Pulley Rupture
A2/A4 Flexor Tendon Pulley
A pop in the finger during a hard pull, grip, or climbing move — followed by pain and visible bowstringing of the flexor tendon across the finger. Dr. R. David Graham at JOI manages all grades of pulley rupture conservatively first. Surgery is reserved for the uncommon case where bowstringing causes functional impairment that persists after 3 months of conservative management.
- A2 pulley is the most commonly ruptured — at the proximal phalanx
- Classic mechanism: climbing, heavy grip, sudden eccentric load
- Bowstringing = flexor tendon bow away from the phalanx with flexion
- Conservative first for ALL grades — taping, splinting, PT
- Surgery only if bowstringing causes functional impairment after 3 months
- MRI confirms pulley integrity and grade of injury
Pulley ruptures heal well conservatively in most cases. The A2 pulley sits at the proximal phalanx and is the critical fulcrum for efficient flexion — but even complete ruptures can be managed without surgery if bowstringing does not cause meaningful functional impairment.
Understanding Pulley Anatomy
The Pulleys That Keep Tendons
Against the Bone
The flexor tendon pulleys are fibrous rings that hold the flexor tendons against the phalanges, converting tendon excursion into efficient finger flexion. The A2 pulley at the proximal phalanx and the A4 pulley at the middle phalanx are the most mechanically important. When force on the tendon exceeds what the pulley can hold — typically during heavy grip, rock climbing, or a sudden loading event — the pulley tears, allowing the tendon to bowstring away from the bone.
Bowstringing is the clinical sign: during finger flexion, the flexor tendon is visible and palpable bowing away from the finger rather than following the phalangeal contour. It produces a characteristic snap or click with flexion and reduces the mechanical efficiency of finger flexion.
In Dr. Graham's approach, all grades of pulley rupture are managed conservatively first — regardless of whether the rupture is partial or complete, single or multiple. H-taping (circumferential taping around the proximal phalanx that mimics A2 pulley function), finger splinting during activity, and progressive PT address the vast majority of pulley ruptures without surgery. Surgery is considered only when bowstringing causes persistent functional impairment after 3 months of appropriate conservative management.
- I Pulley strain — no structural failure. Pain, no bowstringing.
- II A4 rupture OR partial A2 rupture — minimal bowstringing.
- III Complete A2 rupture — bowstringing present and measurable.
- IV Multiple pulley ruptures (A2 + A3, or A2 + A3 + A4) — significant bowstringing, possible lumbrical shift.
All grades: conservative first. Surgery only for Grade III–IV with persistent functional bowstringing after 3 months.
Treatment
Conservative First, Regardless of Grade
H-Taping
Circumferential tape applied around the proximal phalanx during activity mimics the A2 pulley's function — it holds the flexor tendon against the bone and reduces bowstringing. Used during climbing and gripping activities during healing and during the return-to-sport phase.
Progressive Loading
Formal PT with progressive grip loading under therapy supervision. Active finger flexion and extension maintained throughout healing. Return to climbing and grip sports is graded — typically beginning at 6–8 weeks with taped activities and advancing to full loading by 3–4 months.
MRI for Confirmation
MRI confirms pulley integrity, characterizes the grade of rupture, and evaluates for coexisting flexor tendon injury or synovitis. Performed when clinical exam is equivocal or when surgical planning is being considered.
When Surgery Is Needed
The minority of patients — those with persistent bowstringing producing functional impairment (loss of grip power, inability to make a closed fist, ongoing snap with flexion) after 3 months of conservative management — are candidates for surgical pulley reconstruction. The procedure involves recreating the ruptured pulley using a tendon graft (typically palmaris longus) looped around the phalanx. It is outpatient surgery, but recovery to full grip activity takes 3–4 months post-operatively. The decision is based on functional impairment, not on the grade of rupture alone — a complete A2 rupture that the patient has adapted to without meaningful impairment does not require surgery.
FAQs
Frequently Asked Questions
Related Conditions
Next Steps
Pop in the finger during a hard grip —
evaluated same day via JOI Now.
Acute pulley ruptures benefit from early evaluation and initiation of taping and PT. Walk-ins welcome via JOI Now, Monday–Friday for acute finger injuries.
Jacksonville Beach, FL 32250
Walk-ins welcome via JOI Now for acute finger injuries.