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Flashcards in Extensor Tendon Injuries Deck (26)
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How do you test for 

  • ORL tightness
  • Intrinsic tightness
  • Extrinsic tightness

  • ORL tightness
    • extension of PIP leads to less DIP flexion
  • Intrinsic tightness
    • hyperextension of MCP leads to less PIP flexion
  • Extrinsic tightness
    • flexion of MCP leads to less PIP flexion


How do you test for central slip injury?

Elson's test

  • with PIP in max flexion, you normally cannot extend DIP jt because central slip holds extensor apparatus out to length and lateral bands to DIP are lax
  • IF central slip injury, can actively  extend DIP jt with PIP in maximum flexion


What are the extensor zones of the hand/forearm

  • 1- DIPJ
  • 2- MP
  • 3- PIPj
  • 4- PP
  • 5- MCPj
  • 6- MC
  • 7- CT
  • 8- tendinous extrinsics
  • 9- muscle forearm


  • T1-  IPj
  • T2 - PP
  • T3- MCPj
  • T4- MC
  • T5 - CMCj


What is the excursion of wrist extensors and digit extensors?

  • Wirst - 3cm
  • Digit - 5.5cm


Describe your extensor repair for each zone

  • Zone 1
    • dermatotenodesis, running monofilament 
    • splint 6wks, then 2wks nighttime
  • Zone 2 <50% lacerated
    • splint only 1wk then AROM
  • Zone 2 - >50% lacerated
    • running braided 4-0 + epitendinous 5-0
    • splint 6wks, then 2wks nighttime
    • THUMB - CORE + epitendinous (EPL)
  • Zone 3 - central slip
    • splint PIP full extension 6ks w DIP and MCP free, then 2wks nighttime
    • IF failed split, volar dislocation, >50% avulsion f# of MP base
    • Acute with large bone segment; OR ->dorsal approach, ORIF w kwire/tension band/miniscrew. If Acute and CS inadequate length, Snow of Aiche repair then splint 6wks. May add Kwire
    • THUMB: CORE + epitendinous EPL EPB, splint extended 3wks
  • Zone 4
    • centrally can do core/epitendinous. Splint W 30ext, MCP 45-70 flexion, IP straight. Passive extension 1wk, active extension 4wks
  • Zone 5
    • Ext apparatus - as above
    • Sagittal band
      • acute<2wks - flexion block splint to keep MCP at ) for 6wks
      • delayed >2wks - repair , MP extension 1wk then gentle flex/ext exercise
  • Zone 6- 7 - as above
  • Zone 8 - core repair/epitendinous, splint W ext 40, MCP 20, fingers FREE 5wks
  • Zoen 9 - muscle repair figure 8, splint above elbow at 90, W ext 40, MCP 20, fingers free 4wks


What is the sequence of extensor imbalance

  • swan neck
  • boutonniere
  •  extrinsic tightness
  • intrinsic tightness
  • extensor subluxation adn ulnar drift


What is the origin insertion and function of Sagittal bands

O: EDC tendon

I: Volar plae, intermetacarpal ligament

Fx: maintain EDC central over MCPj, assists in extension of MCP



What is the origin insertion and function of TRL

O: flexor sheath

I: Lateral band of lateral conjoined band

Fx: prevent dorsal subluxation of lateral bands



What is the origin insertion and function of trasnverse and oblique fibers

O: IO and lumbricals

I: extensor tendon over PP

Fx: assist in MCP flexion


What is the origin insertion and function of ORL

O: flexor sheath


F: coordinate fx b/w DIP and PIP


How do you classify mallet finger injury

Leddy Packer

  • 1- Closed, with loss of tendon continuity +/- avulsion F# (most common)
  • 2- Open laceration with loss of tnedon continuity
  • 3- deep abrasion with loss of tendon substance
  • 4A- transepiphyseal plate F#
  • 4B - Hyperextension injury involving 20-50% of articular surfcae
  • 4C - Hyperextension injury involving >50% of articular surfcae & early/late volar subluxation of PP


How do you treat mallet finger according to classification

Type 1 - closed

  • splint 6wks then 6wks at night
  • if failed, K-wire

Type 2- open

  • Dermatotenodesis
  • splint 6wks then 6wks at night

Type 3- substance loss

  • ST covreage +/- Kwire (FTSG, 2' intent, local flap)
  • splint 6wks then 6wks at night
  • may delay recon w graft

Type 4A-  transepiphyseal

  • CR
  • splint 6wks then nighttime 6wks

Type 4B - articular F# 20-50%

  • CR. Kwire extension block pinning if unstable
  • splint 6wks then 6wks at night

Type 4C - articular >50%/volar sublux DP

  • Kwire extension block pinning
    • flex DIP, insert pin into MP to wedge fragment
    • extend DP and place longitudinal pin across DP
  • Kwire in place 6wks


