Hand Flashcards
Tell me what are in the 6 dorsal compartments of the wrist?
- Abductor PL, Extensor PB
2.ECRL, ECRB - Extensor PL
- EDC, EIP
- EDM
- ECU
What structure centralizes the extensor mechanism and attaches to the volar plate at the MCP joint?
Sagittal band
What structure helps with PIP extension?
What structure helps with DIP extension?
Central slip
Lateral bands
Injury to the transverse retinacular ligament may result in what deformity?
Swan neck deformity
Whats in the carpal tunnel?
FDS
FDP
FPL
Mediain Nerve
What innervates the interosseous muscles?
Ulnar nerve
Limited PIP flexion with MCP extension?
Intrinsic tightness
Limited PIP flexion with MCP flexion?
Extrinisic tightness
What does the AIN innervate?
FPL
Index and long FDP
Pronator quadtraus
Radial nerve proper innervates?
Triceps
Anconeus
Brachioradialis
ECRL
The terminal branch of the PIN lies where?
Floor of the fourth dorsal compartment
For DRF, what is the average radial height, inclination, volar tilt?
Radial Height: 11 mm (accept less than 5 degree change)
Inclination: 22 deg (accept less than 5 degree change)
Volar tilt: 11 deg (accept less than 10 degree dorsal anglulation)
What is the main blood supply to the scaphoid?
Dorsal branch of the radial artery distal to waist that flows retrograde
DISI indicates what ligament was injured?
SL ligament
CID (Carpal instability dissociative)
Carpal instability adaptive results from ?
Malunited distal radius fracture
What are the 4 stages of a perilunate dislocation?
- SL disruption
- CL disruption
- LT disruption
4, Circumferential disruption, short radiolunate remains attached
What is the acceptable angulation for metacarpal neck fractures of the index and long fingers?
Less than 15-20 degrees
For metacarpal shaft fracture, what is the acceptable shortening?
Less than 5 mm
Every 2 mm of metacarpal shortening leads to how many degrees of extensor lag?
7 degrees
How do I reduce a thumb metacarpal dislocation?
TAPE: traction, abduction, pronation, extension
In Skiers thumb or gamekeepers thumb, what is injured?
The UCL of the MCP
In testing the MCP, what is injured if:
There is instability at 30 degrees
There is instability at neutral
30 deg is proper UCl and/or dorsal capsular injury
Neutral is the accessory UCL and/or volar plate injury
(more than 35 degrees of opening overall or 20 degrees more than the contralateral side)
What is a stener lesion?
Adductor pollicis is between the avulsed UCL and its insertion site
More than what percentage of involvement of the base of the proximal phalanx in a PIP joint fracture dislocation leads to persistent dorsal dislocation?
More than 30%
When do you repair an extensor tendon?
When there is more than 50% involvement
What zone extensor injury can cause a boutonniere?
Zone 3
The Elson test examines rupture of what?
Central slip
The strength of flexor tendon repair is proportional to what?
Number of suture strands that cross the repair site (6-8)
When do you release a pediatric trigger thumb?
2-4 years of age
What compartments are involved in intersection syndrome?
One (APL, EPB)
Two (ECRB, ECRL
The soft tissues convey how much stability (%wise) to the DRUJ?
80%
What part of the TFCC is not vascularized?
Central portion
Repair of TFCC allows getting 80% of wrist ROM and grip strength by 3 months
What finger tip injury size can I allow to heal by secondary intention?
No bone exposed, less than 1 cm ^2 area
When can I use a cross finger flap?
For a volar oblique fingertip injury with exposed bone
The lumbricals originated off what?
FDP
How do I treat a lumbrical plus finger?
Release of radial lateral band
How do I treat a volar oblique thumb injury?
Moberg flap
How do I treat a dorsal thumb injury?
First dorsal metacarpal artery kite flap or heterodigital island flap
Replantation is not recommended for warm ischemia of how many hours and cold ischemia of how many hours?
6 warm hours for proximal to carpus and 12 hours for amputated digit
12 cold hours for proximal to carpus and 24 hours for amputated digit
What is the operative sequence for amputation attachment?
BEFAVNS
-Bone
-Extensor
-Flexors
-Arterial
_Venous
-Nerve
-Skin
Go after index last if multiple fingers
Structure by structure instead of finger by finger is better
What is the main contributor to the superficial arch?
The ulnar artery
Distal sensory latencies of what and distal motor latencies of what are considered abnormal?
3.5 ms and 4.5 ms
When does grip return after carpal tunnel release?
3 months
When should i consider Parsonage Turner syndrome?
Shoulder pain or after viral illness
What is the functional ROM of the elbow?
30-130 flexion/extension
50 degrees pronation/supination
What is the primary restraint to valgus stress of the functional elbow?
Anterior bundle of the MCL (Ulnar collateral ligament)
Originates from the posterior medial epicondyle and inserts onto the sublime tubercle of the medial coronoid process
When is the posterior bundle the primary restraint to valgus stress of the elbow?
Maximum elbow flexion
What is the primary restraint to varus and external rotation stress of the elbow?
Lateral ulnar collateral ligment (LUCL)
Originates from the posterior lateral epicondyle and inserts onto the crista supinatoris of the proximal ulna
What is the histologic finding for lateral epicondylitis?
Angiofibroblastic hyperplasia
If distal biceps rupture left untreated how much supination and flexion strength gain by 1 year?
50% and 70%
What is the risk for treatment of distal biceps rupture:
Single incision?
Double incision?
Single - nerve injury with lateral antebrachial cutaneous nerve
Double - radioulnar synostosis
Endobutton has superior strength
What is an essex lopresti injury?
DRUJ dislocation, interosseous ligament injury and radial head fracture
Posterolateral rotatory instability is caused by incompetence of what structure?
The LUCL
How do I move the arm in a lateral pivot shift test?
Supination, axial compression, valgus loading from full extension to 40 degrees of flexion
What is at risk with the proximal anteromedial portal within the elbow?
Medial antebrachial cutaneous nerve
What is the main dynamic stabilizer to elbow valgus stress?
FCU
FDS is secondary