Capsules of the Metacarpophalangeal Joints, Posterior View

Description

Viewed from the posterior (dorsal) aspect, the metacarpophalangeal (MCP) joint capsules form a thin envelope spanning the distal heads of the metacarpals and the bases of the proximal phalanges. Dorsally, a flexible capsular membrane is visible deep to the extensor tendons, blending laterally with the collateral ligaments and continuing distally toward the extensor hood over each digit. Metacarpals lie proximal and deep, while the phalanges extend distally, with the carpal row positioned more proximal at the wrist. Spatially, the MCP capsules sit superficial to the metacarpal heads but deep to the dorsal tendon apparatus. Clear landmarks. This posterior perspective matters because dorsal capsular integrity and the extensor mechanism govern MCP stability in extension and contribute to controlled flexion, and dorsal thickening or tearing often tracks with traumatic knuckle injuries. Clinically, the view aligns with the operative field for dorsal approaches to the MCP joint used in synovectomy for rheumatoid arthritis, repair of sagittal band rupture with extensor tendon subluxation, and management of dorsal capsular tears after hyperextension. It also supports understanding of why the collateral ligaments tighten in flexion and why joint positioning affects exam findings for MCP collateral injury. Hand anatomy courses and musculoskeletal blocks use this plate to teach MCP joint capsule boundaries, extensor tendon relationships, and surface correlation at the knuckles, while surgical atlases can pair it with descriptions of dorsal incisions between extensor tendons. Orthopaedic and hand therapy publications will also find it suitable for explaining post-injury stiffness, capsular contracture patterns, and guided mobilization after MCP procedures. Anatomical accuracy verified by SciePro's Medical Advisory Board.