Joints of right index finger

Metacarpophalangeal joint opened, medial view

Stanford holds the copyright to the David L. Bassett anatomical images and has assigned Creative Commons license Attribution-Share Alike 4.0 International to all of the images.
For additional information regarding use and permissions, please contact Dr. Drew Bourn at dbourn@stanford.edu.

Image #111-3

Joints of right index finger

Metacarpophalangeal joint opened, medial view

The ligaments and capsule of the joint have been cut. The head of the metacarpal bone has been rotated medially and proximally.

1. Metacarpophalangeal joint capsule
2. Left pointer: Extensor indicis muscle (tendon of insertion) Right pointer: Common extensor digitorum muscle (tendon of insertion)
3. Head of metacarpal II (covered with articular cartilage)
4. Collateral ligament (cut)
5. Body of metacarpal II
6. Dorsal interosseous muscle I
7. Synovial fold
8. Lumbrical muscle I
9. Insertion of extensor tendons on base of proximal phalanx
10. Extensor expansion (reflected dorsally)
11. Phalanx I
12. Ligament of digital sheath
13. Base of phalanx (covered with articular cartilage)
14. Collateral ligament (inner aspect of lateral ligament)
15. Anterior accessory ligament (left pointer on cut edge, right pointer on articular surface of ligament)
16. Tendon of digital sheath
17. Flexor digitorum profundus muscle (tendon)
18. Flexor digitorum superficialis (tendon)