Hand and Wrist Flashcards
Mannerfelt lesion - what is it and what are two ways to treat it?
Rupture of FPL (JAAOS Papp et al, Rheumatoid wrist)
- The Mannerfelt lesion occurs when the distal pole of the scaphoid and trapezium pierce the volar wrist capsule, causing FPL tendon rupture.
**Can also see flexor rupture of the FDP to the index. This is due to synovitis in the carpal tunnel and attritional rupture
- you get rupture from radial to ulnar in contrast to VJS (which is ulnar to radial and on the extensor side). FPL, FDP index, FDS index, FDP middle
TREATMENT
- FDS transfer from ring finger. Tendon transfer using FDS tendon from the ring finger is an option if preserving thumb motion is important, such as in a young, active patient with well-controlled disease
- Thumb IP fusion is the simplest and most reliable solution
- FPL advancement/pull thru bridge graft (FCR or PL) (only if supple joints and compliant, functinoional muscle unit)
Rupture of FDP to index.
- treatment:
- distal IP joint fusion or side-to side FDP transfer
- for FDP and FDS rupture on same finger can swing over FDS from another finger
What is Vaughn-Jackson syndrome and what is the treatment?
Vaughan-Jackson syndrome - describes the rupture of the hand digital extensor tendons which occur from the ulnar side of the wrist first then moves radially
Pathoanatomy- results when DRUJ instability results in dorsal prominence of the ulnar head which results in an attritional rupture of the extensor tendons EDM is the first extensor ruptured.
Treatment: Usually EDM/EDC5 is ruptured first. You can do an side-side ED4 transfer. An EIP transfer is another alternative As you get progressively more extensor tendons involved you have to do more transfers. In general you take the most radial rupture tendon and transfer it to EDC of the adjacent intact tendon and then for the most ulnar (usually EDC4 and 5) you do an EIP transfer. See table From JAAOS Papp et al
What is the most distal muscle innervated by the Radial Nerve, PIN, median, AIN, Ulnar nerve?
Radial nerve proper - ECRL
PIN - EIP
Median - 2nd lumbrical (not the thenar eminence as this is from the recurrent branch which is given off more proximally)
AIN - PQ
Ulnar - Adductor pollicis (1st interossei is the last testable muscle innervated)
Swan neck deformity. What is the key anatomical defect/lesion leading to this condition?
Describe the pathoanatomy.
Can be caused by attenuation or injury of the volar plate at the PIP (RA, volar dislocation at PIP)
Can also be caused by a mallet finger leading to extensor tendon imbalance
Pathoanatomy:
- stretching (or rupture) of the volar plate at PIP joint;
- intrinsic tightness;
- collateral ligament contracture
- DIP laxity;
- this leads to imbalance of forces on the PIP
aWhat are the borders of guyon’s canal?
Roof - Volar carpal ligament
Floor - flexor retinaculum
Ulnar border - pisiform
Radial border - hamate
What are the zones of guyon’s canal?
What is a cause of compression in each zone?
Zone 1 - proximal to the bifurcation into the sensory and motor branch
Cause of compression:
- Ganglion - results in combined deficit
- Hook of Hamate fracture
Zone 2 - the area of the nerve consisting of the motor branch after the bifurcation as it wraps around the hamate
Cause of compression:
- Ganglion
- hook of hamate fracture - results in motor deficit
Zone 3 - the area of the canal which carries the superficial sensory branch
Cause of compression:
- arterial aneurysm or thrombosis - results in sensory deficit
- Synovium/arthritis,
What are the contents of the Guyon’s canal?
Ulnar nerve
Ulnar artery
What are the dorsal compartments of the wrist?
From 1-2 it is APL then EPB then ECRL then ECRB
I - APL/EPB (APL is more palmar. EPB is more dorsal)
II - ECRL, ECRB
III - EPL
IV - EDC, EI
V - EDQ
VI - ECU
Name one pathological condition associated with each of the 6 wrist compartments.
I - De Quervains
II - Intersection syndrome
III - Drummer’s wrist, EPL rupture
IV - Extensor tenosynovitis
V - Vaughn jackson Syndrome
VI - Snapping ECU tendon
Name the 10 compartments in the hand and how you release them.
there are 10 compartments in the hand
thenar
hypothenar
adductor pollicis
dorsal interossei (x4)
volar interossei (x3)
2 dorsal incisions in line with the second and 4th metacarpals
1 incision over the radial aspect of the thenar eminence
1 incision over the hypothenar eminence
+/- carpal tunnel release
What is the blood supply to the scaphoid?
The main blood supply is dorsal coming from the dorsal carpal branch of the radial artery. It enters the scaphoid thru the dorsal ridge.
