Hand / Fingers
Jersey Finger (FDP Avulsion)
저지 핑거 (FDP 건 파열)
Avulsion of flexor digitorum profundus (FDP) from the distal phalanx
- How common
- Common in contact sports
- Typical age
- Young/adult athletes
What is it?
Forced extension against flexed finger avulses FDP from volar base of distal phalanx — with or without bony fragment.
Commonly affected: Ring finger most common (~75%)
How it develops
- Forced ExtensionForced extension during active flexion
- FDP AvulsionFDP avulses from volar base of distal phalanx
- Tendon RetractionFDP retracts — sometimes to palm
- Loss of Active DIP FlexionComplete loss of active DIP flexion
Symptoms
- No active DIP flexionCannot actively flex DIP — diagnostic
- Pain at finger baseTenderness at retracted tendon site
- Volar swelling/bruisingVolar DIP swelling
- Palpable massRetracted tendon palpable in palm or near PIP
- Passive flexion preservedPassive DIP flexion intact
How it is examined
- Isolated DIP flexion testWith PIP held, active DIP flexion absent
- Palpate retracted tendonPalpable mass in palm or proximal finger
- Leddy-Packer classificationType I–III by retraction level and bony fragment
- Vascular assessmentVinculum injury affects surgical timing
Imaging
Lateral X-ray essential — avulsion fragment at volar base of distal phalanx.
- Volar avulsion fragment at base of distal phalanx
- Fragment location indicates retraction
- Assess alignment
- Rule out DIP dislocation
MRI/US helpful for tendon retraction level and vascular assessment.
- FDP tendon discontinuity
- Retraction level (palm, PIP, A4 pulley)
- Vinculum injury assessment
- Hematoma/edema
Non-surgical care
- Urgent referral (surgery is standard)Surgery usually indicated; conservative rare
- Splinting (pre-op)Temporary splint prior to surgery
- Ice/elevation/NSAIDsSwelling/pain control
- Post-op rehabTendon gliding protocol (Duran or Kleinert)
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Nearly all acute FDP avulsions; Type I needs surgery within 7–10 days
Procedures that may be discussed
- Tendon reinsertion (suture anchor or pull-out suture)
- Bony fragment fixation
- Tendon graft (chronic >3 mo)
- DIP arthrodesis (salvage)
Outlook
Early surgery (<10 days) yields good outcomes; delays result in retraction/necrosis and poorer function.