10::Wrist and Hand 1
163
Internal fixation of prox scaphoid fx Kirschner (K) wire fixation or Herbert's screw techniques have been used
41 DISTAL RADIOULNAR JOINT
Kienböck's disease of lunate is assoc w ulnar negative variance
102
LT flap tear w TFCC tear and prox lunate cart damage (chondromalacia)
108
LT lig diastasis w L and TFCC disruption
110
LT lig ganglion overlying dorsal LT fibers
78 Flexor retinaculum
Medially attaches to pisiform and hook of the hamate Laterally attaches to scaphoid and trapezium
166
SL dissociation w dorsal tilted lunate (DISI)
179
Scaphoid nonunion w persistent hypersig fx gap
46 MEDIAN AND ULNAR NERVE
Secondary signs of median neuritis include palmar bowing (bc nerve swollen) of flexor retinaculum and increased thenar muscle sig due to denervation Although most often median neuritis is idiopathic, underlying causes are occasionally demonstrated, such as median nerve tumors, trauma, ganglion cysts, or tenosynovitis of the flexor tendon sheaths.
164
Silastic implant of prox pole of the scaphoid Silicone synovitis may complicate this type of implant replacement arthroplasty
135
Single broad-based attachment of the TFC complex extending from the tip to the base of the ulnar styloid process
184
Stage I Kienböck's dz wo fx line just marrow edema
162
Subacute scaphoid fx wo discontinuity of cortical margins
113 Normal distal radioulnar joint
a = mild DORSAL shift of ulna relative to sigmoid notch during pronation is NORMAL; see ECU med to distal ulna b = mild VOLAR shift of ulna in supination is normal =; ECU may be in its ulnar groove or subluxed medial
193
a = nerve w myelinated and unmyelinated axons perineurium binds separate fascicles b = varied position of motor fascicle w/in cross-section of median nerve c = nml fascicles of median nerve d = bright fascicles of median nerve
105
a = nml LT lig b = ulnar side of LT torn c = nml arcs 1 and 2 surround prox row 3 surrounds one side distal row
106
a = tear of dorsal, MB, volar LT lig b = arc is offset
122
a = torn volar radioulnar lig, so ulna disp dorsally b = diff subluxations and dislocations relative to sigmoid notch
180 Scaphoid nonunion advanced collapse (SNAC)
a/b = scaphoid nonunion + SLAC SNAC considered a greater arc injury c/d = diff case; SNAC w early SLAC OA w cysts in distal scaphoid, rad styloid djd/sclerosis scaphoid nonunion and prox pole AVN
198
a/b = T1 = Fibrolipoma of median nerve (mixed fat, fibrous, and nerve fascicle sig) -is T1 bright sig Distal thenar muscle denervation
182 3 patterns of vascular supply to lunate
acute trauma or repeated microtrauma w excessive shear force can disrupt blood supply --> put at risk for kienbock's Y = 60% ppl I = 30% X = 10%
191
anatomy 4 FDS 4 FDP 1 FPL 1 median nerve FCU and FCR outside (guard rails outside house) palmaris outside (palm trees are outside the house)
10 PRONATOR QUADRATUS the wrist band
anterior interosseous nerve compression can denervate think of like flexor retinaculum
9 FLEXOR POLLICIS LONGUS 1 tendon goes through CTS
anterior interosseous nerve compression can denervate FPL muscle (thumb) isolated or with FDP and pronator quadratus insert on PALMAR thumb (compartment 1s insert on DORSAL thumb)
90 SL tear with DISI
a = traumatic avulsion of lunate aspect of SL lig; SL space widened; arrows show some lig fibers still attached; morphology is amorphous at the avulsed scaphoid remnant (curved arrow) b = cap-lunate angle inc to 46 (nml is 0-30) w dorsal tilted lunate c = scaphoid tilts palmarly with an increased scapholunate angle (arrow) of 142°; volar protrusion now horizontal should point up a bit)
60
b = membranous components of SL and LT ligs; central disc of the TFCC c = Complete osseous lunotriquetral coalitions are fibrous, cartilaginous, or osseous; osseous coalitions may be incomplete or complete
15 EXTENSOR CARPI ULNARIS a common extensor tendon (2 heads, one is a common extensor)
commonly tendinosis and tensynovitis as pass throguh groove on distal ulna can also sublux tendon here due to disrupted or insuff lig covering the tendon in this groove ECU tendon subsheath is a component of the TFCC
83 6 extensor compartments
compartment 1 does ABER = hence abductor and extensor (pollicis) compartment 3 = extensor pollicis LONGUS does crossover to thumb
133
dorsal RUL also see SL and LT ligs here
13 EXTENSOR DIGITORUM a common extensor tendon
extends 4 digits at MCP joint extensor digitorum tendons are connected at level of metacarpal bones by fibrous bands (called juncturae tendinum) Boutonnière deformity from disrupted central slip component of extensor tendon at its insertion into the MP
14 EXTENSOR DIGITI MINIMI a common extensor tendon
extensor = start radial elbow minimi = end ulnar (pinky) extends PP of pinky at MCP often first tendon hit in RA
11 EXTENSOR CARPI RADIALIS LONGUS NOT a common extensor tendon
extensor = start radial elbow radialis = finish radial wrist (inserts on 2nd MCP base!) posterior interosseus nerve compression causes ext carpi ULNAR palsy, get unopposed radial dev from this muscle longus, brevis (insert on 2nd and 3rd base MCs aka 23)
12 EXTENSOR CARPI RADIALIS BREVIS a common extensor tendon
extensor = start radial elbow radialis = finish radial wrist (inserts on 3rd MCP base!) helps wrist EXTENSION, if rupture lose wrist extension longus, brevis (insert on 2nd and 3rd base MCs aka 23)
(Table 10.1) wrist ligs are intrinsic or extrinsic groups .