DCB of RA supplies 80% Also: Superficial palmar branch of the radial artery
Why don’t you get lunate AVN in perilunate dislocation?
main reason is that the lunate general stays put and the carpus dislocate around it.
lunate has a rich blood supply from a volar and dorsal plexus
Per Wheeless;
majority of lunates have both dorsal & palmar vessels & are thus as well vascularized as the other carpal bones;
- neither single intraosseous nor extraosseous disruption alone will cause avascular necrosis in these bones because of the rich external and internal anastomoses;
- lunate blood supply may be jeparidized by dorsal approaches to wrist, but perfusion from palmar radiocarpal arch is adequate in most cases;
- usually there is, an rich anastomotic network fed by multiple dorsal & palmar vessels;
- in < 20% of pts: a single vessel enters palmar surface and branching with in the bone to provide the sole supply;
- w/ this pattern, pts w/ in severe hyperextension injuries or dislocations may have a disruption of palmar nutrient vessels as they enter the bone
What is the Mayfield classification?
4 stages of of progressive perilunate instability leading to dislocation
I) Scapholunate ligament failure
II) capitolunate articulation failure
III) lunotriquetral ligament failure (PERILUNATE DISLOCATION - the lunate remains aligned and you have a dorsal dislocation of the carpus). Can be trans- scaphoid or trans-radial styloid
IV) dorsal radiocarpal ligament failure (LUNATE DISLCATION - the capitate remains aligned and the lunate lunate rotates and it becomes a lunate dislocation (usually volarly into the carpal tunnel)
This has been recreated in a cadaver by pronation and ulnar deviation on a hyperextened wrist
Name the volar extrinsic ligaments from radial to ulnar (9)
stronger than the dorsal ligaments
- Radial Collateral
- Radioscaphocapitate - strongest and most important. This is violated in the volar approach to scaphoid and must be repaired.
- Long radiolunate (aka radiolunotriquetral) - just ulnar to RSC. This is the primary restraint to perilunate dislocations
- Radioscapholunate (ligament of testut) - actually a NV structure
- Short radiolunate
- Ulnolunate
- Ulnocapitate
- Ulnotriquetral
- Ulnar collateral
What are the intrinsic ligaments of the wrist?
these are interosseous and usually have a dorsal, IO and volar portion
Can be identified according to which row they sit
1) Proximal row
scapholunate ligament (dorsal is the strongest). disruption leads to disi deformity
Lunotriquetral ligament - disruption leads to visit deformity
2) Distal row
trapeziotrapezoid ligament
trapeziocapitate ligament
capitohamate ligament
3)Palmar midcarpal
scaphotrapeziotrapezoid
scaphocapitate
Triquetralcapitate
triquetralhamate
What ligaments are the main restraint to subluxation of the DRUJ in supination and pronation?
Supination:
Deep dorsal radioulnar ligament is the main restraint to Volar subluxation of the radius
Pronation:
Deep volar radioulnar ligament is the main restraint to dorsal subluxation of the radius
HOWEVER, this is somewhat controversial. WIKI also says:
During supination the superficial palmar and the deep dorsal ligaments are tighten, they prevent palmar translation of the ulna. In pronation this is reversed, the superficial dorsal and the deep palmar ligaments are tighten. They prevent dorsal translation of the ulna in pronation.
What are the 6 components of the TFCC?
- Articular disc
- Dorsal and volar radioulnar ligaments (superficial and deep components). Deep ligaments known as ligamentum subcruentum
- Meniscus homolog - Disc Carpal ligaments
- Ulnar collateral ligament
- Sheath of ECU
- Origin of the ulnolunate and ulnotriquetral ligaments
Name 5 structures that stabilize the DRUJ.
- TFCC
- Joint capsule (and bony congruity of sigmoid notch)
- IO membrane
- ECU tendon and sheath
- PQ
Can also be broken done into intrinsic vs extrinsic
Intrinsic:
- Bony contact (intrinsic)
- Ligaments
- Superficial radioulnar ligaments (intrinsic)
- Deep radioulnar ligaments (ligamentum Subcruentum) (intrinsic)
- Origin: fovea of ulnar styloid base. This is most important for providing rotation/translation control
Extrinsic
- ECU tendon and sheath
- PQ
- IOM
What is this a picture of? Describe this test.
Elson’s Test
- examines for incompetence of the central slip
Flex PIP and have patient try to extend pip against resistance
If DIP extends and goes rigid, positive test for central slip rupture (the lateral bands, which insert onto the distal phalanx, have been recruited and therefore the DIP joint is rigid
If DIP remains floppy, the extension is through the central slip which inserts onto the middle phalanx, the DIP therefore remains floppy and the central slip is therefore intact
What amount of wrist flexion and extension occur through the midcarpal joint?
