Question

the questions that need to be answered are the 3 learning objectives please. thank you!!

Patient Presentation A 15-year-old male comes to the emergency department complaining of severe pain over his right collarbone. He uses his left hand to hold his right arm close to and across the front of his body. Relevant Clinical Findings History While playing baseball, the patient reports colliding with the pitcher when running to first base. The impact knocked him off his feet and he fell on his right shoulder. His mother, and others nearby, reported hearing a loud snap. When he stood up. he was slouched and complained of extreme pain over his right clavicle. Physical Examination The following findings were noted on physical examination: • Prominence, ecchymosis, and tenderness over the right midclavicular regionale Diffuse swelling over the right clavicle, shoulder, and arm Right upper limb depressed (i.e., lower than left) Mild numbness over right upper limbale Right radial pulse weaker than left Lung sounds normal Imaging Studies Radiography of right shoulder revealed a midclavicular fracture Clinical Problems to Consider Anterior shoulder dislocation Clavicle fracture Shoulder separation LEARNING OBJECTIVES Describe the anatomy of the shoulder Describe the structures that stabilize and move the shoulder Explain the anatomical basis for the signs and symptoms associated with 2. 3. this case

Answer 1

1. Shoulder consists of a ball-and-socket joint formed by the humerus and scapula and their surrounding structures - ligaments, muscles, tendons - which support the bones and maintain the relationship of one to another. These supporting structures attach to the clavicle, humerus, and scapula, the latter providing the glenoid cavity, acromion and coracoid processes. The main joint of the shoulder is the shoulder joint (or glenohumeral joint), between the humerus and the glenoid process of the scapular.]The acromioclavicular joint and sternoclavicular joint also play a role in shoulder movements. White hyaline cartilage on the ends of the bones (called articular cartilage) allows the bones to glide and move on each other, and the joint space is surrounded by a synovial membrane. Around the joint space are muscles - the rotator cuff, which directly surrounds and attaches to the shoulder joint - and other muscles that help provide stability and facilitate movement.

Two filmy sac-like structures called bursae permit smooth gliding between bone, muscle, and tendon. They cushion and protect the rotator cuff from the bony arch of the acromion.

The glenoid labrum is the second kind of cartilage in the shoulder which is distinctly different from the articular cartilage. This cartilage is more fibrous or rigid than the cartilage on the ends of the ball and socket. Also, this cartilage is also found only around the socket where it is attached.]

The shoulder joint (also known as the glenohumeral joint) is the main joint of the shoulder. It is a ball and socket joint that allows the arm to rotate in a circular fashion or to hinge out and up away from the body. It is formed by the articulation between the head of the humerus and the lateral scapula (specifically-the glenoid cavity of the scapula). The "ball" of the joint is the rounded, medial anterior surface of the humerus and the "socket" is formed by the glenoid cavity, the dish-shaped portion of the lateral scapula. The shallowness of the cavity and relatively loose connections between the shoulder and the rest of the body allows the arm to have tremendous mobility, at the expense of being much easier to dislocate than most other joints in the body. There is an approximately 4-to-1 disproportion in size between the large head of the humerus and the shallow glenoid cavity. The glenoid cavity is made deeper by the addition of the fibrocartilaginous ring of the glenoid labrum.

The capsule is a soft tissue envelope that encircles the glenohumeral joint and attaches to the scapula, humerus, and head of the biceps. It is lined by a thin, smooth synovial membrane. This capsule is strengthened by the coracohumeral ligament which attaches the coracoid process of the scapula to the greater tubercle of the humerus. There are also three other ligaments attaching the lesser tubercle of the humerus to lateral scapula and are collectively called the glenohumeral ligament.

The transverse humeral ligament, which passes from the lesser tubercle to the greater tubercle of humerus, covers the intertubercular groove, in which the long head of biceps brachii travels.

ROTATOR CUFF

The rotator cuff is an anatomical term given to the group of four muscles and their tendons that act to stabilize the shoulder. These muscles are the supraspinatus, infraspinatus, teres minor and subscapularis and that hold the head of the humerus in the glenoid cavity during movement. The cuff adheres to the glenohumeral capsule and attaches to the head of the humerus. Together, these keep the humeral head in the glenoid cavity, preventing upward migration of the humeral head caused by the pull of the deltoid muscle at the beginning of arm elevation. The infraspinatus and the teres minor, along with the anterior fibers of the deltoid muscle, are responsible for external rotation of the arm.

