general trauma Flashcards
what is primary bone healing?
Primary bone healing: This process occurs where there is minimal fracture gap (less than about 1mm) and the bone simply bridges the gap with new bone from osteoblasts. This occurs in the healing of hairline fractures and when fractures are fixed with compression screws and plates.
What is secondary bone healing?
Secondary cone healing: In the majority of fractures, there is a gap at the fracture site which needs to be filled temporarily to act as a scaffold for new bone to be laid down. This is known as secondary bone healing and involves an inflammatory response with recruitment of pluropotential stem cells which differentiate into different cells during the healing process.
Describe the 4 steps of secondary bone healing?
Step 1: inflammation
- WBCs clean debris
- infammatory response triggers growth of new blood cells
Step 2: soft callus (2-3weeks)
- new blood vessels develop
- cartilage is created around the bone fracture
Step 3: hard callus (6-12 weeks)
- hard callus replaces soft callus and connects bone fragments more solidly
- bulge is created at site of fracture
- see this in x-rays few weeks after fracture occurs
Step 4: remodelling
- new bone replaces old bone
- bones are stronger, more compact and blood circulation is improved
What can cause an atrophic non-union of bone?
Secondary bone healing requires a good blood supply for oxygen, nutrients and stem cells and also requires a little movement or stress (compression or tension).
Lack of blood supply, no movement (internal fixation with fracture gap), too big a fracture gap or tissue trapped in the fracture gap may result in an atrophic non‐union. Smoking may severely impair fracture healing due to vasospasm whilst vascular disease, chronic ill health and malnutrition will also impair fracture healing.
Hypertrophic non unions occur due to excessive movement at the fracture site with abundant hard callus formation but too much movement give the fracture no chance to bridge the gap.
What are the 5 different fracture patterns?
Segmental Comminuted oblique spiral transverse
What is the difference between displacement and angulation?
Displacement: describes the direction of translation of the distal fragment and is described using anatomic terms. Fractures can be described as anteriorly or posteriorly displaced and medially or laterally displaced.
Angulation: The direction in which the distal fragment points towards and the degree of this deformity.
For an anterior dislocation - which nerve are you worried about?
Axillary:
- deltoid muscle weakness
- numbness in badge patch
What nerve are you worried about in a humeral shaft fracture?
- radial
- wrist drop
- loss of sensation in the 1st dorsal webspace
-palm flat on table and extend thumb
What nerve are you worried about in a supracondylar fracture of the elbow?
Median:
paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity)
sensory loss to palmar aspect of lateral (radial) 2 ½ fingers
unable to pronate forearm
weak wrist flexion
ulnar deviation of wrist
OK sign for AIN
LOAF muscles
What clinical signs are seen in an ulnar nerve palsy?
- medial 1 and a half fingers sensation
- ‘peace signs’
- froments sign
What nerve are you worried about in carpal tunnel syndrome/colles fracture?
Median:
- paralysis and wasting of thenar eminence muscles and opponens pollicis (ape hand deformity)
- sensory loss to palmar aspect of lateral (radial) 2 ½ fingers
What nerve are you worried about in a posterior dislocation of the hip?
Sciatic nerve
What nerve are you worried about in a ‘bumper’ injury to lateral knee?
common peroneal
-The most characteristic feature of a common peroneal nerve lesion is foot drop
Other features include:
weakness of foot dorsiflexion weakness of foot eversion weakness of extensor hallucis longus sensory loss over the dorsum of the foot and the lower lateral part of the leg wasting of the anterior tibial and peroneal muscles
What is seen in a fracture of the scaphoid bone?
numbness in the anatomical snuffbox
- 4 views are taken if scaphoid fracture is suspected (AP, lateral and 2 oblique views)
- if a scaphoid fracture is suspected clinically but the x‐ray fails to demonstrate a fracture, the wrist is splinted and further clinical assessment +/‐ further x‐ray is arranged around two weeks after the injury. The injury is referred to as a “clinical scaphoid fracture”.
What antibiotics are used for open fractures?
IV broad spectrum antibiotics –typically Flucloxacillin to cover gram positive organisms, Gentamicin to cover gram negatives and Metronidazole to cover anaerobes if there is soil contamination.
