ABSTRACT

SKIN n Volar skin is thicker, less mobile, and has papillary ridges for grasping. n Dorsal skin is thinner and more mobile, and the subcutaneous tissue contains veins and

lymphatics.

RETINACULAR SYSTEM n Volar fascia

• Anchors volar skin to bone for grasping, in contrast to loose skin on dorsum • Superficial volar fascia: Triangular-shaped fascia attached proximally to PL tendon;

composed of longitudinal fibers, vertical fibers, transverse fibers, and natatory ligaments n Retaining ligaments of fingers

• Stabilize skin and extensor mechanism of digits and support neurovascular bundles  Grayson’s ligament: Passes transversely from volar aspect of flexor tendon sheath to

skin1 (Fig. 59-1)  Prevents bowstringing of neurovascular bundle during finger flexion

 Cleland’s ligament: Passes from juncture of periosteum and flexor tendon sheath to skin laterally (see Fig. 59-1)  Lies dorsal to neurovascular bundle

 Transverse retinacular ligament: Lateral side of PIP joint, superficial to collateral ligament  Prevents dorsomedial

displacement of lateral bands  Oblique retinacular ligament

(ligament of Landsmeer): Originates on volar aspect of middle phalanx and inserts on dorsal aspect of distal phalanx  Helps coordinate PIP joint and

DIP joint motion

DeeP Fascial sPaces n Potential spaces that can be sites of

infection • Midvolar space  Boundaries

 Dorsal: Volar interossei and metacarpals

 Volar: Volar aponeurosis and flexor tendons of ring, long, and small fingers

 Ulnar: Hypothenar septum  Radial: Midvolar (oblique) septum

• Thenar space  Boundaries

 Dorsal: AdP  Volar: Index flexor tendon  Ulnar: Midvolar (oblique) septum  Radial: Adductor insertion and thenar muscle fascia

• Hypothenar space  Boundaries

 Dorsal: Hypothenar muscles  Volar: Small-finger flexor tendon  Ulnar: Hypothenar muscles  Radial: Hypothenar septum

• Interdigital web space  Location of collar button abscess  Boundaries

 Dorsal: Dorsal fascia and skin  Volar: Volar fascia  Ulnar: Extensor mechanism and MP joint capsule  Radial: Extensor mechanism and MP joint capsule

• Parona’s space  Infections can spread to this space from radial or ulnar bursa, or midvolar space.  Boundaries

 Dorsal: Pronator quadratus  Volar: Digital flexors  Ulnar: FCU  Radial: Radial bursa (containing FPL)

Fig. 59-1 Distal volar and digital fascia.