This document summarizes different types of extensor tendon injuries and their treatment. It discusses mallet finger injuries, describing 4 types and their respective treatments which may include splinting or surgical repair. It also covers Boutonniere deformity, its causes, and potential surgical treatments like Fowler tenotomy or Littler tendon graft. Finally, it outlines different injury zones 1-9, from the DIP joint to the muscle belly, and recommendations for treatment including splinting, suturing, or tendon repair depending on the specific zone and nature of the injury.

1. Extensor Tendon Injury
Dr Mujtuba Pervez Khan
Resident Plastic Surgery
DUHS/CHK

8. Zone 1 injury (mallet finger)
• Terminal extensor tendon
• Sudden resisted flexion, baseball
finger
• Proximal and dorsal migration of
lateral bands -> swan neck
deformity

9. Mallet finger type 1 (closed)
• 6 wks splint, 2 wks night splint, splint weaning and active flexion
• If extensor lag at 8 wks, resume splinting till resolves

10. Mallet finger type 2 (open)
• Running tendon repair / Tenodermal suture
• DIPJ axial or oblique K wire fixation for 6 weeks
• Splint for 4 weeks
• *irrigation of DIPJ

11. Mallet finger type 3 (loss of skin/tendon)
• Primary repair if possible
• DIPJ fixation in hyperextension
• Flap coverage
• Stage reconstruction

12. Mallet finger type 4 (#)
• K wire fixation in children
• In adults, operative and conservative
treatment
• 4C volar sublaxation (hyper extension
injury) -> operative

13. Chronic Mallet finger
• Several month after injury ,SND
• 1. Skin imbrication, K wire
fixation for 6 weeks
• 2. Fowler tenotomy
• 3. Spiral ORL reconstruction

14. Zone 2
• Injury to conjoined lateral bands and triangular ligaments
• One band is sufficient for DIPJ extension
• Running sutures and splint for 6 weeks
• Chronic injuries, treat like mallet finger, ORL recon

15. Zone 3
• Open or closed
• Later Boutonniere deformity, stretch at triangular
ligament
• Elson test for central slip
• Closed injury without # = splint/pin PIPJ
in extension for 6 weeks, additional
6 weeks splinting
• Closed injury with # = K wire/ screw fixation
• Open injury = primary repair/ bone anchors/ drill in
the bone, PIPJ pinning for 6 weeks, night splint 3
weeks

16. Boutonniere deformity
• DIPJ hyperextension, PIPJ flexion (central slip rupture)
• Volar migration of lateral bands
• Arthritis, burns, trauma, synovitis
Splint (PIPJ extension) for 2-3
months, if fail  Surgery
Joint fusion

17. Surgery; Boutonniere deformity
Fowler tenotomy

18. Surgery; Boutonniere deformity
Littlers tendon graft

19. Surgery; Boutonniere deformity
Curtis staged reconstruction
Stage 1 and 2 = Intrinsic release
and transverse retinacular
ligament is freed and transected if
necessary
Stage 3 = Fowler tenotomy if
extensor lag present
Stage 4 = Repair of central slip

20. Zone 4
• Lateral bands are shielded by convexity of prox phalanx
• Repair of tendon and splint PIPJ, DIPJ free for 6 weeks

21. Zone 5
• Fight bite
• Wound CS, broad spectrum ABX, Joint irrigation, primary repair
• Isolated sagittal band injuries, radial bands, mostly closed, due to resisted extension of the finger
• Mistaken for trigger finger due to snapping

22. Zone 6
• Juncturae tendons can hide the injury
• Core suture and epitendinous repair

23. Zone 7
• Treatment same as zone 6
• Ext retinaculum prevents bowstringing, excise portion for exposure
and prevents friction
• Preserve 50% of length
• EPL, repair over the retinculum

24. Zone 8
• Most distal belly of EIP, EPL, EPB, APL
• 4cm proximal to wrist are musculotendinous junction
• Tendon to tendon repair is stronger

25. Zone 9
• Muscle bellies,
• Repairs are weaker
• Figure of 8 repair
• Nerve injury

26. Physio
• Zone 1 and 2, static splinting 6
weeks, night splint 2 weeks
• Dynamic splinting and early motion
for zone 3-7
• Zone 8-9, static splinting 3-4 weeks
• Dynamic: Active flexion, passive
extension

27. Swan neck Deformity
• Tendon imbalance -> PIPJ hyperextension,
DIPJ and MCPJ flexion
• PIPJ
1. FDS rupture
2. PIPJ synovitis (attenuation of volar plate
or TRL)
• MCPJ
3. MCPJ synovitis (weak insertion of EDC,
force at PIPJ), weak volar plate 
sublaxation ->
4. Intrinsic tightness (RA -> myofibrosis)
• DIPJ = 5. Mallet finger (force shifts to PIPJ)
• Wrist = 6. Carpal collapse (lengthening of
flexors and extensors)
• Injuries can be overlapping

28. Swan neck Deformity
• TYPE 1. Full PIPJ flexibility – no intrinsic tightness
conservative, DIPJ fusion (if due to mallet finger), flexor
tenodesis (slip to A1), ORL reconstruction by ulnar lateral
band repair to distal phalanx)
• TYPE 2. PIPJ flexible – intrinsic tightness, MCPJ sublaxation –
MCPJ relocation, intrinsic release, relocation of MCPJ, distal
intrinsic release
• TYPE 3. Limited PIPJ mobility, joint surface normal
release of lateral bands (shift volar),
• TYPE 4. Stiff PIPJ, intra articular joint destruction
joint fusion/arthroplasty

30. thanks