70 degrees
Normal and function motion
flexion
(65 normal, 10 functional)
40% radiocarpal, 60% midcarpal
extension
(55 normal, 35 functional)
66% radiocarpal, 33% midcarpal
radial deviation
(15 normal, 10 functional)
90% midcarpal
ulnar deviation
(35 normal, 15 functional)
50% radiocarpal, 50% midcarpal
What is the main function of the midcarpal joint?
radial and ulnar deviation
Describe the motion of the proximal carpal row with ulnar and radial deviation of the wrist
Radial deviation: Proximal row flexes (think scaphoid)
Ulnar deviation: proximal row extends
Name the extrinsic dorsal wrist ligaments
- Dorsal radiocarpal (aka dorsal radiotriquetral)- between radius (ulnar side) and triquetrum
- Dorsal intercarpal - between triquetrum and scaphoid
These converge on the triquetrum and can be used in the Mayo ligament sparing approach that Gammon uses
Name the 9 palmar and 5 dorsal intrinsic carpal ligaments
see picture
Palmar:
scapholunate
lunotriquetral
triquetrohamate
triquetrocapitate
capitohamate
capitotrapezoidal
trapeziotrapezoidal
scaphotrapeziotrapezoidal
scaphocapitate
Dorsal:
scapholunate
lunotriquetral
trapeziotrapezoidal
capitotrapezoidal
capitohamate
Which ligament is violated and must be repaired in the volar approach to the scaphoid?
Radioscaphocapitate ligament
Which ligament resists perilunate dislocations in the wrist?
Long radiolunate ligament
What is the weakest point in the volar wrist?
Space of Poirier
Where is the Space of Poirier located and what is the anatomic definition of this space.
- an atomical defect or weak spot in the floor of the carpal tunnel;
- it lies at the volar aspect of the proximal capitate, lying between the volar radioscaphocapitate and volar radiotriquetral ligaments.
- Bordered by the Radioscaphocapitate & Radiotriquetral ligaments (aka long radiolunate which continues on as the lunotriquetral ligament)
- area expands when wrist is dorsiflexed & disappears in palmar flexion;
- rent develops during dorsal dislocations, & it is thru this defect that lunate displaces into the carpal canal;
- space of Poirier allows concomitant extension at the midcarpal joint w/radiocarpal but also allows escape of distal carpal row from lunate in perilunar dislocations
What are the components of the radioscapholunate ligament?
Vascular branches of the anterior interosseous and radial arteries
Nerve branches of the anterior interosseous nerve
What is the significance of the Space of Poirier?
It is the weakest point in the volar wrist and is where volar lunate dislocations occur most often.
Mayfield Stage 4 lunate dislocation
What “ligament” in the wrist is actually a neurovascular bundle?
What is it’s eponymous name?
Radioscapholunate ligament
Ligament of testut.
Where is the radioscapholunate ligament found?
Between the long and short radiolunate ligaments, piercing the joint capsule
What are the borders of the anatomical snuffbox?
Triangle:
Anterior: EPB, ABL (compartment 1)
Posterior: EPL (Compartment 3)
Base: radial stylus process
Floor: scaphoid & trapezium
What are the contents of the anatomical snuffbox?
Radial artery
Dorsal Sensory branch of the superficial radial nerve
cephalic vein
What are the components of the scapholunate ligament?
Dorsal (strongest)
Palmar
Proximal (thin, membranous)
What is a lesser arc injury?
Purely ligamentous perilunate injury
What is a greater arc injury?
Fracture around the lunate - scaphoid, capitate, hamate, triquetrum
OR radial styloid or ulnar styloid
What is Kienbock’s disease? What is the etiology?
Avascular necrosis of the lunate.
Unsure of etiology:
Likely due to many factors
BIOMECHANICAL
- ulnar negative variance - leads to increased radial-lunate contact stress
- decreased radial inclination
- repetitive trauma
ANATOMIC FACTORS
- geometry of lunate
- vascular supply to lunate- patterns of arterial blood supply have differential incidences of AVN
- disruption of venous outflow leading to increased intraosseous pressure
Describe the blood supply to the Lunate.
Why do you not see AVN with perilunate dislocations?
Dorsal plexus: from radial and anterior interosseous arteries
Volar plexus: from radial, ulnar, anterior interossoues, recurrent branches of deep palmar arch
3 variations:
- Y-pattern (59%, most common)
- X-pattern
- I-pattern 31% of patients, postulated to be at the highest risk for avascular necrosis
You dont see AVN because there is usually a volar dislocation and there the capsule remains intact and therefore bloodflow is undisturbed.
