Mäurer Imaging Strategies for the Shoulder

1. Auflage 2004
ISBN: 978-3-13-257818-0
Verlag: Thieme
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 180 Seiten, ePub

This book presents radiology of the shoulder in a unique didactic concept, with careful organization of material under headings, using margin comments that summarize the most important information. The book begins with a chapter on the basic anatomy of the shoulder joint, and shows examples of various projections of standard radiographs, and what these reveal. Arthrography, ultrasound, CT and MRI are included in all parts of the book. Following this introductory chapter on image technique and interpretation, the individual pathologic chapters cover such topics as trauma, degenerative changes, tumors, inflammation and more. A concise and clearly organized representation of contents in this text allows quick orientation and assimilation of the most important aspects of shoulder imaging.

Mäurer

Zielgruppe

Ärzte

Autoren/Hrsg.

Mäurer, Jürgen

Fachgebiete

• Medizin | Veterinärmedizin Medizin | Public Health | Pharmazie | Zahnmedizin Medizinische Fachgebiete Bildgebende Verfahren, Nuklearmedizin, Strahlentherapie Radiologie, Bildgebende Verfahren
• Medizin | Veterinärmedizin Medizin | Public Health | Pharmazie | Zahnmedizin Chirurgie Orthopädie- und Unfallchirurgie

Inhaltsverzeichnis

1 Anatomy and Imaging of the Shoulder Joint
2 Traumatology
3 Degenerative Changes
4 Inflammatory Conditions
5 Tumors and Tumor-Like Lesions
6 Hormonal and Metabolic Bone Diseases
7 Ischemic Changes
8 Hematological Diseases
9 Neurogenic and Metabolic Bone Diseases
10 Pediatric Radiology

Leseproben

1    Anatomy and Imaging of the Shoulder Joint

Macroscopic Functional Anatomy

The head and the glenoid fossa articulate in the shoulder joint (glenohumeral joint). Functionally, it is a ball-and-socket joint that enables movement in three degrees of freedom. The shoulder is the most mobile of the major joints. Its high mobility, together with its limited osseous embracement accounts for its high rate of injury.

Osseous Structures

Humerus

   Articular surface of the humeral head covered hemispherically with hyaline cartilage

   Rotation of the humeral head around a central point in the depth of the head

   Important markers of the proximal humerus: major and minor tuberosities as well as bicipital groove

   Anatomical neck: Transition of the proximal humerus to the humeral head

   Surgical neck: Frequent fracture site

Scapula

   Gliding and rotation of the scapula on the thoracic surface with arm movement

   The glenoid fossa is perpendicular to the body of the scapula

   The osseous glenoid fossa is markedly smaller than the humeral head (ratio about 1:4)

   According to Bigliani (1982), three different acromial types can be observed in the coronal plane:

–   Type I: Flat acromion

–   Type II: Curved acromion

–   Type III: Hooked acromion with inferior nose

Clavicle

   Flat, sinuous, bridging the upper ribs

   Medial articulation with the sternum at the sternoclavicular joint (SC joint)

   Lateral connection with scapula with the acromioclavicular joint (AC joint)

Soft Tissues

Glenoid Labrum

Since the incongruent osseous articular surfaces alone cannot provide structural and functional integrity of the shoulder joint, it is largely stabilized by the glenoid labrum.

   Circular enlargement of the articular surface

   Fibrous cuff of fibrocartilage reinforcing the joint capsule

   Vascular supply through capsular vessels

   “Transitional zone” (hyaline cartilage) between labrum and osseous glenoid fossa

   Four labrum segments: anterosuperior and posterosuperior, as well as anteroinferior and posteroinferior quadrants

   Surgical localization of the labral lesions following the dial of the clock: right anterior positions 12 to 6 o'clock (left posterior positions 12 to 6 o'clock!)

   Numerous normal variants of the labrum (see Chapter 2, Traumatology)

Fig. 1.1 Types of capsular insertion according to Moseley and Övergaard (1962).

