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
What 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, EIP, PIN
V - EDM
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?
major blood supply is dorsal carpal branch (branch of the radial artery)
enters scaphoid in a nonarticular ridge on the dorsal surface and supplies proximal 80% of scaphoid via retrograde blood flow
minor blood supply from superficial palmar arch (branch of volar radial artery)
enters distal tubercle and supplies distal 20% of scaphoid
creates vascular watershed and poor fracture healing environment
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 DISLOCATION - 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 VISI 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
Orthobullet:
Dorsal ligaments
radiotriquetral
also referred to as dorsal radiocarpal ligament (DRC)
must also be disrupted for VISI deformity to form (in combination with rupture of lunotriquetral interosseous ligament rupture)
dorsal intercarpal (DIC)
radiolunate
radioscaphoid
****+++
1. Dorsal radiocarpal (aka dorsal radiotriquetral)- between radius, Lister’s tubercle (ulnar side) and lunate and triquetrum
2. Dorsal intercarpal - originates from triquetrum and inserts to scaphoid, capitate and trapezoid
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.
- center of a double “V” shape convergence of ligaments
- central weak area of the wrist in the floor of the carpal tunnel at the level of the proximal capitate
- between the volar radioscaphocapitate ligament and volar long radiolunate ligament (radiolunotriquetral ligament)
- wrist palmar flexion:
area of weakness disappears - wrist dorsiflexion:
area of weakness increases - in perilunate dislocations, this space allows the distal carpal row to separate from the lunate
- in lunate dislocations, the lunate escapes into this space
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
Lesser arc injuries are pure ligamentous perilunate injuries and are the baby brother of greater arc injuries that represent fractures of the radial styloid, scaphoid, capitate, triquetrum and ulnar styloid.
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 is the OINA of the palmaris brevis?
O: Flexor retinaculum
I: Palmar surface of skin on ulnar side of hand
N: Ulnar
A: Wrinkles skin on ulnar side of hand
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
Describe the safe position of the hand. Why is it safe?
Intrinsic plus position: - Wrist extended 10 deg - MCP Flexion to 70 deg - IP extended It’s safe b/c with the MCPs in flexion, the collaterals are tight (at their longest) - So they will not get tight in a shortened position (short/lax in extension)
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.
What is the ligament of Testut?
Radioscapholunate ligament. Actually a neurovascular bundle with no contribution to carpal stability
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
The Pisiform is a sesamoid bone for what tendon?
Flexor carpi ulnaris (FCU)
Where does the superficial branch of the radial nerve emerge from at the wrist?
Beneath brachioradialis 7-9cm proximal to tip of radial styloid
What is the most common place for the palmar cutaneous branch of the median nerve to emerge? What is its location with respect to FCR and the carpal tunnel?
- Ulnar to FCR
- Travels outside the carpal tunnel, so not affected by CTS (you get sparing)
Where is the space of Parona?
Space between pronator quadratus and flexor tendons - continuous with carpal tunnel and palmar space
Why is a flexor tendon sheath infection a medical emergency?
B/c the most common anatomical variants have flexor sheaths 1 & 5 communicating with the wrist/carpal tunnel, so infection can easily propagate up the wrist
What is intersection syndrome?
Overuse condition affecting the second dorsal compartment - ECRL and ECRB
What is DeQuervain’s tenosynovitis?
Inflammation of the tenosynovium of the abductor pollicis longus and extensor pollicis brevis tendons
Affects 1st dorsal compartment
Diagnosed with Finklestein’s test - Increase in pain when the thumb is held in palm and wrist is ulnarly deviated - Pain is over the radial side of the wrist (1st dorsal compartment)
What is Wartenberg’s Syndrome
Radial neuritis aka Cheralgia Paraesthetica - Neuritis of the superficial branch of the radial nerve - Inflammation due to stretch, compression or direct blow - Compression occurs between the brachioradialis and ECRL
SRN compressed by scissoring action of brachioradialis and ECRL tendons during forearm pronation
Can also be caused by fascial bands at its exit site in the subcutaneous plane
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
What is the most common variation of the recurrent branch of the median nerve?