extrinsic ligs = around radius, ulna, and metacarpals -maintain relationship of carpus as a whole to distal radius and ulna and metacarpal bases intrinsic ligaments = within the carpus - maintain relationships btw individual carpal bones both crucial to maintaining the intercarpal relationships
200
space-occupying lipoma in carpal tunnel
172
hamate hook fx at hook and body jxn hook adj to carpal tunnel
carpal height index or ratio =
height of carpals / height of 3rd digit index = ratio dom hand / other hand
171 hook of the hamate fx
hook adj to carpal tunnel
48 GANGLION CYSTS
protrude from nearly any wrist articulation, often w funnel-shaped neck back toward the ligament of origin Common sites of origin = dorsal SL lig, volar RC joint, triscaphe joint may be a clue to tears or perfs of the underlying ligaments from which they arise, presumably from fluid extending through a ligament perforation via a one-way valve mechanism
158 Middle-third scaphoid waist fx
scaphoid unique in its relationship w distal radius, distal carpal row, and volar carpal lig and is more susceptible to fx than other carpal bones
27 OPPONENS DIGITI MINIMI
the deep component of the hypothenar eminence
29 DORSAL INTEROSSEI
the intervals between the metacarpal bones
24 PALMARIS BREVIS
thin superficial muscle that connects flexor retinaculum to ulnar skin
123
Class IA: Perf or traumatic tear of TFC disc proper pic = slit-like tear or perf (straight arrow) of radial TFC communication of radiocarpal joint contrast (curved arrow) w DRUJ
124
Class IB: avulsion of ulnar TFCC w or wo U styloid fx pic = w traumatic avulsion of ulna TFC contrast comms btw ulnar styloid and avulsed TFC (arrow) also has ulna sided SL tear and absent LT
126
Class ID: Radial avulsions at distal sigmoid notch w or wo a sigmoid notch fx traumatic avulsion of radial TFC attachment Note exposed art cart at radial sigmoid notch Fluid comms btw radiocarpal and distal radioulnar compartments
127
Class IIA = TFCC wear TFC thinning (arrows) wo perf no lunate CM and LT intact
128
Class IIB = TFCC wear lunate, triquetrum, and possibly ulna CM pic = w djd fraying of the distal TFCC (straight arrow) curved = CM of lunate and triquetrum wo TFC perf SL and LT ligs torn
129
Class IIC = TFCC perf lunate, triquetrum, and possibly ulna CM pic: straight = central TFC perf curved = lunate CM open = LT lig intact djd (class II) lesions = djd, tapering TFC edges traumatic (class I) tears = abrupt or straight margins
131
Class IIE = TFCC perf lunate, triquetrum, and possibly ulna CM LT lig perf, ulna-carpal OA pic: ulnocarpal OA small straight = central TFC perf curved = lunate and triquetral CM open = LT tear long straight = triquetral subchondral erosion
111
Palmar midcarpal instability (MCI) is mc pattern of midcarpal instability assoc w lax ulnar arcuate arm and dorsal radiotriquetral lig with palmar (volar) translation of distal carpal row a/b = lax ulnar arcuate arm c = lax RSC lig in dorsal midcarpal instability in contrast to palmar midcarpal instability Dorsal midcarpal instability is a much less common type of midcarpal instability
142
Palmer class II (djd tear) w lunate erosion/CM and LT tear
141
Palmer class II (djd wear) initial stage of ulnocarpal abutment syndrome
Ulnocarpal (ulnolunate) abutment is equivalent to Palmer class II djd of TFCC; 5 types
Palmer class IIA = TFCC wear Palmer class IIB = TFCC wear lunate, triquetrum, and possibly ulna CM Palmer class IIC = TFCC perf lunate, triquetrum, and possibly ulna CM Palmer class IID = TFCC perf lunate, triquetrum, and possibly ulna CM LT lig perf Palmer class IIE = TFCC perf lunate, triquetrum, and possibly ulna CM LT lig perf, ulna-carpal OA
Scapholunate Ligament Tear
SL lig complex has both intrinsic and extrinsic ligs ex = gross stability int = fine tuning stability separate scaphotrapeziotrapezoid lig complex provides significant volar constraint and consists of: Scaphotrapezial ligament A thin palmar scaphotrapeziotrapezoid capsule/thick fibrous floor of the flexor carpi radialis tendon sheath Scaphocapitate capsular ligament Dorsal capsular ligament (minimal contribution to stability) most common type of carpal instability scaphoid attachment of SL lig more likely to avulse than the stronger lunate attachment. (bc scaphoid side has fewer Sharpey's fibers) MR = gap over 3 mm, volar flexed scaphoid (bc no longer attached) ,DISI (inc cap-lun and scap-lun angles) Stages: Stage I: scapholunate failure Stage I: capitolunate failure Stage III: triquetrolunate failure Stage IV: dorsal radiocarpal ligament failure w volar rotated lunate 1,2 = PTs 3,4 = FTs
152
Type V explosion w comminution extending from distal radius art surfaces to the diaphysis see in massive soft-tissue trauma
118
Radioulnar impingement (rads and ulna impacting e/o) w cysts, CM, TFC djd
6 extensor compartments
1st = dequervain's in 1st row at APL EPB (APL EPB) - must have P (pollicis) -compartment 1 does ABER = hence abductor and extensor (pollicis) 2nd = combo ECRB and ECRL (ECRB and ECRL)-must have radialis (bc radial) Lister's TwoThree Tubercle (betw 2 and 3) 3rd = 3PL = EPL (EPL) 4th = extensor digitorum and extensor indicis 5th = minimi by the mini (pinky, 5th) = extensor digiti minimi (EDM) 6th = get RA in 6th period at ECU (ECU)
22 FLEXOR POLLICIS BREVIS
2 portions: lateral and medial lateral = arises from flexor retinaculum medial = arises from the trapezium
192
FC sheath inside flexor retinaculum (but not in carpal tunnel)
99
Absent MB fibers of SL allows direct extension of fluid from radiocarpal joint
143
Advanced ulnocarpal abutment (Palmer class II) w TFC tear and lunate, triquetral and ulnar CM and LT lig tear
Carpal tunnel contents
FCR and FCU no go through tunnel bc they attach at rads and ulnar wrist contents (10 things) = 4 FDS (superficial; goes toto MPs) 4 FDP (deep goes to DPs) 1 FPL (thumb) 1 median nerve D only (aka RPU of RPUD) in CT
117
CM and djd of lunate and triquetrum in ulnocarpal (ulnolunate) abutment
Common flexor and extensor tendon
FLEXOR = P-RPUD (Pronator above/outside) (rad, palm, uln, digit) flex carp RAD palmaris longus (btw) flex carp ULN flex digitorum superficialis (aka sublimis) EXTENSOR = BL-RDMU (Brachiorads, rad longus above/outside) (rad, digit, mini, uln) ext carp RAD (BREVIS) extensor digitorum (btw) ext digiti minimi ext carp ULN supinator (brachioradialis and ex carp rad LONGUS attach alone higher up on hum)
170
Eccentric fx on volar ulnar side of lunate fracture (NOT related to Kienböck's) volar pole fx of lunate is mc non-Kienböck's fx pattern
Common flexor and extensor tendon
FLEXOR = P-RPUD (Pronator above/outside) (rad, palm, uln, digit) flex carp RAD palmaris longus (btw) flex carp ULN flex digitorum superficialis (aka sublimis) EXTENSOR = BL-RDMU (Brachiorads, rad longus above/outside) (rad, digit, mini, uln) ext carp RAD (BREVIS)-comp 2 extensor digitorum (btw)-comp 4 ext digiti minimi-comp 5 ext carp ULN-comp 6 supinator (brachioradialis and ex carp rad LONGUS attach alone higher up on hum) RPU = all land on carpals or metacarpals in order from rads (radialis), mid (palmaris), ulna (ulnaris); no reach into fingers) D = reaches into fingers
114
Negative ulnar variance in severe neg ulnar variance, TFCC is deformed and goes proximal
Distal Radioulnar Joint
R and U articulate at sigmoid notch (aka ulnar notch) in NORMAL pronation and supination, ulna head moves dorsal and palmar, respectively, in the sigmoid notch (sticks superior either way) ulnar head moves distal in pronation and proximal in supination
65 sulcus btw radioscaphocapitate (RSC) and radiolunotriquetral ligs
RLT is volar to RSC
Triangular Fibrocartilage Complex Anatomy 1742
TFCC contents = dorsal and volar RU ligs ulnar collateral ligament meniscus homologue articular disc TFC ECU sheath ulnolunate lig ulnotriquetral lig
134
TFCC inserts into ulnar styloid (s) via separate fascicles directed (black and white arrows) aimed at styloid's tip and base ulnar collateral ligament (UCL) is distinct structure of TFCC complex, extends from outer ulnar styloid to triquetrum, hamate, and 5th metacarpal meniscus homologue (m) = are thickened longitudinally oriented fibers of the UCL lig
