Gamekeeper's thumb--a treatment-oriented magnetic resonance imaging classification

Area of Science:

• Orthopedic surgery
• Radiology
• Sports medicine

Background:

• Thumb ulnar collateral ligament (UCL) injuries are common, particularly in athletes.
• Accurate assessment of UCL injury severity is crucial for guiding treatment decisions.
• Current classification systems may not fully capture the nuances of UCL displacement.

Purpose of the Study:

• To develop a simple classification system for thumb UCL injuries based on magnetic resonance imaging (MRI) findings.
• To correlate the degree of UCL displacement with clinical outcomes and treatment requirements.
• To aid surgeons in determining which UCL injuries necessitate surgical intervention.

Main Methods:

• Retrospective analysis of 43 cases with thumb UCL injuries.
• Dedicated extremity MRI was used to evaluate ligament displacement.
• Correlation of MRI findings with clinical outcomes and surgical intervention necessity.

Main Results:

• A 4-stage classification system based on UCL displacement was generated.
• Type 1 (minimally displaced) and Type 2 (displacement < 3 mm) tears generally healed with immobilization.
• Type 3 (displacement > 3 mm) and Type 4 (Stener lesion) tears frequently failed immobilization and required surgery.

Conclusions:

• A 4-stage, treatment-oriented classification for thumb UCL injuries is proposed.
• The degree of UCL displacement on MRI is a key predictor of treatment success.
• UCL tears with > 3 mm displacement warrant consideration for operative repair, irrespective of a Stener lesion.