Justin Fields/Bears MGMT protecting his right thumb in Week 7.

[DrGonzo]

UCL tear? The ulnar collateral ligament? What? He dislocated his thumb not his elbow!

Skier's thumb. Treatment, prevention and recommendations - PubMed

Skier's thumb is an injury to the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal joint (MCPJ) which has a serious risk of disabling chronic instability if not treated adequately. The lesion most often occurs in skiers when the ski pole forces the thumb to deviate radially...

pubmed.ncbi.nlm.nih.gov

Thumb Ligament Injuries

Thumb ligament injuries are common, particularly those involving the metacarpophalangeal joint.Two major ligaments stabilize the MCP joint of the thumb: the ulnar collateral ligament (UCL) and the radial collateral ligament (RCL)[1]

www.physio-pedia.com

 

[MDB111™]

UCL tear? The ulnar collateral ligament? What? He dislocated his thumb not his elbow!

Maybe the ulnar nerve? That can affect the thumb over thumb over time.