93 dorsal SL tear
Tearing of strong dorsal SL often assoc w djd or tears of MB part c= nml lig
174
Transverse fx capitate body fx can be isolated or assoc w perilunate dislocation (when cap slides off lunate)
75 arcuate or deltoid ligament
V shaped thing with point attached at capitate 2 arms: cap-triquetrum/lunate cap-scaphoid
168
VOLAR transscaphoid perilunate dislocation w scaphoid fx, SL dissociation, lunate volar flexion, and volar shifted capitate less common than DORSAL transscaphoid perilunate dislocation
Unstable Scaphoid Fracture-DIslocations
Wrist dislocations have varying degrees of perilunar instability (PLI) degree of PLI divided into 4 stages based on degree of carpal dislocation and lig injury that starts at SL joint and progresses around lunate 4 PLI stages in next pic
116
a = ulnocarpal (ulnolunate) abutment w LT tear, TFC perf and bone edema b = ulnar sided edema and sclerosis of prox lunate in + ulnar variance
Lister's tubercle (dorsal tubercle)
betw compartments 2 and 3
Lister's tubercle(dorsal tubercle)
betw compartments 2 and 3
Hamate Fractures
bipartite hook or os hamuli proprium (incomplete fusion of ossification center of hook) may mimic fx hook is ulnar attachment for distal flexor retinaculum and origins of flexor digiti minimi and opponens digiti minimi Prox pole fx's are osteochondral; mc mech is impaction against lunate; osteochondral fractures of the triquetral articular surface are caused by shearing injury or impaction against lunate. Body fx and fx-dislocations are mc caused by direct crushing injuries or punch-press accidents XR oten neg in hamate fx most body fx heal w immobilization
85 nml wrist dorsiflexion
black line = cap and lunate aligned arcuate ligament (small white arrows) and RL lig (short radiolunate) (large white arrow) and RSC lig (radioscaphocapitate) tighten up (cuz pulled on), stabilize the wrist a = cap and lunate b = scaph and lunate
18 EXTENSOR POLLICIS LONGUS 3rd extensor compartment
both compartment 1 and 3 tendons insert on DORSAL THUMB
40 CARPOMETACARPAL JOINTS
carpal boss = prominent protuberance (or ossicle) at base of dorsal 2nd or 3rd MC carpal boss impingement = bedema, djd and adj ganglion cysts) os styloideus = ossicle at base of 2nd or 3rd MC; also assoc w djd of CMC joint
160 scaphoid fx
dark fx line w marrow edema
59 anatomy
in bipartite scaphoid, prox carpal row includes only prox scaphoid pole distal pole is part of distal row midcarpal joint = btw prox and distal carpal rows
31
no pic
32
no pic
101
torn LT lig
149
a = Displaced die-punch fx of lunate fossa b = dorsal tilting and shortening of the radius
HYPOTHENAR MUSCLES
AFO abductor digit minimi (pulls out) opponens (pulls in) flexor digiti minimi (most palmar)
197
Benign peripheral nerve sheath tumor of median nerve (prox to carpal tunnel)
195
CTS w bright median nerve
183 4 stages of Kienböck's disease
3 and 4 = lunate collapse in the cor and elongation in sag (squished/collapsed like gum from the sides); prox migration of cap, SL dissociation, scaph flexion, ulnar migration of triquetrum 4 = gen djd of carpus 1 = extensive lunate edema a = its turning into a pancake
34 SCAPHOLUNATE LIGAMENT
dorsal, membranous and volar parts
51 CARPAL ALIGNMENT
DISI suggested when capitate lunate angle exceeds 30° when have DISI, eval SL for assoc tear
94
complete SL tear (dorsal, MB, volar)
161 scaphoid fx w flexion
is humpback? c = dorsal SL lig intact
Carpal Instabilities
"Stability" = ability of two structures to maintain a normal physiologic spatial relationship under applied physiologic loading "Unstable" = two structures that cannot maintain nml relationship under physiologic loading conditions when radial deviate = scaphoid volar flexes forward (mechanics) when ulnar deviate = scaphoid becomes more horizontal)
Classification of Wrist Instabilities (may need to reread; did incomplete review of all text under 10.104)
4 characteristics of carpal instabilities: Severity = dynamic, static subluxation, or static dislocation Direction of displacement: dorsal (DISI), volar (VISI), or radioulnar/proximodistal translation Location of injury Type of injury Carpal instabilities = grouped into perilunar (perilunate) instabilities, midcarpal instabilities, and proximal carpal instabilities Perilunate instabilities divided into lesser and greater arc injuries Lesser arc injuries = disruptions that follow the contour of the lunate itself greater arc injuries = transscaphoid, capitate, hamate, or triquetral Perilunar instability includes dorsal perilunate dislocation and lunate dislocation VISI and DISI are intrinsic
Melone tx
2A = ext fixation 2B = ORIF Melone type IIA (unstable dorsal or volar displacement): reduction and external fixation Melone type IIB: not reducible by closed techniques, treatment with open reduction and internal fixation (ORIF) Melone type III: treatment with ORIF; volar spike fragment from metaphysis places adjacent nerves and tendons at risk Melone type IV: arthroscopic percutaneous reduction and pinning or ORIF
Triquetrum Fractures
2nd mc carpal bone fx (after scaphoid) mc chip fx of dorsal surface SECONDARY to avulsion at ulno-triq lig or trauma in hyperextension and ulnar deviation fx through body of triq less common
Instability of the Distal Radioulnar Joint
= loss of the normal anatomic relationship btw distal radius and ulna with carpus It may be secondary to sprain, dislocation or malalignment forearm fx, synovitis, or ligamentous laxity disrupted volar R-U lig = ulna go dorsal disrupted dorsal R-U lig = ulna go ventral TFC = made of central disc, and dorsal and volar R-U ligs sigmoid notch, dorsal and volar R-U lig, interosseous MB, dorsal retinaculum maintain R-U joint stability might see tear of the dorsal infratendinous extensor retinaculum (ECU subsheath, seen in ulnar dorsal dislocation) might see pronator quadratus and distal interosseous MB hypersig as part of forced hypersupination and ulnar palmar dislocation
THENAR MUSCLES
AFO abductor pollicis brevis (most palmar) opponens pollicis (most lat) FLEXOR POLLICIS BREVIS (most inner) and then ADDUCTOR POLLICIS (stener muscle) on inner webbing
Kienböck's Disease aka lunatomalacia, aseptic necrosis, osteochondritis, traumatic osteoporosis, and osteitis of the lunate
AVN of lunate CENTRAL sclerosis or edema (NOT eccentric/ulnar) often initially pw wo fx line in 80% lunate gets both palmar and dorsal supply in 20% lunate only get palmar (risk AVN) assoc w negative ulnar variance (but not always) from trauma (acute or repetitive microtrauma) subchond bone adj to radius is most avascular (mc collapse here) aka radial notch side stage 1 = nml XR, T1 nml -can have dark or bright fx line stage 2 = sclerotic lunate (bright XR, dark dark MR) maybe slight collapse on rads side -broken down further see under 182 if want stage 3 = collapse or entire lunate, there is 3a, 3b, 3c (see under 182 if want) -cap go prox bc lunate collapsing stage 4 = all stage 3 stuff + gen djd throughout carpals (lunte down so get djd everywhere) MR = CENTRAL sclerosis (dark dark) and linear or compression fx; contrasts tells u if theres viable marrow tx is under 186
Carpal Tunnel Syndrome (under 189)
All eight flexor tendons (4 FDS and FDP) are invested in a common synovial sheath FPL has its down sheath median nerve round/oval at distal rads median nerve ellipital (oval?) at pisiform and hamate lesions can be extrinsic to the median nerve (schwannoma) or part of the nerve (neurofibroma) acromegaly. hypothyroidism, pregnancy, DM, SLE can cause CTS too; systemic processes extracaps fluid retention and cause ST swelling median nerve has sensory and motor fibers, but sensory fibers predominate at level of carpal tunnel, hence get numbness, tingling initially, then later on get thenar atrophy -and numbness of first 3.5 digits -no anesthesia of thenar eminence (bc supplied by cutaneous branch of the median nerve) aka muscle atrophy and weakness is a LATE finding (after chronic CTS)
69 TFCC complex
Black arrows = radial attachments of TFC white arrows and UC = ulnar collateral ligament M = meniscus homologue pr = prestyloid recess.
