Thumb MCP Problems

Hyperextension of the middle joint of the thumb beyond a neutral position may result in a painful and unstable joint, decreased power, and difficulty in grasping large objects. Without stabilizing or “blocking” the hyperextension, the joint can become dislocated resulting in a loss of function.

  • Thumb MCP Problems


For Thumb MCP Hyperextension

Use the SIRIS™ Thumb MCP Splint to block hyperextension of a MCP joint. Use on thumbs that can actively abduct; do not use on thumbs that are adducted. A bracelet is available to secure this splint on the thumb. Other options are:

  • To block radial deviation (skiers thumb, game keepers thumb) both Ulnar Lateral Support and Proximal Radial Extension need to be added.  When these additions are added the splint will be sent unfinished to verify fit.  One remake is allowed at no additional charge.  Any further remakes or returns for credit will incur a 25% restocking fee
  • SIRIS™ Thumb MCP Splint used to block hyperextension of a MCP joint

  • Standard bracelet comes with lobster clasp, if requested a 'S' hook can be substituted

  • Ulnar Lateral Support

  • Proximal Radial Extension


SIRIS™ Thumb MCP Splint with PVX

A proximal volar extension is frequently added to fit under the head of the metacarpal joint for additional stability. This is good if the MCP hyperextends more than 20 degrees.

  • SIRIS™ Thumb MCP Splint with PVX

  • Standard bracelets comes with lobster clasp, if requested a ‘S’ hook can be substituted


For Extension

Use the SIRIS™ Stable Thumb Splint when extension at the thumb MCP joint is needed and the MCP joint has the ability to be passively corrected to neutral. A bracelet comes standard and links can be removed for optimal fit. The bracelet keeps the splint from migrating and is attached with a clasp (standard) or an S-hook (optional – if fine motor skills are limited). This splint can easily be worn at the same time with a splint on the IP joint.

  • SIRIS™ Stable Thumb Splint used to correct extension at the thumb MCP joint

  • Standard bracelets comes with lobster clasp, if requested a ‘S’ hook can be substituted

  • Flyer showing the 3 different models we offer


For Hyperextension and Flexion

Use the SIRIS™ Stable Thumb Splint with Proximal Volar Extension (PVX) when there are significant CMC changes (very little or no motion at the CMC joint, a “step off” or subluxation at the CMC joint) or if the thumb moves predominantly in an adducted prehension pattern when grasping. This splint stabilizes the MCP joint dorsal and volar to prevent hyperextension and flexion. It is used for MP hyperextension when there are significant joint changes at the CMC joint with an adducted prehension pattern. A bracelet keeps the splint from migrating and is attached with a clasp (standard) or an S-hook (optional – if fine motor skills are limited). This splint can easily be worn at the same time with a splint on the IP joint.

  • SIRIS™ Stable Thumb Splint with Proximal Volar Extension (PVX) correcting CMC changes

  • Standard bracelets comes with lobster clasp, if requested a ‘S’ hook can be substituted

  • Flyer showing the 3 different models we offer