Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Jul;16(4):467-473.
doi: 10.1177/1558944719868518. Epub 2019 Aug 20.

Biomechanical Analysis of Thumb Ulnar Collateral Ligament Tear Kinematics

Charles C Lin  1   2 , Nilay A Patel  2   3 , Yasuo Itami  2   4 , Michelle H McGarry  2 , Steven S Shin  5 , Thay Q Lee  2
Affiliations

Biomechanical Analysis of Thumb Ulnar Collateral Ligament Tear Kinematics

Charles C Lin et al. Hand (N Y). 2021 Jul.

Abstract

Background: Thumb ulnar collateral ligament (UCL) injuries are common, but the kinematics of these injuries have not been comprehensively described, especially regarding kinematic changes with progressive UCL injury. Methods: Eleven cadaveric thumbs underwent kinematic testing under 4 conditions: intact, partial tear (50%) of the proper UCL, full tear of the proper UCL, and complete tear of both the proper and accessory UCL. Kinematic testing parameters included varus/valgus stress, pronation/supination, and volar/dorsal translation at -10 degree, 0 degree, 15 degree, and 30 degree of metacarpophalangeal flexion. Results: Partial tear of the proper UCL did not result in significant increases in laxity in any direction compared with intact (P ≥ .132). Full tear of the proper UCL resulted in a significant increase in valgus angulation (18.8° ± 1.7° vs 11.5° ± 1.5°; P = .024) and pronation (15.4° ± 2.5° vs 12.6° ± 2.3°; P = .034) at 30 degree of flexion relative to intact. Complete tear of both the proper and accessory collateral ligaments resulted in increased valgus angulation at all degrees of flexion (P < .001). Complete tear also resulted in a significant volar translation at 0 degree, 15 degree, and 30 degree of flexion (P ≤ .016). Conclusion: Partial tear of the proper UCL does not significantly affect the stability of the joint, but full tear of the proper UCL increases valgus instability at 30 degree of flexion. Complete tear of the UCL is necessary for increased varus/valgus instability at all degrees of flexion and results in significant increases in pronation/supination and volar translation.

Keywords: kinematics; thumb; ulnar collateral ligament.

PubMed Disclaimer

Conflict of interest statement

Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Test setup. Note. Test setup with proximal portion of metacarpal potted in a PVC pipe with plaster of Paris. Thumb flexion angle is set by adjusting the angle of the cylinder holding the PVC pipe. Lines of pull are attached directly to the specimen or to pins placed through the specimen and run over pulleys to hanging weights. Six degrees of movement are able to be tested, including varus/valgus, pronation/supination, and volar/dorsal translation.
Figure 2.
Figure 2.
Tear conditions: (a) intact (pUCL, aUCL), (b) partial pUCL tear (50% of the proper collateral ligament), (c) full pUCL tear, and (d) complete UCL tear (proper and accessory collateral ligaments fully transected). Note. pUCL = proper ulnar collateral ligament; aUCL = accessory ulnar collateral ligament; UCL = ulnar collateral ligament.
Figure 3.
Figure 3.
Varus-valgus angulation. Statistically significant at P < .05: * vs Intact; # vs PP-UCL tear; † vs FP-UCL tear. Note. PP-UCL = partial proper ulnar collateral ligament; FP-UCL = full proper ulnar collateral ligament.
Figure 4.
Figure 4.
Pronation-supination rotation. Statistically significant at P < .05: * vs Intact; # vs PP-UCL tear; † vs FP-UCL tear. Note. PP-UCL = partial proper ulnar collateral ligament; FP-UCL = full proper ulnar collateral ligament.
Figure 5.
Figure 5.
Volar-dorsal translation. Statistically significant at P < .05: * vs Intact; # vs PP-UCL tear; † vs FP-UCL tear. PP-UCL = partial proper ulnar collateral ligament; FP-UCL = full proper ulnar collateral ligament.
See this image and copyright information in PMC

References

    1. Hinke DH, Erickson SJ, Chamoy Let al.. Ulnar collateral ligament of the thumb: MR findings in cadavers, volunteers, and patients with ligamentous injury (gamekeeper’s thumb). AJR Am J Roentgenol. 1994;163(6):1431-1434. - PubMed
    1. Mogensen BA, Mattsson HS. Post-traumatic instability of the metacarpophalangeal joint of the thumb. Hand. 1980;12(1):85-90. - PubMed
    1. Helm RH. Hand function after injuries to the collateral ligaments of the metacarpophalangeal joint of the thumb. J Hand Surg Br. 1987;12(2):252-255. - PubMed
    1. Gerber C, Senn E, Matter P. Skier’s thumb. Am J Sports Med. 1981;9(3):171-177. - PubMed
    1. Rettig AC. Athletic injuries of the wrist and hand: part II: overuse injuries of the wrist and traumatic injuries to the hand. Am J Sports Med. 2004;32(1):262-273. - PubMed

Publication types

LinkOut - more resources