92 scapholunate ligament
C-shaped open distally (towards the fingers) membranous or prox component forms base of the C dorsal radiocarpal joint capsule inserts into dorsal component prox dorsal and volar components merge w membranous component Volarly, RSL lig radioscapholunate ligament inserts at jxn volar and membranous components
125
Class I = avulsion of distal TFCC through its lunate attachment (ulnolunate lig) or its triquetrum attachment (ulnotriquetral lig) a = intact ulnocarpal (ulno-lun and ulno-triq) lig vs b = avulsed osseous insertions (curved arrow) of ulnocarpal lig assoc tearing of the dorsal radial TFC Isolated distal ulnolunate or ulnotriquetral lig avulsion (class IC lesion) is not common
44 EXTENSOR COMPARTMENT
Compartment 1 = along lateral radius; extensor pollicis brevis and abductor pollicis longus Compartment 2 = the extensor carpi radialis brevis and longus Compartment 3 = extensor pollicis longus Compartment 4 = extensor digitorum tendons Compartment 5 = extensor digiti minimi Compartment 6 = extensor carpi ulnaris, which runs within the groove formed by the ulnar styloid
98 DISI
DISI w dorsal tilted lunate DISI = S-L angle over 70° and cap-L angle over 20°, dorsiflexed and volarly displaced lunate. DISI is not pathog for scapholunate instability; can be assoc w unstable scaphoid fx (bony DISI), distal radius fx (compensatory DISI), radius malunion (adaptive DISI), and capsular/ligamentous pathology, including scapholunate instability (ligamentous DISI)
119
DRUJ OP
25 ABDUCTOR DIGITI MINIMI
In connective tissue diseases like RA, prolonged contraction of abductor digiti minimi can occur, resulting in ulnar deviation that requires surgical release
132
TFC complex, volar aspect a = arrow = radial attachment of volar radioulnar lig (volar RUL) ulnolunate (UL) and ulnotriquetral (UT) ligs (components of the ulnocarpal ligament) extend from the volar RU lig to attach to volar-ulnar aspect of the lunate and triquetrum b = ulnotriquetral ligament (UT) continuing in an ulnar distal course toward triquetrum at level of the volar aspect of articular disc (d) c = ulnolunate (straight arrow) and ulnotriquetral (curved arrow) ligs merge or confluent extension from the volar RU lig d = lunate (L) insertion (arrows) and triquetrum insertion of the ulnolunate (UL) and ulnotriquetral (UT) ligaments, respectively curved arrow = Note the broad-based common origin of these ligaments from distal volar aspect RU lig radial aspect of TFC is torn in this patient e = separate case w continuity of the hypointense sheet of tissue representing the ulnolunate (UL) and ulnotriquetral (UT) ligs extending from the volar aspect of the volar radioulnar lig (curved arrow). RLT and straight arrow, radiolunotriquetral ligament; R, radius; L, lunate; U, ulna; T, triquetrum; P, pisiform; S, scaphoid.
COMMON FLEXOR TENDON
X land on wrist in order = rad side (rad), palmaris (mid), uln side (uln)
178 scaphoid AVN w early SLAC
a = black arrow = low sig "corner sign" of rad styloid subchondral sclerosis large white arrow = w prox scaphoid nonunion and AVN small white arrows = mild narrowing of joint betw distal scaphoid and radius (aka djd of distal scaphoid and radius) open arrow = SL lig intact b = arrows = attenuated art cart in prox part of DISTAL scaphoid in early SLAC djd (aka djd of distal scaphoid and radius) radiolunate joint is characteristically unaffected
194
a = small straight arrow = neurofibroma of motor branch of median nerve (m) is T1 interm (a) and inc STIR (b) b = curved = its causing thenar muscle denervation (think first 3 digits and thenar muscles) c = arrows = gross pic of tumor
157 Scaphoid fx w DISI
a = curved = 3D shortened scaphoid on 2D background b = curved = humpback scaphoid deformity (flexed distal pole aka look like diving humpback) relative to fx line (straight arrow) RSL lig not seen and there is local synovitis in its expected location. c = DISI due to humpback deformity and wrist shortening wo SL lig tear curved = dorsal tilted and inc cap-lunate angle (double-arrow) capitate dorsally disp relative to radius
185 Stage 1 kienbocks
a = large arrow = tx'ed stage 1 kienbocks w recovering marrow sig small arrows = lunate and TFC nml open arrows = low sig artifact due to radial shortening to bring it to level of lunate (make neutral variance) b = untx'ed severe neg ulnar variance (double arrow) white = deformed but intact TFCC
137
a = small black arrows = distal TFC or central disk is contig w distal lunate fossa cart volar and dorsal RU ligs contribute to striated tissue btw ulnar styloid and central disc large white = high sig cart at central disc's radial attachment to sigmoid notch central disc in direct contact w ulna head cart when have no DRUJ joint fluid distention nar joint fluid distention (small white arrow) b = ECU tendon and sheath on a more dorsal coronal image in plane of TFC TFC attaches to ECU sheath
71 dorsal carpal ligaments
a = 3 things attach to triquetrum dorsally: 1) radiotriquetral ligament (RT)-radius 2) triquetroscaphoid (TS)-scaphoid 3) triquetrotrapezial (TT)-trapezium are fascicles of the dorsal intercarpal ligament b = dorsal and palmar TS connecting scaphoid and trapezium
89
a = DISI w dorsal tilted lunate double arrow = angle 32 degs (use straight line through radius vs cap-lunate line) b = palmar tilted scaphoid w inc scapholunate angle; volar protrusion now horizontal should point up a bit)
147
a = IA nondisp rads fx wo separation of medial complex (lunate fossa and related ST components) b = intact lunate fossa
63
a = RLT lig is divided into a radiolunate ligament and lunotriquetral component (aka RL and LT parts) RLT fxns as volar sling for lunate proximal (b) and distal (c) radial styloid show volar course of RLT ligament (large) from radial styloid (R) inserting into lunate (L) and blending with volar portion of lunotriquetral interosseus ligament lunate attachment of scapholunate interosseous ligament volar fibers is deep (under) to lunate attachment of the RLT ligament
67 radioscapholunate (RSL) and radioscaphocapitate (RSC) ligs
a = RSL lig is a neurovascular structure from distal radius into scapho-lunate articulation RSL lig aka ligament of Testut and Kuenz located volar to SL lig b = RSL (arrow) extends btw scaphoid and lunate Note the volar location of the extrinsic RSL to the intrinsic SL lig c = normal articular cartilage (AC) ridge btw scaphoid fossa and lunate fossa; triangule shape, see in same plane as the intrinsic SL lig
140
a = Radial avulsion of the TFC b = Vertical radial-sided TFC tear
66 short radiolunate ligament (SRL)
a = SRL (arrows) seen extending volarly to distal radius' lunate fossa to its insertion on the radial volar aspect of lunate b = SRL is identified
153
a = Type 1 ulnar styloid fx nonunion w intact TFCC b = U styloid nonunion distal to TFCC attachment fx of TIP due to styloid carpal impaction and avulsion of tip is assoc w intact periosteal sleeve fx of the BASE assoc w avulsion of TFC styloid attachment or avulsion of the fovea attachment (prox to the styloid tip) which destabilizes TFC's ulnar attachment
150
a = Type III spike fx w articular disruption seen in a type II injury and then extra volar metaphysis spike frag volar spike frag disp can injure adj nerves and tendons b = volar spike frag
151
a = Type IV fx w wide separation/rotation of dorsal and palmar medial fragments b = splitting and depression of lunate fossa (small white arrows) w prox migration of lunate (black arrow). large white arrow = assoc diastasis of DRUJ w complete disruption of TFCC
154
a = U styloid fx w unstable DRUJ TFCC and ulnocarpal ligs attached to U styloid fx of the BASE assoc w avulsion of TFC styloid attachment or avulsion of the fovea attachment (prox to the styloid tip) which destabilizes TFC's ulnar attachment
87 Palmarflexion
a = cap and lunate rotate volar small white arrows = arcuate lig lax (bc not taut) b = scaph rotates volar straight arrows = RSC lig lax also
86 neutral position
a = cap-lunate angle 0-30 degs (straight) b = cap-scaph angle 30-60 degs (this is nml position of scaphoid; left is volar, right is dorsal on this pic; scaphoid has volar facing protrusion)
146
a = dorsal disp distal radius fx (Colles' fracture); from FOOSH (imag upward dorsal C) b = nondisp transverse Colles fx prox to distal IA surface of radius
