Hand Flashcards
In Dupuytren’s, the natatory ligament contributes to…
web space contracture.
In Dupuytren’s, the pretendinous cord causes…
MCP contracture.
In Dupuytrens, the spiral cord causes…
PIP (and MCP) contracture.
In Dupuytrens, the retrovascular cord causes…
DIP hyperextension.
Positive NCV study findings for compressive neuropathy
distal motor latency > 4.5 msec
sensory motor latency > 3.5 msec
Adson test
diminished radial artery pulse with inhalation. seen in thoracic outlet syndrome 2/2 subclavian vessel compression.
What characteristic best correlates to the excursion (or amplitude) of a tendon for transfer?
fiber length
The force a muscle can generate is directly proportional to…
the physiologic cross sectional area of all its muscle fibers.
The greatest force of contraction is exerted when the muscle is at…
resting length.
Tendon transfers for radial nerve deficit
FCR –> EDC
PT –> ECRB
PL –> EPL
The deep fibers of the radioulnar ligaments attach to…
the ulnar fovea and this is more important for DRUJ stability than the superficial fibers which attach to the styloid.
Role of proper collateral and accessory collateral in thumb MCP joint stability
PCL is primary restraint to radial deviation w/ MCPJ in flexion.
ACL provides restraint to radial deviation w/ MCPJ in extension.
Position to immobilize in for stability of subluxing ECU
pronation, extension and ulnar deviation
Most common PE finding for midcarpal instability
a clunk as the wrist is moved from neutral and forearm pronation to ulnar deviation with an axial and palmarly directed load.
The protein commonly used in synthetic nerve conduits is…
type I collagen.
When to use a volar approach to the scaphoid
distal pole fractures
humback deformity
When to use a dorsal approach to the scaphoid
proximal pole fractures
*tends to promote more central placement of screw
Vascularized bone graft for Scaphoid fracture AVN w/o humpback deformity
1-2 ICSRA
Vascularized bone graft for scaphoid fracture AVN w/ humpback
MFC
SNAC Stage 1
radial styloid arthritis
tx with styloidectomy but not more than 4 mm due to origin of RSC
SNAC Stage 2
radioscaphoid arthritis
SNAC Stage 3
scaphocapitate and lunocapitate arthritis
SNAC Stage 4
pancarapal DJD
Continuing pain with dorsal chip triquetral fracture after SAC, think…
DIC/DRC ligament injury
The scapholunate ligament is strongest…
dorsally.
The lunotriquetral ligament is strongest…
palmarly.
The scaphoid tends to…
palmar flex.
The triquetrum tends to…
dorsiflex.
The lunate is “along for the ride” so if you have division of the scapholunate ligament, the lunate willl.
extend because it goes with the triquetrum (DISI).
Gold standard for dx of schapholunate ligament injury
arthroscopy
Division of the lunotriquetral ligament will cause the lunate to…
flex with the scaphoid (VISI).
Sequence of events with perilunate dislocation
SL ligament disrupted (can have scaphoid fx) –>
capitolunate dissociation –>
lunotriquetral disruption (can have triquetral fx) –>
failure of dorsal radiocarpal ligaments –> lunate dislocation
Treatment of perilunate dislocation
-use dorsal approach to fix SL and volar approach to fix LT and perform CTR
The primary blood supply to the scaphoid enters at the…
oblique dorsal ridge.
Deforming forces of MC base fractures
2nd CMC: ECRL
3rd CMC: ECRB
5th CMC: ECU
There is apex dorsal angulation of MC neck fracutres 2/2…
intrinsic pull.
5 degrees of rotation at MC leads to…
1.5 cm overlap
MC shortening of 2 mm leads to…
7 degrees extensor lag
What ligament prevents dorsal dislocation of the 1st CMC joint?
dorsoradial
Treatment of extra-articular (epibasal) thumb MC fractures
< 30 degrees of angulation well tolerated non-op
> 30 degrees , CRPP (otherwise can get MCPJ hyperextension)
With pinch, force seen at IP, MCP and CMC joints of the thumb
IP 4x
MP 6 x
CMC 12 x
Herbeden’s nodes
DIP
Arthroplasty of the DIP is associated with…
extensor lag.
Schapholunate ligament rupture can be associated with…
gout.
Which cord causes contracture of the DIP joint in Dupuytren’s?
retrovascular
Parona’s space lies between…
the fascia of the pronator quadratus and FDP conjointed tendon sheaths.
The attachments of the transverse carpal ligament include…
scaphoid and trapezium radially and pisiform and hook of hamate ulnarly
The medial femoral condyle vascularized graft is supplied by….
the longitudinal branch of the descending geniculate artery.
