This study is a cadaveric investigation on the role of the coronoid process in varus stability of the elbow. The authors tested the stability of ten cadaveric elbows at multiple different flexion angles. After testing, the authors removed incrementally increasing amounts of the coronoid process. The authors found for each flexion angle that removal of more than fifty percent of the height of the coronoid process produced a statistically significant decrease in the load required for varus displacement, when compared with all lesser resection levels. Further removal of over fifty percent of the coronoid height resulted in increasing ease of displacement with varus load.
The authors also found that the elbow was inherently more stable to varus displacement in flexion than in extension. The resistance to varus displacement as measured by a percentage of the control elbows tended to decrease at lower flexion angles, indicating that the coronoid process may contribute to elbow stability more in extension than in flexion.
The conclusions of the article, found to be valid from a statistical perspective, indicated that: 1) loss of over fifty percent of the coronoid height resulted in a significant loss of stability to varus displacement in the elbow; 2) the role of the coronoid process in elbow stability as related to varus displacement was more significant in elbow flexion than in elbow extension.
J Shoulder and Elbow Surg