For a young or middle‑aged patient with a chronic or sub‑acute left thumb ulnar collateral ligament (UCL) tear and no significant comorbidities, what is the recommended surgical technique using a palmaris longus allograft and an Arthrex internal‑brace (suture‑tape) system, including peri‑operative antibiotic prophylaxis, postoperative immobilization, and rehabilitation protocol?

Thumb UCL Reconstruction with Palmaris Allograft and Internal Brace

For chronic or subacute thumb UCL tears requiring reconstruction, use a palmaris longus allograft with suture tape augmentation (Arthrex internal brace) secured via dual 3.5-mm SwiveLock anchors, positioning the MCP joint at 30° flexion during fixation to optimize tension and allow accelerated rehabilitation with return to activities in 5-6 weeks.

Surgical Technique

Graft Selection and Preparation

While the ACL literature strongly favors autograft over allograft in young/active patients 1, thumb UCL reconstruction differs fundamentally—the provided evidence specifically describes successful palmaris longus allograft techniques for chronic thumb UCL injuries 2. The allograft approach is reasonable here given the smaller biomechanical demands compared to knee ligaments and the chronic nature of the injury where native tissue quality is poor 3.

Internal Brace Augmentation

The internal brace technique provides superior biomechanical strength compared to repair alone, with significantly higher maximum load, improved load at clinical failure, and better resistance to gap formation under cyclic loading 4. This enhanced construct stability is the key advantage enabling earlier mobilization.

Anchor placement and tensioning:

• Use dual 3.5-mm SwiveLock anchors spanning the MCP joint
• Position the MCP joint at 30° of flexion during repair to achieve optimal tension 4
• Secure the palmaris allograft first, then apply the FiberTape internal brace
• The suture tape should parallel the native UCL anatomy to preserve proprioception while providing additional stability during early healing 4

Technical Considerations

For chronic injuries (>3 months), direct repair is rarely feasible due to poor tissue quality and retraction 3. Anatomic reconstruction is the predominant and most consistently successful strategy 3. The internal brace augmentation addresses the fundamental problem: chronic UCL tears have compromised tissue that requires mechanical support during the 12+ week healing phase.

Perioperative Antibiotic Prophylaxis

Standard surgical prophylaxis with a first-generation cephalosporin (cefazolin 1-2g IV) within 60 minutes of incision is appropriate. No evidence supports extended postoperative antibiotics for clean elective hand surgery without gross contamination.

Postoperative Immobilization

Immobilize the thumb in a thumb spica splint or cast for 4-6 weeks 3. Some surgeons add temporary MCP joint K-wire fixation for approximately 6 weeks to protect the reconstruction, though this is not universally required with internal brace augmentation 3.

The internal brace construct allows for accelerated rehabilitation compared to traditional reconstruction, with potential return to sport and work activities in 5-6 weeks rather than the typical 12+ weeks 4. However, this timeline assumes adequate healing and should be individualized based on tissue quality and patient demands.

Rehabilitation Protocol

Drawing from ACL rehabilitation principles that apply to ligament reconstruction generally 5, 6, 5:

Weeks 0-4:

• Thumb spica immobilization
• Cryotherapy may be used in the first postoperative week to reduce pain and swelling 5
• Maintain motion in uninvolved digits

Weeks 4-6:

• Begin gentle active range of motion as tolerated
• Avoid resistance or pinch activities
• Progress to functional support (removable splint) rather than rigid immobilization 7

Weeks 6-8:

• Initiate progressive strengthening exercises
• Both open and closed kinetic chain exercises (grip strengthening, pinch activities) 5
• Neuromuscular training for proprioception 6, 5

Weeks 8-12:

• Advance to sport-specific or work-specific activities
• Functional testing to assess stability and strength

Return to unrestricted activities: With internal brace augmentation, return at 5-6 weeks is possible for many patients 4, though traditional reconstruction timelines extend to 12+ weeks. The enhanced construct strength is the differentiating factor.

Expected Outcomes

Reconstruction for chronic UCL injuries yields 81% stability rates and 84% return to unrestricted activities 8, which is notably lower than acute repairs (95% stability, 93-96% unrestricted return) 8. This difference reflects the inherent challenges of chronic injuries with poor tissue quality rather than technical failure.

Internal brace augmentation specifically improves these outcomes by providing mechanical support during the critical healing phase, potentially narrowing the gap between chronic reconstruction and acute repair results 4.

Key Pitfalls to Avoid

• Incorrect joint positioning during tensioning: The 30° flexion position is critical—excessive extension or flexion will create abnormal joint mechanics 4
• Inadequate graft fixation: Ensure secure anchor placement in healthy bone; chronic injuries may have associated bone quality issues
• Premature loading: Despite enhanced construct strength, respect the 4-6 week immobilization period to allow biological healing
• Ignoring associated injuries: Chronic instability may cause secondary MCP joint cartilage damage; address this if present to optimize outcomes

The internal brace technique represents a biomechanical enhancement that addresses the fundamental weakness of chronic UCL reconstruction—poor native tissue quality requiring extended healing time. The suture tape augmentation provides immediate mechanical stability while preserving the proprioceptive benefits of anatomic reconstruction 4.