Wrist and hand (OCS-A summary) Flashcards
What are the muscles of the thenar eminence with innervation? (4)
- adductor pollicis (ulnar)
- abductor pollicis brevis (median)
- flexor pollicis brevis (median and ulnar)
- opponens pollicis (median)
What are the muscles of the hypothenar eminence with innervation? (3)
- abductor digiti minimi (ulnar)
- flexor digiti minimi (ulnar)
- opponens digiti minimi (ulnar)
What is the action of the lumbricals with innervation?
- actively flexes MCPs, with passive PIP/DIP extension
- 1st/2nd - median
- 3rd/4th - ulnar
What are the actions of the interossei with innervation?
- palmar interossei - adduction (PAD)
- dorsal interossei - abduction (DAB)
- ulnar innervation
What is the sequence of the proximal and distal carpal bones?
- proximal: scaphoid, lunate, triquetrum, pisiform
- dorsal: trapezium (“um, Thumb”), trapezoid, capitate, hamate
(She, Likes, To, Park)
(Tiny, Toy, Cars, Here)
Which carpal bone is most commonly fractured?
- scaphoid
What is a carpal attachment for the flexor retinaculum that is often fractured?
- hook of hamate
Which carpal bone is most important structurally for the rest of the carpals?
- capitate; it’s a keystone
What is a normal angle of inclination at the distal forearm (radius/ulna)?
- 15-20*
- radius is longer than ulna
What are normal ROMs for wrist:
- flexion
- extension
- radial deviation
- ulnar deviation
- flexion: 80-90*
- extension: 70-80*
- radial deviation: 15*
- ulnar deviation: 30-45*
The MCP collateral ligaments are taut with:
- abd/add
MCP volar plates are taut with:
- extension; resist hyperextension
Which ligament for the 1st CMC helps avoid dorsal subluxation?
- dorsoradial ligament
- strongest ligament for the 1st CMC
The TFCC is on what side of the wrist?
- attaches the ulnar styloid process to the edge of the radiocarpal articular surface
What muscles are associated with DeQuervain’s tendinopathy?
- abductor pollicis longus
- extensor pollicis brevis
- both lie in the radial styloid space
What’s the difference in action between the flexor digitorum profundus and superficialis?
- profundus flexes both PIP and DIP
- superficialis only flexes PIP
How many pulleys are there in the hand? Which are considered most important for hand function?
- 3 cruciate pulleys and 5 annular pulleys per finger (different for thumb)
- A2 and A4 are considered most important
Which pulley is often resected with a trigger finger?
- A1
“Bowstringing” is seen at the PIP. What is the likely cause?
- A2 failure; will likely have reduced flexion in the finger as well
What is supplied by the anterior interosseous nerve? What nerve does it branch from?
- flexor pollicis longus
- flexor digitorum profundus
- pronator quadratus
- branch of the median nerve
Where is Guyon’s canal? What is the result of entrapment in this region? What activity is associated with compression in this region?
- between the pisiform and hook of hamate
- ulnar nerve can become compressed, leading to sensation loss and intrinsic hand weakness
- associated with cycling
What is supplied by the posterior interosseous nerve? What nerve does it branch from?
- all extensors except extensor carpi radialis longus
- supinator
- abductor pollicus longus
- radial nerve
What is the blood supply for the distal scapoid?
- superficial and deep branches of the radial artery
What does the Finklestein test look for? How is it performed?
- Dequervain’s tendinitis
- Clench fist and ulnarly deviate
- pain in APL and EPB tendons
What is similar to Dequervain’s in presentation? What is the difference?
- intersection syndrome
- pain in intersection syndrome is more proximal (~1/3rd up the forearm from the wrist), and more likely to have pain with wrist extension
What is the CPR for potential scaphoid fx? (i.e., want imaging)
- TTP at snuffbox
- TTP at scaphoid tubercle
- TTP with scaphoid longitudinal compression
- high sensitivity
What’s the difference between a Smith and Colles fracture?
- both are distal radius fractures, associated with FOOSH
- Smith: fall with wrist FLEXED; distal radius angles VOLARLY (SV; alphabetical)
- Colles: fall with wrist EXTENDED; distal radius angles DORSALLY; dinner fork (CD)
- defined by the direction the distal fragment is displaced; makes sense with MOI
What is Kienbock’s disease? What is the general demographic? What type of imaging can detect it?
- AVN of the lunate
- associated with middle aged men, trauma, or medical conditions that affect blood supply (anemia, steroids, pancreatitis)
- can detect more advanced AVN with X-ray (triangular shape), but best w/ MRI
What’s a Boxer’s fx vs Gamekeeper’s thumb?
