Kinematics and stability of the fractured and implant-reconstructed radial head

Johnson, James A.; Beingessner, Daphne M.; Gordon, Karen D.; Dunning, Cynthia E.; Stacpoole, Rebecca A.; King, Graham J.W.

doi:10.1016/j.jse.2004.09.034

Next »Journal of Shoulder and Elbow Surgery
Volume 14, Issue 1, Supplement , Pages S195-S201, January 2005

Kinematics and stability of the fractured and implant-reconstructed radial head

James A. Johnson, PhD
- Department of Surgery, Faculty of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, Canada
- Hand and Upper Limb Centre, Bioengineering Laboratory, St Joseph’s Health Care London, London, Ontario, Canada.
- Reprint requests: James A. Johnson, PhD, Hand and Upper Limb Centre, Bioengineering Research Laboratory, St Joseph’s Health Care London, University of Western Ontario, 268 Grosvenor St, London, Ontario, Canada N6A 4L6.
Daphne M. Beingessner, MD
- Hand and Upper Limb Centre, Bioengineering Laboratory, St Joseph’s Health Care London, London, Ontario, Canada.
Karen D. Gordon, PhD
- Hand and Upper Limb Centre, Bioengineering Laboratory, St Joseph’s Health Care London, London, Ontario, Canada.
Cynthia E. Dunning, PhD
- Department of Surgery, Faculty of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, Canada
- Hand and Upper Limb Centre, Bioengineering Laboratory, St Joseph’s Health Care London, London, Ontario, Canada.
Rebecca A. Stacpoole, MSc
- Hand and Upper Limb Centre, Bioengineering Laboratory, St Joseph’s Health Care London, London, Ontario, Canada.
Graham J.W. King, MD
- Department of Surgery, Faculty of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada
- Department of Mechanical and Materials Engineering, University of Western Ontario, London, Ontario, Canada
- Hand and Upper Limb Centre, Bioengineering Laboratory, St Joseph’s Health Care London, London, Ontario, Canada.

Controversy exists as to the optimal management of radial head fractures. Biomechanical studies have been conducted to quantify elbow stability for simulated wedge fractures, head excision, and head replacement, with and without the integrity of the collateral ligaments. Our in vitro studies have demonstrated that in the ligamentously intact elbow, kinematics and stability are slightly altered with simulated depressed wedge fractures up to 120° of the radial head, markedly altered with head resection, and improved after radial head replacement. Radial head excision decreases elbow stability in the ligament-deficient elbow, and radial head replacement improves stability similar to that of the native radial head. The ligaments have the most marked influence on stability, particularly when the upper limb is positioned such that valgus and varus gravity loads are applied to the elbow. Whereas the radial head acts as a secondary stabilizer to the collateral ligaments with the arm in these positions, its relative role is greater when the arm is in the dependent position and elbow flexion is simulated, particularly in extension. Further studies are needed to elucidate the complex interaction of the radial head with the capitellum, the ulnohumeral joint, and the ligamentous structures for different activities of daily living.