Hip mishaps

Question 1

what supplies blood to the femoral head?

Answer 1

• artery of ligamentum teres, contribution decreases with age.
• branches of medial and lateral circumflex femoral arteries. (highly susceptible for injury with dislocation).

Question 2

differentiate between primary and secondary osteoarthritis.

Answer 2

• primary cause is unknown but age, females, genetics, nutrition seem to be risk factors.
• Whereas secondary causes include obesity, trauma, infection, RA, haem disorders etc.

Question 3

describe the pathology of osteoarthritis?

Answer 3

• flaking and fibrillation of articular cartilage and erosion.
• subchondral sclerosis, cysts, osteophytes.

Question 4

Name some radiological features of OA.

Answer 4

OA XR = LOSS

• loss of joint space.
• osteophytes appearing more white.
• sclerosis of bone.
• subchondral cysts appear darker.

Question 5

Name some symptoms and management of OA specific to hip.

Answer 5

• joint stiffness when sitting for long.
• pain, swelling, tenderness in hip joint.
• crepitus of bone on bone rubbing.
• activity modified, weight loss, walker, physiotherapy.
• NSAIDs COX-2 inhibitors as anti-inflammatories.
• corticosteroid injections.
  or if severe osteotomy or hip replacement.

Question 6

what are the common hip fractures and what risks do they carry?

Answer 6

intra-capsular fractures : more common in women and elderly. *medial femoral circumflex at risk of injury which could lead to avascular necrosis of femoral head.

extra-capsular fractures : more common in young. Blood supply not affected as distal to sight of fracture.

*both short, abducted and externally rotated hip presentation.

Question 7

how does hip type of fracture affect level of treatment?

Answer 7

if displaced intracapsular fracture, high risk of AVN needing hemiarthroplasty or total hip replacement.

Question 8

describe the common mechanism of a posterior hip dislocation.

Answer 8

• shortened gluteus maximus, hamstrings and adductors.
• internally rotated, adducted and flexed.
• also may present sciatic nerve palsy.

Question 9

describe the common mechanism of an anterior hip dislocation.

Answer 9

• externally rotated, abducted, slightly flexed.

- rarely damages femoral nerve.

Question 10

describe the common mechanism of a central hip dislocation.

Answer 10

• always a fracture dislocation.

- femoral head palpable per rectum and intrapelvic haemorrhage.

Question 11

what are the complications of hip dislocation?

Answer 11

• avascular necrosis.
• post traumatic OA.
• recurrent dislocation.
• sciatic nerve injury leading to foot drop.
• infection.