There are multiple patterns of arterial supply.with the lunate in most cadaveric specimens receiving contributions from branches entering both dorsally and palmarly . How- ever, the lunate was supplied by only a single palmar artery in 7% of wrists in one study. In addition, intraosseous branching patterns vary, with 31% of specimens in one study showing a single path through the bone without significant arborization (Fig. 2). A lunate with a single vessel and minimal branching may be at increased risk of osteonecrosis after hyperflexion or hyperextension injuries or a minimally displaced fracture.
Why do perilunate dislocations usually NOT end up in AVN?
Because it has a rich blood supply including: Dorsal and volar radial branches Branches of the dorsal and volar intercarpal arch Anterior interosseous artery
How many articulations does the scaphoid have?
5
Radius
capitate
lunate
trapezoid
trapezium
What is the bony articulation of the distal radioulnar joint?
Sigmoid notch of the radius articulation with the ulna
i.e. “lesser” sigmoid notch
What are the muscular attachments of the proximal row of the carpal bones?
None
What carpal bones do not contribute to carpal motion?
Pisiform: it’s a sesamoid bone of the flexor carpi ulnaris
What are the contents of the carpal tunnel?
9 flexor tendons:
- 4 for flexor digitorum superficialis
- 4 for flexor digitorum profundus
- Flexor pollicis longus
and the Median nerve
What are the borders of the carpal tunnel?
Radially: scaphoid tubercle & Trapezium
Ulnar: Hook of hamate & pisiform
Roof: flexor retinaculum (aka transverse carpal ligament)
Floor: proximal carpal row & radiocarpal ligaments
The FR attaches to the ST and trap, and the hook and pisiform
During carpal tunnel release, what nerve is most at risk when cutting the transverse carpal ligament? How do you avoid it?
Recurrent motor branch of the median nerve Avoid it by making your cut as ulnar as possible - Ulnar side of the 4th digit when flexed to the palm
What are the borders of Guyon’s Canal?
- Roof - Volar carpal ligament
- Floor - flexor retinaculum
- Ulnar border - pisiform
- Radial border - hook of hamate
What is the major contributor to the deep and superficial palmar arches respectively?
Radial artery: deep
ulnar artery: superficial
What muscles attach to the scaphoid?
None
How much of the scaphoid is covered in articular cartilage?
70%
Name the intrinsic hand muscles of the thenar eminence and their function.
Abductor pollicis brevis - Abducts thumb at CMC & MCP
Flexor pollicis brevis - Flexes thumb at CMC & MCP
Opponens pollicis - Opposition of thumb
What is the innervation of flexor pollicis brevis?
Dual innervation:
Superficial head: Recurrent branch of median Deep (and medial) head: deep branch of ulnar
What are the intrinsic hand muscles of the hypothenar eminence and their actions?
Abductor digiti minimi brevis - Abducts 5th digit at MCP
Flexor digiti minimi - Flexes 5th digit at MCP
Opponens digiti minimi - Opposition of 5th digit
Name the intrinsic hand muscles of the hypothenar eminence and their nervous innervation
Abductor digiti minimi Flexor digiti mimini brevis Opponens digiti minimi - All innervated by ulnar nerve
Name the intrinsic muscles of the thenar eminence and their nervous innervation:
Abductor pollicis brevis - Median nerve Flexor pollicis brevis - Dual innevation - Superficial: median nerve - Deep: ulnar nerve Opponens pollicis - Median nerve
What are the muscles of the hand innervated by the median nerve?
LOAF -
- Lumbricals (radial 2 aka 1 & 2)
- Opponens pollicis
- Abductor pollicis brevis
- Flexor pollicis brevis - note this has dual innervation - Superficial: median - Deep: ulnar
What is the only muscle to originate and insert onto a tendon? Which tendons does it originate and insert into?
Lumbricals
- Originate from tendons of flexor digitorum profundus
- Insert into extensor expansion on dorsal aspect of each digit’s radial side
What is the function of the dorsal and palmar interossei?
Dorsal: Abduct the fingers
Palmar: Adduct the fingers
- Remember DAB and PAD
What is the OINA of the palmar interossei?
O: They originate on the side facing the long finger
1st: ulnar side of 2nd MC
2nd: radial side of 4th MC
3rd: radial side of 5th MC
I: Extensor expansion of 2,4,5 digits
N: ulnar
A: adduction of 1,2,4,5th digits
nb: adduction/abduction is named relative to long finger
What is the OINA of the dorsal interossei?
