UCL Injury
Tommy John Injury - Ulnar Collateral Ligament
Expert care for throwing athletes - from diagnosis to return to sport
Understanding UCL Injury
The ulnar collateral ligament (UCL) is the primary stabilizer against valgus stress at the elbow. During throwing, this ligament experiences near-failure loads with each pitch. Over time, repetitive microtrauma can lead to progressive attenuation and eventual failure.
Anatomy & Biomechanics
- • Anterior bundle: Primary stabilizer (taut 30-120° flexion)
- • Valgus torque during pitching: up to 64 Nm
- • UCL failure load: approximately 34 Nm
- • The gap is compensated by flexor muscles and bony stability
- • Late cocking and acceleration phases put maximum stress on UCL
Historical Note
The first UCL reconstruction was performed by Dr. Frank Jobe on pitcher Tommy John in 1974. John returned to pitch for 14 more seasons. Today, 25-30% of MLB pitchers have had the surgery.
Clinical Presentation
Symptoms
Clinical Tests
Valgus Stress Test
Apply valgus force at 30° flexion - pain and/or laxity positive
Moving Valgus Stress Test
Valgus force while moving elbow through arc - pain reproduced at late cocking position (highly specific)
Milking Maneuver
Pull thumb with shoulder extended, elbow flexed - medial pain indicates UCL injury
Imaging
MRI Arthrogram
Gold standard - contrast improves sensitivity for partial tears. T-sign indicates full-thickness tear.
Stress Radiographs
Valgus stress X-rays - >3mm opening compared to opposite side is significant
Treatment Options
~50% return to play rate for non-throwers
- • Rest from throwing (3-6 months)
- • Anti-inflammatory medications
- • Physical therapy - flexor-pronator strengthening
- • PRP injections (emerging evidence)
- • Gradual return to throwing program
Best for: Non-throwers, recreational athletes, partial tears, patients who don't require high-level throwing
80-90% return to same level of play in MLB pitchers
Graft Choices
- • Palmaris longus (autograft): Most common, present in ~85% of population
- • Gracilis (autograft): Alternative when palmaris absent
- • Hamstring allograft: Option for revision surgery
Surgical Techniques
- • Docking Technique: Most popular - two humeral tunnels, single ulnar tunnel
- • DANE TJ: Direct attachment with interference screws
- • Figure-of-8: Original Jobe technique, rarely used now
Ulnar Nerve Management
Subcutaneous transposition in ~40% of cases if symptomatic or subluxating
Emerging technique for select patients:
- • Primary repair with internal brace augmentation
- • Best for acute, proximal avulsions in competitive throwers
- • Potentially faster return (6-9 months vs 12-18 months)
- • Patient selection critical
Return to Throwing Protocol
Evidence & References
• Jobe FW, et al. Reconstruction of the ulnar collateral ligament in athletes. JBJS Am 1986
• Cain EL, et al. Elbow injuries in throwing athletes: A current concepts review. Am J Sports Med 2003
• Rohrbough JT, et al. Medial collateral ligament reconstruction of the elbow using the docking technique. Am J Sports Med 2002
• Erickson BJ, et al. Performance and return to sport after Tommy John surgery in Major League Baseball pitchers. Sports Health 2014
Last Updated: January 2025 | Content reviewed by Dr. Deepthi Nandan Reddy, FRCS (Ortho)