120
a = dorsal subluxed ulna b = disrupted volar TFCC in a rads fx c = dorsal subluxed ulna due to disrupted volar radioulnar lig; ECU also ruptured
103 normal variant LTs
a = eccentric ulnar position of delta shaped LT lig on lunate insertion (white arrows) black arrows = direct contact btw LT and triquetrum cortex b = Commonly seen linear morphology of LT lig; no hyaline cartilage signal at insertion sites of lig
88 SL tear wo carpal instability
a = high sig in SL lig LT lig absent b = still straight line w cap and lunate
156
a = hyposig healing prox scaphoid fx w nml fatty sig still and intact cortex margins b = no cortical or trabecular fx; consistent w MR images
138
a = intact TFC vs b = torn TFC curved = TFC tear involves the radial part of dis wo injury to volar ulnocarpal ligs (straight arrow)- aka only mid central disc torn p = pisiform
186 Stage II Kienböck's disease
a = lunate sclerosis b = hypersig on STIR aka sclerosis and edema c = diff case, stage 2 w visible fx line
181 Kienböck's disease
a = lunate sclerosis and collapse b = open arrow = low sig lunate = white arrow = torn SL lig small white arrow = intact TFC
136 Meniscus homologue and prestyloid recess
a = triangular meniscus homologue (m) and prestyloid recess (p) prestyloid recess is btw meniscus homologue and where TFCC attaches to ulnar styloid TFC, or central disc, is located radial to prestyloid recess, whereas the medial capsule defines ulnar aspect of the recess ECU sheath courses dorsal to the prestyloid recess b = more dorsal coronal image shows confluence of meniscus homologue (m) and dorsal RU lig (large arrow) A fold from the dorsal RU lig forms the prox attachment of the TFC complex (small arrow)
148
a = type II IA fx w die-punch impaction of dorsal medial component b = selective fx extension of radius's lunate fossa's dorsal lip c = dorsal die-punch of lunate fossa
70 TFC complex
a = volar view ulnar sided ligs meniscus homologue = inserts on volar triquetrum; common origin from dorsal ulnar corner of radius with the TFC TFC extend volar from meniscus homologue ulnar styloid base ulnolunate component of ulnocarpal ligament considered to be part of or a continuation of the short radiolunate ligament b = dorsal view, ulnar and dorsal TFCC invested by a thick ligamentous layer (the meniscus reflection; reflection attaches to TFCC and base of 5th MC c/d = dorsal views w reflection taken off; dorsal and volar radioulnar ligaments are separate from TFCC articular disc TFC = central horizontal disc and volar and dorsal radioulnar ligs TFC complex = TFC and any additional ulnar ligamentous structures (like homologue, ulnar collateral ligament, subsheath of the extensor carpi ulnaris tendon, and ulnolunate and ulnotriquetral ligaments)
196
a/b = CTS w tenosynovitis c = diff case w PVNS; get djd, edema and vascular sclerosis
die-punch fx
axial loading causing impaction fx on distal IA radius (on lunate fossa) named after the machining technique of shearing a shape, depression or hole in a material with a die implement or cutter used in the tool-and-die trade die-punch mechanism mc refers to lunate fossa of the radius but can occur from any loading injury
Radioscapholunate Ligament (RSL)
btw long and short RL lig aka lig of Testut or lig of Testut or Kuenz (ppl who found it) most elastic tissue of any wrist lig vascular pedicle that supplies RSL lig may provide clinically significant blood prox scaphoid via the scapholunate interosseous lig and a sensory or proprioceptive pathway to the scapholunate joint RSL gets NVI from anterior interosseous artery and nerve
Ulnar Styloid Fractures
caused by styloid-carpal impaction, and avulsion may be associated with an intact periosteal sleeve assoc w distal rads fx, ECU subsheath may be avaulsed or stripped adjacent to the styloid fx of TIP due to styloid carpal impaction and avulsion of tip is assoc w intact periosteal sleeve fx of the BASE assoc w avulsion of TFC styloid attachment or avulsion of the fovea attachment (prox to the styloid tip) which destabilizes TFC's ulnar attachment base fx assoc w unstable radiocarpal and DRUJ joints when displaced over 3 mm classified according to TFCC abnormalities and nonunion Class I = traumatic TFCC abnormalities (not associated with class II djd tears) may be central perfs (Palmer class IA), ulnar avulsions (Palmer class IB) w or wo distal ulna fx, distal avulsion (Palmer class ID), or radial avulsion (Palmer class D) w or wo sigmoid notch fx Ulnar styloid nonunions are classified as either type 1 (distal styloid fracture) or type 2 (fx of styloid base) tx: tip fx = not sig disp base fx (mc assoc w lig and TFCC tears and DRUJ unstable) at risk for nonunion (25%) conservative tx for tip and nodisp base fx w stable DRUJ surg tx for nondisp base fx w unstable DRUJ or base fx w over 2 mm disp or sevre lig or TFCC injury
91
chronic avulsion fx of scaphoid straight arrow = SL lig still attached to lunate and scaphoid frag fracture (curved arrow)
130
class IID = TFCC perf lunate, triquetrum, and possibly ulna CM LT lig perf pic = straight = TFC perf curved = loss of lunate cart open = LT lig tear TFC enhancement common seen djd lesions
96
complete SL tear (dorsal, MB, volar)
97
complete SL tear (dorsal, MB, volar) w scaphoid flexion (protrusion is horizontal)
MR better than XR arthrography bc communication across a pinhole or small perforation of thin MB portion of lig may not be significant
contrast would float through and make u think its bad
145 Melone classification of distal radius articular fx
d = dorsal medial fragment p = palmar medial fragment disp of the medial complex (medial frags and and ligamentous attachments to ulnar styloid and carpus) is basis for classifying 4 types of IA fx: type I = medial complex may be displaced or not, w stable reduction and congruity of joint surface type II = comminuted fx that is unstable; medial complex is posteriorly or anteriorly displaced; 2A: Dorsally displaced (mc) or volarly displaced 2B: Die-punch fx w lunate impaction (mc dorsal medial component.); greater communication and displacement of the medial frags, usually in a dorsal direction double die-punch fx = scaphoid and lunate impact the articular surface of the distal radius. Articular offset of the radiocarpal joint may exceed 2 mm type III = medial complex displaced and there's spike frag from the comminuted radial shaft type IV = dorsal and palmar medial fragments separate or rotate w severe disruption of distal radial IA surface type V = explosion fx w comminution from art surface to diaphysis Small and large curved arrows indicate rotation of distal and palmar medial fragment
Carpal Instability, Dissociative
debate on the treatment of the various forms of dissociative carpal instability. In many cases, these conditions remain unsolved problems; scapholunate dissociation is an excellent example. Early cases of ligament rupture without rotatory subluxation can usually be satisfactorily treated by pinning the scapholunate ligament and performing open suture repair of the torn ligament, followed by immobilization.73 Accurate reduction is necessary to align the ligament fibers for optimal healing. Once rotation of the scaphoid is accomplished, the proximal pole must be reduced in relation to the lunate and a procedure performed to hold it firmly in place. Ligament reconstructions similar in concept to those devised for the anterior cruciate in the knee have met with uniformly poor results.74 When the scaphoid rotates or flexes, its proximal pole becomes incongruent in the radial fossa. Several methods use intercarpal fusions to ensure that the proximal pole remains congruent in the scaphoid fossa of the radius. Watson and Mempton have reported on the successful use of triscaphe (i.e., scaphoid-trapezoid-trapezius) arthrodesis.75 Others have performed scaphocapitate fusions with similar results. An alternative to intercarpal fusion is dorsal capsulodesis.76 In this procedure, a strip of the dorsal capsule of the wrist is left attached proximally to the radius on one end, and the other is inserted into the distal pole of the scaphoid. By pulling dorsally on the distal pole, the scaphoid is held in a horizontal, reduced position. If possible, the scapholunate ligament should be repaired.