O:
1st medial head: radial side of 2nd MC
1st lateral head: ulnar side of 1st MC
2nd, 3rd, 4th: space between the Metacarpals
I:
1st: radial sid of 2nd proximal phalanx
2nd: radial side of 3rd PP
3rd: ulnar side of 3rd PP
4th ulnar side of 4th PP
N: ulnar
A: ABduction of 2,3,5 fingers (away from midline)
Name the OINA of Flexor Pollicis Brevis
O:
- Superficial Head: trapezium
- Deep Head: trapezoid, capitate and palmar ligaments of distal carpal bones
I: Base of 1st proximal phalanx on radial side & extensor expansion
N:
Superficial: median
Deep: ulnar
F: CMC & MCP thumb flexion
What are the OINA of the lumbricals?
O: tendons of flexor digitorum profundus
I: extensor expansion on dorsal aspect of each digit’s radial side
N: 1/2: median, 3/4: ulnar
A: flexion of MCP of digist 2-5 - Extension of DIP & PIP of digits 2-5
What are the components of the extensor hood?
- Common Extensor tendon
- central slip
- lateral slips
- Terminal intrinsic tendons
- Lumbricals
- Interossei
- Retaining Ligaments
- Intertendinous connections
- Juncturae Tendinae
- Transverse fibers of interosseous hood
- Sagittal band
- Triangular ligament
- Retinacular ligaments (Landsmeer’s)
- Transverse
- Oblique
- Intertendinous connections
What is a Stener’s lesion?
Ulnar collateral ligament tear with interposed adductor pollicis tendon - prevents healing so is an indiation for surgical repair
Normally, the UCL is deep to the adductor pollicis tendon
A Stener lesion is characterised by slippage of the torn end of the ulnar collateral ligament superficial to the adductor aponeurosis / adductor pollicis muscle
AKA the tendon/aponeurosis is now interposed between the ulnar collateral ligament and the MCP joint
This prevents healing and is an indication for surgical repair.
Describe the pulley system of the fingers?
Fingers:
5 annular pulleys:
- A1, A3, A5 at MCP, PIP, DIP
- A2, A4 at proximal and distal phalanx. These are most important in preventing bowstringing
3 cruciate pulleys
- C1: at distal end of proximal phalanx
- C2: at middle phalanx
- C3: at distal end of middle phalanx
Thumb: A1 at MCP, A2 at IP Oblique between them at proximal phalanx
Where is the space of Parona?
Space between pronator quadratus and flexor tendons - continuous with carpal tunnel and palmar space
Describe Eaton’s classification of the radiographic stages of thumb CMC OA
1: Normal
2: Joint spacer narrowing, osteophytes 2mm
3: Joint space narrowing, osteophytes >2mm
4: pantrapezial arthritis
Where are the superficial and deep palmar arches?
Superficial: distal transverse palmar crease
Deep: Kaplan’s cardinal line
This may not be entitrely true but this is textbook defiintion. Recent literature proves this unreliable and the superficial arch is actually more proximal at Kaplans line
Describe the extensor zones of the hand and wrist
Odd numbers are at the joints:
I: DIP
III: PIP
V: MCP
VII: radiocarpal
IX: forarm muscle belly
Zone I
• Disruption of terminal extensor tendon distal to or at the DIP joint of the fingers and IP joint of the thumb (EPL)
• Mallet Finger
Zone II
• Disruption of tendon over middle phalanx or proximal phalanx of thumb (EPL)
Zone III
- Disruption over the PIP joint of digit (central slip) or MCP joint of thumb (EPL and EPB
- Boutonniere deformity
Zone IV
• Disruption over the proximal phalanx of digit or metacarpal of thumb (EPL and EPB)
Zone V
- Disruption over MCP joint of digit or CMC joint of thumb (EPL and EPB)
- “Fight bite” common
- Sagittal band rupture
Zone VI
- Disruption over the metacarpal
- Nerve and vessel injury likely
Zone VII • Disruption at the wrist joint
• Must repair retinaculum to prevent bowstringing
• Tendon repair followed by immobilization with wrist in 40° extension and MCP joint in 20° flexion for 3-4 weeks
Zone VIII
• Disruption at the distal forearm
Zone IX• Extensor muscle belly
• Usually from penetrating trauma
• Often have associated neurologic injury
• Tendon repair followed by immobilization with elbow in flexion and wrist in extension
Describe the flexor tendon injury zones:
1: Distal of FDS insertion (Jersey finger)
2: FDS insertion to A1 pulley/distal palmar crease (no man’s land)
3: A1 pulley to carpal tunnel (Assoc w/ neurovasc injury)
4: Carpal tunnel (post-op adhesions)
5: Wrist to forearm: (Assoc w/ neurovasc injury)
THUMB:
- Zone TI is distal to the proximal part of the A2 pulley (spanning the IP joint) (basically everything distal to the IP joint)
- Zone TII is from the proximal part of the A2 pulley to the distal part of the A1 pulley.
