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
. 2017 Sep;26(9):1636-1643.
doi: 10.1016/j.jse.2017.04.011. Epub 2017 Jul 6.

Role of the lateral collateral ligament in posteromedial rotatory instability of the elbow

Enrico Bellato  1 , Youngbok Kim  2 , James S Fitzsimmons  3 , Alexander W Hooke  3 , Lawrence J Berglund  3 , Daniel R Bachman  3 , Shawn W O'Driscoll  4
Affiliations

Role of the lateral collateral ligament in posteromedial rotatory instability of the elbow

Enrico Bellato et al. J Shoulder Elbow Surg. 2017 Sep.

Abstract

Background: Posteromedial rotatory instability (PMRI) of the elbow consists of an anteromedial coronoid fracture with lateral collateral ligament (LCL) and posterior bundle of the medial collateral ligament (PMCL) tears. We hypothesized that the LCL tear is required for elbow subluxation/joint incongruity and that an elbow affected by an anteromedial subtype 2 coronoid fracture and a PMCL tear exhibits contact pressures different from both an intact elbow and an elbow affected by PMRI.

Materials and methods: Six cadaveric elbows were tested under gravity varus stress using a custom-made machine designed to simulate muscle loads and to passively flex the elbow from 0° to 90° and measure joint contact pressures. After testing of the intact specimen (INTACT-elbow), an anteromedial subtype 2 coronoid fracture with a PMCL tear (COR+PMCL-elbow) and a PMRI injury (PMRI-elbow), after adding an LCL tear, were tested. The highest values of mean contact pressure were used for the comparison among the 3 groups.

Results: Neither subluxation nor joint incongruity was observed in the COR+PMCL-elbow. The addition of an LCL detachment consistently caused subluxation and joint incongruity. Mean contact pressures were higher in the COR+PMCL-elbow compared with the INTACT-elbow (P < .03) but lower than in the PMRI-elbow (P < .001).

Conclusions: The LCL lesion in PMRI is necessary for elbow subluxation and causes marked elevations in contact pressures. Even without subluxation, the COR+PMCL-elbow showed higher contact pressures compared with the INTACT-elbow. Treatment of PMRI should be directed toward prevention of joint incongruity, whether by surgical or nonsurgical means, to prevent high articular contact pressures.

Keywords: Posteromedial rotatory instability; anteromedial coronoid fracture; articular contact pressure; elbow subluxation; joint incongruity; lateral collateral ligament; posterior bundle of the medial collateral ligament.

PubMed Disclaimer

LinkOut - more resources