2 - Clinical Conditions of the Hip Flashcards
What is the blood supply to the femoral head
artery of ligamentum teres
- Femoral head → acetabulum
- Located at fovea of femoral head
- Most important source in children
- Contribution to blood supply decreases with age, and is pretty insignificant in elderly patients
ascending cervical branches
- Arise from ring at base of neck, which goes to femoral head
- Formed by branches of the medial + lateral circumflex arteries
- Perforate bone just distal to articular cartilage
- Highly susceptible to injury with hip dislocation
Osteoarthritis risk factors
- Age (more common in elderly patients)
- Sex (more common in females)
- Ethnicity (more common and severe in Caucasians + African-americans)
- Nutrition
- Genetics (OA runs in families)
Primary and secondary osteoarthritis
primary
Cause is unknown
secondary
- Obesity
- Trauma (eg sports and occupation )
- Malalignment (eg developmental dysplasia)
- Infection (eg septic arthritis + tuberculosis)
- Inflammatory arthritis (eg rheumatoid arthritis)
- Metabolic disorders affecting joints (eg gout)
- Haematological disorders (eg haemophilia with bleeding into joints)
- Endocrine abnormalities (eg DM)
Pathology of osteoarthritis
- Precipitating risk factors → excessive loading of joint + damage to articular cartilage
- Increased proteoglycan synthesis (initial attempt to repair cartilage damage)
- Flaking + fibrillation of articular cartilage (meant to be smooth)
- Causes erosion of cartilage all the way down to subchondral bone (appears as lack of joint space on x-ray)
- Altered joint biomechanics lead to…
☞ vascular invasion + increased cellularity of subchondral bone (subchondral sclerosis)
☞ cystic degeneration of bone (subchondral bone cysts)
☞ osseus metaplasia of connective tissue (osteophytes)
Radiological features of osteoarthritis
- Lack of joint space (bone on bone)
- Sclerosis or hardening of the bone (looks more white)
- Cysts (ie in femur head)
Symptoms of osteoarthritis of the hip
- joint stiffness after getting out of bed / sitting still for long time
- pain + tenderness in hip joint
- swelling but this is not obvious in the hip
- crepitus is a sound or feeling of the bone rubbing against the bone
- reduced mobility which can be disabling or debilitating
- Trendelenburg sign (next card)
What is the Trendelenburg sign + gait
- Ask individual to stand on one leg
- If arthritis, affected hip will go up
- Shows lack of pelvic stability
Overview of management of hip osteoarthritis
- non pharmalogical management eg education, exercise, weight loss, appropriate footwear
- non pharmacological management eg physio, braces, simple analgesia
- pharmacological management eg NSAIDs, opioids (can be injected) or steorids injections for anti-inflammatory
-
surgery eg osteotomy, total joint replacement
☞ this all depends on the severity of the symptoms
Non-operative management of hip osteoarthritis
primary (by GP)
- Activity management (if it hurts, don’t do it → more detrimental for younger patients)
- Weight loss
- Stick/walker (improves biomechanics)
- Physiotherapy (strengthen muscles + improve recovery if operated on)
medications
- NSAIDs
- COX-2 inhibitors (eg celecoxib)
- Nutritional supplementation (glucosamine – works with 1/3 patients)
injections
Most commonly corticosteroids to reduce inflammation. Viscosupplementation may be beneficial but disputed.
Surgical management of hip osteoarthritis
total hip replacement
- Implants replace damaged surfaces
- Helps relieve pain + restore mobility
- Improved patient wellbeing
Symptoms + signs of hip fractures (proximal femur)
- Both intracapsular + extracapsular fractures present with a shortened, abducted + externally rotated leg at the hip
- Reduced mobility + sudden inability to bear weight on affected leg
- Pain in hip (sometimes also groin + knee)
Reasoning for external rotation of leg in hip fractures
- Hip fractures result in a shortened, abducted + externally rotated leg
- This is due to distal fragment being pulled upwards + rotated laterally
- Unopposed muscle pull, while femoral head remains in joint
Extracapsular vs intracapsular fractures
intracapsular
- Ie at neck or head of the femur
- More common in women + elderly (demographics with osteoporosis)
- Medial femoral circumflex artery is at risk of injury
- This can cause avascular necrosis (more details on sep card)
- Displaced fractures bring higher risk of this
- Treatment often involves full or partial hip replacement
extracapsular
- More common in young or middle aged people
- Avascular necrosis is much rarer (this is because the fracture is distal to the medial femoral artery, so blood supply remains intact)
Avascular necrosis – causes on separate card
- Death of bone tissue due to a lack of blood supply
- Can lead to tiny breaks in the bone
- This can eventually cause the bone to collapse
- Most common cause is a broken hip (proximal femur fracture in intracapsular region, due to disruption of blood supply)
- There are other causes (sep card)
Causes of avascular necrosis
- Most common cause is a broken hip (proximal femur fracture in intracapsular region, due to disruption of blood supply)
- Alcoholism
- Excessive steroid use
- Post trauma (injury)
- Thrombosis (blood clot)
- Hypertension (high blood pressure)
