Collateral Ligament Medial Elbow

The bony architecture of the elbow contributes to the stability of the joint, which is reinforced by the medial (ulnar) and lateral (radial) collateral ligaments, which provide most of the stability. 

Avulsion fractures of the medial epicondyle are seen between the ages of 9 and 15, after the apophysis becomes a separate ossification nucleus from the epiphysis of the distal humerus and before it fuses with the distal humerus. The medial epicondyle is a traction apophysis for the flexor group of forearm muscles, and also serves as an attachment for the ulnar collateral ligaments and the joint capsule. This injury accounts for up to 10% of elbow fractures. 

The joint capsule and several ligaments support the elbow joints. Maintaining the most support and resisting valgus and varus strains are the medial and lateral collateral ligaments, respectively. Other anatomical considerations in-... 

Somatic dysfunctions can involve contraction of the related muscles, compression of the neural elements, strain of the ligamentous aspects, and restriction primarily of the secondary motions of the joint components. The radial head typically entails posterior or anterior dysfunctions and may involve the muscles, the annular ligament, and the lateral collateral ligament. The humero-olecranon dysfunctions can involve the muscles, the medial collateral ligament, and can be related to symptoms involving the ulnar nerve. Restriction of elbow... 

Ward SI, Teefey SA, Paletta GA Jr et al (2003) Sonography of the medial collateral ligament of the elbow a study of cadavers and healthy adult male volunteers. AJR Am J Roentgenol... 

Anterior Elbow Pathology 371 Distal Biceps Tendon Tear 371 Bicipitoradial (Cubital) Bursitis 372 Medial Elbow Pathology 376 Medial Epicondylitis (Epitrochleitis) 376 Medial Collateral Ligament Injury 377 Epitrochlear Lymphadenopathies 377 Lateral Elbow Pathology 378 Lateral Epicondylitis 378... 

The elbow is composed of three articulations-radio-capitellar, proximal radio-ulnar and trochlea-ulnasharing in a common joint cavity and stabilized by a number of soft-tissue structures, including the lateral and medial collateral ligaments and the anterior portion of the joint capsule. 

The elbow is one of the most stable joints of the body. In normal states, elbow joint motion ranges approximately from 0° to 150° of flexion and from 75° in pronation to 85° in supination. Elbow extension is limited by contact of the olecranon in the posterior humeral fossa, and tightening of the anterior band of the medial collateral ligament, of the joint capsule and of flexor muscles. On the other hand, the bulk of anterior muscles of the arm, the tension of the triceps and the contact of the coronoid process in the anterior humeral fossa limit elbow flexion. Pronation and supination movements are primarily limited by passive muscle constraints rather than ligaments. 

The medial aspect of the elbow is examined with the elbow extended, resting on a table. Then, the patient is asked to lean toward the side with the forearm in forceful external rotation (Barr and Babcock 1991). On the medial side of the elbow, there are two main structures amenable to US evaluation the common flexor tendon and the medial collateral ligament. 

Fig. 8.35. Medial collateral ligament injury. Longitudinal 12-5 MHz US image obtained with valgus stress over the anterior band of the medial collateral ligament (arrowheads) shows a focal hypoechoic area in the proximal ligament and mild widening of the elbow joint (arrows) compatible with a ligamentous injury. ME, medial epicondyle jin, flexor muscles...

Static constraint of the elbow is the result of both bony structure and capsuloligamentous stabilizers. The soft tissue stabilizers include the medial and lateral collateral ligament complexes, the joint capsule, the annular ligament, and the interosseous membrane (Figure 10.3). 

The joint capsule surrounds all three articulations of the elbow joint and is thickened medially and laterally to form the collateral ligament complexes [2]. The joint capsule is loose anteriorly and especially posterior to allow full flexion and extension of the elbow [1]. It is most lax in 80 degrees of elbow flexion. Transverse and obliquely directed bands in the anterior capsule provide significant stability when taut in extension [4]. 

The medial collateral ligament complex consists of three components the anterior bundle, posterior bundle, and transverse ligament. The anterior bundle is the main stabilizer against valgus torques of the elbow [2]. The anterior bundle provides maximal constraint when the elbow is fully extended. The posterior bundle is tauL providing constraint when the elbow is flexed. The transverse bundle is not believed to contribute significantly to joint stability [1]. 

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