Anatomy of extensor apparatus of fingers. A, Dorsal. B, Lateral. 1, interosseous muscle; 2, extensor digitorum communis tendon; 3, lumbrical muscle; 4, flexor tendon sheath; 5, sagittal bands; 6, transverse metacarpal ligament; 7, interosseous hood; 8, interosseous hood, oblique fibers; 9, extensor lateral band; 10, extensor middle band; 11, interosseous middle band; 12, interosseous lateral band; 13, oblique retinacular ligament; 14, central extensor tendon; 15, spiral fibers; 16, transverse retinacular ligament; 17, lateral extensor tendon; 18, triangular lamina; 19, terminal extensor tendon.