Finger Deformity

 

Mallet Finger

  • Finger deformity caused by disruption of the terminal extensor tendon distal to DIP joint

  • may be bony or tendinous: Xrays are needed

  • Treatment

    • extension splinting of DIP joint for 6-8 weeks for 24 hours daily

      • for soft tissue injury or for non displaced bony avulsion

      • avoid hyper-extension

      • PIP joint must be FREE

    • Surgery

      • ORIF or percutaneous

        • Indications

          • volar subluxation of distal phalanx 

          • >50% of articular surface involved ( relative indication)

          • >2mm articular gap ( relative indication)

      • Surgical reconstruction for chronic cases ( if normal joint, but results not so good)

      • DIP arthrodesis ( if painful joint)

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Finger splint

Finger splint

Wire

Wire

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Tenodermodesis

Tenodermodesis

 
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Swan Neck Deformity

  • Characterized by

    • hyperextension of PIP

    • flexion of DIP

  • Caused by

    • Primary lesion: lax volar plate

    • Secondary lesion: imbalance of muscle forces on PIP (extension force > flexion force)

      • MCP joint volar subluxation (rheumatoid arthritis)

      • Mallet finger

      • FDS laceration

      • Intrinsic contracture (Seen in rheumatoid arthritis)

Treatment

  • Conservative : double ring splint (to prevent hyper extension of PIP)

  • Surgical: volar plate advancement and correct PIP joint muscles imbalances with either

    • Central slip tenotomy (Fowler) : most used

    • FDS tenodesis indicated with FDS rupture

    • Spiral oblique retinacular ligament reconstruction

Xray showing the deformity: PIP hyperextension and PID flexion

Xray showing the deformity: PIP hyperextension and PID flexion

Double ring splint

Double ring splint

Double ring splint

Double ring splint

 

Boutonniere Deformity

  • Deformity characterized by

    • PIP flexion

    • DIP extension

  • Caused by rupture of the central slip over PIP joint from (laceration, traumatic avulsion (jammed finger),

    capsular distension in rheumatoid arthritis

  • pathoanatomic sequence includes

    • rupture of central slip 

    • attenuation of triangular ligament and palmar migration of collateral bands and lateral bands

      • causes intrinsic muscles of the hand (lumbricals) to act as flexors at the PIP joint

      • lumbricals also extend the DIP joint without an opposing or balancing force

Associated conditions

  • rheumatoid arthritis

  • pseudo-boutonniere: refers to PIP joint flexion contracture in the absence of DIP extension

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Physical exam

  • Deformity

  • Elson test is the most reliable way to diagnose a central slip injury before the deformity is evident

 
 

Treatment

  • Nonoperative

    • splint PIP joint in full extension for 6 weeks

      • indications

        • acute closed injuries (< 4 weeks)

      • technique

        • encourage active DIP extension and flexion in splint to avoid contraction of oblique retinacular ligament

        • complete part-time splinting for an additional 4-6 weeks

  • Operative

    • primary central band repair

      • indications

        • acute displaced avulsion fx (proximal MP avulsion seen on x-ray)

        • open wound that needs exploration

    •  lateral band relocation vs. terminal tendon tenotomy vs. tendon reconstruction 

      • indications

        • in chronic injuries after FROM is obtained with therapy or surgical release

      • technique

        • terminal tendon tenotomy (modified Fowler or Dolphin tenotomy)(never central slip tenotomy)

        • secondary tendon reconstruction (tendon graft, Littler, Matev)

        • triangular ligament reconstruction

    • PIP arthrodesis

      • indications

        • rheumatoid patients

        • painful, stiff and arthritic PIP joint

 
 
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