Jersey Finger
Summary
Jersey Finger is a closed avulsion of the Flexor Digitorum Profundus (FDP) tendon from its insertion at the base of the distal phalanx. It represents the functional opposite of "Mallet Finger". It is a classic sports injury (Rugby, American Football, Judo) caused by forced extension of the DIPJ while the finger is actively flexing (i.e., grabbing an opponent's jersey). Surgical repair is mandatory for restoration of function. [1,2]
Clinical Pearls
The Ring Finger Rule: 75% of cases involve the Ring Finger. Why? > 1. It protrudes furthest in the gripping fist (along with the middle finger). > 2. It is bound by the lumbricals to the adjacent tendons involved, restricting independent extension. > 3. The FDP insertion is anatomically weaker here.
Quadriga Syndrome: A complication of overtightening the FDP during repair. Because the FDP tendons to the Middle, Ring, and Little fingers share a common muscle belly (unlike the Index), shortening one limits the excursion of all of them. The patient cannot make a full fist with ANY finger.
Testing Trap: You MUST hold the PIP joint perfectly straight to test the FDP. If the PIP bends even slightly, the FDP is slack, and intrinsic muscles can mimic weak DIP flexion.
Demographics
- Population: Young active males (Rugby/Football players).
- Incidence: Uncommon compared to Mallet/Boutonniere.
Anatomy
- FDP: The primary flexor of the Distal Interphalangeal Joint (DIPJ).
- Vincula: The delicate blood supply vessels (Short and Long Vincula).
- Mechanism: The FDP is maximally contracted. A sudden extension force overcomes the tendon's tensile strength at the weakest point (the insertion), snapping it.
Crucial for prognosis and urgency.
| Type | Description | Retraction Level | Blood Supply | Urgency |
|---|---|---|---|---|
| Type I | Tendon retracts all the way to Palm. | Metacarpal Neck | Severed (Vincula ruptured) | Urgent (less than 1 week) |
| Type II | Tendon retracts to PIPJ. | A3 Pulley | Intact (Long vincula holds it) | Prompt (less than 2 weeks) |
| Type III | Large Bony fragment avulsed. | A4 Pulley (DIPJ) | Intact | Prompt |
| Type IV | Type III + Avulsion of tendon from the bone fragment. | Variable | Variable | Rare |
History
Signs
Imaging
- X-Ray:
- Often normal (soft tissue injury).
- Look for loose bony fragment (Type III/IV).
- Look for avulsion fracture at the base of distal phalanx.
- Ultrasound / MRI:
- Can define the level of retraction (Palm vs PIPJ) to plan the surgical incision.
Management Algorithm
JERSEY FINGER DIAGNOSED
(No DIPJ flexion, Ring Finger)
↓
X-RAY (Exclude fracture/Type III)
↓
ASSESS LEVEL OF TENDON STUMP
(Ultrasound or Palpation tenderness)
┌─────────┴─────────┐
PALM TENDERNESS PIPJ TENDERNESS
(Type I) (Type II/III)
↓ ↓
URGENT SURGERY PROMPT SURGERY
(less than 7 days) (less than 10-14 days)
(Risk of necrosis) (Blood supply OK)
↓ ↓
SURGICAL REPAIR
- Retrieve tendon (suction catheter trick)
- Thread through pulleys (A2/A4)
- Reattach to bone (Mitek Anchor / Button)
↓
REHABILITATION (3 months)
- Dorsal blocking splint
- Early Active Motion (Duran Protocol)
Surgical Techniques
- Button Repair: Tendon sutures passed through bone and tied over a button on the fingernail. (Historical but secure).
- Suture Anchor: Bone anchor drilled into distal phalanx. (Modern standard).
- Pull-out Suture: Barb wire technique.
Conservative?
- Only for patients who refuse surgery or are high risk. Result is a stiff DIPJ with no flexion. Grip strength is reduced but functional.
- Stiffness: Flexion contracture of PIPJ is common.
- Tendon Rupture: 5-10% post-op failure rate.
- Infection: Especially with button repairs.
- Quadriga Effect: See Clinical Pearls.
- Type I: Poor prognosis if delayed >10 days. Tendon becomes necrotic and scarred. Requires 2-stage grafting.
- Type III: Excellent prognosis (bone-to-bone healing is reliable).
Key Guidelines
| Guideline | Organisation | Key Recommendations |
|---|---|---|
| Tendon Injuries | BSSH | Audit standards for flexor tendon repair success. |
Landmark Evidence
1. Leddy & Packer (1977)
- The definitive classification paper. Established the link between level of retraction, disruption of vincula, and ischemic necrosis urgency.
What is Jersey Finger?
You have snapped the main tendon that bends the fingertip. It is called Jersey Finger because it happens when grabbing a shirt; the finger gets pulled straight while you are trying to bend it, ripping the tendon off the bone.
Where has the tendon gone?
Imagine letting go of a stretched elastic band. The tendon has snapped at the fingertip and shot back down your finger. In your case (Type I), it has recoiled all the way into your palm.
Do I need an operation?
Yes. The tendon cannot heal itself because the ends are inches apart. Without surgery, you will never be able to bend the fingertip again. Because the blood supply to the tendon is damaged, we need to operate within a week, or the tendon will die and become unfixable.
Recovery
It takes 3 months. You will be in a splint for 6 weeks to stop you straightening the finger and snapping the repair. Hand therapy is intense.
Primary Sources
- Leddy JP, Packer JW. Avulsion of the profundus tendon insertion in athletes. J Hand Surg Am. 1977.
- Tang JB. Flexor tendon injuries. Clin Plast Surg. 2019.
Common Exam Questions
- Anatomy: "Finger most commonly affected?"
- Answer: Ring finger (75%).
- Pathology: "Type I vs Type II difference?"
- Answer: Type I retracts to palm (vincula torn). Type II retracts to PIPJ (vincula intact).
- Clinical Sign: "How to test FDP?"
- Answer: Hold PIPJ fixed in extension. Ask to flex DIPJ.
- Complication: "Inability to flex other fingers after repair?"
- Answer: Quadriga Effect.
Viva Points
- The "Suction" Trick: In surgery, if the tendon is lost in the palm, how to get it back up the sheath? Pass a pediatric feeding tube down the sheath, suction the tendon tip, and pull it up.
- Vincula System: Understanding the Long and Short Vincula is the key to understanding why Type I is an emergency (ischaemia) and Type II is not.
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.