  • Attempt splint
  • Kwire w dermatotenodesis OR
  • Arthrodesis if OA
  • Fowler tenotomy - release central slip=>improved DP extension


How do you manage a fight bite

  • Xray - FB
  • I&D, 2' intention healing
  • Joint invovlement - washout, packing, IV abx


Describe rehabilitation protocols for extensor repairs

  • Immobilization
  • Controlled Early Passive (Dynamic Extension Splinting)
    • static splint 2wks then DES 4wks
  • Early Active


What are two methods of central slip injury repair when there is insufficent length/tissue for repair

Snow - distally based flap from extensor aponeurosis

Aiche - bilateral advancement flaps 


List 3 methods of secondary reconstruction of ruptured unrepaired sagittal bands (with ED slipping into ulnar gutter

  • Dorsal Tenodesis
    • release ulnar sagittal band
    • on adjacent radial EDC, create longitudinal distally absed flap and wrap around EDC of interest to keep centralized
  • Sling procedure
    • distally absed flap on injured EDC is used slung around intrinsics or dTMClig
  • Dynamic Lumbrical muscle transfer
    • transfer lumbrical to serve as a direct antagonist


What is a swan neck deformity and the acute and chronic changes which occur

Def: PIP Hyperextension, DIP hyperflexion


  • dorsal subluxation of lateral bands
  • attenuation of TRL
  • laxity of PIP Volar Plate


  • lateral bands contract
  • PIP DIPjoint contractures
  • extensor tendon adhesions
  • joint surface changes


What are causes of Swan neck Deformity


  • VP injury (dorsal dislocation, synovitis, RA)
  • Intrinsic tightness (intrinsic contracture post stroke/CP, RA)
  • FDS injury


  • chronic Mallet
  • shortened MP


How do you classify Swan neck deformity

Stage 1 - supple, no tightness/ full AROM/PROM

Stage 2 - Intrinsic tightness - less PIP flexion w MCP extension

Stage 3- LImited PIP PROM - capsule contraction, tendon adhesions

Stage 4 - fixed PIP hyperextension


What are treatment options for swan neck deformity


  • splint and exercise for contractures and intrinsic tightness


  1. Correct MP length
  2. Repair Mallet
  3. Limit PIP hyperextension
    1. VP capsulodesis/repair
    2. FDS tensodeis to PP bone (one slip only)
    3. Intrinsic rerouting (ulnar lateral band distally based flap rerouted palmar and into flexor sheath at PP
    4. SORL reconstruction - spiral ORL - tendon graft inserted into drill hole dorsal DP,  routed palmar to PIP and insert palmar into drill hole of PP

For ALL, Kwire at 30' flexion PIP and  dorsal block splint for DIP


What is boutonniere deformity and features of the deformity

Def: PIP flexion with DIp hyperextension

ALWAYS starts with PIPJ


  • central slip discontinuity
  • lateral bands sublux volarly and become PIP flexors


  • ORL tightness


How is the boutonniere deformity staged?

  • 1- central slip disrupted, lat bands dorsal to PIP axis
    • PIP extensor lag <30
  • 2- volar subluxation of lat bands
    • PIP extensor lag >30
  • 3- ORL contracture
    • limited flexion DIP w PIP flex.+ORL tightness
  • 4- Fixed flexion contracture PIP
    • contracture of VP, ORL, TRL, collaterals
  • 5- PIP arthritis


How is boutonniere deformity treated non-operatively?


MOST (acute AND chronic) treated non-op successfully

Step 1- restore passive PIP extension

- spliting, capsulotomy


Step 2- Rebalance extensor apparatus

- with PIP fully extended, AROM/PROM of DIP to relocate the lateral bands and ORL


Step 3 - maintain PIP extension

- static splint 8wks PIP only




How is boutonniere deformity treated operatively?


* requires tenolysis of contracted segemtns (ORL, TRL), repositioning of lat bands and reconstitution of CS


1- Fowler terminal tenotomy (or dolphin - just distal to CS to ensure ORL preserved)

- release TT to allow DIP flexion. Ext apparatus migrates proximally, allows strong flexors to work on DIP and ORL maintains concerted fx of PIP/DIP


2- Extensor apparatus recon (of CS) with tendon graft

- PL graft used- 2drill holes in MP, graft passd through, secured to contralateral lateral band

3- Littler lateral band transfer

- lateral bands (minus the lumbricals) are excised off conjoint bands and centralized to reconstruct CS (extension force transfered form DIP to PIP). ORL and lumbricals left intact and extend IPs


What is the cause of extrinsic tightness

  • Post-traumatic adhesions, muscle contractures
  • RA- flexion deformity of MCP/wrist
  • CP- muscle spasticity


What is the treatment for extrinsic tightness


  • splinting, exercise program


  • tenolysis, extrinsic extesor tendon release