Mateusz Gładysz FESSH prep

FESSH prep Anatomy

Thumb carpometacarpal joint anatomy and ligaments

Last reviewed v1.0

FESSH-095Anatomy●●○ intermediate

Regarding the anatomy and ligaments of the thumb carpometacarpal (trapeziometacarpal) joint:

  1. 1.The deep anterior oblique ('beak') ligament has been proposed to act as a pivot about which the first metacarpal rotates into pronation during palmar abduction.

  2. 2.With the thumb in flexion–adduction during simulated lateral pinch, joint contact is concentrated in the dorsal compartment of the trapeziometacarpal joint.

  3. 3.The anterior oblique ligament is the primary restraint to acute dorsal dislocation of the thumb carpometacarpal joint.

  4. 4.The dorsal ligaments of the trapeziometacarpal joint contain more nerve endings than the volar ligaments, which suggests a proprioceptive role.

  5. 5.Ligaments running from the trapezium to the second and third metacarpals act as tension bands that resist cantilever bending of the trapezium.

FESSH marking: +1 per correct statement, 0 for blank, −1 for incorrect. Click the same TRUE/FALSE button twice to clear it.

Question ID
FESSH-095
First published
Last reviewed
Version
v1.0
Answer key and explanations — open after answering

  1. 1. The deep anterior oblique ('beak') ligament has been proposed to act as a pivot about which the first metacarpal rotates into pronation during palmar abduction.

    True

    Bettinger's anatomical study identified 16 ligaments stabilising the trapezium and trapeziometacarpal joint. It concluded that the dorsoradial and deep anterior oblique ligaments play a substantial role in stabilising the joint, and that the deep anterior oblique ligament may act as a pivot for the first metacarpal during palmar abduction, allowing pronation.

    • Bettinger PC, Linscheid RL, Berger RA, Cooney WP, An KN. An anatomic study of the stabilizing ligaments of the trapezium and trapeziometacarpal joint. J Hand Surg Am. 1999;24(4):786-98. PMID 10447171

  2. 2. With the thumb in flexion–adduction during simulated lateral pinch, joint contact is concentrated in the dorsal compartment of the trapeziometacarpal joint.

    False

    In Pellegrini's cadaver study using pressure-sensitive film, the palmar compartment was the primary contact area during flexion–adduction of the thumb in lateral pinch. Detaching the palmar beak ligament translated the contact area dorsally, producing a pattern similar to the cartilage degeneration of the osteoarthritic joint.

    • Pellegrini VD, Olcott CW, Hollenberg G. Contact patterns in the trapeziometacarpal joint: the role of the palmar beak ligament. J Hand Surg Am. 1993;18(2):238-44. PMID 8463587

  3. 3. The anterior oblique ligament is the primary restraint to acute dorsal dislocation of the thumb carpometacarpal joint.

    False

    Strauch's sectioning study of 38 cadaver thumbs found the dorsoradial ligament to be the primary restraint to dorsal dislocation; the anterior oblique ligament allowed dislocation by stripping subperiosteally from the base of the first metacarpal. Van Brenk similarly found that sectioning the dorsoradial ligament produced the greatest dorsoradial subluxation of the metacarpal.

    • Strauch RJ, Behrman MJ, Rosenwasser MP. Acute dislocation of the carpometacarpal joint of the thumb: an anatomic and cadaver study. J Hand Surg Am. 1994;19(1):93-8. PMID 8169374
    • Van Brenk B, Richards RR, Mackay MB, Boynton EL. A biomechanical assessment of ligaments preventing dorsoradial subluxation of the trapeziometacarpal joint. J Hand Surg Am. 1998;23(4):607-11. PMID 9708373

  4. 4. The dorsal ligaments of the trapeziometacarpal joint contain more nerve endings than the volar ligaments, which suggests a proprioceptive role.

    True

    Hagert's immunofluorescence study of ligaments from 10 cadaver hands found significantly more nerve endings in the three dorsal ligaments than in the two volar ligaments, mostly Ruffini endings near the metacarpal insertion; the anterior oblique ligament had little or no innervation. Ladd's histological study likewise found the dorsal ligaments thicker, more cellular and more richly innervated than the anterior oblique ligament.

    • Hagert E, Lee J, Ladd AL. Innervation patterns of thumb trapeziometacarpal joint ligaments. J Hand Surg Am. 2012;37(4):706-714.e1. PMID 22464234
    • Ladd AL, Lee J, Hagert E. Macroscopic and microscopic analysis of the thumb carpometacarpal ligaments: a cadaveric study of ligament anatomy and histology. J Bone Joint Surg Am. 2012;94(16):1468-77. PMID 22992815

  5. 5. Ligaments running from the trapezium to the second and third metacarpals act as tension bands that resist cantilever bending of the trapezium.

    True

    Bettinger described the dorsal and volar trapezio-second metacarpal ligaments and the trapezio-third metacarpal ligament as tension bands needed to prevent instability from cantilever bending forces on the trapezium. In a companion study of material properties, these ligaments were relatively strong and aligned to restrain the trapezium against bending forces applied by the thumb in key or tip pinch.

    • Bettinger PC, Linscheid RL, Berger RA, Cooney WP, An KN. An anatomic study of the stabilizing ligaments of the trapezium and trapeziometacarpal joint. J Hand Surg Am. 1999;24(4):786-98. PMID 10447171
    • Bettinger PC, Smutz WP, Linscheid RL, Cooney WP, An KN. Material properties of the trapezial and trapeziometacarpal ligaments. J Hand Surg Am. 2000;25(6):1085-95. PMID 11119667