Metacarpophalangeal joints, interphalangeal joints

What are metacarpophalangeal joints?

Joints between the heads of metacarpals and bases of proximal phalanges.

What type of joints are MCP joints?

Synovial condyloid/ellipsoid joints.

What movements occur at MCP joints?

Flexion, extension, abduction, adduction, and circumduction.

Finger abduction/adduction is described relative to which finger?

The middle finger.

What ligaments stabilize the sides of MCP joints?

Collateral ligaments.

Are MCP collateral ligaments tight in flexion or extension?

Tight in flexion.

Are MCP collateral ligaments loose in flexion or extension?

Loose in extension.

What are palmar ligaments/volar plates?

Thick fibrocartilaginous plates that prevent hyperextension.

What does the deep transverse metacarpal ligament connect?

Palmar ligaments of MCP joints II–V. (functions to hold metacarpal heads together)

Does the thumb attach to the deep transverse metacarpal ligament?

no

Which hand joints are commonly affected in rheumatoid arthritis?

MCP joints.

What deformity can rheumatoid arthritis cause at MCP joints?

Ulnar deviation of the fingers.

What is a boxer’s fracture?

Fracture of the neck of the 5th metacarpal.

• caused by punching with closed fist

What is the blood supply of MCP joints

Branches of radial & ulnar arteries:

• Princeps pollicis artery (supplies the MCPJ of the thumb)

• Palmar and dorsal metacarpal arteries

• Radialis indicis artery (supplies the MCPJ of the index finger)

• Common palmar digital arteries

Innervation of MCPJ?

• posterior interosseus brach (branch of radial nerve)

• deep terminal branches of ulnar nerve

• palmar branches of median nerve

What are interphalangeal joints?

Joints between the phalanges.

What type of joints are IP joints?

Synovial hinge joints.

What movements occur at IP joints?

Flexion and extension only.

What forms the PIP joint?

Proximal phalanx and middle phalanx.

What forms the DIP joint?

Middle phalanx and distal phalanx.

What stabilizes the sides of IP joints?

Collateral ligaments.

What prevents hyperextension of IP joints?

Palmar ligaments/volar plates. (same thing)

Blood supply of IPJ?

Palmar digital arteries

Innervation of IPJ?

• palmar digital nerves (branches of median and ulnar nerves)