- TIII
- Zone TIII is proximal to the A1 pulley as far as the carpal tunnel.
ORTHOBULLETS
Zone I
- Distal to FDS insertion
- Jersey finger
Zone 2
AKA NO MAN’S LAND
FDS insertion to distal palmar crease
Zone is unique in that FDP and FDS in same tendon sheath.
Zone II extends from the middle of the middle phalanx to distal palmar crease. It contains both flexor tendon superficialis and flexor tendon profundus. Proximal to zone II, the flexor digitorum superficialis tendons lie superficial to the FDP tendons. Within zone II and at the level of the proximal third of the proximal phalanx, the FDS tendons split into 2 slips, collectively known as Camper chiasma. These slips then divide around the FDP tendon and reunite on the dorsal aspect of the FDP, inserting into the distal end of the middle phalanx.
Direct repair of both tendons followed by early ROM (Duran, Kleinert). Be sure to preserve A2 and A4 pulley. This zone historically had very poor results but results have improved due to advances in postoperative motion protocols
ZONE 3
A1 pulley (distal palmar crease) to carpal tunnel (transverse carpal ligament)
aka Palm zone
Often associated with neurovascular injury which carries a worse prognosis
Direct tendon repair. Good results from direct repair can be expected due to absence of retinacular structures (if no neurovascular injury)
Zone 4
Carpal tunnel
Often complicated by postoperative adhesions due to close quarters and synovial sheath of the carpal tunnel
Direct tendon repair. Transverse carpal ligament should be repaired in a lengthened fashion
Zone 5
Wrist to forearm
Often associated with neurovascular injury which carries a worse prognosis
Direct tendon repair
Thumb
TI, TII, TIII
Outcomes different than fingers. Early motion protocols do not improve long-term results and there is a higher re-rupture rate than flexor tendon repair in fingers
Direct end-to-end repair of FPL is advocated. Try to avoid Zone III to avoid injury to the recurrent motor branch of the median nerve. Oblique pulley is more important than the A1 pulley; however both may be incised if necessary. Attempt to leave one pulley intact to prevent bowstringing
What carpal bones do the following MC align with?
1st MC
2 MC
3 MC
4/5th MC
1st MC: Trapezium
2nd MC: Trapezoid
3rd MC: Capitate
4th/5th MC: Hamate
Name the bands affected & not affected by Dupuytren’s Disease
Affected:
Pretendinous
Spiral
Natatory
Lateral
Grayson’s
Not Affected:
Trasnverse fibers
Cleland’s ligaments
(Some say only Cleland’s is not affected)
What are the variants of the flexor tendon sheath anatomy?
Why is this important?
Communication between 1st, 5th flexors (most common)
Communication between 1st, 2nd, 5th flexors
No communication between 1st and anywhere else
Can get horseshoe abscesses if there is communication between the 2st/5th digists
Name the potential spaces in the hand (3) and forearm (1)
Hand:
- Thenar space
- a bursa (potential space) just palmar to adductor pollicis and dorsal to flexor tendons
- separated from midpalmar potential space by a fascial septum
- Midpalmar space
- located dorsal and radial to hypothenar space
- Hypothenar space
- located palmar to fifth metacarpal, dorsal and radial to hypothenar fascia, ulnar to hypothenar septum
Forearm:
Parona’s space
Describe the pathoanatomy of a swan neck deformity
Lesion: Hyperextension of PIP + flexion of DIP
- Any force that causes hyper-extension at PIP will lead to this deformity
- can be caused by attenuation or injury of the volar plate (RA, volar dislocation at PIP)
- can also be caused by a mallet finger leading to extensor tendon imbalance
Describe the pathology
- stretching of the volar plate at PIP joint;
- intrinsic tightness;
- collateral ligament contracture
- DIP laxity;
- this leads to imbalance of forces on the PIP
Primary lesion: Lax volar plate caused by:
- Trauma
- Generalized Laxity
- RA
Secondary lesion: Imbalance of forces on PIP joint (PIP extension > PIP flexion). Causes:
- Mallet finger: leads to transfer of DIP extension force into PIP extension forces
- FDS rupture: leads to unopposed PIP extension combined with loss of integrity of the volar plate
- Intrinsic contracture
- MCPJ volar subluxation: in RA
What are the junctura tendinae?
