Thumb (1st metacarpal) Fractures

Thumb fractures, and by this I mean 1st metacarpal fractures, have a couple of distinct patterns that are different from the other metacarpals.

Type I: Bennett Fracture

  • This fracture is intra-articular on the ulnar side of the first metacarpal, basically making a little triangle
  • It’s that little ulnar fragment that stays attached to the trapezium by the virtue of the volar ligament
  • The distal aspect of the metacarpal gets supinated and dislocated radially no thanks to the adductor pollicis
  • The fragment gets pulled proximally by the abductor pollicis brevis and abductor pollicis longus

Type II: Rolando Fracture

  • You can think of this fracture as a really busted up Bennett’s (comminuted). It is also intra-articular and usually makes a Y or T shape
  • These kind generally heal poorly but thankfully are fairly rare

Type III: Other extra-articular fractures

  • This is basically any other 1st metacarpal fracture (all the extra-articular ones)
  • They are the most common, but don’t have fancy names, just lame ones like “transverse“, “oblique“, etc.

Type IV

  • These really only exist in paediatrics and involve the proximal physis (growth plate)

Treatment: it’s best to treat Bennett and Rolando Fractures with thumb spica splints and then refer them to your friendly neighbourhood plastic surgeon or orthopaedic surgeon as they might need pinning or an open reduction.

Teeth (and how to number and name them)

Teeth are pesky things, there are a bunch of them and they all seem to have a bunch of different names. Technically speaking, a full set of adult teeth is 32. However many people end up getting their wisdom teeth taken out, bringing them down to only 28 teeth in total.

There are 4 “types” of teeth

  1. Incisors – 8 in total
  2. Cuspids aka Canines – 4 in total
  3. Bicuspids aka Premolars – 8 in total
  4. Molars – 12 in total (counting the wisdom teeth)

Of course, to say “the 2nd incisor on the top right” is just far too many words to say and write down, so different coding systems were developed to make things snappier. The most commonly used system in North America and the one that’s used by the World Health Organization is the FDI World Dental Federation notation.

The FDI system numbers the 4 quadrants of the mouth, starting at the top-right and going clockwise:

  • 1 = top right
  • 2 = top left
  • 3 = bottom left
  • 4 = bottom right

Each tooth is then numbered starting at the middle and working back:

  • 1 = first incisor
  • 2 = second incisor
  • 3 = cuspid/canine
  • 4 = first bicuspid/premolar
  • 5 = second bicuspid/premolar
  • 6 = first molar
  • 7 = second molar
  • 8 = third molar (wisdom tooth)

Flexor Tenosynovitis (Kanavel’s Signs)

Suppurative (infectious) flexor tenosynovitis is a medical emergency because the tendon sheath is a closed space and too much swelling can lead to compartment syndrome and necrosis.

* You can’t really get these complications in extensor tendons as it is an open space (no tendon sheath)

There are 4 cardinal signs of flexor tenosynovitis (Kanavel’s Signs)

  1. Tenderness along the whole tendon sheath (late sign)
  2. Finger held in flexion
  3. Fusiform swelling (sausage finger)
  4. Pain with passive extension *this is the earliest finding

It is usually caused by some sort of inoculation, but this can be something very small and the patient may not be aware that he/she had ever been injured (can also be caused by local or hematogenous spread). It’s not unreasonable to get an x-ray to rule out other things and if there’s a fever or they seem very unwell, you can do blood cultures. You also probably want to start the patient on some broad spectrum antibiotics such as vancomycin + ciprofloxacin (or ceftriaxone).

Treatment is tendon sheath drainage and debridement as well as antibiotics.

Glasgow Coma Scale (GCS)

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The Glasgow Coma Scale is a scoring system used to evaluate someone’s level of consciousness. It is scored out of 15 with 15 being totally awake and alert and 3 being totally not.

The important thing to remember is that the lowest score possible is 3.

Absolutely anything can score a 3, however if you are a living, breathing human being, hopefully you are scoring well up into the 10s.

Generally the GSC is applied in trauma situations and can be used as part of the decision making process of such thing things like should this patient be intubated?

  • ≥13 correlates with mild brain injury (or being ok)
  • 9-12 correlates with moderate injury
  • ≤8 represents severe brain injury – you should probably consider intubating them as they most likely cannot protect their airway
Thanks to Mike for the guest doodle!

Cytology of the Cervix and Testing for Abnormalities

In the cervix there is a nice transition from the rough and tough squamous epithelial cells of the outside world (vagina) to the squishy secretory columnar epithelial cells of the inside (uterus). Over time the junction between these two cell types moves towards the inside (more squamous cells) and this is normal metaplasia. This is not to be confused with dysplasia, which is the transformation of normal squamous cells to less differentiated cells.

When women get colposcopies the examiner is looking for dysplasia, and two of the tricks they have up their sleeves to make the dysplasia more apparent are vinegar and iodine.

