Radiographic analysis of elbow size.

Abstract

Background : Aseptic loosening is a serious complication in total elbow arthroplasty. Its etiologies are multifactorial. The mechanical failure is a major etiology of loosening that occurs from the micromotion between bone and cement interfaces. We study inappropriate sizes between elbow prostheses and patients’ elbows. If elbow prosthesis is too small, its stress is higher in latter: and mechanical failure and aseptic loosening then occur.

Objective : To study the distal humeral, proximal ulnar medullary canal diameters and the location of flexion-extension axis, and compare the elbow sizes in cadavers with elbow prostheses.

Design : Descriptive study.

Method : We studied 30 cadaveric elbows (16 males and 14 females) in distal humeral and proximal ulnar medullary canal diameters. These parameters were compared with commercial elbow prostheses. The flexion-extension axis and the carrying angle were also studied.

Result : Distal humeral and proximal ulnar medullary canal diameters were significantly larger in the male than the female in the periarticular area. The angle between the flexion-extension axis and the medullary canal axis of the humerus was 86.0 ± 3.7°. Except the ulna in the female, distal humerus and proximal ulna in the male were larger than the elbow prostheses.

Conclusion : The diameters of elbow prostheses should be improved to be more appropriate for the humans’ elbows.