The MCP collateral ligaments have a cam-shaped metacarpal head origin that makes them taut in MCP flexion and lax in extension. This biomechanical property means MCP joints must be immobilised in flexion (70-90 degrees) to keep the collaterals at maximum length and prevent contracture — a principle fundamental to hand injury management. After injury or surgery, collateral ligament shortening in extension produces the intrinsic minus contracture.
| Origin | Metacarpal head lateral tubercles |
|---|---|
| Insertion | Lateral proximal phalanx base |
| Actions | Lateral MCP joint stability — taut in flexion (cam effect), lax in extension allowing abduction-adduction |
|---|
The intrinsic plus position (MCP flexion, IP extension) is the standard position for hand immobilisation after injury and surgery — it keeps MCP collaterals at full length and IP joint volar plates unfolded, preventing the most common post-traumatic contracture patterns. Any hand splint that immobilises MCPs in extension risks permanent MCP collateral shortening.
MCP collateral ligament shortening from immobilisation in extension producing fixed MCP extension contracture prevented by intrinsic-plus splinting.
This website uses cookies to enhance your experience. Some are essential for site functionality, while others help us analyze and improve your usage experience. Please review your options and make your choice.
If you are under 16 years old, please ensure that you have received consent from your parent or guardian for any non-essential cookies.
Your privacy is important to us. You can adjust your cookie settings at any time. For more information about how we use data, please read our privacy policy. You may change your preferences at any time by clicking on the settings button below.
Note that if you choose to disable some types of cookies, it may impact your experience of the site and the services we are able to offer.
Some required resources have been blocked, which can affect third-party services and may cause the site to not function properly.
This website uses cookies to enhance your browsing experience and ensure the site functions properly. By continuing to use this site, you acknowledge and accept our use of cookies.
