Functional Hand Anatomy Flashcards
List muscles innervated by the median nerve in order of innervation
PT, FCR, PL, FDS, FDP D3
AIN: FPL, FDP D2, PQ
Recurrent br: OP, APB, FPB (supericial head)
Lumbricals 1, 2
Describe course of median nerve
BP: roots C5-T1, br of lateral cord from anterior division of upper/middle trunk + br of medial cord from anterior division of lower trunk
ARM:
- Lateral to Brachial artery, between brachialis and biceps
- cross over coracobrachialis and run medial to brachial artery
- *Ligament of Struthers forms tunnel to enter forearm between supracondylar process and medial epicondyle
FOREARM
- deep to *Lacertus FIbrosis* and bicipital aponeurosis
- between *2heads of PT*
-
AIN runs between FDP, FPL and deep to PQ with AIA (ulnar source)
- FPL, FDP D2, PQ
-
Median proper runs b/w FDS and FDP
- PT, FCR, PL, FDS, FDP
- Palmar cut br 5cm proximal to wrist crease b/w FCr PL
WRIST
- Recurrent motor br 50% distal to TCL, 30% wihtin CT, 20% pierce TCL
- APB, FPBs, OP
- Lumbrical 1,2
- Sensory D1,2,3.5
List muscles innervated by radial nerve
Triceps (long, lateral, medial heads), BR, ECRL
Anconeus, Supinator
PIN: +/-ECRB, EDC, EDM, ECU, APL, EPB, EPL, EIP
Describe course of radial nerve
BP: roots C5-T1, posterior cord
ARM:
-
triangular interval (triceps long/lateral heads and teres major)
- posterior to brachial artery, medial to humerus, along long head of triceps
- Radial groove with deep brachial artery
- PCN antebrachial
- Triceps long/lateral/medial, BR, ECRL, ECRB, anconeus, Brachialis (medial only)
- LIMS 10cm above lateral epicondyle w radial collateral artery
- Radial Tunnel (Lat ECRB, ECRL, BR, Medial biceps brachialis, Floor Radiocapitellar joint, Roof BR)
ELBOW:
- Deep branch and superficial br 4cm above supinator
- SBRN run under BR radial to radial artery, emerge between BR and ECRL 9cm before styloid, superficial to EPB,APL,extensor retinaculum.
-
Deep br pierce supinator and wrap around radius neck to go to Posterior ocmpartment
- Arcade of frohse = proximal edge of supinator
- PIN as exiting supinator
- +/- ECRB, EDC, EDM, ECU,APL, EPB, EPL, EIP
- PIN & PIA run together deep to 4th compartment
What are the surface landmarks for identifying the A1 pulleys for each digit
- Distal palmar crease -> D4, D5 A1 pulley
- Proximal palmar crease ->D2
- Midway between 2 above - > D3
- MCP crease -> thumb
What is kaplan’s line
- Line drawn parallel to proximal palmar crease begining in first web space and coursing through hook of hamate
- at line perpendicular to radial border of D3 and kaplan = recurrent motor br of median n
- at line perpendicular to ulnar border of D4 and kaplan = common ulnar digital n
Where are cleland and grayson ligaments relative to NV bundle and what is there function?
- Cleland - dorsal to NV. Fx to retain integument in position
- Grayson - volar to NV. Fx to prevent bowstringing of NV bundle with movement
Name the potential spaces in the hand
- Deep
- Thenar
- Hypothenar
- Midpalm
- Superficial
- Dorsal sub-aponeurotic
- Dorsl subcutaneous
- Interdigital web (collar button)
- Extend into Forearm
- Parona’s space
- Radial bursa
- Ulnar bursa
- Palmar space
What are theories of carpal alignment trasnlating to function (3)
- Classic
- 2 rows
- proximal radiocarpal row = S, L, Tq, (+Ps)
- Mid carpal row = Tz, Tm, C, H
- 2 rows
- Navarro
- 3 longitudinal colums
- central - flex-extend = C, L, H
- radial - trasnfers load of thumb = Tz Tm S
- Ulnar - prono-sup.= Tq
- 3 longitudinal colums
- Lichtman
- oval ring concept made of 4 elements
- S, L, Tq and the distal row
- oval ring concept made of 4 elements
How do you determine if a carpal height is normal?
