Wrist and Forearm Injuries

1. Wrist and Forearm Injuries Rebecca Burton-MacLeod R2, Emergency Medicine July 29, 2004

2. Anatomy of the wrist

3. Anatomy of the wrist Thanks Trevor…

4. Anatomy of the forearm • Volar compartment: • Flexors • pronators • Dorsal compartment: • Extensor muscles

5. History Mechanism Point of maximal pain Physical Inspection Palpation (Lister’s tubercle, snuffbox, ulnar styloid) ROM Neurovascular (document presence of radial/ulnar/brachial pulses and radial/median/ulnar nerves) History and physical

6. Case • 19y.o. male presents to ED after partying all night. Fell down stairs, can’t quite remember how he landed. But c/o pain “in the wrist”. O/E right wrist is swollen and diffusely tender over dorsum distal radius and lunate. Otherwise normal exam. • You decide to order xrays and xray tech wants to know what views you want?

7. Xrays • 3 main views: • PA • Lateral • Oblique

8. Case cont’d • You get your xrays back, what is your approach to reading this film? • Radial length measurement 9-12mm • Ulnar slant of distal radius 15-25 degrees • Approx 2mm between each of carpal bones • 3 smooth curves along carpal articular surfaces

9. Carpal bone arcs

10. Case cont’d • How do you approach reading a lateral film? • Volar tilt of radius 10-25 degrees • 3 concentric cups of radius, lunate, capitate • Normal straight alignment <10 degrees • Scapholunate angle 30-60 degrees • Capitolunate angle 0-30 degrees • Soft tissue displacement

11. Case • 27y.o. M was hit with hockey stick across right arm and has swollen mid forearm. Tender over entire length of ulna. • What views do you want? • AP and lat • Anything else you want to make sure is included in xrays? • Joint above and below #

12. Case cont’d • How would you determine if proximal radius is appropriately aligned? • Line through prox radial shaft and head should intersect capitellum

13. Carpal injuries

14. Scaphoid # • Makes up 60% of carpal bone # • MoI: FOOSH • # through waist of scaphoid most common • Risks of AVN due to distal source of blood supply (3%) • 17% of pts have associated # in wrist/forearm

15. Scaphoid complications

16. Scaphoid complications • Nonunion, arthritis, AVN, collapse of pole, settling of capitate into proximal row • Post-surgical proximal carpectomy

17. Case • 27y.o. M presents to ED after falling off mountain bike. Swelling and pain in left wrist. On exam, how would you identify scaphoid #? • Tenderness over snuffbox, tenderness over scaphoid tubercle, pain with axial compression of MC jt, pain with resisted supination

18. Case cont’d • Anything noticeable on xray?

19. Case cont’d • What if xray were completely normal, but worrisome exam? • 15% of scaphoid # do not show up on xray • If clinically suspicious then cast immobilization and rpt xray in 10-14 days • If rpt xray still negative but suspicious exam, then CT may show #

20. Scaphoid # • What type of cast: • Acute nondisplaced stable scaphoid #? • Below elbow thumb spica cast x 12 wks • Delayed nondisplaced stable scaphoid #? • Long arm thumb spica cast x 6 wks, then short arm thumb spica cast for remainder (time to union is 3 mos faster)

21. Case • 42y.o. F sustained FOOSH to right hand. O/E tender over dorsal aspect of wrist distal to ulnar styloid, decreased wrist ROM. • What xrays do you want to order?

22. Case cont’d • Interpretation of xray? • Small dorsal chip fragment • Triquetral #

23. Case cont’d • Management of triquetral #? • Immobilize in short arm cast x 4-6 wks • Similar treatment recommended for pisiform #, trapezium #, capitate #, trapezoid #

24. Case • Xray interpretation? • Trapezium #

25. Case • What type of xray is this? • Carpal tunnel view • What bones are fractured? • Trapezium and hamate

26. Hamate # • Hook of hamate is most common site of # • Treatment is immobilization in short arm cast, with ortho f/u in 1-2wks • Complications: • Ulnar nerve injury • nonunion • May require surgical excision of hook

27. Case • 35y.o. M who is right-handed and presents with remote hx of being hit in dorsiflexed right hand with jack hammer while at work 2 yrs ago. Since c/o gradually worsening tender wrist. No other recent trauma • You do xrays and see…

