Orthopaedics, gen surg Flashcards
Give four key XR changes in OA
L – Loss of joint space
O – Osteophytes (bone spurs)
S – Subarticular sclerosis (increased density of the bone along the joint line)
S – Subchondral cysts (fluid-filled holes in the bone)
Give two renal side effects of ibuprofen use
AKI (e.g. acute tubular necrosis) or progressive kidney disease
Give two CVS SEs of ibuprofen use
HTN, HF, MI, stroke
How long do we give VTE prophylaxis for with TKRs and THRs?
28 days post elective hip replacement
14 days post elective knee replacement
What do we use to avoid prosthetic joint infections?
Prophylactic abx
What is a compound fracture?
A compound fracture is when the skin is broken and the broken bone is exposed to the air. The broken bone can puncture through the skin.
What is a pathological fracture?
A pathological fracture refers to when a bone breaks due to an abnormality within the bone (see below).
There are terms used to describe in what way a bone breaks:
What is a Colle’s fracture?
A Colle’s fracture refers to a transverse fracture of the distal radius near the wrist, causing the distal portion to displace posteriorly (upwards), causing a “dinner fork deformity”.
What is the usual cause of a Colle’s fracture?
This is usually the result of a fall onto an outstretched hand (FOOSH).
Give the key sign with a scaphoid fracture.
Tenderness in the anatomical snuffbox
What is the usual cause of a scaphoid fracture?
FOOSH
Give a complication of a scaphoid fracture.
It is worth noting that the scaphoid has a retrograde blood supply, with blood vessels supplying the bone from only one direction. This means a fracture can cut off the blood supply, resulting in avascular necrosis and non-union.
What is the Weber classification used for?
The Weber classification can be used to describe fractures of the lateral malleolus (distal fibula).
Why is a pelvic fracture so concerning?
The pelvis forms a ring. When one part of the pelvic ring fractures, another part will also fracture (similar to fracturing a polo mint).
Pelvic fractures often lead to significant intra-abdominal bleeding, either due to vascular injury or from the cancellous bone of the pelvis. This can lead to shock and death, so needs emergency resuscitation and trauma management.
What causes pathological fractures?
Pathological fractures occur due to an underlying disease of the bone, such as a tumour, osteoporosis or Paget’s disease of the bone.
Name three main cancers that metastasise to the bones
PoRTaBLe
Po – Prostate
R – Renal
Ta – Thyroid
B – Breast
Le – Lung
How do we medically treat osteoporosis first line?
Calcium and vitamin D
Bisphosphonates (e.g., alendronic acid)
How do bisphosphonates work?
Interfering with osteoclasts and reducing their activity, preventing the reabsorption of bone
Give two key SEs of bisphosphonates
Reflux and oesophageal erosions (oral bisphosphonates are taken on an empty stomach sitting upright for 30 minutes before moving or eating to prevent this)
Atypical fractures (e.g. atypical femoral fractures)
Osteonecrosis of the jaw
Osteonecrosis of the external auditory canal
What is denosumab?
Denosumab is a monoclonal antibody that works by blocking the activity of osteoclasts. It is an alternative to bisphosphonates where they are contraindicated, not tolerated or not effective.
What is relative stability in regards to bone fractures?
In fractures where closed and open reduction aren’t suitable, treatment involves providing relative stability for some time to allow healing to occur. This can be done by fixing the bone in the correct position while it heals. There are various ways the bone can be fixed in position:
External casts (e.g., plaster cast)
K wires
Intramedullary wires
Intramedullary nails
Screws
Plate and screws
When does fat embolism present after fracture?
24-72 hours afterwards
What are Gurd’s criteria used for?
Diagnosis of fat embolism:
Gurd’s major criteria:
Respiratory distress
Petechial rash
Cerebral involvement
There is a long list of Gurd’s minor criteria, including:
Jaundice
Thrombocytopenia
Fever
Tachycardia
Describe the blood supply to the head of the femur
The head of the femur has a retrograde blood supply. The medial and lateral circumflex femoral arteries join the femoral neck just proximal to the intertrochanteric line. Branches of this artery run along the surface of the femoral neck towards the femoral head. They provide the only blood supply to the femoral head. A fracture of the intra-capsular neck of the femur can damage these blood vessels, removing the blood supply to the femoral head, leading to avascular necrosis. Therefore, patients with a displaced intra-capsular fracture need to have the femoral head replaced with a hemiarthroplasty or total hip replacement.