kienbochs can be assoc w Madelung's deformity =
developmental anomaly of distal radisu and carpus
74 Membranous wedge-shaped component of SL lig
distal apex is a free distal protrusion (not attached to anything)
3
dorsal SL and LT ligs
Coronal Plane Checklist
dorsal SL strongest (most important in maintaining carpal stability) thin band of gray articular carti often interposed btw membranous SL lig and the underlying scaphoid and lunate articulations and should not be mistaken for a tear LT also has dorsal, membranous and volar parts, but is harder to see on MR than SL -not uncommonly to see as part of ulnar abutment syndrome
95
dorsal and MB SL tear off scaphoid (which has weaker attachment site)
100
dorsal ganglion communicating w MB SL tear w fluid herniating through dorsal SL
112
dorsal rad-triq lig passes across dorsal lunate (to which its attached) and terminates at dorsal triquetrum fx frag at distal rads attach to the prox R-T lig b = lax RT lig
36 Triangular Fibrocartilage
dorsal, central disc and volar parts triangle shaped in cross-section tears are djd (older asympto pts) or post-trauma (younger pts)
165 Perilunate patterns of instability
fail around lunate (scaphoid side, cap side, triq side, dorsal side) Stage I = SL fails/tears -scaphoid dislocates -RSL lig injury too Stage II = CL-lunate fails -w opening of the space of Poirier Stage III = LT fails -triquetrum dislocates -and RT lig fails Stage IV = dorsal radiocarpal, rad-cap, rad-triq lligs fail -causes lunate to rotate volar After stage I PLI (SL dissociation), more hyperextension force causes tears of RSC lig or avulsion fracture of radial styloid and dorsal dislocation of the capitate relative to lunate (stage II PLI) With further hyperextension and intercarpal supination, tears occur in the dorsal and volar rad-triq ligaments (stage III PLI) Volar dislocation of the lunate then results with spont reduction of distal carpus, which forces the lunate in a volar direction (stage IV PLI) Displaced scaphoid fx over 1 mm of step-off indicate instability and are usually the result of incomplete or spontaneously reduced perilunate dislocation
8 FLEXOR DIGITORUM PROFUNDUS (FDP) 4 tendons go through CTS
flex DP and DIP (aka deeper tendon reaches farther into finger than superficial) jersey finger = Distal avulsions FDP (when finger caught in opposing player's jersey)
7 FLEXOR DIGITORUM SUPERFICIALIS (FDS) 4 tendons go through CTS
flex MPs of 4 fingers its deep fibers are closely apposed w ant anterior bundle elbow UCL; seeing edema and hemorrhage of this muscle common in UCL tears In forearm, median nerve is just deep to the flexor digitorum superficialis arch; its potential nerve compression site divides into 4 musculotendinous units in the distal forearm, and tendons travel though carpal tunnel before dividing again at the level of the proximal phalanges 4 tendons go through CTS
4 FLEXOR CARPI RADIALIS a common flexor tendon
flexor = start on ulnar elbow radialis = end radial wrist lies radial to palmaris longus and ulnar to the pronator teres
6 FLEXOR CARPI ULNARIS a common flexor tendon (2 heads, one is a common flexor)
flexor = start on ulnar elbow ulnaris - ends ulnar wrist lies superficial and just medial to ulnar nerve; serves as marker when ulnar nerve block performed.
80
flexor carp uln and rads ride jus outside the CT (lat to central tendons inside)
45 FLEXOR COMPARTMENT
flexor carpi radialis as it travels through arm
190
flexor retinaculum (transverse carpal ligament)
173
fluid in hamate hook fx
76 palmar aponeurosis
from palmaris longus
Radioscaphocapitate Ligament (RSC)
from radial styloid to radial scaphoid and center of capitate forms sling that supprors scaphoid can get interposed btw scaphoid fx frags and contribute to nonunion looks striated on cor MR
Short Radiolunate Ligament
from radius to volar lunate fibers merge at its insertion on lunate w long RL lig major role in preventing DISI s with lunate extension
58 Lister's tubercle (dorsal tubercle)
functions as pulley for extensor pollicis longus a site of OPs and attrition ruptures in RA
scaphoid fx cont
fx considered stable if noncomminuted and perpendicular to scaphoid long axis Inc obliquity, dorsal comminution, and displ all indicate instability may need to delay/repeat imaging to see fx: XR = may need 2- to 3-week delay repeat if initial XR neg MR may edema prior defined cortex fx may need contrast to document prox pole viability
Scaphoid Fractures
fx line (trabecular) may persist with intact radial and ulnar cortices in healing phase (hence use MR to tell if its acute (extends to cortex) or subacute/chronic (only in trabecula w now intact cortex) assess for flexion of scaphoid distal frag and dorsiflexion instability of lunate usually the result of an incomplete or spontaneously reduced perilunate dislocation mc type of carpal fx mc adolescents and young males (think baron) palmar (volar) surface concavity contains RSC lig blood supply from radial artery
175 prox pole scaphoid fx w AVN
fx line dark on both see edema in bone
scaphoid fx tx
fx/diastasis gap under 1 mm considered stable (but in reality all incomplete fx's potenitally unstable even if no displacement) incomplete and tubercle fx have good prog wo surg unstable scaphoid fx have 50% non union rate 70% are waist = 20% risk AVN/nonunion 20% are prox = 15-40% AVN/nonunion (most risk) 10% are distal scaphoid blood supply mc through distal pole, entering via dorsal ridge from branches of radial artery fx through waist causes poor blood supply to prox pole, causing AVN and delayed healing
Scaphoid AVN
get AVN post trauma which causes fx of prox pole or waist bc of low blood supply often sclerosis of prox pole due to osteopenia and hyperemia of adj non-necrotic bone by time sclerosis, resorption, and collapse seen on XR dx is in advanced state Preiser's disease = avn in absence of fx MR = IV gad enhances hyperemic tissue at fx site and adj subchondral BM; absent prox pole enhancement means no vasc perfusion in development of AVN; aka prox pole dark T1 and FS PD, reactive marrow edema of distal pole, fluid separating fx frags, fx healing shows hyperemia at fx site and adj marrow
2
good normal MR
CTS MR
hypersig and swelling of median nerve more info: pseudoneuroma = swelling or enlarged median nerve PROX to craptal tunnel; fat med nerve gets trapped in carpal tunnel
Carpal Instability, Nondissociative
in extrinsic forms of nondissociative carpal instability caused by malunited distal rads fx, surgery aimed restoring anatomy of radius in RA, injured soft-tissue constraints seen in nondissociative carpal instability with ulnar translation cannot be reconstructed surgically. Reduction of the carpus and radiolunate fusion may be successful in preventing recurrence of ulnar translation. The lunate, when fused to the radius, acts as a doorstop and prevents the carpus from sliding down the inclined plane of the radius. Nondissociative carpal instability associated with dorsal midcarpal instability secondary to a malunited distal radius fracture with dorsal tilt of the articular surface can be treated with an osteotomy of the distal radius, which restores normal volar angulation. Nondissociative carpal instability with palmar and carpal instability presents a more difficult problem. The pathology is excessive volar tilt of the lunate caused by laxity of the ulnar arm of the volar arcuate ligament. Lichtman and others have devised a soft-tissue reconstruction that consists of tightening the volar arcuate and dorsal radiolunate ligaments to correct the excessive VISI of the lunate. This procedure has been successfully performed in a small number of patients. A more reliable operation is the four corner fusion' an intercarpal fusion of the lunate-triquetrum-capitate-hamate. Although some range of motion is lost with this procedure, it has been quite successful in eliminating the clunk since the subluxing joint is fused.
