Please enable JavaScript.

Coggle requires JavaScript to display documents.

Wrist Complex, Ulnar Variance, Triangular fibrocartilage complex (TFC) -…

- - - - Distal radius
        
        biconcave curvature
        
        Lateral radial facet
        
        articulates with
        scaphoid
        
        Medial radial facet
        
        articulates with
        lunate
      - Articular disc of distal radioulnar joint (TFC)
        
        articulates with
        triquetrum
    - - Line of inclination of radius is 23 degrees
      - Distal radius is tilted 11 degrees volarly
    - - Proximal row of carpals
        
        Scaphoid - lateral facet
        
        Lunate - medial facet
        
        Triquetrum - articular disc
        
        Pisiform does not participate in the
        radiocarpal joint
        
        Function as a sesamoid bone to increase the
        moment arm of FCU
      - Distal segment of the Radiocarpal joint
        
        Scaphoid, lunate and triquetrum
        
        Covered by cartilage proximally to articulate
        with distal radius
        
        Connected by 2 interosseous ligaments
        
        Scapholunate
        
        Lunotriquetral
        
        Together with the ligaments appear to be a
        single biconvex cartilage covered joint surface
        
        Incongruent due to sharper distal radiocarpal
        articular surface of the joint when compared
        with proximal radiocarpal articular surface
  - - - Reinforced by the capsular and
        intracapsular ligaments
        
        Radiocarpal joint ligaments will provide stability for the midcarpal joint as well
        
        Muscles associated also cross the midcarpal joint aswell and will not act alone
        on the radiocarpal joint
        
        Flexor carpi ulnaris muscle is the only muscle that will attach to the proximal carpal row
        
        Pisiform
        
        Loosely connected to the triquetrum below
        
        Forces are translated to the hamate and 5th metacarpal via the pisiform ligament
- - - - Gliding movements at these joints increase overall range of motion of wrist
        
        Functional unit, because of the many articulations of the carpals
        
        Articulation between the proximal row and distal row of carpals
        
        Capitate and hamate are strongly bound together
        
        Proximal – scaphoid, lunate and triquetrum
        
        Distal – trapezium, trapezoid, capitate and hamate
        
        Separate capsule from radiocarpal joint but may be continuous with the intercarpal articulation and carpometacarpal (CMC) joints
        
        Nearly equal force distribution of forces within the articulations
        
        Articular surfaces are
        reciprocally concave-convex configuration
      - Radial/ulnar deviation
      - Flexion extension
- - - - Abnormal force distribution across the RC joint
        
        and potential degeneration
        
        kienbocks disease associated with
        negative variance ,
        
        Thicker TFC – negative varaiance
        
        causes avascular necrosis of the lunate
  - - - Distal radius fracture can result a positive variance when healed in a shortened position
        
        Pain present in end range pronation
        and ulnar deviation
        
        Potential for impingement of TFC structures
        
        Thinner TFC – positive variance
- - - - Lower via
        
        sheath of the ECU tendon,
        
        carpals and to
        
        5th MC base
        
        through ulnar collateral ligament
      - Upper via the
        
        radioulnar ligaments
        
        to the base of styloid process
    - - Palmar and dorsal radioulnar ligaments
      - Ulnolunate ligament
      - Ulnotriquetral ligament
      - Meniscus homologue
      - Extensor Carpi Ulnaris sheath