Extra ligamentous, distal to the carpal tunnel (46-95%)
Orthobullets:
- 50% are extraligamentous with recurrent innervation
- 30% are subligamentous with recurrent innervation
- 20% are transligamentous with recurrent innervation
- ***cut transverse ligament far ulnar to avoid cutting if nerve is transligamentous
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 lumbrical is the last testable muscle innervated)
Where does the dorsal branch of the ulnar nerve branch off?
Palmar Branch
The dorsal cutaneous branch of the ulnar nerve branches from the ulnar nerve within the ulnar aspect of the volar mid-forearm. It separates from the main trunk of the ulnar nerve about 5-12 cm proximal to the level of the wrist crease (avg 9cm). It then curves dorsally to innervate the dorsal ulnar aspect of the hand.
Can be injured in lacerations or in ORIF of ulnar styloid fractures
Palmar branch
The palmar cutaneous branch of the ulnar nerve can branch as an individual branch from the medial aspect of the ulnar nerve at the wrist just proximal to Guyon’s canal. The nerve continues distally and superficially to innervate the medial palmar aspect of the hand.
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
Which is more distal, superficial or deep palmar arch?
Superficial - it is at the distal transverse palmar crease
In what position is the radius shortest compared to the ulna (or the ulna longest compared to the radius)?
In pronation
THINK: supination is anatomic position so bones are uncrossed. In pronation, radius must cross over ulna, shortening it compared with the ulna
That’s why positive ulnar variance is mostly detected in pronation x-rays
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
What is the strongest wrist ligament?
Radioscaphocapitate
**Note that the long radiolunate is the primary restraint to perilunate dislocations but not the strongest volar wrist ligament
What type of joints are the 1st - 5th CMC joints?
1st: saddle
2-5: Arthrodial aka a plane joint and allow only gliding joint
(An arthrodial joint - the opposed surfaces of the bones are flat or almost flat, with movement limited by their tight joint capsules)
What structures is the flexor retinaculum a continuation of in the forearm and hand?
Starts as: antebrachial fascia
Becomes: Transverse carpal ligament
Becomes Thenar & Hypothnar aponeurosis/Deep palmar fascia
What are the components of the superficial wrist retinaculum?
Carpal ligament and palmar ligament
What are the positions of Grayson’s and Clelands Ligaments with respect to each other
Grayson’s: (grip) are volar to the NV bundle
Cleland’s (ceiling) are dorsal to the NV bundle
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
What is the OINA of opponens pollicis?
O: Trapezium & TCL
I: 1st MC shaft, radial side
N: median
A: Opposition
Name the anatomic variants of the Million Dollar Nerve
Recurrent Motor branch of the Median Nerve
Variants:
Extraligamentous: most common
Subligamentous: next
Transligamentous: Rarest
Name the OINA of Abductor Pollicis Brevis
O: Scaphoid tuberosity, trapezium ridge, TCL
I: Proximal 1st phalanx, lateral base
N: Median
F: ABduction of CMC & MCP of thumb
Name the OINA for adductor pollicis
O:
Oblique head: capitate, base of 2/3 MC
Transverse head: proximal 2/3 of palmar surface of 3rd MC
I: base of 1st proximal phalanx, ulnar side
N: ulnar nerve
A: adduction of 1st CMC
Name the OINA for abductor digiti minimi:
O: pisiform
I: base of 5th proximal phalanx, ulnar side
N: ulnar
A: Abduction of 5th MCP/digit
Describe the OINA for flexor digiti minimi
O: hamate, TCL
I: Proximal 5th phalanx, ulnar side
N: ulnar
A: flexion of 5th digit/MCP
Name the OINA for opponens digiti minimi
O: hook of hamate, TCL
I: 5th MC - entire ulnar border
N: ulnar
A: 5th MCP flexion and rotation of entire 5th digit
How do the lumbricals exert their function?
They relax it’s own antagonist (FDP) when they are contracting
It originates from the FDP tendon
When it is relaxed, and the FDP contracts, the IP joint flexes
When the lumbricals contract, it extends the IP joint by relaxation of the FDP tendon distal to the lumbrical origin and by proximal pull on the lateral band and dorsal aponeurosis
What is the intrinsic plus position?
