Talks about DISI, VISI and various forms of Carpal instability and their surgical treatment

1. Carpal Instability

3. Scapholunate ligament
• C shaped ligament composed of dorsal,
central and palmar subregions.
• Dorsal aspect most thick.
• Central aspect separated from the volar region
by radioscapholunate ligament.
• Ligament of Testut

4. • The Scaphocapitate and STT ligaments present
dorsally resist palmar flexion of scaphoid.
• The RSC ligament and short and long
radiolunate ligament on palmar aspect.
• The Lunotriquetral ligament also has 2 layers,
with the volar region more thick.

5. • Proximal carpal row has no tendinous
attachments and is called intercalated
segment.
• Movement between the carpal bones is
determined by ligamentous attachments and
mechanical forces crossing the wrist.

6. Biomechanics
• Lunate exists in suspension between the
scapholunate ligament and lunotriquetrum lig.
• Scaphoid and triquetrum exert flexion and
extension moment respectively.
• Tendons crossing the carpus exert
compressive force on lunate through capitate.

7. Mechanism of injury
• Fall on outstretched hand, high energy
injuries.
• Hyperextension of wrist.
• Mayfield- 4 stage progression.
– Wrist extension.
– Ulnar deviation.
– Carpal supination.

8. Progressive Perilunar Instability
• I- dorsal migration of
proximal pole of
scaphoid 
Scapholunate injury.
• II- extension, supination
and ulnar deviation
leads to force
transmitted through
space of Poirier.

9. • Triquetrum translates
away from lunate  LT
ligament injury
• Dorsal radiocarpal
ligament dissociation
lunate rotates on its
palmar hinge and
dislocates with capitate
articulating with the
radius.

10. • Arthritic changes may occur in the setting of
chronic scapholunate ligament injury and
deformity of lunate, capitate and scaphoid
may become static.
• Scapholunate advanced collapse (SLAC)

11. SLAC

12. History
• H/o specific injury to the wrist.
• Position of wrist.
• Pain, swelling and instability; progressing to
inability to use the hand.
• Carpal Tunnel Syndrome.
• Subacute or chronic injuries may present with
pain and decreased grip.

13. Examination
• Localise point tenderness.
• Pain elicited by radial or ulnar deviation of
wrist.
• Tenderness over the lunotriquetral ligament
or scapholunate ligament.
• Pain with subjective or palpable clicking or
popping feel.

15. Watson Shift Test

16. • Pain, apprehension and subluxation of
scaphoid.
• Movement of the wrist- smooth or with
crepitus.
• Positive clunk on releasing pressure as
scpahoid relocates.
• Examine opposite side for laxity which can
give false positive results.

17. Scaphoid Ballotment Test

18. Lunotriquetral ligament injury
• Ulnar sided wrist pain.
• Reagan test- Lunotriquetral ballottement.
• Kleinman shear test( Lunotriquetral Shuck
test)

19. X rays
• PA, Lateral and Oblique
• Evaluate static
instability patterns,
fractures, or
dislocations.
• PA films in radial/ ulnar
deviation.
• Clenched fist/Pencil
view.
• Flexion and extension
laterals
• Dynamic stability.
• Forearm in neutral
rotation.

20. Gilula lines

21. Terry Thomas sign

22. Signet ring sign
• Distal pole of scaphoid is
palmar flexed while the
lunate is extended
dorsally.
• Cortical border of distal
and proximal pole align in
PA view.
• Lunate triangular not
hexagonal

23. • Longitudnal axes of
third metacarpal,
lunate,capitate and
radius are collinear.

24. • Perilunate dislocations
show collinearity of
radius and lunate while
the capitate is dorsally
located.

25. • Scaphoid axis- line that
connects the proximal
and distal poles.
• Lunate axis- Line
connecting the
midpoint of the convex
proximal surface to the
concave distal articular
surface.

27. • Scapholunate angle more >60 deg – DISI
• < 30 deg- VISI
• Dissociative instability- disruption of intrinsic
interosseous ligaments.
• Nondissociative- Extrinsic radiocarpal ligaments
disrupted, intact intrinsic ligaments.

28. • 3-T MRI has sensitivity of 86% for detecting
scapholunate tears and 82% for detecting
lunotriquetral tears compared with
arthroscopy.
Magee T.Comparison of 3-T MRI and arthroscopy of intrinsic wrist ligament and TFCC tears.
AJR Am J Roentgenol 2009;192:80–5

29. • Injection of gadolinium into the midcarpal
joint should show the flow of dye into the
midportion of the scapholunate interval, but
not into the radiocarpal joint.
Tirman RM, Weber ER, Snyder LL, et al. Midcarpal wrist arthrography for detection of tears
of the scapholunate and lunotriquetral ligaments. AJR Am J Roentgenol 1985;144:107–8.

30. Wrist arthroscopy
• Gold standard for detecting Scapholunate and
lunotriquetral injury.
• Direct visualisation.
• Location and size of insult.
• Presence of arthritic changes within the joint
space.

31. Geisslers classification

32. Carpal Instability
• Carpal instability dissociative( CID)
– Dissociation between interosseous ligaments
• Carpal instability non dissociative(CIND)
– Instability of carpal row as a whole
• Carpal Instability Complex (CIC)
– Combination of above two injuries
• Carpal Injury Adaptive (CIA)
– Secondary changes in carpus resulting from non
union or malunion or the carpal bones

33. Treatment concepts
• Acute injuries- Closed or arthroscopically
controlled manipulation and percutaneous
pinning; Open reconstruction/repair.
• Instability w/o arthrosis- ligament
reconstruction, capsular imbrication and
limited intercarpal arthrodesis.

34. • Dorsal capsulodesis to limit scaphoid flexion.
• Fixed deformity, arthrosis, pain or interference
with function- excisional arthroplasty, limited
intercarpal arthrodesis and wrist fusion.

35. Ligament repair

36. Ligament Reconstruction
• Free tendon grafts or tenodesis using
prolonged slips of wrist flexors or extensors.
• Linscheid and Dobyns suggested that
procedure be limited to patients whose
ligament ruptures cannot be maintained with
closed reduction, patients diagnosed after 1
month.

37. • Not indicated in patients with degenerative
joint disease.
• Complications-
– Tendons may stretch and become lax
– Bone tunnels may lead to fracture and vascular
changes.
– Tightness required to maintain bony apposition
may eventually limit wrist motion.

38. Palmer, Dobyns and Linscheid

41. Almquist repair- 4 bone ligamentous
repair

42. Taleisnik and Linscheid

43. Brunelli and Brunelli

44. Talesnik
VISI (FCU) DISI (ECRB)

45. Capsulodesis (Blatt)
• Useful for scapholunate
dissociation and caput
ulnae syndrome (DRUJ
incongruity)
• Ability to anatomically
reduce the scaphoid.

46. Limited Wrist (Triscaphe) Arthrodesis
• Pain relief with functional arc of motion.
• Indications
– Degn arthritis of STT joint with normal thumb CMC
joint
– Radial hand dislocations
– Rotary subluxation of scaphoid
– Scapholunate diastasis of > 2mm
– Scaphoid angle of >60 deg on true lateral.
– Foreshotening of scaphoid in AP view.

47. STT fusion (Watson)

48. • Scaphocapitate arthrodesis
• Scaphocapitolunate arthrodesis
• Lunotriquetral arthrodesis.