Hand Flashcards
1st extensor compartment
EPB
APL
(de quervains tenosynovitis)
2nd extensor compartment
ECRL
ECRB
(intersection syndrome)
3rd extensor compartment
EPL
4th extensor compartment
EIP
EDC
PIN*
5th extensor compartment
EDM
Vaughn-Jackson Syndrome
6th extensor compartment
ECU
Oblique retinacular ligament links…
the motion of DIP and PIP. With PIP flexion, the ligament relaxes to allow DIP flexion and with PIP extension, it tightens to facilitate DIP extension.
Anatomy of the oblique retinacular ligament
from lateral volar aspect of the proximal phalanx to the terminal extensor insertion dorsally
Contracture of the oblique retinacular ligament causes…
volar displacement of the lateral bands and a Boutonniere deformity.
The transverse retinacular band functions to…
pull the lateral bands volarly with PIP flexion and prevent dorsal translation of the lateral bands with PIP extension.
Anatomy of the transverse retinacular ligament
Originates from the flexor tendon sheath at the PIP and inserts on the lateral border of the lateral bands.
Attenuation of the transverse retinacular ligament leads to…
dorsal translation of lateral bands and resulting swan neck deformity.
The digital cutaneous ligaments act to…
tether the skin to deeper layers of fascia and bone to prevent excessive mobility of skin and improve grip. They stabilize the NV bundle with finger flexion and extension.
(Clelands ligaments and Grayson’s ligaments)
Clelands ligaments
Dorsal to the digital nerves
Grayson’s ligament
volar to digital nerves
The extensor hood functions to…
extend PIP and DIP joint.
The central slip of the extensor hood functions to…
extend the PIP. It inserts into the base of the middle phalanx.
The lateral band of the extensor hood functions to..
extend the DIP. It inserts into the distal phalanx.
Components of the MCP collateral ligaments:
Radial collateral ligaments and ulnar collateral ligaments which each have proper and accessory components.
The accessory collateral ligaments are…
- fan shaped
- more volar (tight in extension)
- attach from the MC head to the palmar plate
- test with adduction/abduction stress in extension
The proper collateral ligaments are…
- cord like
- more dorsal (tight in 30 degrees of flexion)
- attach from the posterior tubercle of MC head to the proximal phalanx base
- test with adduction/abduction stress in 30 degrees of flexion
Function of the deep transverse metacarpal ligament
prevents MC heads from splaying apart
Anatomic components of the deep transverse metacarpal ligaments
connects 2nd to 5th MC heads together at the volar plate of the MCP joiint
Natatory Ligament function
resists abduction
Natatory ligament anatomy
- most superficial MP joint ligament
- originates from distal to the MP joint and inserts proximal phalanx of all 5 fingers
Sagittal bands function
keeps extensor mechanism tracking in the midline during flexion of the MP joint
Anatomy of sagittal bands
originate on the palmar plate and inserts on the extensor mechanism
Triangular ligament function
counteracts the pull of the oblique retinacular ligament, preventing lateral subluxation of the common extensor mechanism
Located on the dorsal side of the extensor mechanism, distal to the PIP joint
Function of the volar plate
prevents hyperextension
Anatomy of the volar plate
- thickening of the joint capsule volar to the MP joint (in the thumbs, sesamoid bones are located here)
- originates on the metacarpal head and inserts on the surface of the proximal phalanx via checkrein ligaments
The volar plate is loose in…
flexion and tight in extension.
Steps for volar approach PIP joint flexion contracture release:
- release check rein ligaments
- release accessory collateral ligament and volar plate
- release proper collateral ligament off the proximal phalanx
Most critical ligaments to prevent bowstringing
A2 and A4
A1, A3, and A5 overlie…
the MP, PIP and DIP joints respectively.
they originate from the volar plate
The cruciate pulleys function to…
prevent sheath collapse and expansion during digital motion.
The oblique pulley originates…
at the proximal half of the proximal phalanx of the thumb.
It is the most important pulley of the thumb.
functions like a cruciate pulley in the finger does
The oblique pulley of the thumb facilitates…
excursion of FPL and prevents bowstringing.
The A1 pulley in the thumb is…
at the level of the volar plate at the MCP joint. The radial digital nerve is closes (about 2.7 mm).
The Av pulley of the thumb (annular variable) is located…
between the A1 and oblique pulley.It functions to prevent bowstringing.
Options for grafts for pulley reconstruction
- Extensor retinaculum (synovialized and thus has the least gliding resistance)
- palmaris, plantaris, FDS, allograft
Techniques for pulley reconstruction
- around the bone (encircling)
- single loop (Bunnell)
- triple loop (Okutsu)** strongest
- nonencircling
- ever present rim (Kleinert)
- belt loop (Karev)
- extensor retinaculum
- palmaris longus transplant thru volar plate
Complications of pulley reconstruction
- phalanx fracture
- stiffness
- persistent bowstringing
Repair of either the oblique pulley or the A1 pulley will restore thumb kinematics as long as…
the A2 pulley is intact.
A2 and A4 pulleys arise from…
the periosteum of the phalanges.
The radial artery runs between…
brachioradialis and FCR. It enters the dorsum of the carpus by passing between FCR and APL/PB tendons. Then gives off superficial palmar branch and finally passes between 2 heads of the 1st dorsal interosseous to form the deep palmar arch.
The ulnar artery runs…
under the FCU, enters the hand through guyon’s canal and lies on the transverse carpal ligament.
The ulnar artery gives off.
the anterior and posterior interosseous arteries.
The superficial palmar arch lies…
deep to the palmar fascia and distal to the deep arch. It lies at the level of a line drawn across the thumb, parallel to the distal edge of the fully abducted thumb.
The predominant blood supply to the superficial palmar arch is the…
ulnar artery.
Branches of the superficial palmar arch:
1: deep branch to the deep palmar arch
2: ulnar digital artery of the small finger
3, 4, 5, 6: common palmar digital arteries