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Arthroscopic removal of the olecranon osteophytes has been widely used as treatment for posterior elbow impingement due to olecranon osteophytes. However, there is controversy regarding how much resection is acceptable. Although many biomechanical and clinical studies about the elbow have been done, there are few studies about the biomechanical effects of olecranon resection.1-5 An et al1 reported that a 50% olecranon osteotomy (resection vertical to the proximal ulna shaft) significantly decreased varus-valgus elbow joint resistant force. Andrews et al2 suggested that at moderate quasistatic valgus loads, ulnar collateral ligament strain is not significantly increased with increasing amounts of olecranon resection.2,5 Recently, Kamineni et al3,4 reported that valgus angulation of the elbow and strain in the medial collateral ligament increased in association with increased amount of olecranon resection. However, it is unclear which olecranon method is most effective, and there is little understanding about the anatomical changes in the elbow joint due to different resection methods.
The aim of the current study was to quantify changes in elbow joint stability after resection of the posteromedial olecranon. Our cut direction of the posteromedial olecranon was parallel to the plane of the proximal ulnar shaft. This osteotomy method simulated the arthroscopic treatment for an overhead thrower with posteromedial olecranon osteophytes. The objectives of this study were to measure the elbow joint kinematics and the regional deformation and strain characteristics of the anterior bundle of the medial ulnar collateral ligament. We also proposed the functional varus-valgus stiffness as a joint stability criterion.
Methods
Seven fresh frozen cadaver elbows were prepared by dissecting all soft tissue except the capsule and ligaments. The average specimen age was 76.3 years (range, 64-84 years; 2 men, 5 women). Four right elbows and 3 left elbows were used. The humeral and forearm ends of the elbow specimen were fixed into PVC pipes using plaster of Paris. A guide rod was attached to the distal forearm to aid in positioning the elbow at flexion positions of 30°, 60°, and 90° and to apply the external valgus torque.
Varus-valgus angulation of the forearm, forearm rotation, and the length of the anterior bundle of the medial ulnar collateral ligament were measured at each olecranon resection stage and at elbow flexion angles of...