Carpal fractures Flashcards
Scaphoid fracture
80% of bone are covered with cartilage
40° in coronal plane, 32° in sagittal plane
scapholunar ligemant is very stout - dorsal and volar portion - dorsal portion resists palmar dorsal translation and gap, volar portion resists roation
two types of morphologic scaphoids (McLean and collegues)
RSC ligament is a fulcrum for the scaphoid - very strong - high densitiy of mechanoreceptors - suggesting a mechanical and proprioceptive role
DIC stabilizer of the wrist and dorsal check for the proximal capitate
vascular anatomy
superficial palmar arch (20 - 30%) of blood supply and dorsal carpal branch (70 - 80%) of blood supply - the main blood supply comes from distal and goes proximally (gelbermann)
radioscaphoid ligament (ligament of Kuenz and Testut) palmar from the insertion of the SLIL with arerioles, venules and small nerves
Handley and all - venous drainage of the dorsal ridge through the venae comitantes of the radial artery
Biomechanis
hyperextension injury and maybe dorsal subluxation (proximal pole)
fractures heal by intramembraneous ossification - callus is needed for ossification and stabilization
displaced >1mm or 15° angulation - non union
rotational force in the first row - lunate and the proximal fragment tend to go in extension - the distal scaphoid fragment goes in flexion
humpback deformity and DISI position - first step to SNAC wrist
SNAC - wrist:
- radioscaphoid arthritis
- midcarpal arthritis
- panarthritis of the carpus
clinic
pain in snuffbox
pain with axial load in thumb
pain in radiocarpal motion
radial-sided wrist pain
most scaphoid fractures heal in about 3 month - radiographs not reliably - CT is the best
we do CT in any suspicion of fracture because of the bad outcome with overseen fractures and the system of treatment in a ambulance, children and young adults get an MRI
classification
Herbert classification
A - stable acute fractures
A1 - fractures of the tubercle
A2 - incomplete waist fractures
B - unstable fractures
B1 - distal oblique fractures
B2 - complete fractures of the waist
B3 - proximal pole fractures
B4 - trans-scaphoid perilunate fracture-dislocation of carpus
C - delayed union
D - establishe nonunion
D1 - fibrous union
D2 - pseudarthrosis
nonoperative treatment
distal pole fractures - heal in 6 - 8 weeks - CT is should be shown no fracture of the joint surface to the trapezium
waist fractures
long cast is postponed - study with signaficantly difference in short to long arm splinting - normally fractures which are good splinted will heal over time - in our department we prefer a surgical closed treatment for all young patients with a A2 or higher fracture - just to prevent a bad outcome in the next years - in the last years good experience with this treatment
operative treatment
implant strenght constructs on 5 variables:
- bone quality
- fragment geometry
- fracture reduction
- choice of implant
- implant placement
K-wires
Herbert headless compression screws
Acutrak screw - variable-pitch cannulated screw with full thread
Ender plate
Herbert screws
position in the centre and as long as possible (literature best rigid fixation)
when micromotion is possible fixation scaphocapitar with a screw for 3 -6 month especially in small proximal pole fractures
dorsal approach over radial based flap - parallel incision to the radio carpal ligemant and the dorsal intercarpal ligament
dorsal open approach for proximal pole fractures, cartilage heal over screw entry point, check the correct position of the k-wire, smaller screw to prevent outbreak and fragmentation of the proximal fragment, 3-6 weeks of splinting
palmar open approach for displaced unreducible waist fractures and scaphoid non-union