Pisiform Fractures
is a sesamoid bone within flexor carpi ulnaris tendon occurs when use heel of hand as a hammer fx can cause pisotriquetral OA
Kienböck's disease = from NEG variance (lunate drop onto ulna) ulnar abutment = from POS variance
kienbock = more central djd of lunate (avn) ulnar abut = more MEDIAL djd of lunate
Radiolunotriquetral Ligament or Long Radiolunate Ligament RLT or long RL
largest lig of wrist striated band on cor MR is interligamentous sulcus btw RSC and RLT
Midcarpal Instabilities
lax ulnar arm of arcuate lig and the dorsal RLT lig seen in palmar midcarpal instability (this is the mc type of midcarpal instability) Nondissociative VISI is mc a chronic condition w gen lig laxity arcuate lig is major stabilizer of the midcarpal joint; injury to ulnar arm of arcuate lig is mc cause; space of Poirier is a weak area btw capitate and lunate Midcarpal instability may be palmar, less commonly dorsal, or extrinsic consider re-reading this section if needed, talkin about diff types of carpal instabilities
64 radiolunotriquetral or long radiolunate ligament (RLT or long RL)
lig acts as volar sling for lunate (volar supporter)
176 Preiser's disease
low sig sclerotic scaphoid wo fx Preiser's disease = avn in absence of fx
187 Stage III Kienböck's
lunate collapse
188 Stage IV Kienböck's
lunate collapse and djd changes
Distal Radius Fractures
lunate fossa fx divided into dorsal and palmar MEDIAL components Melone classification divides IA fx into 4 components: radial shaft, radial styloid, dorsal medial, and volar medial segments; use to decide when open reduction necessary to achieve good anatomic reduction Barton's fx = IA fx-disl or subluxation (palmar or dorsal fx) with disp of the carpus Colles' fx = fx distal metaphysis with dorsal displacement, angulation (silver fork deformity), radial angulation, and radial shortening; Smith's fx (reverse Colles') = palmarly angulated fx (garden spade deformity)
20 ABDUCTOR POLLICIS BREVIS AOA in thenar: adductor poll brevis = deep (hand along bones; causes stener, must be deep) opponens pollicis = mid abductor poll brevis - superficial OAF in hypothenar: opponens digiti minimi abductor digit minimi flexor digiti minimi
may atrophy in CTS bc fed by median nerve
Lunotriquetral Ligament Tear
may be associated with ulnocarpal impaction syndrome get palmarflexion of the lunate see carpal arc step off unlike SL, LT space widening is not common (which may make it a bit harder to dx) VISI pattern usually requires disruption of both the lunotriquetral intrinsic and dorsal extrinsic ligaments (i.e., dorsal radiocarpal ligament)
16 ABDUCTOR POLLICIS LONGUS 1st extensor compartment
mid forearm to THUMB abducts thumb (so attaches to LAT thumb at 1st MC base) in 1st extensor compartment w ext pollicis brevis (thumb is 1st compartment; so both tendons are POLLICIS) APL EPB de Quervain's tenosynovitis = stenosing tenosynovitis of APL EPB (1st compartment) under extensor retinaculum get de quervains in first row at apple bees ddx: intersection syndrome = friction related repetitive trauma to 2nd compartment where abductor pollicis longus and the extensor pollicis brevis muscles cross Intersection syndrome occurs prox to extensor retinaculum both compartment 1 and 3 tendons insert on DORSAL THUMB
17 EXTENSOR POLLICIS BREVIS 1st extensor compartment
mid forearm to THUMB de Quervain's tenosynovitis w APL both compartment 1 and 3 tendons insert on DORSAL THUMB
28 LUMBRICALS
no bony attachments from the tendons of the flexor digitorum profundus merge w interossei to make extensor expansion which extends to the distal fingers
33
no pic
Ulnocarpal Abutment Syndrome also known as ulnar impaction syndrome, ulnolunate abutment, ulnolunate impaction syndrome, ulnar impaction, and ulnocarpal loading
one sided sclerosis of lunate from impaction by ulna mc get when have positive ulnar variance (but dont have to have it to get it) get MEDIAL lunate djd and tfcc djd can be acquired or congenital, mc after trauma of radius (aka causing + variance) tx = ulnar shortening osteotomy ; other options are TFC complex débridement, the wafer procedure (resection of the distal ulna beneath the TFC), and hemiresection of the distal ulna
19 EXTENSOR INDICIS 4th extensor compartment
only extensor that has MUSCLE FIBERS extending to or beyond RC joint sometimes transferred surgically to replace a torn extensor pollicis longus tendon.
167 Unstable scaphoid fx
over 1 mm of step-off at the fracture site scaphoid elongated in axial plane due to flexion Scaphoid disp indicates instability, usually from incomplete or spontaneously reduced perilunate dislocation
Triangular Fibrocartilage Complex
part of EXTRINSIC ligs of ulnocarpal group stabilizes DRUJ and ulno-crap joints traumatic (Palmer class I) or degenerative injuries (Palmer class II) 4 Class I types: (traumatic) Class IA: Perf or traumatic tear of TFC disc proper Class IB: avulsion of ulnar TFCC w or wo U styloid fx Class IC: avulsion of distal TFCC through its lunate attachment (ulnolunate lig) or its triquetrum attachment (ulnotriquetral lig) Class ID: Radial avulsions at distal sigmoid notch w or wo a sigmoid notch fx 5 Class 2 types (djd); spectrum of ulnocarpal abutment syndrome Class IIA = TFCC wear Class IIB = TFCC wear lunate, triquetrum, and possibly ulna CM Class IIC = TFCC perf lunate, triquetrum, and possibly ulna CM Class IID = TFCC perf lunate, triquetrum, and possibly ulna CM LT lig perf Class IIE = TFCC perf lunate, triquetrum, and possibly ulna CM LT lig perf, ulna-carpal OA
26 FLEXOR DIGITI MINIMI
part of hypothenar eminence with abductor digiti minimi and opponens digiti minimi
21 OPPONENS POLLICIS AOA in thenar: abductor poll brevis - exterior opponens pollicis = mid adductor = interior hand along bones (causes stener, must be deep)
part of thenar eminence with abductor pollicis brevis and flexor pollicis brevis
Scapholunate and Lunotriquetral Ligaments (Intrinsic Ligaments)
perfs mc in thin, membranous portions and may not be mechanically significant inner apex of the triangular ligament not attached to bone (floats freely in SL joint) dorsal SL most important for stability MB SL lig fibers attach to both bone and art cart dorsal and volar SL lig fibers attach directly to bone.
Radiocarpal Joint
positive ulnar variance = lead to ulnar abutment syndrome negative ulnar variance = see in Kienböck's disease
109
positive ulnar variance w ulnar impaction
5 PALMARIS LONGUS a common flexor tendon
present in 85% gen pop no tendon sheath (has paratenon) lands/inserts on FLEXOR retinaculum
Triangular Fibrocartilage Complex Cont
radial side injury mc (except young ppl where ula sided mc) central TFCC is thin and mc site of tears dorsal and volar parts are thicker than central central portion is avascular (like central meniscus); repair only peripheral bc will heal; just excise central bc wont heal small TFCC tears affect DRUJ; small volar tear let DRUJ go dorsal and vice versa
72 extensor retinaculum and dorsal carpal ligaments
radiotriquetral lig (an extrinsic dorsal capsular ligament) and the dorsal intercarpal lig (an intrinsic dorsal capsular lig) are seen dorsal intercarpal lig made of separate triquetroscaphoid (TS) and triquetrotrapezial (TT) fascicles vertical septations of extensor retinaculum define the 6extensor compartments a slip of the extensor retinaculum attaches to the dorsal triquetrum
dorsal perilunate dislocation; dont get it
sagittal images demonstrate the longitudinal axis of the capitate dorsal to the longitudinal axis of the radius in association with a flexed scaphoid. In the coronal plane the carpus is foreshortened. There is an overlap of the proximal capitate and distal lunate margin with a diastasis between the scaphoid and lunate. In a lunate dislocation the longitudinal axis of the capitate is colinear with that of the distal radius and the lunate is displaced in a volar direction. There is an intermediate stage of injury that may occur in both perilunate and transscaphoid perilunate dislocations. In this intermediate stage of injury carpal displacements are halfway between a perilunate and lunate dislocation. The capitate is partially dorsal to the longitudinal axis of the radius and the lunate is angulated volarly but not completely dislocated. In dorsal transscaphoid perilunate dislocation there is an associated fracture of the waist of the scaphoid. In the less common volar perilunate and volar transscaphoid perilunate dislocation, the lunate is palmarly flexed and the capitate is displaced volarly (Fig. 10.168). Volar transscaphoid perilunate dislocation is usually widely displaced and is typically more unstable than its dorsal counterpart.