Diagram of the different insertions of the anterior capsule as seen on the axial plane (arrowheads).

Bi	Biceps tendon

Hu

Humerus

Gle	Glenoid process

Capsuloligamentous System

The capsuloligamentous system contributes relatively little to the static stability of the shoulder. The joint is further supported by an intra-articular negative pressure.

   Capsular insertion with fibrous and synovial component in the region of the osseous glenoid fossa

   Three glenohumeral ligaments (superior, medium, and inferior glenohumeral ligaments) to enforce the anterior capsule

   Wide variability of course, insertion, and caliber of the three ligaments

   The inferior ligament is most important for shoulder stability

   Variable anterior capsular insertion at the glenoid fossa; according to Moseley and Övergaard (1962), three capsular insertions can be distinguished in the axial plane (Fig. 1.1):

–   Type I: Insertion at the tip or basis of the anterior labrum

–   Type II: Insertion of the capsule not more than 1 cm medial to the labrum

–   Type III: Insertion of the capsule more than 1 cm medial to the labrum

   Type III should predispose to or be the result of anterior dislocation

Musculature of the Rotator Cuff

Since osseous and ligamentous support is inadequate, stability is achieved by soft tissues. Dynamic stability is primarily provided by the muscles of the rotator cuff together with the deltoid muscle.

   Four muscles: Anteriorly the subscapular muscle (origin at the minor tuberosity), posteriorly the supraspinatus muscle (origin at the major tuberosity), the infraspinatus muscle and the teres minor (origin at the major tuberosity)

   Fibrous “tendon cap” of the rotator cuff around the humeral head

   “Critical zone” within the tendon of the supraspinatus muscle (1–1.5 cm proximal to its origin) presumably predisposes to degeneration with subsequent rupture

   Additional stabilization of the joint provided by muscular compression through pull of the rotator cuff

Bursae of the Shoulder Joint

Several bursae (fluid-containing sacs lined with synovial membrane) serve as gliding layers to facilitate free motion of the shoulder joint and partially communicate with the joint cavity.

   The subacromial bursa and subdeltoid bursa often communicate with each other, but usually not with the joint capsule (important for rotator-cuff tears!)

   The subtendinous bursa of the sub-scapular muscle and the subcoracoid bursa communicate with the joint anteriorly

   Normal bursae are not visualized by conventional radiology, only by ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI)

Conventional Radiology

Standard Projections

Like all other joints, the shoulder is first examined by obtaining a baseline study consisting of two views perpendicular to each other. Many special projections are available for different clinical questions (Table 1.1), but their diagnostic contribution has diminished following the introduction of CT and MRI.

Table 1.1 Recommended radiographic projections of the shoulder joint (please refer to text for technical factors)

Clinical question	Projections

Baseline

AP view    Axial view

Degeneration

AP view    Axial view    90° abduction view

Special impingement

Schweden stage I–III    View of the intertubercular groove    Supraspinatus outlet view    Rockwood view

General trauma

AP view    Axial view

Impaired mobility

Transthoracic view    Y-projection    Velpeau view

Dislocation

AP view    Axial view

Special Bankart lesion

West Point view    Glenoid rim view according to Bernageau    Apical oblique view

Special Hill-Sachs defect

AP view in 60° internal rotation    Stryker view    Hermodsson view

AC joint

AC joint view AP    AC joint view AP with weight bearing    Supraspinatus outlet view    Rockwood view

Anteroposterior View/Tangential View of the Glenoid Fossa

The joint space is superimposed on the straight anteroposterior (AP) view!

Indication

Initial workup for suspected

   Fractures (location and extent, determination of fracture type, orientation of fracture lines, articular involvement, position of fracture fragments)

   Dislocations

   Inflammatory conditions

   Degenerative changes

   Neoplasms

Technique

   Shoulder in contact with the cassett

   Patient sitting with the arm in neutral...

Über Autor(innen)

Mäurer