arthroscopy assited for reduction of scaphoid fractures - also for late first treatment of fractures - control of reduction through midcarpal and 3-4R portal, ligament repair is possible for SL or LT rupture, 3-6 weeks of splinting, if necessary longer
volar percutaneous cannulated screw fixation gives no better outcome in healing or range of motion in comparison to splinting, but the healing was only 7 weeks (12weeks) and the return to work 8 weeks (15 weeks)
some studies say that there is a better outcome in range of motion
trans-scapholunate perilunate fracture-dislocations
wrist extension, ulnar deviation and carpal supination
ligamenteous failure begins radially and goes ulnarly - though the scaphoid, LT ligament and the PSU
proximal pole of the scapoid stays with the lunate
distal row and distal pole dislocated dorsally
when come back lunate is dislocated palmary
short radiolunate ligament holds the lunate in position
early reduction and open fixation of the ligementeous and bony injury depending on the fracture subtype
immobiliziation over 4-8 weeks
maybe LT or SL screws for 6 month
non-union of the scaphoid
Classification by Slade and Geissler
- delayed for 4 to weeks
- fribrious union, minimal fracture line
- minimal sclerosis <1mm
- cystic deformation 1-5 mm, no deformity
- Humpback-Deformity
- wrist arthrosis
type 1 - 3 without substantial bone loss
grade I:
rigid fixation without bone grafting, cast for 6 weeks
grade II:
rigid fixation without bone grafting, cast for 6 weeks
grade III:
minimal deformity <2mm, rigid fixation, cast for 6 weeks
grade IV:
bone grafting after debridement, rigid fixation, cast for 6 weeks, maybe assisted by athroscopy, (Matti-Russe-plastic)
dorsal maybe k-wires are better than screws, dorsal capsule approach over a radial based flap (DIL and DRC - Ligament preserved)
percutanaeous grafting with bone bipsy needles from the distal radius or iliac crest
arthroscopy:
identify ligamentous damages
wrist artholysis
inspection for the non-union fibrous fiber and pseudarthrosis and bleeding (fibrous fiber are the border for cancellous bone graft to migrate to the joint)
grade V and VI:
correction of the deformity:
cortical cancellous bone for correction, open wedge osteotomy from volar, rigid fixation, cast for 6 weeks
measurement of the contralateral wrist for planning of the correction in size and the size of the open-wedge shaped bone graft
if no bleeding - vascularized bone grafting:
most common is the Zaidenberg vascularized bone graft
free vascularized bone graft from the medial femur condyle
Zaidenberg:
1,2/2,3 intercompartmental supraretinacular artery called 1,2/2,3-ICSRA (2,3 better - has the longer pedicle)
others:
pisiforme, metacarpal head, pronator quadratus
maybe K-wires or screws (!!! be careful) and scaphocapitar fixation
there are studies complaining a poor use of vascularizd bone grafts (Straw and collegues)
medial femur condyle graft
better for non-union (Jones and collegues)
metaanalyze:
screws are better than k-wires
AVN better with vascularized bone grafts
corrective osteotomy with wrong union (especially in the lateral angle >45°) play a role in the prevention of second induced osteoarthritis
styloidectomy improve the results of salvage procedures and osteotomy correction
salvage procedures
Proximal row carpectomy - SNAC Stadium I and II with good captiate head cartilage
70-80% of grip strength, 50-60% of ROM
better if older than 40
no hard workers
cast for 4 weeks, early motion is important (dorsal capsule contracture)
maybe bone graft from the inner scaphoid for reconstruction ot the lunate fossa of the radius
four corner fusion (capitate head is degenerative)
correct the lunate position!!!
