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
WHere are the interossei located and what is their function
- Palmar Interossei - Adduction
- unipennate
- form lateral band
- Dorsal interossei - Abduction
- bipennate
- superficial head
- deep head- forms transverse fibers of lateral band
- D2: DIO radial, PIO ulnar
- D3: DIO radial and ulnar
- D4: DIO ulnar, PIO radial
- D5: PIO radial * ADM acts as abductor
What maintains the position of the conjoined lateral bands during motion of the PIP DIP jts
- Triangular ligament - on dorsum, holds conjoint laterla bands from slipping volar
- TRL - volar, prevent dorsal subluxation of conjoint lateral bands durign extension (origin on flexor sheath, insert on lateral bands
What is the fx of the ORL (lig of landsmeer)
- Origin: volar PIP jt
- insertion: dorsal DIP jt at TT
- Fx: links flexion and extension of pip and dip jt
Describe the anatomy of the brachial plexus
Roots
- C5-T1 - preaxial C4, postaxial T2
- C5-C7, roots arises above names vertebrae, C8-T1, nerves arise below C7 and T1
- Located between anterior and middle scalene
Trunks
- Located in the posterior triangle
- Forms upper trunk C5-6, middle trunk C7 Lower trunk C8T1
- Each trunk divides into anterior and posterior divisions
Divisions
- Located posterior to the clavicle
- Anterior division of upper and middle trunk form lateral cord
- Anterior division of lower trunk form medial cord
- Posterior divisions of all trunks for posterior cord
Cords
- Located around axillary artery, posterior to pectoralis minor
- Medial cord divides into medial br of median and ulnar n
- Lateral cord divides into lateral br of median and MSC
- Posterior cord divides into radial and axillary n
Where does the suprascapular nerve originate and its funxtion
most common to least common
- posterior division of upper trunk
- at bifurcaiton of upper trunk
- proximal to bifurcation of upper trunk
Function
- Supraspinatus (first 15’ abduction)
- Infraspinatus (external rotation)
Where does the lateral pectoral nerve originate and its funxtion
most common ->least common
- Anterior division of upper trunk, proximal to lateral cord formation
- at formation of lateral cord
Function
- clavicualr head pectoralis mjor
Describe course of ulnar nerve
BP: terminal br of Medial cord, C8-T1
ARM:
- medial/posterior to brachial artery
- MIMS 8cm proximal to epicondyle
- run ontop of triceps with superior ulnar collateral artery
-
Arcade of struthers* (MIMS, triceps fascia)
- runs between MIMS and Tricep fascia
- Articular br
- Cubital Tunnel - Osborne’s ligament b/w ME and olecranon + FCU aponeurosis, floor is ulnar collateral ligament
FOREARM
- FCU heads*
- FCU, FDP D4,5
- courses between FCU and FDP
- ulnar to ulnar artery at jx of mid&distal 1/3
- DSU 3-6cm proximal to ulnar styloid, uulnar to FCU
WRIST
- Guyon’s canal: roof VCL, floor TCL, ulnar pisiform, radial hook of hamate
- Zone 1 - before bifurcation
- Zone 2 - deep motor br
- Pisohamate ligament * landmark for deep motor br b/w ADM FDM
- pierces ODM, goes radially around Hook
- Deep palmar arch + deep motor ulnar br course together deep to flexors
- Zone 3 - superficial sensory br
- PB, Hypothenar, 4th Common Dig, 5th proper Dig
- Lumbrical 3,4, IO, FPBd, AdP, 1st DIO
List muscles innervated by ulnar n
FCU, FDP D4,5,
PB,
AbDM, FDM, ODM, Lumbrical 5,4, IO, dFPB, AdP, 1st DIO
What is a martin gruber anastomosis
Anomalous innervation of median nerve (AIN) to ulnar intrinsics (17% have some connection)
- type 1 - median to ulnar innervating median intrinsics (60%) (cross back)
- type 2 - median to ulnar innervating ulnar intrinsics (30%)
- type 3 - ulnar to median, innervating median intrinsics (3%)
- type 4- ulnat to median, innervating ulnar intrinsics (cross back)
KATHY - I MADE A NEW/DIFFERENT CARD ON THIS - I DON’T THINK THIS IS RIGHT OR THE DETAIL WE SHOULD KNOW FOR THE EXAM. LET’S TALK ABOUT IT!!! :)
What is a riche cannieu
Ulnar to median n cross connect in palm (b/w deep motor br and recurrent motor br)
Describe course of ulnar artery and its branches
ULNAR ARTERY
- Brachial artery terminal branch
- Antecubital fossa - ulnar artery medial to biceps tendon
- Deep to PT
- b/w FCU and FDP with ulnar nerve
- subcutaneous radial to FCU
- superficial to TCL, radial to Pisiform
- Superificial br forms Superficial palmar arch**main
- Deep branch forms Deep palmar arch
BRANCHES
- Anterior & posterior IO arteries - travel on either side of IOM - AIO may persist as median artery
-
Anterior & posterior recurrent arteries-
- AUR- supplies BR - PT
- PUR - elbow
Describe course of Radial artery and branches
RADIAL ARTERY
- Cubital fossa - deep to BR - runs w SRN
- subcut in wrist
- Superficial palmar arch branch courses over APB to arch
- Snuff box - deep to APL EPL EPB and plunges through 1st DIO
- terminates as deep palmar arch and princeps pollicus
- PP gives rises to common digital artery (thumb) and radialis indicis
What is the median artery?
