Hand injury

Question 1

Flexor digitorum superficialis

Answer 1

Tendon runs from forearm to MCP, splits into 2 at MCP

Flexes MCPJ

Question 2

Flexor digitorum profundus

Answer 2

Runs from forearm, attaches to DIPJ

Flexes DIPJ

Question 3

Sagittal bands

Answer 3

Keep extensor tendon central

Question 4

Sign of sagittal band injury

Answer 4

Deviation of the extensor tendon

Question 5

Central slip injury and deformity

Answer 5

Lateral bands move in volar direction
So PIPJ flexes and DIPJ hyperextends
Causing boutonneire deformity

Question 6

Central slip treatment

Answer 6

Mobilise DIPJ as long as there is no lateral band repair, and MCP
Splint placed on dorsal side of PIPJ for 4 weeks to encourage PIPJ extension
Graded flexion of PIPJ

Question 7

Function of lumbricals

Answer 7

Flex MCP

Extend IPJs

Question 8

Mallet injury and deformity

Answer 8

Lateral bands move in dorsal direction
So cannot support volar plate which becomes lax
Causing PIPJ hyperextension and DIPJ flexion
Known as Swan neck deformity

Question 9

Mallet injury treatment

Answer 9

Use mallet splint for 6 weeks to heal tendon in shortened position
Mobilise MCP and PIPJ

Question 10

Volar plate

Answer 10

Ligament that connects proximal phalanx to middle phalanx on volar side
Prevents hyperextension

Question 11

Cannot actively or passively extend finger…

Answer 11

Flexor tightness

Question 12

Cannot actively extend finger but can passively

Answer 12

Extensor tendon weakness

Question 13

Signs of infection

Answer 13

Increased redness, swelling, pain, discharge

Question 14

Smoking and healing

Answer 14

Nicotine narrows small blood vessels that normally bring oxygen and nutrients to injured area, which can slow down healing