Purpose
To define the role of the dorsal capsule and associated dorsal fibrocartilage (DFC)
and their interactions with the radial collateral ligament (RCL) as a thumb metacarpophalangeal
(MCP) joint stabilizer.
Methods
Eight cadaveric thumbs were mounted onto a custom jig with 20 N of muscle load applied.
The thumb position in space was digitized to measure ulnar-radial, pronation-supination,
and volar-dorsal laxity at 0°, 30°, and 60° MCP joint flexion. Serial sectioning was
performed and measurements were repeated for the intact state, proper RCL insufficiency,
proper and accessory (complete) RCL insufficiency, complete RCL with 50% DFC (radial)
insufficiency, and complete RCL with complete DFC insufficiency.
Results
Ulnar-radial deviation, pronation-supination, and volar-dorsal translation significantly
changed at 30° and 60° MCP joint flexion when comparing complete RCL insufficiency
with complete RCL with 50% DFC insufficiency. At 30° flexion, significant increases
were found in ulnar deviation, pronation, and volar translation, and there was a decrease
in supination. At 60° flexion, ulnar deviation, pronation, and volar translation increased
and radial deviation decreased significantly. At 30° flexion, the resting position
significantly pronated and translated volarly. At 60° flexion, the resting position
significantly shifted ulnarly, pronated, and translated volarly.
Conclusions
The DFC acts as a secondary stabilizer of the thumb MCP joint, working in tandem with
the RCL. It acts by stabilizing the MCP joint dorsoradially when external forces are
applied across the joint. This cadaveric study shows that RCL insufficiency with a
concomitant DFC injury is less likely to be stable than RCL injuries alone, and that
this effect is more pronounced with MCP joint flexion.
Clinical relevance
Increasing incompetence of the secondary stabilizers of the RCL, such as the DFC,
will likely result in increased clinical instability upon physical examination. The
results of this study also suggest the need to consider repair of the DFC at the time
of RCL repair.
Key words
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References
- Thumb collateral ligament injuries: an anatomic basis for treatment.Hand Clin. 2000; 16: 345-357
- Radial collateral ligament injuries of the thumb.J Hand Surg Am. 2008; 33: 760-770
- Thumb metacarpophalangeal joint collateral ligament injury management.Hand Clin. 2012; 28: 361-370
- Impact of joint position and joint morphology on assessment of thumb metacarpophalangeal joint radial collateral ligament integrity.J Hand Surg Am. 2015; 40: 1838-1843
- Radial collateral ligament injuries of the thumb metacarpophalangeal joint: epidemiology in a military population.J Hand Surg Am. 2013; 38: 532-536
- Radial collateral ligament repair of the thumb metacarpophalangeal joint using the abductor pollicis brevis tendon.Plast Reconstr Surg. 2006; 117: 491-496
- Metacarpophalangeal joint injuries of the thumb.Hand Clin. 1992; 8: 713-732
- Ligament stability of the metacarpophalangeal joint: a biomechanical study.J Hand Surg Am. 1985; 10: 255-260
- Radial instability of the metacarpophalangeal joint of the thumb: a biomechanical investigation.J Hand Surg Br. 1995; 20: 102
- The anatomy of the radial side of the thumb: static restraints in preventing subluxation and rotation after injury.Am J Orthop. 1998; 27: 759-763
- Thumb ligament injuries.J Hand Surg Am. 2015; 40: 835-842
- The dorsal triangular fibrocartilage of the metacarpophalangeal joint: a cadaveric study.J Hand Surg Am. 2015; 40: 1410-1415
Doyle JR and. Botte MJ. Surgical Anatomy of the Hand and Upper Extremity. Philadelphia, PA: Lippincott Williams & Wilkins; 2003.
- Biomechanical analysis of static forces in the thumb during hand function.J Bone Joint Surg Am. 1977; 59: 27-36
- Analysis of the musculoskeletal loading of the thumb during pipetting—a pilot study.J Biomech. 2014; 47: 392-399
- Assessment of thumb positioning in the treatment of ulnar collateral ligament injuries: a laboratory study.Am J Sports Med. 1996; 24: 672-675
- The influence of thumb metacarpophalangeal joint rotation on the evaluation of ulnar collateral ligament injuries: a biomechanical study in a cadaver model.J Hand Surg Am. 2014; 39: 474-479
Article info
Publication history
Published online: August 11, 2017
Accepted:
June 28,
2017
Received:
December 6,
2016
Footnotes
This research was funded by a grant from Soonchunhyang University.
Identification
Copyright
© 2017 by the American Society for Surgery of the Hand. All rights reserved.