- persistent AIA off of CIA from ulnar artery
- present in 20% of people
- RF/etiology for CTS
What is the blood supply (arches) to the hand and their location
- Superficial Palmar arch
- superficial to long flexor and lumbrical
- at kaplans cardinal line
- branches: CDA 2nd 3rd 4th web space and proper 5th dig art
- Deep Palmar arch
- deep to long flexors, lumbricals
- proximal to kaplans line
- branches; palmar MC arteries - **join CDAs
- Dorsal arteries
- from PIA and dorsal br of AIA + br of rad/uln to form dorsal carpal arch (deep palmar MC arteries)
- dorsal artery is primary revascularization for thumb?
- Digital arteries
- formed by superficial palm arch + contributing metacarpal arteries from deep palm arch just prior to bifurcation
What is extrinsics tendon tightness
- scarring/adhesions over dorsum of wrist/hand which prevent tendons from gliding
- TEST: wrist, neutral, flex MCPs. PIPs will remain extended and will not be able to flex
How do you test intrinsics
- Lumbrical - MCP flex IP ext
- IO - hand flat on table, D3 hyperextended to eliminated extrinsic extensors, ab/adduct D3
- Hypothenar - abduct D5
- Adductor pollicis - pinch between radial side of index and thumb - Fromments
What is intrinsic muscle tightness
- IO transverse fibers (from deep IO muscle belly to PP)
- TEST -w rist in neutral, MCP extension, PIP cannot be flexed
What are special and specific hand tests during physical examination
- Finkelsteins - traction and stretching over 1st Dorsal compartment reproduces pain = dequervains
- grind test- axial load to 1st CMC jt reproduces pain = OA
- Tnel’s- regenerating axons
- Fromment’s - with pinch of thumb to radial indez, weakness of intrinsics (AddP) causes FPL to flex IP
- Boyes ORL tightness test - decreased DIP flexion w PIP extension
What is the clinical significance of a positive ORL tightness test
Boyes ORL tightness test
- examiner holds PIP extended and passively/actively get DIP flexion to occur - if unable to flex DIP with PIP exteded, means ORL is tight= subacute or chronic central slip injury ->leads to boutoniere deformity
What is the clinical significance of a positive Bunnell intrinsic tightness test
With MCP hyperextended, limited PIP flexion = intrisic tighness - need to release trasnverse fibers form deep head of IO
With MCP flexed, limited PIP flexion = extrinsic tightness
How do you test for DRUJ instability or arthritis?
DRUj compression test
- holdig ulna against sigmoid notch of radius and passively pron/supinating hand - reproduction of pain suggests DRUj arthritis
How do you test for ECU subluxation
- Palpate ECU with supination and ulnar wrist deviaition - if sublux - grossly unstable
- if ECU contraction is needed to sublux, som e stbaility remains
- Pain with ecu subluxation is critical for considering repair
How do you test for cubital tunnel syndrome
- Elbow flexion test - supinated hand, elbow flexion for 60secs
- tinel’s at cubital tunnel
What is elsen’s test
To determine if complete central slip injury
- injured hand placen on table spporting PP and PIP jt is over table. Ask pt with extend
- postiive if unable to actively extend PIP but DIP is rigid
What is foveal sign?
Pain at fovea - (at depression dorsal to FCU = ulnar styloid) - indicates TFCC injury
What is the LIchtman midcarpal shift test
- pronated wrist in ulnar then radial deviation, approx 15’, pressure on downward capitate - midcarpal instability if clunk
for a patient with an apparent motor / functional deficit of the digits of the hand, how do you differentiate between a neurologic etiology vs a musculotendinous etiology?
- by invoking the tenodesis effect; if intact then the musculotendinous units are intact and the problem is neurogenic.
- if not intact, it is possible that are both musculotendinous and nerve injury
What is the Bunnell test?
- test for intrinsic tightness
- have patient flex IP joints when a) MCPJ extended passively and b) MCPJ flexed passively
- test is POSITIVE when IPJ flexion is limited when MCPJ is passively extended, indicating intrinsic tightness
What is Elson’s test?
