Updated: 5/23/2021

Ligaments of the Fingers

0%
Topic
Review Topic
0
0
0%
0%
Flashcards
4
N/A
N/A
Questions
1
0
0
Topic
Images
https://upload.orthobullets.com/topic/6003/images/obretlig..jpg
https://upload.orthobullets.com/topic/6003/images/Cleland's_moved.jpg
https://upload.orthobullets.com/topic/6003/images/cleland-grayson.jpg
https://upload.orthobullets.com/topic/6003/images/gray-cle.jpg
https://upload.orthobullets.com/topic/6003/images/Extensor hood_moved.jpg
  • Extensor Ligaments
    • Lumbrical tendon passes volar to transverse metacarpal ligament
    • Interossei tendon passes dorsal to transverse metacarpal ligament
  • Retinacular Ligaments
    • Function
      • retain and position common extensor mechanism during PIP and DIP flexion
      • similar to sagittal band function
    • Anatomic Components
      • oblique band (oblique retinacular ligament of Landsmeer)
        • function
          • links motion of DIP and PIP
            • lies volar to axis of PIP, but dorsal to axis of DIP
        • anatomy
          • origin: from lateral volar aspect of proximal phalanx,
          • insertion: to lateral terminal extensor dorsally (crosses collateral ligaments)
        • biomechanics
          • with PIP flexion, ligament relaxes to allow DIP flexion
          • with PIP extension, ligament tights to facilitate DIP extension
        • pathology
          • contracture causes volar displacement of lateral bands and a resulting Boutonniere Deformity
          • reconstruction of oblique retinacular ligament used to treat swan neck deformity
          • if ORL is tight,
            • resting finger position is DIP extended, PIP flexed
            • unable to flex DIP if PIP is extended
            • able to flex DIP only after PIP is flexed
              • contrast this with intrinsic tightness, where there is decreased PIP flexion when the MCP is extended, and improved PIP flexion when the MCP is flexed
              • contrast this with extrinsic tightnes (extensor tendon tightness), where there is increased PIP flexion when MCP is extended, and decreased PIP flexion when MCP is flexed
      • transverse band
        • function
          • with PIP flexion, pull lateral bands volarly over PIP
          • with PIP extension, prevents excessive dorsal translation of lateral bands
        • anatomy
          • origin: from edge of flexor tendon sheath at PIP
          • insertion: lateral border of conjointed lateral bands
        • pathology
          • attenuation leads to dorsal translation of lateral bands and a resulting swan neck deformity
          • contracture (with attenuation of triangular ligament) leads to volar translation of lateral bands and resulting boutonniere deformity
  • Digital Cutaneous Ligaments
    • Function
      • tether skin to deeper layers of fascia and bone to prevent excessive mobility of skin and improve grip
      • stabilize the digital neurovascular bundle with finger flexion and extension
    • Anatomic Components
      • Cleland's ligaments (remember "C" for ceiling)
        • dorsal to digital nerves
        • not involved in Dupuytren's disease
      • Grayson's ligament (remember "G" for ground)
        • volar to digital nerves
  • Expansion Hood
    • Function
      • works to extend PIP and DIP joint
    • Anatomic Components
      • central slip
        • functions to extend PIP
        • inserts into base of middle phalanx
      • lateral band
        • functions to extend DIP
        • inserts into distal phalanx
          • lumbricals, extensor indicis, dorsal and palmar interossei insert on lateral band
  • MCP Joint Collateral Ligaments
    • Function
      • stabilize MCP joint during motion
        • MCP joint "cam" nature leads to inconstant arc of motion because of joint asymmetry
          • caused by "snoopy head" configuration of metacarpal head
        • collaterals looser in extension, tighten during increasing flexion
          • as MP joint flexes, proximal phalanx moves further away from metacarpal head, tightening all the ligaments
    • Anatomic Components
      • radial collateral ligaments (RCL) are more horizontal than ulnar collateral ligaments (UCL)
      • RCL and UCL have 2 parts each: proper and accessory ligaments
        • accessory ligament
          • fan shaped
          • more volar
            • tight in extension
          • attachment
            • from metacarpal head at center of rotation
            • to palmar plate and deep transverse metacarpal ligament
          • clinical test
            • adduction/abduction stress in extension
        • proper ligament
          • cord like
          • more dorsal
            • tight in 30 degrees of flexion
          • attachment
            • from posterior tubercle of metacarpal head (dorsal to mid axis)
            • to proximal phalanx base
          • clinical test
            • adduction/abduction stress in 30 degrees flexion to isolate proper ligaments
  • Deep Transverse Metacarpal Ligament
    • Function
      • prevents metacarpal heads from splaying apart (abduction)
      • allows some dorsal-volar translation
    • Anatomic components
      • connects 2nd to 5th metacarpal heads together at volar plate of the MP joint
  • Natatory Ligament (Superficial Transverse Metacarpal Ligament)
    • Function
      • resists abduction
    • Anatomic components
      • most superficial MP joint ligament
      • origin: from distal to the MP joint
      • insertion: proximal phalanx of all 5 fingers (runs in the web space)
  • Sagittal Bands
    • Function
      • keep extensor mechanism tracking in the midline during flexion of MP joint
    • Anatomy
      • origin: palmar plate
      • insertion: extensor mechanism (curves around radial and ulnar side of MP joint)
  • Triangular ligament
    • Function
      • counteracts pull of oblique retinacular ligament, preventing lateral subluxation of the common extensor mechanism
    • Anatomy
      • triangular in shape
      • located on dorsal side of extensor mechanism, distal to PIP joint
    • Pathology
      • contracture leads to swan neck deformity
  • Volar Plate
    • Function
      • prevent hyperextension
    • Anatomy
      • thickening of joint capsule volar to the MP joint
      • in the thumb, sesamoid bones are located here
      • origin: metacarpal head
      • insertion: periarticular surface of proximal phalanx , via checkrein ligaments
    • Biomechanics
      • loose in flexion
        • folds into metacarpal neck during flexion
      • tight in extension
Flashcards (4)
Cards
1 of 4
Questions (1)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
EXPERT COMMENTS (12)
Private Note