Flashcards in general trauma Deck (32):
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?
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?
-deltoid muscle weakness
-numbness in badge patch
What nerve are you worried about in a humeral shaft fracture?
-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?
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
What clinical signs are seen in an ulnar nerve palsy?
-medial 1 and a half fingers sensation
What nerve are you worried about in carpal tunnel syndrome/colles fracture?
-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?
What nerve are you worried about in a 'bumper' injury to lateral knee?
-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.
What is the presentation of septic arthritis?
Acute onset of a severely painful red, hot, swollen and tender joint with severe pain on any movement are the typical presenting features of a septic arthritis.
What bacteria are common in septic arthritis?
Staphylococcus aureus ‐ the most common cause in adults
Streptococci ‐ the second most common cause
Haemophilus influenzae ‐ was the most common cause in children but is now uncommon in areas where Haemophilus vaccination is practiced
Neisseria gonorrhoea ‐ in young adults (now thought rare in Western Europe)
Escherichia coli ‐ in the elderly, IV drug users and the seriously ill
What is the treatment for septic arthritis?
Any joint suspected of septic arthritis should be aspirated under aseptic technique before antibiotics are given to confirm the diagnosis and to identify the causative organism such that appropriate antibiotic therapy can be targeted at the responsible bacteria. A single dose of antibiotics can lead to a falsely negative Gram stain and culture.
If frank pus is aspirated, the clinical picture fits with obvious septic arthritis or a positive Gram stain is found, the treatment is usually surgical washout either via open surgery or using arthroscopic techniques
How do you 'clear a c-spine' following trauma?
No history of loss of consciousness
GCS 15 with no alcohol intoxication
No significant distracting injury (such as head injury, chest trauma or other fractures including more distal spinal fractures)
No neurological symptoms in the upper or lower limbs
No midline tenderness on palpation of the c-spine
No pain on gentle active neck movement (ask the patient to gently flexed forward, then rotate to each side)
-if not cleared have to use a brace
What is central cord syndrome?
-usually occurs with a hyperextension injury in a cervical spine with osteoarthritits.
Paralysis of the arms more than the legs occurs due to the corticospinal (motor) tracts of the upper limbs being more central and those for the lower limbs being more peripheral in the cord. Sacral sparing is typically present.
What is anterior cord syndrome?
-loss of movement pain and temperature
-still able to feel position, vibration and touch
What is posterior cord syndrome?
-loss of position, vibration and touch
What is brown sequard?
-loss of pain/temp/light touch on contralateral side
-loss of motor/vibration/position/deep touch on ipsilateral side
What is the usual pattern for a humeral neck fracture?
The most common pattern is a fracture of the surgical neck (rather than the anatomic neck) with medial displacement of the humeral shaft due to pull of the pectoralis major muscle. The greater and lesser tuberosities may also be avulsed with the attachments of Supraspinatus, Infraspinatus and teres minor for the greater tuberosity and subscapularis for the lesser tuberosity.
What xray sign is seen with posterior shoulder dislocations?
The main Xray finding is the “light bulb” sign where the excessively internally rotated humeral head looks symmetrical like a light bulb on an AP view.
what are the three distal radial fracture patterns?
Colles - dorsal displacement: median nerve is a concern, can use casting or ORIF
Smiths - volar displacement: v. unstable so ORIF
Bartons - intra-articular: ORIF
What 3 fractures occur in the hip?
-hemiarthroplasty if immobile
-THR if mobile
-intertrochanteric: dynamic hip screw
-subtrochanteric: IM nail
What guidance is used to direct which ankle fractures warrant x ray?
In A&E the Ottawa criteria are used to identify a suspected ankle fracture and give guidance as to which ankle injuries require an Xray. Any severe localized tenderness (known as bony tenderness) of the distal tibia or fibula or inability to weight bear for four steps merits an xray.
what is the unhappy triad of the knee?
contact sports, such as basketball, football, or rugby, when there is a lateral force applied to the knee while the foot is fixated on the ground. This produces the "pivot shift" mechanism.
anterior cruciate ligament (ACL) tear
medial collateral ligament (MCL) tear/sprain
medial meniscal tear (lateral compartment bone bruise)
What is a lisfranc fracture dislocation?
This is an uncommon but often overlooked injury where a fracture of the base of the 2nd metatarsal is associated with dislocation of the base of the 2nd metatarsal with or without dislocation of the other metatarsals at the tarso‐metatarsal joints
The patient typically presents with a grossly swollen, bruised foot upon which they're unable to weight bear. In these patients, be very wary of a normal looking xray.
Untreated, these injuries have a fairly high risk of pain and disability and therefore to reduce this risk closed or open reduction with fixation using screws is recommended.
Why do fractures of the base of the 5th metatarsals take place?
Fractures of the base of the 5th metatarsal are common and occur due to an inversion injury with an avulsion fracture at the insertion of the peroneus brevis tendon.
These heal predictably and require a walking cast, supportive bandage or wearing of a stout boot for 4‐6 weeks. Even with those which fail to achieve bony union, many have a stable fibrous non‐union which is usually asymptomatic.