- tests the integrity of the central slip
- the affected digit is flexed over a tabletop at the PIPJ
- extension at the PIPJ is actively resisted by the examiner
- if the central slip is intact, all force will be transmitted through the central slip and the DIPJ will remain slightly flexed and flaccid
- if the central slip is not intact, the force will be transmitted through the lateral bands to the terminal tendon, and the DIPJ will extend and be rigid
What is the Bouvier test?
- the Bouvier test tests the integrity of the central slip in the context of chronic ulnar nerve injury
- with the patient’s MCPJ claw hyperextension deformity passively corrected, by being passively held to neutral or just slightly flexed at MCPJ, the patient is asked to extend the PIPJ
- if PIPJ extension is intact, there is sufficient tension along the central slip and static reconstructive maneuvers can be employed to correct the claw
- if PIPJ extension is not intact, there is laxity/attenutation of central slip and dynamic reconstructive maneuvers will be employed to correct the claw
what is the origin/insertion/function of transverse retinacular ligament
- TRL originates from PP/FTS at PIPJ laterally and terminates in the conjoined lateral band
- fxn: prevent excessive dorsal translation of lateral band during extension, and facilitates volar translation during flexion
- when attenuated, dorsal displacement lateral bands - swan neck
- when contracted, volar displacement lateral bands - boutonniere
what is the origin/insertion/function of the oblique retinacular ligament?
- runs from volar PP / FTS dorsolaterally to insert into terminal tendon
- facilitates coordinated movement (flxn/extn) between PIP and DIP joints
- when contracted - lateral bands displaced volar - boutonniere
what muscles does the deep motor branch innervate once it is in zone 2 of guyon’s canal?
- hypothenar muscles: FDMB, AbdDM, OppDM
- ulnar 2 lumbricals
- dorsal (4) and volar (3) interossei
- AddP
- 1/2 of FPB
what does superficial sensory branch of ulnar nerve innervate once it enters zone 3 in Guyon’s canal?
- palmaris brevis muscle
- sensation to D5 and ulnar 1/2 of D4
what is the checkrein ligament, where is it found, and what is its function
- checkrein ligaments are proximal thickened extensions of the volar plate at the PIPJ
- function to prevent hyperextension while permitting flexion
draw the extensor apparatus
IN A PATIENT WITH A MARTIN-GRUBER ANASTOMOSIS, DESCRIBE THE INTRINSIC MUSCLE FINDINGS IN THE HAND IN THE FOLLOWING SCENARIOS:
- proximal median n injury
- distal median n injury
- proximal ulnar n. injury:
- distal ulnar n injury:
- Martin Gruber is MEDIAN TO ULNAR Nerve communication in the forearm
- proximal median n injury – median n. AND ulnar n intrinsics OUT
- distal median n injury – median n intrinsics OUT, ulnar intrinsic IN
- proximal ulnar n. injury: ulnar n intrinsics IN, median n intrinsics IN
- distal ulnar n injury: ulnar intrinsics OUT, median n intrinsics IN
What is a Marinacci communication?
- ULNAR TO MEDIAN nerve communication in the FOREARM
In a patient wiht a Riche-Cannieau communication, what are the intrinsic muscle findings and sensory findings in the hand in the following situations?
- median n injury proximal to wrist
- ulnar n injury proximal to wrist
- Rich-Canneau is a DMB to RMB in the palm
- median n injury proximal to wrist: NORMAL thenar muscle function
- ulnar n injury proximal to wrist: NO intrinsic muscle function
- both: sensation normal
What is a sensory communication between the superficial sensory branch of ulnar nerve and sensory branch of median nerve in the palm called?
- Berrettini communication
If you could only repair 1 proper digital artery in a replant, which one would you repair?
- Least traumatized / smallest zone of injury / not requiring vein graft / good flow
- All other things being equal, then choose the “dominant” vessel:
- in general, dominance heads to equator of hand (long finger)
- thumb, index, long (less obvious): ulnar
- ring (less obvious), small: radial
how do you test interossei function while eliminating the extrinsic extensor function on IPJ extension?
- hand / palm flat on table
- lift index / hyperextend MCPJ off table then adduct/abduct (dorsal/volar interossei)
how do you test for ORL tightness? who’s eponym goes w the test?
- see Boutonneire
- with flexible digit - when PIPJ held extended, there is limited passive flexion of DIPJ
- Boyes
what physical examination maneuver indicates tightness or contracture of extrinsic flexors?
- with flexion of wrist/MCPJ the IPJ easily are passively extended
- vs. w extension of wrist and (hyper) extension of MCPJ the IPJs will not be passively extended
what diagnosis is confirmed when Love test and Hildreth sign are positive?
- glomus tumour
