Hand and Wrist Flashcards
Most of the forearm flexors are supplied by what nerve?
Median
Most of the forearm extensors are supplied by what nerve?
Radial
What arteries supply the forearm?
Ulnar and radial
Where do ganglion cysts develop?
In the extensor tendons
What is the functional carrying angle?
The palm is turned in with 20-30 degrees of finger flexion with about 15 degrees of wrist extension
What is the MOI of mallet finger?
Blow to the tip of the finger
What is mallet finger?
Avulsion of the extensor tendon
What does the patient present with a mallet finger?
Pain at the DIP and they can’t actively extend the DIP
What degrees does someone with a mallet finger carry their DIP at?
30 of flexion (they can’t extend)
What does the x-ray show in the case of a mallet finger?
Avulsed bone on the dorsal proximal distal phalanx
Which is more acute, a mallet finger or boutonniere deformity?
Mallet finger
Which is more chronic, a mallet finger or boutonniere deformity?
Boutonniere deformity
What is a boutonniere deformity?
A rupture of the extensor tendon (central slip) at the middle phalanx–it forces the DIP into extension and the PIP into flexion
Why does a boutonniere deformity force the PIP into flexion and the DIP into extension?
The lateral bands are still pulling on the joint
What causes a boutonniere deformity?
The bones slip into the space where the tendon used to be and then they get stuck.
What are the signs and symptoms of a boutonniere deformity?
Severe pain, obvious deformity, and an inability to extend the PIP…there is also swelling and point tenderness
What is the immediate treatment of a boutonniere deformity?
Splint the PIP
How long will a boutonniere deformity be immobilized?
6 weeks
What is the treatment for a mallet finger?
Splint the DIP in extension–it will have to be splinted for about 6 weeks
What is a jersey finger?
A rupture of the flexor digitorum profundus tendon from its insertion on the distal phalanx.
What causes a jersey finger?
An eccentric load on the DIP joint
What finger does a jersey finger typically affect?
Ring finger
What is a common MOI of jersey finger?
An athlete trying to grab a jersey and putting an eccentric load on the DIP
What is the treatment for jersey finger?
Surgery
What happens with the athlete with a jersey finger?
The DIP cannot be flexed so the finger remains extended
What is more chronic of an injury? Jersey finger or swan neck deformity?
Swan neck deformity
What happens with a swan neck deformity?
A distal tear of the volar plate
What happens with a pseudoboutonniere deformity?
A proximal tear of the volar plate
What does the volar plate do?
Prevents hyperextension and creates a firm endfeel when the fingers are extended
With a swan neck deformity or pseudoboutonniere deformity, what happens with the middle phalanx?
It slides down where the volar plate would be–so it causes hyperextension at the PIP and flexion at the DIP. This creates extra stress to be placed on the tendons
What does a white line running through a nail indicate?
A past trauma (3-4 months prior) to the nail bed while it was growing
What do clubbed nails indicate?
Cardiovascular disease
What do spoon nails indicate?
A fungus or vitamin deficiency
What do scaling or ridging of nails indicate?
Psoriasis
What do ridging and more development of nails indicate?
Hyperthyroidism
What is an acute injury, swan neck deformity or jersey finger?
Jersey finger
True or false:
The radius and ulna typically fracture individually.
True
