Extensor Tendon Injuries: ED Management and Follow-up

1. Extensor Tendon Injuries:ED Management and Follow-up Jon Friesen, CCFP-EM Resident Guest Consultant: Dr. Earl Campbell May 16, 2002

2. outline • why extensor tendon injuries? • anatomy • injury zones • basic principles…what’s the evidence? • extensor tendon zone i-vi injuries: • ED management, splinting, and follow-up • hand OT/PT resources in Calgary

3. why extensor tendon injuries? • acute injuries we see and initially manage • initial rx NB to hand functional outcome • poorly described in EM texts and literature • hit and miss in clinical education/practice • do we really know what we’re doing?

4. how good are we? • one study (!!) that examines follow-up of extensor tendons done by EM docs • Evans JD; 1995 • EM housestaff in UK repaired 65 extensor tendon lacs • follow-up within 6 mos. re: functional outcome • results (as per Miller system): 80% good to excellent results in proximal injuries vs. 18% good to excellent results in distal injuries • weaknesses: unconventional splinting of distal injuries, poor physio f/u, small numbers • conclusion: we don’t know how we’re doing!

5. why anatomy matters • complex anatomy • different from flexors • role of juncturae • role of paratenon • EDM, EIP • extrinsics vs. intrinsics

6. why anatomy matters • digits are v. complex! • clinical relevance • disruption of anatomy at one joint has consequences for function of adjacent joints • initial management very important to injury outcome

7. Verdan’s zones of injury • 8 zones of injury • each zone has: • particular injuries • variations in acute management • different splinting requirements • not all extensor tendon injuries are the same!!

8. what about suture material? • based on experience and expert opinion • absorbable vs. non-absorbable synthetics • non-absorbs most often used, but may cause knot irritation at site of repair • absorbs less prone to producing knot irritation, but ? strength • size: 4.0-5.0

9. suture techniques? • little data re: extensor tendon repairs • may be more important as dynamic splinting becomes “en vogue” in extensor injuries • Newport ML and CD Williams; 1992 • compared simple mattress, figure-of-eight, Kessler, and Bunnell suture techniques • Bunnell and Kessler stronger, but not much difference with regards to tendon shortening or decreased ROM • difficult to apply to all extensor tendon injuries!

10. suture techniques • Bunnel suture • advantages: • strong • disadvantages: • time constraints • technical skills • need good tendon cross-sectional area

11. suture techniques • Kessler suture • advantages: • strong • disadvantages: • time constraints • technical skills • need good tendon cross-sectional area

12. suture techniques • horizontal mattress suture • advantages: • easy to do, even on thinner tendons • disadvantages: • decreased strength

13. suture techniques? • practicality in the ED: • time constraints • limited opportunity to use new techniques • barbaric equipment for fine repairs in the ER • general guidelines: • zones i-v: figure-of-8, horizontal mattress • zone vi, thumb extensors: Kessler, Bunnel

14. incomplete lacerations • flexor tendon studies: • studies suggest that 0 repair and early mobilization produces comparable outcomes to conventional rx in Zone II injuries • applicable to extensor injuries? what zones? • recommendations based on expert opinion: • lacs<30-50%, wound closure and splint for shortened period w/early mobilization • lacs>30-50%, repair and treat as complete • all partial zone i-v injuries should be repaired? • variable amongst surgeons

15. shredded ends • important to consider in injuries where primary tendon repair is indicated • fine trimming acceptable • excursion of extensors < flexors • overzealous trimming results in: • undue wound tension post-suturing • flexion loss during rehabilitation • general rule: if gap not breachable, or undue tension on wound distorts anatomy, refer to plastics for repair/tendon grafting

16. what about antibiotics? • little evidence specific to simple tendon lacs • ACEP Guidelines: • abx indicated for both hand and tendon lacs • Stone JF, 1998 • retrospective review of 140 pts w/simple flexor lacs • timing to repair and abx not associated w/increased infx • can these results be extrapolated to extensor repair? • surgeon dependent • absolute indications: • bites, crush injuries, associated open fractures, joint capsule disruption

17. zone 1: mallet finger • common injury • closed vs. open in ed • goal of rx: • <10 degrees extension lag • good flexion • prevention of swanneck deformity