28. Case cont’d • Interpretation? • Sclerotic lunate fragment • What is the name of this condition? • Kienbock’s disease • AVN of lunate following traumatic # • Treatment--ortho

29. Lunate # • Because of risk of Kienbock’s disease, all suspected lunate # should be immobilized in short arm cast • Should receive ortho f/u in 1-2wks

30. Carpal # general rules • All displaced carpal bone #, carpal dislocation, or # involving carpal-metacarpal jt should be referred to ortho for ORIF

31. Carpal instability • Stage 1—scapholunate failure • Stage 2—capitolunate failure • Stage 3—triquetrolunate failure • Stage 4—lunate dislocation

32. Carpal instability • Stage 1: • Fall on extended wrist is usual cause • Frequently c/o pain in wrist with activity followed by aching • Scaphoid test and catch-up clunk • 4 fingers on dorsum or radius and thumb over scaphoid tuberosity, move hand from ulnar deviation to radial deviation and apply pressure with thumb—pain as scaphoid is moved dorsally if unstable • Move wrist from radial to ulnar deviation and will hear clunk as lunate catches up with alignment of scaphoid

33. Carpal instability • Stage 1: • Terry Thomas sign (2mm between scaphoid and lunate) • Gap increases with clenched fist AP view • Signet ring sign

34. Carpal instability • Stage 2: • Fall on extended wrist

35. Carpal instability • Stage 2: • Best seen on lat view • Capitate is dorsally dislocated • Lunate in normal position

36. Stage 3: Axial loading on hyperextended pronated wrist Pain and laxity on ulnar side of wrist Xray show triquetrum displaced proximally on AP view; may be exaggerated with ulnar deviation Carpal instability

37. Carpal instability • Stage 4: • Major complication is acute compression of median nerve • xray shows triangular lunate, and on lat view spilled teacup and dorsal displacement of capitate

38. Carpal instability • All carpal dislocation injuries need ortho referral for reduction/stabilization • Complications include median nerve palsy, chronic carpal instability, degenerative arthritis

39. Distal radius / ulna injuries

40. Quiz • What # is associated with “dinner fork” deformity? • Colles # • What is the other name for a “reverse Colles #”? • Smith’s # • Which type of # gives classical “chauffeurs #”? • Hutchinson #

41. Case • 56y.o. F fell onto dorsum of right wrist. Now painful, swollen wrist. What type of # is this? • Smith’s # • Volar displacement and angulation of metaphysis of distal radius

42. Case cont’d • What would your management be of this #? • Attempt closed reduction, if unsuccessful then ORIF necessary • Cast x 6-8 wks

43. Colles’ # • Most common wrist # in adults • Dorsal displacement and angulation of distal radial metaphysis • Often associated # of ulnar styloid

44. Colles’ # • Management: • Prompt closed reduction • If marked dorsal comminution, intraarticular extension of #, displacement >20 degrees dorsal angulation, then require ortho f/u • If open #, neurovasc compromise, or failed attempt at reduction then immediate ortho referral

45. Xray criteria: Radiulnar length Radial inclination Radial tilt Articular incongruity Measurements: <5mm radial shortening >= 15 degrees 15 degree dorsal tilt and 30 degree volar <= 2mm at radiocarpal joint Acceptable measurements for healing of distal radius #

46. Case • 33y.o. M construction worker was tightening a crank pulley when he lost grip and crank hit him in back of right wrist. • Xray interpretation? • Transverse # of radial metaphysis with extension into radiocarpal joint • Type of #? • Hutchinson #

47. Case cont’d • Management of nondisplaced #? • Short arm cast x 4-6 wks • Management of displaced #? • ORIF

48. Barton’s # • Oblique intraarticular # of rim of distal radius with displacement of carpal and # fragment • Usually volar subluxation • “volar Barton’s #” • Use lat xray for determination of degree of articular surface involvement and displacement • Require ortho ORIF

49. DRUJ • Dislocation of radioulnar joint • Often associated with distal radius or Galeazzi’s # • Clinical high suspicion for diagnosis • May either be dorsal or volar dislocation of ulna • Disruption of triangular fibrocartilage complex, avulsion # of ulna styloid common

50. DRUJ • With dorsal dislocation: • Prominent ulnar styloid • Pain and limitation with supination • With volar dislocation: • Loss of normal ulnar styloid prominence • Pain and limitation with pronation