midcarpal

The midcarpal joint, or midcarpal articulation, is the wrist joint formed between the proximal and distal rows of carpal bones. It comprises several small articulations that connect the proximal row—consisting of the scaphoid, lunate, and triquetrum—with the distal row, which includes the trapezium, trapezoid, capitate, and hamate. Functionally, the midcarpal joint is often described as having two compartments: a lateral (radial) compartment mainly involving the scaphoid with the trapezium and trapezoid, and a medial (ulnar) compartment involving the lunate and triquetrum with the capitate and hamate. The joint is enclosed by a capsule and stabilized by intrinsic ligaments, including the scapholunate and lunotriquetral interosseous ligaments, as well as dorsal and palmar intercarpal ligaments, with additional reinforcement from extrinsic ligaments.

Functionally, the midcarpal joint works in concert with the radiocarpal joint to produce wrist flexion and extension and to contribute to radial and ulnar deviation. It allows complex gliding movements between carpal bones during wrist motion and plays a key role in the overall range and smoothness of movement.

Clinical relevance includes conditions that disrupt midcarpal kinematics, such as ligamentous injuries leading to instability (for example, scapholunate dissociation) and degenerative changes in the midcarpal joints. Diagnosis typically involves clinical examination and imaging studies (X-ray, MRI, CT) to assess alignment and stability. Treatment ranges from conservative approaches, such as immobilization and rehabilitation, to surgical intervention in cases of persistent instability or arthritis.