Both rely on the fact that dysplastic cells are more active and have a much larger nucleus:cytoplasm ratio.

  • When vinegar (acetic acid) is applied, the cells become dehydrated, and the nuclei reflect more light. This makes the cells with larger nuclei more prominent because they appear more white. This includes dysplastic cells and cells infected with HPV.
  • With an iodine solution (Lugol’s iodine) the iodine binds to glycogen in cells making them appear dark brown. Healthy columnar cells don’t have glycogen and due to their small amount of cytoplasm, dysplastic and HPV-infected cells don’t either.

Using these two techniques can help differentiate areas of dysplasia and guide sampling biopsies.

The Menstrual Cycle

The menstrual cycle. What more of a classic drawing can you get? Though it has been done a million times over, here’s the Sketchy Medicine version of the classic hormonal interplay that allows for the endometrial lining to build up, shed, build up, shed, build up, shed…

The nice thing is the the pituitary hormones are aptly named so that FSH (follicle stimulating hormone) stimulates the follicle to grow and LH (luteinizing hormone) causes ovulation (the infamous LH surge) and subsequent corpus luteum development.

Meanwhile the developing follicle secretes estradiol which stimulates the proliferative phase of the cycle. Then the corpus luteum secretes estradiol and progesterone to kick things into high gear for the secretory phase.

You can now passively study this all the time (and keep your own notes) on a notebook or a mug. Nothing says “mmm, coffee” like the hormonal phases of the female reproductive system.

Signs of the 3rd Stage of Labour

There are three stages of labour, even though most people just think of labour as what is technically just the first stage.

  1. Cervical dilatation (all the way to 10 cm): which is divided into three more stages, just to make things more complicated
    1. Latent: contractions start and the cervix kind of sort of changes (but slowly)
    2. Active: cervix gets its butt in gear (this starts once it’s 2-4 cm dilated),
    3. Descent: baby drops down, this part is on a blurred line between stages 1 and 2
  2. Delivery of the baby: pretty self-explanatory
  3. Delivery of the placenta: within 30 minutes after the baby, more than 60 minutes counts as a retained placenta

It’s very important to not try to yank the placenta out before having seen the signs of the third stage because chances are it has not separated from the endometrium and doing so will cause uterine inversion (it will be pulled inside out). And though you’d think that after the baby is out all the fun is over and the job is done, the 3rd stage is associated with significant potential morbidity such as hemorrhage, retained placenta (which can lead to hemorrhage) and the uterine inversion (and you guessed it, hemorrhage).

This is because the uterus is trying to contract down and squeeze off all the little blood vessels and having something in the way or being inside out prevents it from doing that properly.

Leopold Maneuvers

Leopold Maneuvers are a slick series of abdominal palpations that let you determine which way the baby is facing in a pregnant woman.

It’s akin to palm reading, but cooler and more accurate. With the four maneuvers you can figure out which part of the baby is facing towards the pelvis (presentation aka bum first/breach or head first/cephalic), if it’s facing to the right or left and how far it is into the pelvis (engagement).

Skilled physicians can even estimate the weight based on Leopold maneuvers.

Signs of Meningitis

Meningitis is very literally inflammation of the meninges. Something swollen in a closed space is never good, so it’s important to not miss meningitis when it presents.

Classic triad of meningitis

  1. Fever
  2. Neck stiffness
    • Brudzinski
    • Kernig
  3. Mental status change – in babies this can be an increase in somnolence or irritability (unconsolably crying)

Important organisms:

  • Bacterial
    • Listeria*
    • E. coli*
    • GBS (Group B strep)*
    • Neisseria meningitidis
    • Strep pneumoniae
    • Staph aureus
    • Gram neg bacilli
    • Haemophilus influenza
  • Viral (“aseptic”)
    • HSV
    • Enterovirus
    • HIV
    • Mumps

* These are the common ones in the neonatal period

Bacterial:

  • Positive Gram stain
  • CSF white blood cell (WBC) count >1000/uL with a predominance of neutrophils
  • Low CSF glucose concentration <40 mg/dL (2.2 mmol/L)
  • Empiric treatment: high doses of a 3rd generation cephalosporin (cefotaxime, ceftriaxone) and vancomycin (this covers antibiotic-resistant S. pneumoniaeN. meningitidis, and Hib)

Femoral Triangle

The femoral triangle is a convenient triangle where the femoral nerve, artery and vein pass from the abdomen to the leg. The best part about this is that they’re all quite superficial, making it a great place to stick things in (place catheters, nerve blocks, etc).

Because the femoral triangle is often getting poked at for various reasons, it’s important to know what’s where because you don’t want to be hitting the nerve when you meant for the artery (or vice versa).

The triangle is made up by the sartorius, adductor longus and inguinal ligament and if you just remember NAVVAN.