A Posterior Perspective of the Capsule of the Carpometacarpal Joint

Description

Posteriorly, the dorsal capsule of the carpometacarpal (CMC) joint is rendered as a thickened sleeve spanning the distal carpal row to the bases of the metacarpals, draping across the dorsal aspects of the capitate and hamate with their articulations to the third through fifth metacarpal bases. Lateral in the image, the first ray sits to the right, so the thumb CMC region aligns with the trapezium and base of the first metacarpal, while the second metacarpal base relates more medially to the trapezoid and capitate. Distal to the CMC line, the metacarpal shafts lead to the metacarpophalangeal joints and phalanges, maintaining the dorsal hand relationship of proximal to distal along each digit. Dorsal thickening stands out. Dorsal capsular anatomy at the CMC level matters because it constrains translation during grip and pinch, and it is a common pain generator when the CMC complex becomes unstable or arthritic, most classically at the trapeziometacarpal joint of the thumb. Hand surgeons and therapists track these capsuloligamentous planes when planning approaches that respect the dorsal sensory branches and when distinguishing capsular contracture from intra-articular synovitis in post-traumatic stiffness. Small shifts here have big functional consequences. Use this art for gross anatomy and kinesiology teaching on wrist and hand biomechanics, for orthopedic and hand surgery texts describing CMC arthrodesis, trapeziectomy, or ligament reconstruction, and for patient education materials explaining why dorsal hand pain can localize near the metacarpal bases after sprain or degenerative change. Anatomical accuracy verified by SciePro's Medical Advisory Board.