Which injury is an UCL injury of the thumb metacarpophalangeal joint, with or without fracture?

Which injury is an UCL injury of the thumb metacarpophalangeal joint, with or without fracture?

• A. Chauffeur's
• B. Gamekeeper's
• C. Bennett
• D. Barton's

Answer: (B)

Gamekeeper's thumb is an injury to the ulnar collateral ligament of the thumb’s metacarpophalangeal joint, with or without an avulsion fracture at the base of the proximal phalanx. It happens when the thumb is forced away from the hand (valgus stress or a forced abducting force), such as a fall on an outstretched hand or during sports with a strong grip. Clinically, you’d expect tenderness and swelling at the ulnar side of the MCP joint, pain with valgus stress testing of the thumb, and sometimes a small fracture fragment on the base of the proximal phalanx if an avulsion occurred. A Stener lesion can complicate tears: the torn UCL end is displaced under the adductor pollicis aponeurosis, preventing healing unless surgically repaired. Management depends on the injury pattern: partial tears or sprains without a Stener lesion are often treated with immobilization in a thumb spica cast to allow healing, while complete tears or a Stener lesion typically require surgical repair. Chauffeur’s fracture is a radial styloid fracture, not a thumb UCL injury. Bennett fracture involves the base of the first metacarpal with carpometacarpal joint involvement. Barton's fracture is a distal radius intra-articular fracture. These are different injuries and explain why the UCL thumb injury is the distinct gamekeeper’s thumb.

Gamekeeper's thumb is an injury to the ulnar collateral ligament of the thumb’s metacarpophalangeal joint, with or without an avulsion fracture at the base of the proximal phalanx. It happens when the thumb is forced away from the hand (valgus stress or a forced abducting force), such as a fall on an outstretched hand or during sports with a strong grip.

Clinically, you’d expect tenderness and swelling at the ulnar side of the MCP joint, pain with valgus stress testing of the thumb, and sometimes a small fracture fragment on the base of the proximal phalanx if an avulsion occurred. A Stener lesion can complicate tears: the torn UCL end is displaced under the adductor pollicis aponeurosis, preventing healing unless surgically repaired.

Management depends on the injury pattern: partial tears or sprains without a Stener lesion are often treated with immobilization in a thumb spica cast to allow healing, while complete tears or a Stener lesion typically require surgical repair.

Chauffeur’s fracture is a radial styloid fracture, not a thumb UCL injury. Bennett fracture involves the base of the first metacarpal with carpometacarpal joint involvement. Barton's fracture is a distal radius intra-articular fracture. These are different injuries and explain why the UCL thumb injury is the distinct gamekeeper’s thumb.