1) The document discusses various carpal dislocations including perilunate dislocations and fractures, scapholunate dissociation, and their anatomy, mechanisms of injury, clinical features, imaging, and management. 2) Perilunate dislocations are high energy injuries that commonly involve disruption of the scapholunate ligament followed by other ligaments and can be classified using the Mayfield classification system. Management involves early closed reduction and surgery including open reduction, ligament repair and fixation. 3) Scapholunate dissociation is an important cause of carpal instability that can lead to DISI deformity if left untreated. The scapholunate ligament maintains carpal stability and its anatomy and biomechan

1. DR RASHIK ISMAIL
20/11/17
CARPUS DISLOCATIONS

2. INCLUDES
1) PERILUNATE DISLOCATIONS & # - DISLOCATIONS
2) SCAPHOLUNATE DISSOCIATION
3) LUNOTRIQUETRAL DISSOCIATION
4) ULNOCARPAL DISSOCIATION

3. ANATOMY
The wrist is composed of two rows of bones that provide motion and transfer forces.
C, capitate; H, hamate; L, lunate;
S, scaphoid; T, triquetrum; P, pisiform; Td, trapezoid; Tm, trapezium.

5. Gilula arcs outline proximal and distal surfaces of the proximal carpal row and
the proximal cortical margins of capitate and hamate.

6. Normal anatomic
relationships
1)Radial inclination (23 degrees)
2)Radial length (11mm)
3)Volar tilt (12 degreee)
4) Zero degree Capitolunate angle
5)Carpal height ratio (0.53)
6)Scapholunate angle (47 degrees)
Lunate is the key to carpal stability.
Carpal height ratio
SL ANGLE

7. Wrist Ligaments
Extrinsic
Connect radius to carpus & carpus to metacarpals
Intrinsic
Connect carpal to carpal bone.
o Space of Poirier: ligament free area btw
radioscapholunate lig & long radiolunate ligament- at
level of midcarpal joint;an area of potential weakness.

8. Extrinsic ligaments
EXTRINSIC : Palmar aspect EXTRINSIC : Dorsal

9. Pathomechanics
Classically, the radius, lunate, and capitate have
been described as a central “link” that is colinear in
the sagittal plane.
 Scaphoid serves as a connecting strut. Any flexion
moment transmitted across the scaphoid is balanced
by an extension moment at the triquetrum.

10. DISI
 When the scaphoid is
destabilized by fracture or
scapholunate ligament
disruption, the lunate and
triquetrum assume a position
of excessive dorsiflexion
(dorsal intercalated segmental
instability [DISI] ) and the
scapholunate angle becomes
abnormally high (>70
degrees).

11. VISI
When the triquetrum is
destabilized (usually by
disruption of the
lunotriquetral ligament
complex), the opposite
pattern (volar intercalated
segmental instability [VISI] )
is seen as the lunate
(intercalated segment) volar
flexes.

12. MECHANISM OF INJURY
FOOSH; axial compressive force
wrist hyperextension,
ulnar deviation, and
intercarpal supination

13. PERILUNATE DISLOCATION &
FRACTURE -DISLOCATIONS

14. Introduction
High energy injury with poor functional outcomes.
Commonly missed (~25%) on initial presentation.

15. Two categories
Perilunate dislocation
lunate stays in position while carpus dislocates
4 types
 transcaphoid-perilunate (MC)
 perilunate
 transradial-styloid
 transcaphoid-trans-capitate-perilunar
 Lunate dislocation
lunate forced volar or dorsal while carpus remains aligned

16. Mechanism
traumatic, high energy
occurs when wrist extended and ulnarly deviated
leads to intercarpal supination

17. Pathoanatomy
Sequence of events (Mayfield)
 scapholunate ligament disrupted -->
 disruption of capitolunate articulation -->
 disruption of lunotriquetral articulation -->
 failure of dorsal radiocarpal ligament -->
 lunate rotates and dislocates, usually into carpal tunnel.

18. Dislocation can course through
Greater arc
 ligamentous disruptions with associated fractures of
the radius, ulnar, or carpal bones.
Lesser arc
 purely ligamentous.
Greater
Lesser

19. Mayfield Classification
STAGE
1 Scapholunate dissociation
2 + Lunocapitate disruption
3 + Lunotriquetral disruption, "perilunate"
4 Lunate dislocated from lunate fossa (usually volar)
•associated with median nerve compression

20. 1.SCAPHOLUNATE
DISSOCIATION
2. LUNOCAPITATE
DISRUPTION

21. 3. LUNOTRIQUETRAL DISRUPTION,
“PERILUNATE"
4.LUNATE DISLOCATION

22. CLINICAL FEATURES
Symptoms
acute wrist swelling and pain
Median nerve symptoms may occur in ~25% of patients
MC in Mayfield stage IV where the lunate dislocates into
the carpal tunnel