What is the principle behind this position?
Safe position for immobilization of the hand
Wrist in 30 deg extension
MCP 70deg flexion
IP neutral
Principle”
Wrist in extension: optimal position for grip strength
MCP flexion: MCP collateral ligament at their longest in 90 deg flexion, but this is painful so only do 70 deg
PIP collateral ligaments: at same length throughout ROM but flexors are stronger than extensors and gaining PIP flexion is easier than gaining back extension
What allows for independent motion of the index and small fingers (most of the time)?
Generally, no junctura tendinae between EIP and EDM so they get independent motion
Name the course of the radial artery
Arises from the bifurcation of the brachial artery in the cubital fossa
Runs distally on anterior forearm winding laterally around the wrist radial to FCR
Passes through the anatomical snuff box
Then between the heads of the first dorsal interosseous muscle
It passes anteriorly between the heads of the adductor pollicis & winds around 1st MC between heads of oblique and transverse opponens pollicis
Gives off major contributions fo deep palmar arch, which joins with deep branch of ulnar artery
Course of the Anterior interosseous artery
Comes down the forearm on palmar surface of the IoM
Accompanied by palmar interosseous branch of the median nerve & overlapped by FDP & FPL giving off muscular branches and nutrient vessels to radius/ulna
At the upper border of the pronator quadratus, it pierces the IoM, winding to dorsal forearm to anastomose with the dorsal interosseous artery.
It then descends with the terminal part of the dorsal interosseous nerve to the dorsal wrist to join dorsal carpal network.
Before it pierces the interosseous membrane the anterior interosseous sends a branch downward behind the pronator quadratus muscle to join the palmar carpal network.
What is the orientation of the digital artery and nerves in the fingers?
- the artery is volar in the palm but dorsal in the finger past the MCP
Describe the course of the palmar cutaneous branch of the median nerve. What common surgery to you have to watch out for it
Arises from radial border of median nerve approximately 5 to 6 cm proximal to distal transverse flexion crease of the wrist;
- it runs along the median nerve for 2 to 3 cm, and then runs along the ulnar border of the flexor carpi radialis tendon;
- in some cases it may run along the ulnar side of the palmaris longus tendon;
- when the tendon enters the flexor retinaculum comparment, the nerve passes between the two layers of the forearm fascia into the root of the palmar aponeurosis;
- after 5-10 mm, the nerve divides into three terminal branches which cross the midpalmar aponeurosis to supply deep layers of dermis
Watch out for it during Carpal Tunnel Approach and with any incision ulnar to FCR
Where can you find the dorsal cutaneous branch of the ulnar nerve?
emerges from under FCU and becomes subcutaneous 5cm proximal to pisiform
0.2-2cm proximal to the ulnar styloid at the subcutaneous border of the ulna
What is the terminal branch of the ulnar nerve and what does it supply?
Deep branch of ulnar nerve
Last mm innervated is the adductor pollicis. Last testable muscle is 1st dorsal interossei
describe path of superficial radial nerve at the level of the wrist/hand:
emerges where?
branches where?
emerges from under BR, 7-9cm proximal to radial styloid tip on dorsoradial aspect of wrist
branches out 5cm proximal to radial styloid tip into terminal branches
What is the strongest part of the lunotiquetral ligament?
volar
Name the compartments of the hand
(not wrist)
There are ten:
- Thenar compartment
- Hypothenar compartment - may have subcompartments
- Adductor pollicis
- 4x dorsal interossei compartments
- 3x palmar interossei compartments
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 last muscle to be reinnervated after PIN injury? Bonus marks for full order of reinnervation.
Last to reinnervate: EIP
The Journal Of Hand Surgery 22(2):232-7 ·
Though variable in individual specimens, innervation order from proximal to distal (based on mean shortest branch lengths) was:
- brachioradialis (radial nn)
- extensor carpi radialis longus (radial nn)
- supinator (deep branch radial nn vs PIN)
- ECRB extensor carpi radialis brevis (deep branch radial nn vs PIN)
- EDC extensor digitorum communis
- ECU extensor carpi ulnaris
- EDM extensor digiti quinti
- APL abductor policis longus
- EPL extensor policis longus
- EPB extensor policis brevis
- EIP extensor indicis proprius
The radial nerve gives off the deep branch of the radial nerve which dives under supinator and becomes the pin.
