[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Upper limb](https://durgical.com/en/anatomy/region/upper-limb/) › Volar plates (knuckles) [Joints and ligaments](https://durgical.com/en/anatomy/system/joints-and-ligaments/) · [Upper limb](https://durgical.com/en/anatomy/region/upper-limb/) # Volar plates (knuckles) The volar plates of the knuckles are pads on the palm side of the finger knuckles; they limit backward bending and anchor the tendon pulleys. Official name: Volar (palmar) plates of the MCP joints [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=upper_limb&select=volar_plates_mcp&side=r) Opens in the Durgical app, no sign-up needed. ## What it is Thick pads on the palm side of the knuckles. ## What it does Limit the knuckles bending backward and anchor the pulleys and the deep [transverse ligament](https://durgical.com/en/anatomy/transverse-ligament-of-knee/). ## Key points - Complex (irreducible) dorsal MCP dislocation: the volar plate is trapped between the metacarpal head and the proximal phalanx; the index finger is most often affected - In the index, the metacarpal head buttonholes into the palm between the lumbrical (radially) and the flexor tendons (ulnarly) - The thumb MCP volar plate holds the two [thumb sesamoids](https://durgical.com/en/anatomy/sesamoid-bones-of-the-thumb/), where [flexor pollicis brevis](https://durgical.com/en/anatomy/flexor-pollicis-brevis/) and [adductor pollicis](https://durgical.com/en/anatomy/adductor-pollicis/) insert - Unlike the PIP plate, the MCP plate is loosely attached proximally, so many people can hyperextend their knuckles ## Key facts **Attaches** Base of the proximal phalanx; linked by the deep transverse metacarpal ligament **Function** Prevent MCP hyperextension; anchor the A1 pulley **Tight in** MCP extension ## Relations **In front** A1 pulley, which arises from it, and the flexor tendons; the [deep transverse metacarpal ligament](https://durgical.com/en/anatomy/deep-transverse-metacarpal-ligament/) links it to its neighbours **Behind** Metacarpal head **Lateral** Accessory collateral ligaments inserting on its sides; further out the lumbricals and [digital nerves](https://durgical.com/en/anatomy/palmar-digital-nerves/) ## How to find it Not felt directly; it lies deep to the flexor tendons near the distal palmar crease for the ring and little fingers and the proximal palmar crease for the index. At the thumb, the two [sesamoids](https://durgical.com/en/anatomy/sesamoid-bones-of-foot/) carried in the plate can be felt as small hard nodules in front of the first metacarpal head. ## Examination - Hyperextension stress of the MCP compared with the other hand: pain and excess hyperextension suggest a volar plate injury ## On imaging Lateral and oblique X-rays: in a complex dislocation the joint surfaces lie nearly parallel and a sesamoid inside a widened joint space (thumb or index) is a clue to an entrapped plate. Ultrasound and MRI show plate tears. ## Clinical notes - Traction or hyperextension during reduction can turn a simple dislocation into a complex one by pulling the plate into the joint - Puckering of the palmar [skin](https://durgical.com/en/anatomy/skin/) over the metacarpal head is a sign of a complex dislocation - Complex dislocations need open reduction, from the back or the palm; in the palmar approach the digital nerves stretched over the metacarpal head are at risk ## Development The thumb sesamoids in this plate ossify around puberty; on a hand X-ray for bone age, the appearance of the ulnar (adductor) sesamoid is used as a sign that the pubertal growth spurt has begun. ## Related conditions - [Systemic lupus erythematosus](https://durgical.com/en/conditions/systemic-lupus-erythematosus/) - [Rheumatoid arthritis](https://durgical.com/en/conditions/rheumatoid-arthritis/) ## Test yourself Think of the answer, then tap the question to see it. ## What makes a dorsal MCP dislocation complex (irreducible)? The MCP volar plate is trapped between the metacarpal head and the proximal phalanx; the index finger is most often affected. ## Which reduction manoeuvre can turn a simple MCP dislocation into a complex one? Traction or hyperextension, which can pull the volar plate into the joint. ## Why can many people hyperextend their knuckles but not their PIP joints? The MCP volar plate is loosely attached proximally, unlike the PIP plate. ## What skin sign suggests a complex MCP dislocation? Puckering of the palmar skin over the metacarpal head. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/anatomy/volar-plates-of-the-mcp-joints/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** ligamenta metacarpophalangea palmaria TA2 1837 **Official Spanish (DeCS)** Ligamentos palmares metacarpofalángicos **English (TA2)** Volar (palmar) plates of the MCP joints **Also called** volar plate · palmar plate · Palmar metacarpophalangeal ligaments ## Related - [A1 pulleys](https://durgical.com/en/anatomy/a1-pulleys-of-the-flexor-tendon-sheaths/) - [Knuckle collateral ligaments](https://durgical.com/en/anatomy/collateral-ligaments-of-the-metacarpophalangeal-joints/) - [Deep transverse metacarpal ligament](https://durgical.com/en/anatomy/deep-transverse-metacarpal-ligament/) - [2nd metacarpal](https://durgical.com/en/anatomy/2nd-metacarpal/) - [3rd metacarpal](https://durgical.com/en/anatomy/3rd-metacarpal/) - [4th metacarpal](https://durgical.com/en/anatomy/4th-metacarpal/) - [5th metacarpal](https://durgical.com/en/anatomy/5th-metacarpal/) - [Proximal phalanx, middle finger](https://durgical.com/en/anatomy/proximal-phalanx-of-the-middle-finger/) Sources: Terminologia Anatomica (TA2); [Anatomy, Shoulder and Upper Limb, Metacarpophalangeal Joints](https://www.ncbi.nlm.nih.gov/books/NBK538428/); [Anatomy, Shoulder and Upper Limb, Hand Metacarpal Phalangeal Joint](https://www.ncbi.nlm.nih.gov/books/NBK538343/); Anatomy of the Human Body (20th ed.): Surface Anatomy of the Upper Extremity (Lea & Febiger (Gray's Anatomy, 1918), 1918) · adapted, Public domain. ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/volar-plates-of-the-mcp-joints/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/volar-plates-of-the-mcp-joints/