Lunate, wrist, injury

1. Perilunate Injuries
1
Prof. Bijayendra Singh
Consultant Trauma & Orthopaedic Surgeon
Medway NHS Foundation Trust
Visiting Professor, Canterbury Christ Church University

2. Declaration
• Nothing to Disclose

3. Perilunate dislocations and perilunate
fracture dislocations are potentially
devastating closed wrist injuries that
are often missed on initial imaging.
These injuries involve dislocation of
the carpus relative to the lunate which
remains in normal alignment with the
distal radius

4. Ligaments of Wrist
• Extrinsic ligaments :
• bridge carpal bones to the radius or
metacarpals
• include volar and dorsal ligaments
• Intrinsic ligaments:
• originate & insert on carpal bones

5. Extrinsic Ligaments
• Dorsal Ligaments

6. Ligaments of Wrist

7. Extrinsic Ligaments
• Dorsal Ligaments
• Volar:
• radiocarpal ligaments
• ulnocarpal ligaments

10. Intrinsic Ligaments
• Proximal Row
• Scapholunate Ligament
• 3 parts
• Dorsal - thickest & strongest, prevents translation
• Volar - prevents rotation
• Proximal - not much strength
• disruption causes lunate extension - i.e. DISI
• Luno-triquetral
• 3 parts
• Dorsal, Volar & Proximal
• disruption causes lunate flexion - i.e. VISI

11. • Distal Row
• trapezio-trapezoid
• trapeziocapitate
• capitohamate
• Palmar mid carpal
• mid carpal
• scaphotrapeziotrapezoid
• scaphocapitate
• triquetralcapitate
• triquetralhamate

12. Wrist Biomechanics
• Various concepts
• Link Concept
• Column Concept
• Rows Concept
• Taleisnik’s Concept
• Lichtman’s Ring Concept

13. Link Concept
• Three links in a chain composed
of radius, lunate and capitate
• head of capitate acts as centre of
rotation
• Advantage
• Efficient motion, strong volar
ligaments
• Disadvantage
• More links increases instability
• scaphoid more at risk
Gelberman et al - Carpal Instability J Bone Joint Surg Am, 2000 Apr; 82 (4): 578 -578

14. Column Concept
• Lateral (Mobile) Column
• Scaphoid, Trapezoid & Trapezium
• Central (Flexion-Extension) Column
• Lunate, Capitate & Hamate
• Luno-capitate articulation is centre of motion
• Medial (Rotation) Column
• Triquetrum & distal Carpal bones

15. Rows Concept
• Proximal & Distal Rows
• Scaphoid works as
Bridge

16. Taleisnik’s Concept
• Concept involves
distal row and the
lunate
• Scaphoid Lateral
• Triquetrum Medial

17. Lichtman’s Ring Concept
• Proximal & Distal Rows
- Semirigid Posts
• Movements at scapho-
trapezial & triquetrum -
hamate joint
• Break in ring causes
instability
Lichtman DM, et. Al: Ulnar midcarpal instability – Clinical and laboratory analysis. JHS [A] 5:515-523, 1981

18. Kinematics
• Radial Deviation:
• scaphoid flexes pulling lunate
• proximal row flexes
• Ulnar Deviation:
• scaphoid extends
• proximal row extends

19. Force Transmission
• Principal force transmitted from
capitate - lunate and proximal
scaphoid
• 75 - 80% radius & 20 - 25% ulna

20. • Carpal Instability Dissociative (CID)
• Dissociation within S-L & L-T
• Carpal Instability Non Dissociative (CIND)
• Between Carpal Row
• Carpal Instability Complex (CIC)
• Perilunate Dislocation
• Carpal Instability Adaptive (CIA)
• Instability not in carpus (malunited distal radius)

21. Typical Features
• High Energy Injury
• Often Missed in ED
• Needs prompt treatment

22. Assessment

23. Neurology

24. Radiology

27. Alignment

30. 10days later

31. Stages / Sequence
• I = Scapho-Lunate
• II = I + Capito-Lunate
• III = II + Luno-Triquetral
• IV = III + Dorsal Radio-Carpal
Mayfield JK et al: Carpal Dislocations: Pathomechanics and Progressive Perilunar Instability, JHS(A), 1980, 226-41

32. • Perilunate Dislocation
• Peri-Lunate
• Transcaphoid
• Transradial - styloid
• Transcaphoid-trans-capitate perilunar
• Lunate Dislocation

33. • Lesser Arc Injury
• Greater Arc Injury

36. Management
• Emergent Treatment
• Planned Early Repair
• Rehabilitation

37. Close Reduction
✴Reduction of the displaced lunate is achieved
by distracting the wrist and applying direct
thumb pressure over the lunate from palmar to
dorsal.
✴The hand is then gently flexed, and once
reduction has occurred, the distraction is gently
relaxed.
✴After emergency reduction, the wrist is
immobilized in a back slab

38. Open Repair

39. • Dorsal Approach

40. Release Extensor Retinaculum

41. Capsulotomy

42. Reduction Joy Stick

43. • K wires into scaphoid & lunate - joy stick
• Reduce the S-L joint
• Anchors
• K wires - to stabilise the repair
• Immobilize for 6 - 8 weeks

53. Chronic Injury
• Reconstruction
• Capsulodesis

54. SLAC
• Stage 1 - Radio-Scaphoid
• Stage 2 - Involvement Scaphoid Facet
• Stage 3 - Involvement of Capitate &
Lunate

55. 57
Questions?