177 chronic scaphoid AVN (dark T1 and PD)
scaphoid waist fx w prox pole AVN blood supply to prox pole via radial artery coming from distal pole
Scaphoid Nonunion cont
see DISI on sag bc scaphoid injury destabilizes rest of hand all nonunions lasting over 5 years get OA in this order: radio-scaph (first), cap-scap (second), and then cap-lun (third) in NOT DISPLACED nonunions, mc get djd at rads-scaph joint (aka first part only)
Capitate Fractures
similar to scaphoid fx bc blood supply extends through capitate waist, making prox prone to AVN mc fx site at waist or neck scaphocapitate syndrome = cap fx w perilunate dislocation (cap falls off lunate); capitate head fx'ed and rotated 180°, prox cap has squared-off contour
Arcuate Ligaments aka Deltoid Ligaments
stabilize DISTAL row (SL and LT stabilize prox carpal row) 2 arms: cap-triquetrum/lunate cap-scaphoid space of Poirier = thin tissue btw 2 limbs of the lig; weak area in lig floor of the carpus may function as a trap door through which lunate or capitate may dislocate
1 intra-articular contrast into radiocarpal compartment
torn lunotriquetral lig (straight) allows contrast into midcarpal compartment torn radial TFCC (curved) directs contrast into distal radioulnar joint
155
transverse scaphoid fx wo without interruption of scaphoid cortex
AVN and Nonunion of the Scaphoid
triq, lun and prox scaphoid frag slide volar in stage 1 perilunar instability (PLI)
39 CARPAL JOINTS
triscaphe joint = distal scaphoid articulating w trapezoid and trapezium 2nd mc site of wrist OA/djd (after radio-scaphoid)
79 carpal tunnel anatomy
ulnar nerve and art jus outside CT deep tendons are DEEP in CT
Ulnocarpal Ligaments
ulnar portion of the extrinsic volar ligaments of the wrist is formed by the TFC complex TFC = 3 parts = central horizontal disc and volar and dorsal radioulnar ligs TFC complex = TFC and any additional ulnar ligamentous structures (like homologue, ulnar collateral ligament, subsheath of the extensor carpi ulnaris tendon, and ulnolunate and ulnotriquetral ligaments); aka all structures that suspend distal radius and ulnar sided carpal bones
other lig instabilities in wrist
ulnar translocation = carpals are ulnar in position; SL and CL angles nml; space betw rad styloid and scaphoid inc -ulnar translocation might be caused by synovial disorders, severe trauma or surgical excision of ulnar head or radial styloid dorsal subluxation = carpals go dorsal relative to radius; SL and CL angles nml; often have dorsally impacted distal radius fracture palmar subluxation = carpals are palmar relative to radius. SL and CL angles normal; may be assoc ulnar translocation
wrist arthrography
used to evaluate integrity of SL, LT and TFCC ligs more diagnostic and useful for ulnar sided tears used to inject 3 spots (RC, RU, mid carpal joints), but found single compartment was good enough
107
volar LT tear
61 anatomy
volar extrinsic ligaments are the most constant and strongest of the extrinsic ligs impt ligs originate from radial styloid and distal radius, including radial collateral and palmar radiocarpal ligaments like: radioscaphocapitate ligament (RSC) radiolunotriquetral (RLT) lig (aka long radiolunate ligament) (long RL lig) radioscapholunate ligament (RSL) short radiolunate ligament (short RL lig) these maintain carpus within its radial articulation Loss of these ligaments lets carpus to move down the inclined plane of the distal radius and undergo ulnar translation; not in RA where pannus burns these supporting w ulnar translation, distance btw radial styloid and scaphoid inc and scaphoid and lunate are displaced from their radius fossas lunate rests on its ulna articulation and scaphoid perches on the ridge between its own articulation and the lunate fossa this incongruent loading causes cart djd and ulnolunate impingement Overexuberant surgical resection of the radial styloid can destroy these ligs and may cause this type of instability Distal ulna resection (the Darrach procedure) in RA wrist can also lead to ulnar translation of the carpus with the loss of the ulnar buttress
199
volar ganglion arising from triscaphe origin deforms carpal tunnel and causes median nerve compression
Dorsal Ligaments
volar ligs get more attention bc more impt but dorsal ligs have role too dorsal ligaments aren't discrete anatomic entities and they vary considerably by ppl 2 major components: 1) dorsal radioscapholunotriquetral lig (R-SLT lig); a thickening of the dorsal capsule that courses from dorsal radius to dorsal SLT (scaphoid, lunate, and triquetrum); is checkrein on prox carpal row and prevents excessive volarflexion studies shown that final stage of ulnar-sided perilunate instability, is R-SLT lig injury R-SLT lig laxity implicated in palmar midcarpal instability where lunate allowed to volarflex, causing instability 2) scaphotriquetral (or triquetroscaphoid) lig (TS lig) -transversely oriented thickening of dorsal capsular fibers runs from scaphoid to triquetrum radiotriquetral lig (RT) = single band arising distal radius, adj to Lister's tubercle dorsal intercarpal ligament = seen either as a broad fused band (a branched structure) with separate triquetroscaphoid and triquetrotrapezoid fascicles, or as completely separate triquetroscaphoid and triquetrotrapezoid fascicles
121
volar subluxed ulna and dorsal subluxed radius w disrupted dorsal TFCC
104 VISI w midcarpal instability
volar tilted lunate, inc cap-lung angle, subchondral sclerosis of capi and lun ulnar arm of arcuate lig not visible in midcarpal instability
VISI MR
volar tilted lunate, palmarflexion instability and translocation of the distal row Synovitis, attenuation, or lax ulnar arm of arcuate ligament and dorsal RT lig
144 Nondisplaced IA distal radius fx (Frykman type III)
w SL tear, hamate hook fx, nondisp fx of distal scaphoid in Frykman classification = IA distal radius fx classified as class III or higher, based on radiocarpal, distal radioulnar joint, and distal ulnar involvement Complex IA fx have a poor prognosis
23 ADDUCTOR POLLICIS
webbing in inner hand (from 1st to 3rd) responsible for stener lesion 2 heads that converge into a tendon that inserts, along w adj FPB, onto ulnar thumb PP base a sesamoid bone is present in the tendon. in UCL tears of thumb (gamekeeper's thumb), the adductor pollicis aponeurosis can interpose between the torn UCL and thumb which precluding healing (Stener's lesion) must fix Stener's lesions to prevent persistent instability of the metacarpophalangeal joint
Scaphoid Nonunion
when a scaphoid fx fails to unite w/in 6 mos of injury see in prox 1/3 pole fx, vertical oblique fx of middle 1/3 fx or fx disp over 1 mm (cortical offset over 1 mm) characterized by stage I PLI (triq, lun, and prox scaphoid frag slide volar into extension) and a volar defect caused by trabecular erosion SLAC occurs w DISI and advanced djd djd changes in scaphoid nonunion are sim to changes seen in scapholunate dissociation Scaphoid nonunion is greater arc injury scapholunate dissociation is lesser arc injury, and both pw as stage I PLI (bc source is SL injury i think) Thus "SNAC" means LATE djd changes due to scaphoid nonunion 5 classifications: Type 1: Simple nonunion -nondisplaced and no djd Type 2: Unstable nonunion -over 1 mm disp or DISI (SL angle greater 70°), but no djd Type 3: Early OA nonunion w radioscaphoid arthritis Type 4: SNAC wrist Type 5: Scaphoid nonunion advanced collapse-plus (SNAC plus), and OA throughout wrist