- Carpal height = 1/2 length of D3 MC
- Carpal height = 1.5 x Capitate height
What are normal angles of relation to the lunate ? (b/w S-L, R-L, C-L)
- R-L <15’
- C-L <15’
- S-L 30-60
What are the ligaments of the wrist
- Extrinsics - span radiocarpal and midcarpal
- Volar
- RSC (radioscaphocapitate)
- long and short RL
- UL
- UTq
- Dorsal
- DRC (Dorsal radiocarpal - to Tq)
- Volar
- Intrinsics - b/w carpal bones
- S-L, L-Tq, T-T, T-C, C-H
- DIC (dorsal intercarpal - S-Tz - Tq)
What is the TFCC, what does it consist of, and its fx
Triangular fibrocartilage complex
- origin: sigmoid fossa & lunate fossa of distal radius
- insertion - ulnar styloid
- fx; primary stabilizer of the DRUJ
Consists of:
- triangular fibrocartilage
- ulnar meniscus homologue
- dorsal and volar radioulnar ligaments
- UL and UT interosseous ligaments
- ECU tendon sheath
Define the boundaries and contents of the carpal tunnel
- Roof: TCL
- Floor: volar radiocarpal ligaments
- Radial; Trapezium and scaphoid tubercle
- Ulnar; Pisiform and hook of hamate
Contents
- 4FDP 4FDS tendons
- FPL
- median nerve
Define the boudaries and contents of Guyons canal
- Roof: Volar carpal ligament and Pisohamate lig,
- Floor/Radial wall: Hook or hamate and TCL insertion
- Ulnar wall: Pisiform and PHlig insertion
Contents
Ulnar nerve and artery (nerve is ulnar)
List the extensor compartments
- APL, EPB
- ECRL, ECRB
- EPL
- EDC, EIP
- EDM
- ECU
What is the important stabilizer of the first CMC joint?
Saddle joint - biconcave b/w Tm and 1st MC
Allows for 3planes of motion (flex-ext, abd-add, pron-sup
Volar oblique (beak)ligament is primary stbailizer
APL insertion on dorsal base of MC is 2’ stabilizer
What tendons insert on the dorsal base of D2,3,4,5?
- D2- ECRL
- D3- ECRB
- D4- none
- D5- ECU
Name and describe the stabilizers of the MCP jts
- Volar plate - Accessory CL and CL
- areolar tissue prximal to allow for shrinkage w flexion
- Condyloid shape of MC head with narrow dorsal and wide volar shape - non-spherical
- DTMC - attaches to VP - lumbricals are volar and IO are dorsal to DTMC
What is unique about the volar plate of the MCPjt of the thumb
- contains two sesamoid bones
- Radial sesamoid- insertion of FPB +/- APB
- Ulnar sesamoid - insertion of adductor pollicis
What is the difference between the proper and accessory collateral ligaments
- proper CL originate on BONE (lateral condyle of MC) and the accessory originate on ligament (the Proper CL)
- Both CLs insert on volar plate, only Proper Cl insert on bone (PP)
- Function: Proper CL are tight in flexion and stabilize power grip
- Function: Accessory are tight in extension
How do IP joints differ from MCP joints
- IPs are hinge joints, MCPs are condyloid joints
- VP prevents hyperextension in IPs
Where are the annular and cruciate pulleys located
- 5 annular pulleys
- A1,3,5 overlie MCP PIP DIP jts and insert on volap plate and bone
- A2,4 lie in between
- 3 cruciate pulleys
- lie b/w A2-3, 3-4, 4-5 - at location of trasnverse digital arteries
WHat is the vascular supply ot the tendons
- Segmental
- Arises from vincula (condensation of mesotenon), bony insertions, paratenon
- each tendon has 2 vincula - VB and VL
- the VBS and VBP insert just proxial to FDS and FDP insertions
- VLP (at PIP jt), VLS (at base PP)
What abnormalities in extensor tendons can be expected?
- EDC multiple slips to D4, D5
- Absent EDC to D5
*
What is the fx of the sagittal bands
- maintains EDC tendon centralized over MCP
- Origin: VP and DTMC
- Insertion: EDC
What is fx of Lateral bands
- flexion MCP, extension IPs
- Formed by Lumbrical + IO radially and just IO ulnarly
What is the function of the trasnverse retinacular ligament and where are they located
- Origin: flexor sheath of PP
- Insertion: conjoined tendons of lateral band,
- Course: Runs lateral to PIP joint & superficial to collaterals
- Function: Prevents excessive dorsal translation of lateral bands w PIPJ extension, facilitates volar translation of lateral bands w flxn
- attenuation leads to dorsal translation of lateral bands —> swan neck
- contracture leads to volar translocation —> boutonierre
- (KI I CHANGED THIS, REVIEW YOURSELF AS WELL)
- origin: deep belly of IO
- insert: extensor hood, distal to and parallel w sagittal bands
- Fx: insertion of IO to PP to facilitate MCP j flexion
- ***Transverse bands Tighten in intrinsic tightness
What is the function of the oblique retinacular ligament and where are they located
- Originates on volar PP / FTS
- inserts after oblique course on terminal tendon
- fxn: Coordinated PIP & DIP flexion and extension
- (as DIP flexes, ORL tightens causing flexion of PIP; as PIP extends, ORL tightens causing extension of DIP; passive flexion of PIP relaxes ORL and allows DIP flxn)
- contracture causes volar displacement of lateral bands (boutonierre)
- becomes lax in swan neck
- test: extend the PIP joint (tightens the ligament) and note resistance to passive DIP flexion (relative to when the PIP is flexed)
*
What is the fx, origin, insertion of the lumbricals
- Fx- PIP jt extension
- Origin - FDP tendon
- Insertion
- form RADIAL lateral band =>PIP extension
- form Oblique fibers of extensor hood =>MCP flexion