LUNATE DISLOCATION.power pointvelammal med college

lunate

1. LUNATE DISLOCATION DR SIVA M

2. INCIDENCE 5–7 % of all wrist injuries high energy trauma most frequently involved is young male individuals, in the second or third decade of life

3. These injuries prone to being missed on initial presentation which can occur in up to 25% of cases

4. MISDIAGNOSIS Severity of associated injuries Inadequate radiographs Inexperienced doctors Underestimation because of spontaneous reduction

5. ANATOMY

6. INTINSIC LIGAMENTS

7. EXTRINSIC LIGAMENTS

8. BLOOD SUPPLY

9. MECHANISM OF INJURY Graham supported that carpal instability is best considered either as compressive transverse

10. since the derangement, is both within and between carpal rows, these injuries are considered as carpal instabilities complex (CIC), which is a combination of dissociative (CID) and non-dissociative (CIND) instabilities

11. Application of force at the thenar area produces a three-dimensional mechanism of injury: hyperextension, midcarpal supination, and ulnar deviation

12. Johnson , introduced the concept of greater and lesser arc injuries later in 1980

13. Johnson supported that most of the carpal fractures and dislocations, are confined to a ‘‘vulnerable zone

14. Most common are osseoligamentous injuries , with one or two bones fractured around the lunate, which only constitutes a partial greater arc injury

15. Graham 2003 described a pattern of injury in which the intercarpal region is spared and the lesion extends from radial to ulnar and through the radiocarpal joint

16. SEQUENCE OF INJURY

17. TYPES LUNATE dislocation PERILUNATE dislocation

18. TYPES OF PERILUNATE DISLOCATION transcaphoid-perilunate perilunate transradial -styloid transcaphoid -trans-capitate- perilunar

19. MAYFIELD CLASSIFICATION

20. STAGE 1

21. STAGE 2

22. STAGE 3

23. STAGE 4

24. LIMITATIONS It does not include Transscaphoid variants Ulnar-sided injuries Volar dislocations of the capitate

25. CLINICAL FINDINGS Acute pain Swelling Median nerve symptoms if there is dislocation into carpal tunnel

26. radiographs POSTERO ANTERIOR LATERAL

27. POSTEROANTERIOR BREAK IN GILULA LINES

28. PIECE OF PIE SIGN DUE TO PALMAR ROTATION OF CARPUS

29. LATERAL loss of colinearity of radius, lunate, and capitate SL angle >70 degrees spilled teacup sign 

30. CARPAL HEIGHT RATIO

31. TREATMENT Nonoperative closed reduction and casting all acute injuries < 8 weeks old decreased risk of median nerve damage decreased risk of cartilage damage

32. OPERATIVE E mergeny closed reduction/splinting followed by open reduction ligament repair Fixation & possible carpal tunnel release proximal row carpectomy total wrist arthrodesis

33. Open reduction 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

34. PROXIMAL ROW CARPECTOMY perform via 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

35. WRIST ARTHRODESIS

36. COMPLICATIONS TRANSIENT ISHEMIA OF LUNATE KIENBLOCKS DISEASE

37. visi  volar intercalated segment instability (VISI) which is caused by a combination of injury to the lunotriquetral ligament Dorsal-rotation Volar -extension dorsal radiotriquetral ligament volar radiolunate ligament

38. LT shuck test Kleinman's shear test Lunotriquetral compression test

39. disi dorsal intercalated segmental instability occurs most commonly with wrist positioned in extension, ulnar deviation and carpal supination scapholunate dissociation causes the scaphoid to flex palmar and the lunate to dorsiflex  

40. Scapholunate ligament dorsal component provides the greatest constraint to translation between the scaphoid and lunate bones proximal fibers have minimal mechanical strength