3 compression screws or spider plate
total wrist fusion (SNAC stadium III)
Preiser disease
AVN of the scaphoid:
collagen vascular disease
steroid therapy
repetitive trauma
idiopathic causes
vascular graft:
if not: PRC, Four-corner-fusion
other carpal fractures
ligamentous or carpal fracture around the lunate without perilunate instability:
“less arc” injuries
ligementous or carpal fractures of fhe scaphoid, caiptate and triqetrum or all three with perlunate instability:
“great arc” injuries
scaphoid (70%) - Triquetrum (about 20%) - Trapezium (about 10 or less) - rest other bones
Triquetrum fracture
dorsal most common - with 4-6 weeks of splinting- good results
(palmar flexion with radial deviation - not so common)
most common - dorsiflexion with ulnar deviation - with the PSU as a fulcrum (Hebelpunkt)
body fractures common with perilunate fractures - high-velocitiy fractures with a combination of other injuries
volar avulsion with rupture of the LT-Ligament
Trapezium fracture
mostly in combination with metacarpal or radius fractures
ridge fractures are not so common
(Classification by Palmer with:
Type I - base fractures - maybe conservative (non-union) - fixation is sometimes better
Type II - tip of the ridge - conservative, remains often painful - than excision of the little bony fragment
Capitate fracture
centred in the carpus and protect to injury
rare as an isolated injury
most common: trans-scaphoid periluntae fracture-dislocation “scaphocapitate fracture syndrome” by Fenton
4 patterns:
- transverse of the proximal pole
- transverse of the body
- verticofrontal fracture
- parasagittal fracture
mostly transvere fractures - in trans-scaphoid, trans-capitate fractures often seen rotation of 180° of the proximal fragment
mechanism
hyperextension and radial deviation - scaphoid fracture - capitate impacts against the dorsal ridge of the radius - when the wrist returns to neutral the distal fragments maybe initiate a flexion of the proximal fragment which leads to a rotation of maybe 180°
open reduction and fixation - incision through the 3. and 4. dorsal compartement - 2 headless screws - maybe corticancellous bone grafts are needed for reconstruction of the carpal height
AVN is similar to the scaphoid and its blood supply - especially the capitate head is in risk
vibration exposure
steroid use
repetitive wrist extension
ligamentous laxity
AVN capitate: by Milliez and collegues
type I: proximal involvement (most common)
type II: distal or body involvement
type III: total involvement
hamate fracture
fairly rare - 2% off all carpal fractures
hook is the insertion of:
FDM - ODM - hypothenar muscles, pisihamate ligament and distal attachement of the transverse carpal ligament
2 groups
hook fractures
body fractures
hook fracture:
rarely in normal population - more common in atheltic population with persons who swing a racket, club or bat - primary compression from beating leads to fracture
non-dominant hand: golfers and baseball players
dominant hand: tennis and racketball players
clinic:
paresthesia, in small and ringfinger - weakened grip strength - pain with resistance of ring- and small finger flexion in ulnar deviation and lessend in radial deviation - chronic superficial flexor tendon rupture may be caused by a hamate fracture
3 radiographs to show the hook of the hamate
carpal tunnel view
supinated oblique view with hand in supination
lateral view with the thumb abducted through the first web space
in addition a CT scan should be performed (100% sensitivity)
hamate has 3 vascular pedicles - only 71% have a vascular pedicle at the tip - 29% are at risk for osteonecrosis with a fracture distal to the basal nutrient artery
classification: by Milch
Type I - hook fractures
I - tip of the hook
II - through the base
III - through the waist
Type II - body fractures
IIa - coronal
IIb - transversal
if not heal conservatively most authors recommended the excision of the bony fragment with closing of the periosteum - some authors described percutaneous compression screw though the tip of the hamate - difficult to perform - artery and ulnar nerve at risk
body fractures
less common - coronal fractures mostly to axial load through the CMC joint of the 4. and 5. MC
CMC joint about 30° of motion
management of coronal fractures which involve the CMC joint should be treated by open reduction and fixation - maybe a little LCP
pisiform fracture
2% of fractures
attachement pisohamate and pisotriquetral ligament - transcarpal ligament and ADM
mostly direct struck to the bone - or avulsion fractures from the ligamentous tissue
pisiform fracture are suspicious for worse damage to the radius or carpus
best visualized in oblique radiographs in 30, 45 and 60° to see the pisitriquitral joint, clenched fist AP with the wrist in ulnar deviation
pain over the FCU (sesamoid bone) with dislocation of the proximal fragment - treatment maybe with resection of the pisiform
