Identifying the location and volume of bony impingement in elbow osteoarthritis by 3-dimensional computational modeling.

PURPOSE: To determine the locations and volumes of bone requiring resection to restore range of motion in patients with osteoarthritis of the elbow, using computational modeling.

METHODS

A total of 30 patients with primary osteoarthritis of the elbow and restricted range of motion underwent computed tomography. We used the computed tomography data to generate 3-dimensional models. We simulated flexion and extension of the elbow by flexing and extending the radius and ulna about the flexion-extension axis. The locations and volumes of impinging bone were calculated by the model at flexion angles of 0°, 10°, 20°, 120°, 130°, and 140°.

RESULTS

Flexion simulations demonstrated bony overlap in many patients between the coronoid process and the coronoid fossa and between the radial head and the radial fossa. The volumes of these overlapping regions increased as the flexion angle increased. Extension simulations demonstrated bony overlap between the tip and sides of the olecranon and the corresponding regions of the olecranon fossa in most patients. These overlapping volumes increased in greater degrees of elbow extension. In addition, we found bony overlap in extension in several patients between the radial head and an osteophyte present on the posterior aspect of the capitellum. The mean total overlapping volumes at each flexion angle were 59 mm(3) at 120°, 238 mm(3) at 130°, and 589 mm(3) at 140° in flexion; and 184 mm(3) at 20°, 395 mm(3) at 10°, and 741 mm(3) at 0° in extension.

CONCLUSIONS

Three-dimensional computational models identified the locations and volumes of bony impingement in patients with osteoarthritis of the elbow. They also highlighted certain unique regions of impingement, such as between the radial head with a posterior capitellar osteophyte in extension.

CLINICAL RELEVANCE: This modeling approach may provide the surgeon with a useful patient-specific guide to ensure complete resection of impinging osteophytes.