Intertendinous connections
Transverse connections between EDC tendons
EIP & EDM not typically involved, therefore allowing for independent extension of D2 and D5
Passive stabilization of extensor tendon over MC head in full flexion (fist)
Describe the pathoanatomy of a Boutonniere Deformity:
Force causing hyperflexion at PIP joint
Central slip rupture –> more force going through terminal slip –> hyperextenio of DIP, Volar subluxation of alteral bands –> PIP hyperflexion
Triangular ligament rupture –> subluxation of lateral bands –> hyperflexion of PIP –> increased extension force through DIP
What is Camper’s Chiasm?
Where FDP passes through the 2 slips of FDS located at the PIP joint in zone 2.
Describe the blood supply to the flexor tendons
From Diffusion and Vascular supply from vincular system
- Each tendon has a short and long vinculum
Name the course of the ulnar artery
From brachial artery
Arises just distal to cubital fossa (5-9cm)
Deep proximally: covered by the PT, FCR, FDS; It lies on Brachialis FDP
The median nerve is in relation with the medial side of the artery for about 2.5 cm. and then crosses the vessel, being separated from it by the ulnar head of the Pronator teres.
Distally in forearm, it sits on FDP being covered by the integument and the superficial and deep fasciæ, and sits between the FCU & FDS
Runs with 2 venæ comitantes
Covered in middle 1/3 by FCU
Ulnar nerve is ulnar in distal 2/3
Palmar cutaneous branch of the nerve descends on the lower part of the vessel to the palm of the hand.
Major contributions to superficial palmar arch
Name the anatomic variants of the Million Dollar Nerve
Recurrent Motor branch of the Median Nerve
Variants:
Extraligamentous: most common
Subligamentous: next
Transligamentous: Rarest
What structure is at risk during trigger thumb release?
Radial digital nerve because of it’s oblique orientation overlying the A1 pulley
What is the order of carpal bone ossification?
capitate: 1-3 months
hamate: 2-4 months
triquetrum: 2-3 years
lunate: 2-4 years
scaphoid: 4-6 years
trapezium: 4-6 years
trapezoid: 4-6 years
pisiform: 8-12 years
i. e. starting with capitate, go clockwise on left wrist , with pisiform at end
In the first dorsal wrist compartment, which of the two tendons is more radial?
APL is more dorsal/radial. EPB is more palmar/ulnar
How do you draw Kaplan’s Cardinal line and what is it a surface landmark for?
From the first webspace to the hook of hamate.
It is a landmark for the deep transverse palmar arch as well as the recurrent branch of the median nerve.
The recurrent motor branch lies at the point where Kaplans line intersects with a line drawn down the radial border of the middle finger. See picture
Where does the lumbricals and interossei run with respect to the deep transverse metacarpal ligament?
Lumbricals run VOLAR
Interossei run DORSAL
How are the FDS and FDP tendons arranged in the carpal tunnel?
FDP is deep.
FDS is superficial with the tendons to D3/4 superifical to D2/5. See diagram
What are the 3 potential spaces in the hand?
What are their boundaries?
- Thenar Space
- Radial - thenar eminence/lateral palmar septum
- Ulnar - midpalmar septum
- Dorsal - Adductor Pollicis
- Volar - Flexor tendons
- Hypothenar Space - not really a recognized space, see orthobullets.
- Radial - medial palmar septum/hypothenar eminence
- Ulnar - hypothenar fascia
- Dorsal - 5th MC
- Volar - Hypothenar eminence
- located palmar to fifth metacarpal, dorsal and radial to hypothenar fascia, ulnar to hypothenar septum
3. Midpalmar space
- Radial - intermediate palmar septum
- Ulnar - medial palmar septum
- Dorsal - Interossei and D3-5 MC.
- Volar - long flexors (D3-5)
*
What is the lumbrical plus finger/sign?
What are 4 causes of Lumbrical plus finger?
-
4 causes of lumbrical plus finger include:
- FDP transection after the origin of the lumbrical
- FDP avulsion
- Too long tendon graft
- DIP amputation
- The lumbrical plus sign/finger is a situation in which there is a FDP tendon rupture distal of the lumbrical origin, or is also present in the situation where a graft has been used that was too long. The FDP now pulls through the lumbrical muscle rather than through its tendon, causing paradoxical PIP extension when you try to flex the fingers and make a fist
Draw the carpal bones
See picture
A - Scaphoid
B - Lunate
C - Triquetrum
D - Pisiform
E - Trapezium
F - Trapezoid
G - Capitate
H - Hamate
What is the surface landmark for the dorsal approach to the scaphoid and what is the indication to go dorsal?
Centered over listers tubercle. Indication is proximal pole fractures whereas the volar approach is used for distal fractures.