23. IMAGING
Radiographs
PA/lateral wrist radiographs
 AP
 break in Gilula's arc
 Lunate and capitate overlap
 Lunate appears triangular "piece-of-pie“ sign
 Lateral
 loss of colinearity of radius, lunate, and capitate
 SL angle >70 degrees
MRI
usually not required for diagnosis

24. MANAGEMENT
NON OPERATIVE
Closed reduction and casting
 Indications
o no indications when used as definitive
management
 Outcomes
o universally poor functional outcomes with non-
operative management
o recurrent dislocation is common

25. Closed Reduction technique of Tavernier
finger traps, elbow at 90 degrees of flexion
hand 5-10 lbs traction for 15 minutes
dorsal dislocations are reduced through wrist extension,
traction, and flexion of wrist.
apply sugar tong splint
follow with surgery.

26. OPERATIVE
1) Emergent closed reduction/splinting followed
by open reduction, ligament repair, fixation, possible
carpal tunnel release.
2) Proximal row carpectomy
3) Total wrist arthrodesis

27. 1) Emergent closed reduction/splinting
followed by open reduction,ligament
repair, fixation,
Indications
 all acute injuries <8 weeks old
Outcomes
Emergent closed reduction leads to
Decreased risk of median nerve damage
Decreased risk of cartilage damage
Return to full function unlikely
Decreased grip strength and stiffness are common

28. Approaches – Dorsal, Volar, Combined.
Dorsal approach
longitudinal incision centered at Lister's tubercle
excellent exposure of proximal carpal row and
midcarpal joints
does not allow for carpal tunnel release
Volar approach
extended carpal tunnel incision just proximal to
volar wrist crease

29. Combined dorsal/volar approach
Pros
added exposure
easier reduction
access to distal scaphoid fractures
ability to repair volar ligaments
carpal tunnel decompression
Cons
some believe volar ligament repair not necessary
increased swelling
potential carpal devascularization
difficulty regaining digital flexion and grip

30. Technique
Fix associated fractures
Repair scapholunate ligament
Protect scapholunate ligament repair
Repair of lunotriquetral interosseous ligament
Post-op
Short arm thumb spica splint converted to short arm
cast at first post-op visit
Duration of casting varies, but at least 6 weeks

31. 2) Proximal row carpectomy
 Technique
Dorsal and volar incisions if median nerve compression is present
Volar approach allows median nerve decompression with excision
of lunate
Dorsal approach facilitates excision of the scaphoid and
triquetrum

32. Complications
 Median N neuropathy.
Chronic perilunate injury.
Post traumatic arthritis.

33. SCAPHOLUNATE
DISSOCIATION

34. INTRODUCTION
Scapholunate ligament is important for carpal stability
chronic scapholunate deficiency DISI
Ligamentous analog of scaphoid #
Acute/ Degenerative injury.
3components: Dorsal, Proximal & Volar
Associated injuries
DISI
Scaphoid flexes palmar and the lunate dorsiflexes
if untreated, progress into a SLAC

35. ANATOMY
Scapholunate interosseous ligament
Location
C-shaped structure connecting the dorsal, proximal and
volar surfaces of the scaphoid and lunate bones
dorsal fiber thickened (2-3mm) compared to volar
Biomechanics
Dorsal component provides the greatest constraint
to translation between the scaphoid and lunate bones

36. CLINICAL EXAMINATION
ASB tenderness
Pain increased with extreme wrist extension and radial deviation
Watson test +ve
When deviating from ulnar to radial, pressure over volar aspect of
scaphoid produces a clunk secondary to dorsal subluxation of the
scaphoid over the dorsal rim of the radius.

37. IMAGING
o Additional radial and ulnar deviation views & clenched fist
Findings
PA radiographs
SL gap > 3mm (Terry Thomas sign)
cortical ring sign (caused by scaphoid malalignment)
scaphoid shortening
Lateral radiographs
dorsal tilt of lunate leads to SL angle > 70°
capitolunate angle > 20°

38. Terry Thomas sign
Cortical
ring

39. Imaging (Contd…)
Arthrography
as screening tool
always assess the contralateral wrist for comparison
demonstrate the presence of a tear.
Arthroscopy
gold standard for diagnosis

40. MANAGEMENT
Nonoperative
 NSAIDS, rest +/- immobilization
 Indications
 acute, undisplaced SLIL injuries
 chronic, asymptomatic tears

41. Operative
SURGERY INDICATION
SL Ligament repair acute scapholunate ligament injury
without carpal malalignment
SL reconstruction Acute, SL lig not ammenable to repair
Scaphoid ORIF vs. CRPP SL ligament injury is d/t scaphoid #
Stabilization with wrist fusion
(STT/SLC)
rigid and unreducible DISI deformity

42. Complications
Disease progression (e.g. SLAC wrist)
Arthritis
Post-operative pain, stiffness, fatigue
Reduced grip strength

43. THANK YOU