In 1962, Bertil<unk>  described a<unk>  which he observed to occur in a subset of patients suffering from gamekeeper's thumb. In these patients, the distal attachment of the UCL was traumatically avulsed from its site of insertion at the base of the proximal phalanx of the thumb. The severed end of the ligament would become trapped under the aponeurosis of the adductor pollicis muscle and therefore be unable to return to its proper anatomic position. Consequently, the severed ligament would fold on itself and thus be prevented from healing and restoring stability to the MCP joint. For a<unk>  to occur, both the proper and accessory collateral ligaments of the thumb must be completely ruptured. The<unk>  is present in more than 80% of complete ruptures of the UCL of the thumb.
Stener lesion
Fungating lesion
Atypia
Harlequin color change
Kniest dysplasia
Scalding
Cameron lesions
Sclerosis 