ECRB and Supinator are innervated by the deep branch. Some sources call this the PIN.
ECRB and Supinator are therefore the first mm reinnervated if there is a radial nn palsy at the elbow.
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
What is the Quadrigia effect?
The quadriga effect is characterized by an active flexion lag in fingers adjacent to a digit with a previously injured or repaired flexor digitorum profundus tendon.
FDP tendons of long, ring, and little fingers share a common muscle belly therefore excursion of the combined tendons is equal to the shortest tendon
Improper shortening of a tendon during repair results in inability to fully flex adjacent fingers
Mechanism most commonly caused by a functional shortening of the FDP tendon due to:
- over-advancement of the FDP during tendon repair
- >1 cm advancement associated with quadriga
- adhesions
- retraction of the tendon
- “over-the-top” FDP repair of the distal phalanx after amputation
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 boundaries of the thenar space?
Radial - thenar eminence
Ulnar - midpalmar septum
Dorsal - Adductor Pollicis
Volar - Flexor tendons
What is the blood supply to the lumbricals?
Interossei?
Blood supply to the lumbricals is from FOUR seperate sources:
- Superficial palmar arch
- Deep palmar arch
- Common palmar digital artery
- Dorsal digital artery.
The Blood supply to the interossei is from:
- Palmer IO - Palmar metacarpal artery of deep palmar arch
- Dorsal - Dorsal and palmar metacarpal arteries
The ulnar artery contributes predominantly to the deep or superficial palmar arch? Lies proximal or distal?
The radial artery contributes predominantly to the deep or superficial palmar arch?
The ulnar artery contributes predominantly to the superficial palmar arch and lies distal to the deep palmar arch
The radial artery contributes predominantly to the deep palmar arch and lies more proximal in the hand
What is a dorsal radial flap for a scaphoid non-union based on? What is the eponymous name?
1,2 intercompartmental supra retinacular artery
Zaidemberg graft/artery
What are the 3 potential spaces in the hand?
What are their boundaries?
Orthobullet:
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
- 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)
*
Origin/insertion/innnervation of:
- ECRB
- EPL
- FPL
- ECRB
- lateral epicondylar ridge
- base of third (ECRL to base of 2nd)
- radial nerve (sometimes quoted as PIN or deep branch of radial nerve)
- EPL
- posterior ulna and IOM
- base of distal phalanx
- PIN
- FPL
- radius and IOM
- distal phalanx
- median nerve
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
What are the muscles of the thenar eminence?
abductor pollicis brevis
opponens pollicis
flexor pollicis brevis
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 Safe position?
Wrist in 30 ° extension
MCP 70-90 °
IP in 0°
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 is the primary stabilizer of the extensor tendon at the MCP?
Secondary stabilizer?
Primary: Sagittal bands
Secondary: Juncturae tendinum
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 Vickers Ligament?
What condition is it responsible for?
What gene mutation is associated?
Vickers ligament is the short radiolunate ligament
Said to be responsible for madelung’s deformity. A result of disruption of the volar ulnar physis of the distal radius (leading to radial inclination and a radiopalmar tilt). Symptoms from the wrist deformity include ulnocarpal impaction, restricted forearm rotation, and median nerve compression.. Autosommal dominant
Associated with Leri-Weill dyschondrosteosis
rare genetic disorder caused by mutation in the SHOX gene (SHOX stands for short-statute homeobox-containing gene) anatomically at the tip of the sex chromosome causes mesomelic dwarfism (short stature). associated Madelung’s deformity of the forearm
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 are indications for fixation of a scaphoid fracture?
indications
(in unstable fractures as shown by )
- proximal pole fractures
- displacement > 1 mm
- 15° scaphoid humpback deformity
- radiolunate angle > 15° (DISI)
- intrascaphoid angle of > 35°
- scaphoid fractures associated with perilunate dislocation
- comminuted fractures
- unstable vertical or oblique fractures
- in non-displaced waist fractures
- to allow decreased time to union, faster return to work/sport, similar total costs compared to casting
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