NOTES:
- 3-4 cm incision at lister’s and distal following along EPL
- Identify branches of radial nerve at 2nd compartment (AT RISK)
- free up the 2nd and 3rd compartments
- ECRL, ECRB, EPL goes radially
- PIN is ulnar to listers
- Scapholunate ligament is in-line with lister’s
- Proximal pole exposed with wrist flex and radial deviation
- difficult to address humpback deformity
What is the surface landmark for the volar (russe) approach to the scaphoid and what is the interval?
What are 3 indications to go Volar?
Incision is centered over the scaphoid tubercle and curve radially to the bulk of the thenar eminence
INTERVAL:
- Interval between sup. Radial artery and FCR
- Split thenar muscles distally to expose the ST joint
3 indications:
- distal pole fracture
- waist fracture
- humpback deformity
**No risk to dorsal blood supply
** risk to radial artery, often have to ligate the superior branch
** difficult screw trajectory, often have to bite off a piece of trapezium
What are 4 functions of the sagittal band?
Rupture of the sagittal band causes what condition?
- Attaches EDC tendon to sides of volar plate
- Stabilizes EDC during flexion
- Hyperextends MCP
- Limits proximal excursion of EDC
Rupture causes “Boxer’s knuckle” aka dislocating Extensor tendons
What are the retaining ligaments of the extensor hood and what is their functions? (3)
- Sagittal Band
- Triangular ligament
- Retinacular ligaments
Also considered part of the retaining structures are:
- Junturae tendinum
- transverse fibers of the extensor hood
Sagittal Band
- attaches EDC tendon to sides of volar plate
- Stabilizes EDC during flexion
- Hyperextends MCP
- Limits proximal excursion of EDC
Triangular ligament
- spans the lateral bands dorsally (distal close to insertion) and stabilizes them.
Retinacular ligaments (Landsmeer’s)
- Transverse - connects lateral conjoined extensor tendon to volar plate of PIP
- Oblique - Extends from volar proximal phalanx to dorsal distal phalanx
- As PIP extends, ligament tightens which extends DIP
- “linked extension”
- As DIP flexes (FDP), ligament tightens and flexes PIP
- “linked flexion”
- As PIP extends, ligament tightens which extends DIP
What is two names for this deformity?
What are 6 causes?
- intrinsic minus hand
- Claw hand
Causes:
- ulnar or median nerve palsy
- Volkmann’s ischemic contracture
- leprosy
- hereditary motor-sensory neuropathy
- failure to splint a crush-injured hand using intrinsic plus posture
- compartment syndrome of the hand
The clinical presenatation is consistent with a claw hand deformity characterized by MCP hyperextension and IP joint flexion.
Imbalance between strong extrinsics and deficient intrinsics is the pathoanatomic process of a claw hand, also called intrinsic minus hand deformity.
What ligaments do you see from radial to medial when looking anteriorly from a 3-4 wrist portal?
Radioscaphocapitate
Long radiolunate (aka radiolunotriquetral)
Radioscapholunate (ligament of testut)
Short radiolunate
What are the components of the UCL ligament of the thumb?
What is the block to reduction of an avulsion fragment?
What is this lesion called?
UCL is composed of
- proper collateral ligament - resists valgus load with thumb in flexion
- accessory collateral ligament and volar plate resists valgus load with thumb in extension
valgus laxity in both flexion and extension is indicative of a complete UCL rupture
STENER lesion is the avulsion fracture and it is blocked to reduction by the adductor aponeurosis.
Also called a skiers thumb or a gamekeepers thumb
TREATMENT:
Nonoperative immobilization for 4 to 6 weeks
indications:
- partial tears with < 20° side to side variation of varus/valgus instability
Operative ligament repair
indications
acute injuries with
- > 20° side to side variation of varus/valgus instability
- >35° of opening
- Stener lesion - avulsed ligament with or without bony attachment is displaced above the adductor aponeurosis. will not heal without surgical repair
*
What is the eponymous name of idiopathic AVN of the scaphoid?
Presier’s disease
What are the intrinsic ligaments of the wrist?
these are interosseous and usually have a dorsal, IO and volar portion
Can be identified according to which row they sit
Proximal row
- scapholunate ligament (dorsal is the strongest). disruption leads to disi deformity
- Lunotriquetral ligament - disruption leads to visit deformity
Distal row
- trapeziotrapezoid ligament
- trapeziocapitate ligament
- capitohamate ligament
Palmar midcarpal
- scaphotrapeziotrapezoid
- scaphocapitate
- Triquetralcapitate
- triquetralhamate
Draw the carpal bones