- Boxer’s fx: fracture of the neck of the MC, most commonly the 5th
- Gamekeeper’s: avulsion or sprain of the UCL of the MCP, often presenting with hyperextension
Describe thumb movements.
- abduction: thumb moves in a palmar direction, away from the plane of the hand
- adduction: thumb moves from the palm, dorsally toward the plane of the fingers
- flexion: thumb moves in the plane of the hand toward the 5th digit
- extension: thumb moves in the plane of the hand, away from the other digits
- opposition: thumb moves towards a finger
- makes sense in cardinal planes if you align the palm of the hand with the sagittal plane, facing away from the body
How does the scapholunate angle related to instability?
What is an appropriate test?
- > 70* is dorsal instability
- <30* is volar instability
- due to ligament tears in the proximal carpal row
- Scapholunate dissociation test: stabilize the lunate and mobilize the scaphoid, looking for gross instability or reproduction of pain with forearm pronated
What is a Bennett fx?
- fracture of the base of the 1st MC
- usually requires ORIF
What is the presentation for a Bishop’s deformity? Ape hand? Drop wrist?
- Bishop’s: ulnar n. palsey; inability to fully extend 4th/5th digits, with hypothenar wasting
- Ape: median n. palsey; unable to extend 2nd/3rd digits, with thenar wasting
- drop wrist: radial n. palsey; unable to extend wrist
** of note, the median/ulnar n. palseys have different presentations depending on distal vs proximal impingement
What is the presentation of a Mallet finger deformity?
- avulsion fx at the base of the DIP, or tear of the extensor digitorum of any digit
- DIP flexion
How many flexor tendon zones are there? What is a key zone for prognosis?
- 5 zones, numbered distal to proximal
- injury in zone 2 has poor prognosis due to poor blood supply
How many extensor zones are there?
- 8
What is the standard care for injury at extensor zone 1-2? What is presentation?
- mallet finger
- splint up to 8 weeks, then can begin gentle DIP ROM
What is the standard of care for injury at extensor zone 3-4? What is the presentation?
- Central slip injury
- splint for 6 weeks, but can use DIP AROM during splinting
What is a concern for injury for extensor zone 7?
- at higher risk for scar formation; a dorsal wrist injury
What is a 5 variable CPR for carpal tunnel?
- shaking hands produces symptom relief
- Wrist ratio index >0.67
- symptom severity scale > 1.9
- reduced median nerve sensory perception at 1st digit
- age >45
- if all 5 present, +LR = 18.3
- if 4, +LR = 4.6
- if 3, +LR = 2.1
What is normal for monofilament testing? What is considered loss of protective sensation?
- normal: 2.83
- loss of protective sensation: 4.56
What are 2 keys to rehab post tendon repair at the hand/wrist?
- early protective motion is important to prevent adhesions or stiffness
- splinting position should place the affected tendon on slack
What is the presentation for a Jersey finger?
- lack of DIP flexion, due to FDP tear or avulsion
What is the intrinsic plus splinting position?
- MCP flexion, with PIP and DIP extension
What is the difference between a Boutonniere and Swan Neck deformity?
- Boutonniere: PIP flexion with DIP hyperextension
- Swan neck: PIP hyperextension with DIP flexion
If scissoring or cross over effect is seen with MC fracture, what is the concern?
- could indicate a MC rotational deformity, which should be addressed prior to continuing therapy
What is Dupuytren’s? What deformity is it associated with?
- contracture of the palmar fascia
- can create cords and flexion contractures of the MP or PIP
- more common in males of European descent
- can lead to Boutonniere deformity
- managed with surgery/injection/manipulation
What is trigger finger?
- locking of digit during active flexion due to A1 thickening. More common in women. Typically idiopathic.
- often managed with conservative care; tendon glides, splinting, injection, but can use surgery
What is Froment’s sign?
- excessive thumb IP flexion during gripping task (holding piece of paper) due to ulnar nerve injury
What are the outcomes for surgery vs conservative care for CTS?
- surgery is often more favorable than conservative care due to the concern for prolonged nerve compression
What is nail clubbing concerning for?
- pulmonary disorder such as fibrosis or CA. Yellowed clubbing is concerning for lung CA
- of note, clubbing is NOT associated with COPD
What is spoon nails concerning for?
- soft nails that look scooped out
- sign of iron deficiency or liver disorder
What is tripe hand? What is it concerning for?
- rough, thickened, velvety appearance of the palms
- highly associated with visceral malignancy or lung CA
