The Applied Anatomic And Biomechanical Study Of The Elbow Stability

Objective: The stability of elbow is maintained by the bones, joints, ligaments and capsule which consist of the elbow, and it is important to the function of the upper extremity. The effect of bones and joints of the elbow has been well defined, but the effect of the ligaments of elbow is unclear The purpose of present study is aimed to further definite the morphology of the collateral ligaments, to clear the feature of MRI signs of injuring ligaments, to provide the repair or reconstruction save approach for the ligaments surgely through applied anatomic study, And to determine the role of the collateral ligaments and the radial head in the stability of elbow through biomechanical study. So we can provide the anatomic basis for clinic diagnose and treatment acute or chronic instability of the elbow Material and Methods: There were 48 fresh-frozen adult cadaveric elbows and 44 embaded adult cadaveric elbows to dissect and test in this study. I. To observe the morphology of the collateral ligaments and gross measure the length of the ligaments in different angle of the elbow flexion. 2. To observe the anatomic relationship between the extensor muscle and the radial collateral ligament. To measure the posterolateral rotatory instability of the elbow in serial sectioning the lateral soft tissue (including the radial collateral ligament ) with a specially designed equipment. 3. To measure the valgus rotatory instability of the elbow in serial sectioning the ulnar collateral ligament complex with material test system ( MIS). 4. To measure the force transferred through radial head and the stress scattering change in ulno-ttocblear articulation. 5. To observe the relationship of the posterior interosscous nerve, the radial collateral ligament, the supinator muscle and the radial head, and the relationship between the flexor-pronator muscle mass and the ulnar collateral ligament. On these anatomic bases, to design save surgical approaches to repair or reconstruct the radial or ulnar ligament. 6. To study the method of elbow MRI examining and the morphology of the injury ligaments on the MRI signs. Results: 1 .The ulnar collateral ligament of the elbow is composed of an anterior bundle and a posterior bundle. The anterior bundle arise from the inferior aspect of the medial epicondly and inserts immediately adjacent to the joint surface on the ulnar near the sublimis tubercle. The anterior bundle can be subdivided into anterior and posterior band of equal width from anatomy and function. The posterior bundle arises from the medial epicondyle slightly posterior to its most inferior portion and inserts broadly on the olecranon process. The lateral collateral ligament arises from the inferior aspect of the lateral epicondyle. Two types of conjoined lateral collateral and annular ligamentous insertions on the ulna were observed. Type I (61.2%) was biobed and type 11(38.8%) was a single broad conjoined insert. 2.The anterior band of anterior bundle was more tighten than the posterior band as the elbow flexed less than 600 .When the elbow flexed over 60 o ,the two parts of anterior bundle were tighten equivalent The posterior bundle was tighten as the elbow was flexed more than 900 . The lateral collateral ligament was increased tighten as the elbow flexed. 3.The ligament fascia of the extensor mass originates from the lateral epicondyle. One part of the fascia changes into intermuscular septa a...