hand deformities

Question 1

heberdens nodes

Answer 1

OA enlargement of DIP on the dorsal surface

Question 2

bouchards node

Answer 2

OA enlargement of the PIP on the dorsal surface

Question 3

dupuytrens contracture

Answer 3

D4-D5 contracture of the palmar fascia
results in fixed flexion deformity of MCP and PIP joints

Question 4

Trigger finger

Answer 4

thickening of the FLEXOR tendon sheath D3-D4
tendon sticking, catching, locking when flexing finger
often associated with RA

Question 5

Mallet finger

Answer 5

flexion of the DIP at rest
avulsion/rupture of the extensor tendon at DIP insertion
hyperflexion injury
splint in extension 6-8 weeks

Question 6

swan neck deformity

Answer 6

DIP flexion, PIP hyperextension, MCP flexion
volar capsule slipping at the PIP
or rupture of the extensor digitorum communis at DIP causing muscle imbalance (stronger) at flexor digitorum profundus
RA

Question 7

Boutenniere deformity

Answer 7

DIP hyperextension, PIP flexion, MCP extension
chronic synovitis leads to CENTRAL TENDON SLIP at insertion of extensor digitorum communis
RA

Question 8

unlar drift (of MCPs)

Answer 8

proximal row MCP ulnar subluxation
distal row MCP radial subluxation
reduced ulnar deviation ROM leads to ulnar drift of MCPs
zigzag effect as phalanges try to move back to normal position

Question 9

thumb RA deformities

Answer 9

type 1: IP hyperextension and MCP flexion (Z deformity)
type 2: CMC subluxation and IP hyperextension (least common)
type 3: CMC subluxation and MCP hyperextension

Question 10

ape hand

Answer 10

median nerve injury
inability to abduct or oppose thumb
can be due to low level lesion such as carpal tunnel

Question 11

hand of benediction

Answer 11

median nerve injury
inability to flex D1-D3 when attempting to make fist actively
high level lesion

Question 12

claw hand

Answer 12

ulnar nerve injury
hyperextension of MCP and flexion of IP joints D4-D5
muscles are unopposed, fixed in this position

Question 13

wrist drop

Answer 13

radial nerve injury
inability to extend the wrist or MCP joints
effects the extensor muscles of the wrist due to radial nerve innervation

Question 14

gamekeepers thumb

Answer 14

sprain of the ulnar collateral ligament (UCL) of the thumb
occurs due to valgus force at MCP joint of the thumb
skiers, volleyball players, game keepers

Question 15

thumb OA (CMC)

Answer 15

OA of the CMC joint of the thumb
may lead to hyperextension injury of the CMC joint of thumb