18. mallet finger: who to refer • closed: • tendon avulsion with bony fragment involving >30% of the articular surface • associated w/volar distal phalanx subluxation or # • associated w/transepiphyseal plate # in kids • swanneck deformity • active pts: refer for k-wire fixation • open: • abrasion w/tendon erosion • associated w/open #

19. closed mallet finger • classification: • type 1: distal extensor mechanism rupture, no fracture • type 2: tendon avulsion w/ small bony fragment of distal phalanx • type 3: tendon avulsion with bony fragment involving >30% of the articular surface • ed management: • dorsal/volar splint w/DIP extension; PIP free x 6w • important to emphasize NO DIP FLEXION • splint care: remove daily to avoid skin erosion

20. closed mallet finger • early vs. delayed presentation for closed injuries: • Garberman et al.; 1994 • small study of 40 pts with closed mallet finger, ½ with early (<2w), ½ w/delayed (>4w) • 0 change in outcomes with regards to extensor lag, rx of dorsal lip #s <30%, or splint type • conclusion: splinting equally effective in both • implication: we can manage both in the ed

21. open mallet finger • ed management: • tendon suture vs. skin closure and splint • if suturing: • use figure-of-8, keep in mind tendon is friable • suture tendon and skin in one bite • suture removal in 10-12d • splinting as for closed injuries

22. mallet finger: f/u & OT/PT • continuous splint x 6w • at 6w, begin guarded DIP flexion • flex DIP 10-20x q1h • 20-25 degrees for 1st week • if no lag after 1st week, 35 degrees and progress as limited by pain • if lag, reapply splint x 2w • night splinting x 2w

23. what about mallet thumb? • extremely rare due to thickness of EPL tendon • closed: • management identical to mallet finger for closed deformities • open: • clean lacs should be sutured as described for open mallet finger • follow-up and OT/PT as for mallet finger

24. zone 2: middle phalanx injuries • most injuries are either partial lacs/crush injuries • referral criteria similar to open mallet • suture technique: • lateral bands are very friable and difficult to suture • suture type: figure-of-8 • epl on thumb: use core-type suture • splinting and follow-up as for mallet finger • wound care and splinting x 7-10d for partial lacs <50%

25. zone 3: the PIP • worst prognosis of extensor tendon injuries • closed vs. open in ed • consider central slip and lateral bands • goal of rx: maximize flexion and extension, prevention of Boutonniere deformity

26. closed zone 3: clinical pearls • central slip rupture is not a simple dx! • have high degree of suspicion if: • pip extensor lag >15-20 degrees while MCP and wrist in full flexion • decreased strength to resistance or pain to pip extension • tenderness over pip and appropriate mechanism of injury • may present with acute Boutonniere deformity • need to assess laxity of lateral bands via passive PIP extension • assess PIP stability!

27. closed zone 3: who to refer • displaced avulsion # at base of middle phalanx • axial/lateral instability of PIP • ie. post-reduction of volar dislocation • irreducible volar dislocation • Boutonniere deformity not correctable by passive PIP extension • time to rx less important than joint laxity

28. closed zone 3 injuries • ed management: • continuous splint x 6w • volar splint with DIP and MCP free to move • when splint removed, PIP MUST BE HELD IN EXTENSION • splint care: remove daily to avoid skin erosion

29. closed zone 3 injuries • if associated volar dislocation: • reduce by applying traction w/MCP and PIP in full flexion • if this fails, try adding in wrist extension for extensor relaxation • reassess PIP stability

30. open zone 3: clinical pearls • anatomy is complex!! • high degree of suspicion for joint capsule penetration in lacs over PIP • look closely for lateral band lacs • lacs rarely involve entire dorsal apparatus • failure to repair may result in Boutonniere deformity

31. open zone 3: who to refer • distal central slip stump too short for tendon suturing • abrasion w/tendon erosion • associated w/open # • lateral band laceration?? • PIP joint capsule penetration??

