Jersey Finger is a flexor tendon injury caused by avulsion of the FDP (Flexor Digitorum Profundus) from its insertion at the base of the distal phalanx.
Diagnosis: Affected finger lies in slight extension at the DIP joint relative to others; radiographs may reveal a bony avulsion.
Treatment: Direct tendon repair or open reduction and internal fixation (ORIF) depending on presence and size of bony avulsion.
Epidemiology
Anatomic Location: Ring finger is involved in 75% of cases.
During grip, the ring fingertip is more prominent, exposing it to greater force.
Etiology
Pathophysiology: FDP muscle is in maximal contraction during forceful extension of the DIP.
Anatomy
Muscles: Flexor Digitorum Profundus (innervated by ulnar nerve and Anterior Interosseous Nerve).
Flexor Zones: Zone I extends from the insertion of FDS distally.
Classification (Leddy and Packer)
Type I: FDP tendon retracts to palm, disrupting vascular supply. Requires prompt surgical treatment (within 7-10 days).
Type II: FDP retracts to PIP joint level. Optimal repair within several weeks.
Type III: Large avulsion fracture limits retraction to DIP joint level. Repair within several weeks is optimal.
Type IV: Double avulsion with tendon usually retracting to palm. Fracture fixation followed by tendon reattachment.
Type V: Ruptured tendon with bony comminution (Va, extraarticular; Vb, intra-articular).
Presentation
Physical Exam:
Pain and tenderness over volar distal finger.
Finger lies in slight extension relative to others in resting position.
No active flexion of DIP.
Possible palpation of retracted tendon along flexor sheath.
Imaging
Radiographs: Used to identify avulsion fragment.
Treatment
Operative:
Direct tendon repair or reinsertion with dorsal button or suture anchor.
Acute injuries (< 3 weeks) require advancement of > 1 cm, risk DIP flexion contracture or quadrigia.
Postoperative rehab includes patient-assisted passive ROM (Duran) or dynamic splint-assisted passive ROM (Kleinert).
ORIF fracture fragment in Type III and IV injuries.
Two-stage flexor tendon grafting for chronic injuries (> 3 months) with full PROM of DIP joint.
DIP arthrodesis as a salvage procedure in chronic injury (> 3 months) with stiffness.
Complications
Quadrigia: Advancement of > 1 cm can risk DIP flexion contracture.