletes, especially if not warmed up
- tension on hamstrings results in muscle sprain, partial/complete tear of origin of hamstring muscles from ischial tuberosity, avulsion fracture
What is an avulsion fracture?
Injury to bone where tendon/ligament attaches to bone
tendon/ligament pulls off a piece of bone
What is osteoarthritis?
Most common disease affecting synovial joints
- degenerative disorder arising from the breakdown of hyaline cartilage
- chronic disease, non-inflammatory
What age range does osteoarthritis affect & what are the symptoms?
Elderly
- joint pain
- functional limitation
- reduced quality of life
What are the common joints affected by osteoarthritis?
- hips
- knees
- cervial/lumbar spine
- small joints of the hand
What are the different classes of osteoarthritis?
Primary: cause is unknown
Secondary: known precipitating cause
What are the risk factors of primary osteoarthritis?
- age
- female sex
- ethnicity (increased risk in african-americans, american indian, hispanic)
- genetics
- nutrition (consumption of vit C&E may help)
What are some secondary causes of osteoarthritis?
- obesity
- trauma (including sports)
- malalignment (developmental dysplasia of hip- congenital hip displacement)
- infection (TB, septic arthritis)
- inflammatory arthritis (rheumatoid, ankylosing spondylitis)
- metabolic disorders affecting joints (gout)
- haematological disorders (bleeding into joints)
- endocrine abnormalities (diabetes with neurovascular impairment-chronic malalignment of articular surfaces)
Symptoms of osteoarthritis?
- deep aching joint pain, worsened by use
- reduced range of motion
- crepitus (grinding)
- stiffness during rest
What leads to hyaline damage?
Uneven loading of the joint due to risk factors
What happens to the hyaline cartilage?
- becomes swollen due to increased proteoglycan synthesis by chondrocytes, with increased number of chondrocytes differentiating from chondroprogenitor cells (reflects attempt to repair cartilage)
- proteoglycan content gradually falls as disease progresses
- cartilage softens and loses elasticity
- flaking and fibrillation seen
- cartilage becomes eroded down to the bone resulting in loss of joint space
What does the surface changes in osteoarthritis trigger?
Alter the distribution of biomechanical forces
- subchondral bone responds with vascular invasion and increased cellularity: becoming thicker and denser
- subchondral bone may undergo cystic degeneration to form subchondral bone cysts (fluid filled spots in bone) which make the bones weak, attributes to osseous necrosis/intrusion of synovial fluid
What is eburnation?
Subchondral bone responds with vascular invasion and increased cellularity: becoming thicker and denser
(subchondral sclerosis: hardening of bone just below cartilage surface)
What occurs at articular margin of the bones?
Osseous metaplasia of connective tissue
-irregular outgrowth of new bone (osteophytes)
What are the 4 signs of osteoarthritis on an X-Ray?
- reduced joint space
- subchondral sclerosis
- bone cysts
- osteophytes
Which sex is osteoarthritis of the hip most common?
Males over 40
Symptoms of osteoarthritis in the hip?
- joint stiffness (getting out of bed/ after sitting)
- pain in hip/gluteal/groin regions, radiating down to knee via obturator nerve
- mechanical pain (pain accentuated by mobilisation/weight bearing)
- crepitus (grating/crunching)
- redcued mobility
How is osteoarthritis of the hip diagnosed?
- clinical presentation (signs/symptoms)
- supported by X-Ray changes
How can you treat/cure osteoarthritis of the hip?
-weight reduction (if overweight)
-activity modification
-walking stick/frame to reduce load through arthritic joint
-muscle strengthening exercises/orthotic footwear can rebalance a misaligned load through the joint
-analgesia-paracetomol/anti-inflammtories-NSAIDS /nutritional supplements
-steroid injections into joint to reduce swelling, alleviating stiffness/pain
-hyaluronic acids injections: increase lubraction, promote cartilage repair
Only cure is total hip replacement
What region is classed as being a fracture to the neck of the femur?
-up to 5 cm below lesser trochanter
What are fractured NOF’s classed as?
- intracapsular
- extracapsular (intertrochanteric, subtrochanteric)
Which fracture is most likely to disrupt blood supply to the femoral head?
Intracapsular
- disrupts ascending cervical branches of medial femoral circumflex artery
- due to inability of artery of ligamentum teres to sustain metabolic demand of the head, high risk of avascular necrosis of the bone, especially if the fracture is displaced
In whom are extra/intracapsular ligaments more common?
Intra: elderly/postmenopausal women- osteoporic bone
Extra: young population- traumatic force
How is a displaced intracapsular fracture treated?
-surgical replacement of femoral head
Hemiarthroplasty: femoral head only
Total hip replacement
Why is the mortaility increasing due to NOF?
Often seen in the elderly with other co-morbidities
Symptoms of NOF?
- reduced mobility
- sudden inability to bear weight on the limb
- pain in hip/groin/knee
What does it look like if the fracture is displaced?
- shortened leg
- abducted
- externally rotated
- exacerbation of pain of palpitation of greater trochanter/rotation of hip
Why should you avoid vigorous examination on a suspected hip fracture?
Risk of displacing the fracture
What is dislocation of the hip?
Femur being fully displaced out of the acetabulum
What causes hip dislocation?
Congenital: developmental displasia (used to be congenital dislocation of hip- renamed as varyin degrees of displacement and can occur after birth)
Trauma: road traffic collisions, massive amount of force required
Symptoms of hip dislocation:
- extremely painful
- resists any movement of limb
What are the types of hip displacement?
Posterior (90% of dislocations) -impact of dashboard and knee during collision -sciatic nerve palsy occurs sometimes Anterior Central
What will the leg look like after a posterior hip dislocation?
- shortened
- flexion
- adduction
- medial rotation
Why does the leg look shortened, externally rotated and abducted when in a displaced NOF?
Shaft of femur moves independently of the hip joint
- the axis of rotation of femur that usually passes obliquely (slanted) through head & down neck of femur, shifts to pass through greater trochanter and vertically along femoral shaft
- short lateral rotators (piriformis, obturator internus, gemelli, quadratus fermoris) contract, laterally rotating the leg
- iliopsoas acts as a lateral rotator pulling the lesser trochanter anteriorly about new axis of rotation
- abductors (gluteus medius/minimus) abduct femur, and rotate greater trochanter laterally
- shortening of limb is due to muscles of the thigh pulling the distal fragment of femur upwards
Why does shortening & internal rotation of the hip occur in dislocation of hip?
- femoral head is pushed back and lies on lateral surface of ilium
- head of femur is then pulled upwards by strong extensors (gluteus max/hamstrings) causing limb shortening
- anterior fibres of gluteus medius/minimus pull on greater trochanter causing the femur to rotate medially
What does the limb look like in anterior dislocation of hip?
- limb held in position of external rotation and abduction, slight flexion
- femoral nerve palsies are rare
What occurs in central dislocationof hip?
- head of femur driven into pelvis through the acetabulum
- always a fracture dislocation
- femoral head is palpable of rectal examination
- high risk of intrapelvic haemorrhage due to disruption of pelvic venous plexuses
- can be life-threatening
