Hip Disorders Flashcards
Osteoarthritis pathology
Excessive loading of joint
= Breakdown of articular cartilage
Increased proteoglycan from chondrocytes to try and repair
Flaking and fibrillation of cartilage (replaced by fibro)
Erosion of cartilage
Primary osteoarthritis causes and risk factors
Cause unknown Risk factors: Age sex (female > male) Ethnicity Nutrition Genetics
Secondary osteoarthritis causes (8)
Causes: Obesity Trauma (sports) Malalignment - developmental dysplasia Infection Inflammatory conditions Metabolic disorders (gout) Haematological disorders Endocrine abnormalities
What does osteoarthritis lead to?
Symptoms of osteoarthritis in any joint (3)
• A deep aching joint pain, exacerbated by use
• Reduced range of motion and crepitus (grinding)
• Stiffness during rest (morning stiffness, usually lasting < 1 hour)
How is OA diagnosed?
Clinical signs and symptoms + Xray to confirm
Management osteoarthritis (no op)
Activity modification
Weight loss
Walking stick/frame
Physiotherapy/muscule-strenthening exercises
Orthotic footwear
Medications for OA
- Analgesia (e.g. paracetamol)
- Anti-inflammatories (NSAIDs, COX-2 inhibitors)
- Nutritional supplements e.g. glucosamine and chondroitin sulfate.
Injections:
- Steroid injections can be performed into the joint to reduce swelling and thereby alleviate shoulder stiffness and pain.
- Hyaluronic acid injections into the joint (viscosupplementation) may increase lubrication and possibly promote cartilage repair, although the evidence for this is limited.
Surgical procedures for OA
What does it do?
Total Hip replacement -replaces the damaged surfaces with implants and helps to relieve pain and restore mobility.
(metal ball and socket joint down femur)
Types of femoral fractures
Intracapsular - neck of femur (above intertrochanteric line)
Extracapsular - below intertrochanteric line
Blood supply effects femoral fractures
- In intracapsullar fractures, there is a high risk of avascular necrosis of the bone.
- This is because intracapsular fractures are likely to disrupt the ascending cervical (retinacular) branches of the medial femoral circumflex artery (MFCA).
- Due to the inability of the Artery of the Ligamentum Teres to sustain the metabolic demand of the femoral head, there is a high risk of avascular necrosis of the bone.
- This risk is increased if the fracture is displaced.
- With extracapsular fractures, the retinacular arterial supply to the femoral head is likely to remain intact.
Symptoms/signs of femoral fracture
What are the symptoms of Fractured neck of femur? (2)
What does the doctor find on examination if the fracture is displaced?
- Reduced mobility / sudden inability to bear weight on the limb
- Pain which may be felt in the hip, groin and/or knee
- On examination, if the fracture is displaced, the affected leg is usually shortened, abducted, and externally rotated. There is exacerbation of pain on palpation of the greater trochanter and pain is exacerbated by rotation of the hip.
Why do legs externally rotate in NOF fracture?
- The axis of rotation of the femur that normally passes obliquely through the head and down the neck of the femur, shifts to pass through the greater trochanter and vertically down the long axis of the femoral shaft.
- The short lateral rotators of the hip (piriformis, obturator internus, superior and inferior gemelli and quadratus femoris) contract and laterally (externally) rotate the femoral shaft.
- The iliopsoas also now acts as a lateral rotator of the femur as it pulls the lesser trochanter anteriorly about the new axis of rotation, so the femoral shaft rotates externally.
Types of Surgery for hip fracture
Hemiarthroplasty (femoral head replaced)
Total hip replacement (femoral head and acetabulum replaced)
Causes of avascular necrosis (6)
Mechanical disruption (fracture) Alcoholism Steroid use Post trauma Thrombosis Hypertension
Most common type of hip dislocation
90% posterior
Types of people intracapsular and extracapsular occur in
Intracapsular - mostly elderly, post menopausal women with osteoporotic bone after a minor fall
Extracapsular - young/middle aged after a significant trauma force (road traffic accident/rugby)
Signs of posterior hip dislocation (5)
Shortening Flexion Adduction Internal (medial) rotation Sciatic nerve palsy (foot drop) can occur
Why does shortening and internal rotation occur after posterior dislocation?
- The femoral head is pushed backwards over the posterior margin of the acetabulum and comes to lie on the lateral surface of the ilium.
- The head of the femur is then pulled upwards by the strong extensors (gluteus maximus and hamstrings) and adductors of the hip, causing limb shortening.
- The anterior fibres of the gluteus medius and minimus pull on the posteriorly- displaced greater trochanter and cause the femur to rotate internally.
Anterior hip dislocation (4)
- External rotation
- Abduction
- Slight flexion
Femoral nerve palsy can be present but uncommon
Central dislocation
- In central dislocation, the head of the femur is driven into the pelvis through the acetabulum. It is always a fracture-dislocation.
- The femoral head is palpable on rectal examination and there is a high risk of intrapelvic haemorrhage due to disruption of the pelvic venous plexuses.
- This can be a life-threatening injury.