Midcarpal joint

The midcarpal joint is a functional compound synovial joint in the wrist between the scaphoid, lunate and triquetrum proximally and the trapezium, trapezoid, capitate and hamate distally. 

Summary

• complex joint between the proximal and distal carpal bones of the wrist 
• permits flexion, extension, adduction and abduction of the wrist
• receives vascular supply from posterior carpal branches of the radial and ulnar artery and the anterior interosseous artery

Gross anatomy

The midcarpal joint, as implied by the name, is present between the proximal and distal carpal bones of the wrist. It is formed of two saddle joints; first between the capitate, hamate and scaphoid, lunate, triquetrum, second between trapezium, trapezeoid and scaphoid ¹. 

Movement

The joint, although consisting of two saddle joints, is itself a condylar joint implying movement in two planes: flexion/extension and abduction/adduction of the wrist. It is the primary joint involved in radial and ulnar deviation of the wrist ². 

Ligaments

The midcarpal joint is stabilized by the palmar and dorsal midcarpal ligaments. 

Blood supply

The midcarpal joint receives vascular supply from posterior carpal branches of the radial and ulnar artery and the anterior interosseous artery (branch of the ulnar artery) ¹.

Innervation

The innervation for the midcarpal joint comes from the deep terminal branch of the ulnar nerve and the anterior interosseous branch of the median nerve. The posterior interosseous branch of the radial nerve may also be involved ¹. 

Related pathology

• carpal instability