32. open zone 3 injuries: ed rx • wound irrigation and exploration is NB • lacs require suturing • suture technique: figure-of-8 • suture type: 5.0 non-absorbable/absorbable • suture lateral bands as well

33. open zone 3 injuries • splinting as for closed injuries • if lateral bands lacerated, splint DIP for 4w • antibiotics • use if joint capsule penetration present

34. zone 3 injuries: f/u & OT/PT • much more complex than DIP, get hand physio involved at 6w • at 6w: exercises 10-20x q1h • active PIP extension w/MCP in flexion to encourage intrinsic extension • gentle active flexion (to pain) w/wrist and MCP extension • reapply splint between hand physio sessions • if extensor lag develops, decrease flexion and reapply splint

35. zone 3 injuries: f/u & OT/PT • at 8w • continue active flexion, gentle resistance applied • splint at night or d/c splint • at 10w • increase resistance exercises • progress to full grasp

36. zone 3 thumb injuries: the MCP • may involve EPB and/or EPL • closed: • rare injuries: refer to plastics for management • open: • thicker tendons; use Kessler suture for open lacs • repair both EPB and EPL • splint with CMC neutral, MCP 0 degrees, and IP 0 degrees • complex OT/PT: refer for follow-up

37. zone 4 injuries: proximal phalanx • tendon is very broad at this level • lacs tend to be partial • if 0 loss of extension, splint as for PIP x 3-4w and then begin active motion • suture complete lacs • may be able to use Kessler suture • treat as for PIP lacs, but mobilize at 3-4w b/c of higher degree of “scarring down” at this zone • f/u and OT/PT as for PIP injuries • thumb injuries: rx as for zone 3 thumb injuries

38. zone 5: the MCP • consider importance of dorsal hood and sagittal bands in addition to tendon • closed vs. open injuries • open injuries are considered “fight bite” until proven otherwise

39. closed zone 5 • injuries are rare and usually due to a crush mechanism over the MCP • classic: tendon dislocation and relocation with passive extension • suspect sagittal band/dorsal hood disruption when painful flexion at MCP occurs • who to refer: all injuries • ed management: • splint w/MCP in extension at place of tendon relocation • leave other MCPs free to move

40. open zone 5: who to refer • fight bite • sagittal band/dorsal hood involvement • may repair if comfortable with anatomy • associated open fractures • tendon abrasions

41. open zone 5: fight bite • early presentation: ie. non-infected • irrigation and exploration required • if any disruption of joint capsule/tendon, start abx and refer to plastics • if underlying structures OK, start abx and ensure close f/u in 24-48h • wound closure in 5-7d post-abx • abx prophylaxis: clavulin x 5d • splint: as for other zone 5 lacs

42. open zone 5: ed rx • irrigation and wound debridement • tendon is thick at this point • ends tend not to retract • suture material: 4.0 nonabsorbable • suture techniqure: Kessler suture vs. figure-of-8

43. open zone 5: ed rx • what about dorsal hood lacs? • need to be repaired to prevent central tendon subluxation • what about sagittal band lacs? • need to be repaired for same reason

44. open zone 5: splinting • tendon lac: • splint wrist in 40-45 degrees extension, MCPs 20 degrees flexion, and IPs in 0 degrees • time: 4-5w • isolated dorsal hood/sagittal band lac: • avoiding abduction/adduction exercises is key • buddy tape adjacent finger • begin flexion/extension in 3-5 days

45. open zone 5: f/u & OT/PT • static splinting x 4w • may take off IP splint to allow mobility periodically • hand physio NB!! • at 4w: • gentle active extension at MCP • alternating flexion of MCP and IPs • wrist extension and flexion to neutral • splint worn b/t sessions, IPs now free

46. open zone 5: f/u & OT/PT • at 5w: • claw postion to encourage extrinsic extension • intrinsic + to stretch collateral ligaments • alternate finger and wrist flexion • night splinting only, unless extensor lag persists • at 7w: • resisted exercises

47. open zone 5: thumb • what about thumb zone 5? • involves CMCJ, EPB and/or APL • also consider radial artery/nerve branch lacs • ed rx: • refer if APL avulsed off bone • repair as for zone 5 digit injuries • splint: • thumb in extension and moderate abduction • f/u and pt: • refer to hand physio

48. zone 6 injuries • better prognosis than injuries to distal counterparts • open injuries prevail • who to refer: • associated w/open #s, crush injuries • significant tendon retraction • infection

49. zone 6 injuries • ed rx: • tendon is well formed and thick • suturing as for zone 5 lacs • splinting: • as for zone 5 lacs • f/u & OT/PT • as for zone 5 lacs

50. hand resources: OT & PT • FHH hand clinic • (403) 670-1432 • ask to speak to a hand pt to book patient • Lindsay Park (2 hand pts) • (403) 221-8340 • must indicate you want a hand pt to reception and they will book for you