Jersey Finger: Definition and Clinical Overview
Jersey finger is an avulsion injury of the flexor digitorum profundus (FDP) tendon from its insertion at the base of the distal phalanx, typically occurring when an athlete's finger is forcibly extended while actively flexing, such as when grabbing an opponent's jersey in contact sports like rugby or football 1.
Mechanism and Epidemiology
- The injury occurs most commonly in the ring finger due to its anatomical position and biomechanical vulnerability during gripping activities 2, 3
- Contact sports players, particularly rugby and football athletes, are at highest risk for this injury pattern 2, 4
- The forceful hyperextension of the distal interphalangeal joint while the FDP is actively contracting causes the tendon to avulsed from its bony insertion 5
Classification and Prognostic Implications
The Leddy and Packer classification system categorizes jersey finger based on the level of tendon retraction, which directly impacts surgical planning and outcomes 5:
- Type I: Tendon retracts into the palm with disruption of both vincula (blood supply compromised)
- Type II: Tendon retracts to the level of the proximal interphalangeal joint with intact long vinculum (better prognosis)
- Type III: Large bony fragment prevents retraction past the distal interphalangeal joint
- Type IV (Smith addition): Tendon separates from the avulsed bony fragment 5
- Type Vb: Associated with other injuries including pulley system damage 2
The level of tendon retraction and status of the vincula post-injury are critical determinants of repair outcomes 5.
Diagnostic Approach
Radiographs are always indicated as initial imaging to detect avulsion fractures or bony fragments 6. However, standard radiographs may be normal in purely tendinous avulsions 1.
Advanced Imaging
- MRI is ideal for evaluating tendon injuries and surgical planning, including assessment of the level of tendon retraction, quality of the tendon stump, and associated pulley injuries 1
- Ultrasound has emerged as a valuable, cost-effective imaging modality for diagnosis and preoperative planning, with proven utility in identifying the level of tendon retraction 2, 3
- Ultrasound can guide intraoperative assessment and postoperative rehabilitation 7
Treatment Principles
Jersey finger requires surgical treatment, and early presentation (within 10 days) is associated with superior functional outcomes 2, 3.
Surgical Management
Multiple repair techniques have been described with good outcomes when performed early 2:
- Intraosseous sutures for direct tendon-to-bone repair 2
- Suture anchor fixation for secure reattachment 2
- Pull-through suture over button technique for large bony fragments 2
- Tendon lengthening procedures for late presentations with myostatic contracture 2
- One-stage tendon grafting using palmaris longus for chronic cases 7
Wide-awake local anesthesia no tourniquet (WALANT) surgery offers optimal intraoperative assessment of tendon repair tension and gliding 3, 7.
Return to Play
- Most athletes require 8-12 weeks of inability to compete in contact sports following surgical repair 3
- Adequate patient compliance with postoperative rehabilitation is essential for satisfactory functional outcomes 2
Critical Clinical Pitfalls
- Late presentation (beyond 10 days) significantly compromises outcomes and may require more complex reconstructive procedures including tendon grafting or lengthening 2, 7
- Type I injuries with complete vincular disruption have compromised tendon vascularity and require urgent surgical intervention 5
- Unusual injury patterns with large extra-articular bony fragments may not fit standard classification systems but can be successfully managed with open reduction and internal fixation 5
- Misdiagnosis or delayed treatment can lead to permanent loss of distal interphalangeal joint flexion and grip strength impairment 4