Quantifying the Center of Elbow Rotation in Relation to the Capitellum: Implications for Lateral Ulnar Collateral Ligament Reconstruction

INTRODUCTION: Elbow lateral collateral ligament reconstruction is used to restore joint stability and mandates accurate characterization of where the centerline of ulnohumeral joint rotation (CLOR) is located on the lateral epicondyle. We hypothesized that the centerline of rotation is located in the same region as the geometric center of the capitellum. METHODS: Twenty-nine nonarthritic uninjured elbows were analyzed with three-dimensional modeling of computed tomography (CT) scans performed on each elbow. The projection of the CLOR on the cortex of the lateral epicondyle was recorded as was the center of the capitellum in the transverse plane. The relationship of these points to a fixed point on the lateral epicondyle was measured. RESULTS: A consistent region on the lateral epicondyle was identified where the CLOR intersected the outer cortex of the lateral epicondyle. This intersection did not significantly differ from the center of the capitellum in the sagittal plane. CONCLUSIONS: This study demonstrates that the center of the capitellum as viewed laterally is clinically equivalent to the CLOR and thus defines the location where a lateral ligament reconstruction limb may be placed to maximize isometric motion. This knowledge may be of surgical importance when locating a point of rotational isometry.