The four tendons of these muscles converge to form the rotator cuff tendon. This tendon, along with the articular capsule, the coracohumeral ligament, and the glenohumeral ligament complex, blend into a confluent sheet before insertion into the humeral tuberosity. The infraspinatus and teres minor fuse near their musculotendinous junctions, while the supraspinatus and subscapularis tendons join as a sheath that surrounds the biceps tendon at the entrance of the bicipital groove.

Other muscles

In addition to the four muscles of the rotator cuff, the deltoid muscle and teres major muscles arise and exist in the shoulder region itself. The deltoid muscle covers the shoulder joint on three sides, arising from the front upper third of the clavicle, the acromion, and the spine of the scapula, and travelling to insert on the deltoid tubercle of the humerus. Contraction of each part of the deltoid assists in different movements of the shoulder - flexion (clavicular part), abduction (middle part) and extension (scapular part). The teres major attaches to the outer part of the back of the scapula, beneath the teres minor, and attaches to the upper part of the humerus. It helps with medial rotation of the humerus.

NERVE SUPPLY

The skin around the shoulder is supplied by C2-C4 (upper), and C7 and T2 (lower area). The brachial plexus emerges as nerve roots from the cervical vertebrae C5-T1. Branches of the plexus, in particular from C5-C6, supply the majority of the muscles of the shoulder.

Blood vessels

The subclavian artery arises from the brachiocephalic trunk on the right and directly from the aorta from the left.This becomes the axillary artery as it passes beyond the first rib. The axillary artery also supplies blood to the arm, and is one of the major sources of blood to the shoulder region. The other major sources are the transverse cervical artery and the supra scapular artery, both branches of the thyro cervical trunk which itself is a branch of the subclavian artery.The blood vessels form a network (anastamosis) behind the shoulder that helps to supply blood to the arm even when the axillary artery is compromised.

2. The glenohumeral (GH) joint is a true synovial ball-and-socket style diarthroidal joint that is responsible for connecting the upper extremity to the trunk. It is one of four joints that comprise the shoulder complex. This joint is formed from the combination of the humeral head and the glenoid fossa of the scapula. This joint is considered to be the most mobile and least stable joint in the body, and is the most commonly dislocated diarthoidal joint.

Abduction

Elevation of the humerus on the glenoid in the frontal (coronal) plane.

Flexion

Forward and upward movement of the humerus on the glenoid in the sagittal plane.

Extension

Upward movement of the humerus on the glenoid in the sagittal plane towards the rear of the body.

Internal Rotation

Rotation of the humerus on the glenoid in a medial direction.

External Rotation

Rotation of the humerus on the glenoid in a lateral direction.

Scapular Plane Abduction

Elevation of the humerus on the glenoid in the scapular plane, which is midway between the coronal and sagittal planes.

Horizontal Adduction

Movement of the humerus on the glenoid in a medial direction, usually accompanied with some degree of shoulder flexion.

Joint Capsule and Ligaments

Together, the Joint Capsule and the Ligaments of the GH Joint work to provide a passive restraint to keep the humeral head in contact with the Glenoid Fossa.

Joint Capsule:

· The lateral attachment of the GH Joint capsule attaches to the anatomical neck of the humerus.

· The medial attachment of the joint capsule is the glenoid and the labrum.

· According to some sources, overall strength of the capsule bears an inverse relationship to the patient's age; the older the patient, the weaker the Joint Capsule.

· With the arm in a resting position the inferior and anterior portions of the capsule are lax, while the superior portion is taut.

· The anterior portion of the capsule is reinforced by the superior, middle, and inferior glenohumeral ligaments which form a Z-shaped pattern on the capsule.

· The muscles of the rotator cuff act to reinforce the joint capsule superiorly, posteriorly, and anteriorly.

· The joint capsule provides little support to the GH joint without the reinforcement of ligaments and the surrounding musculature.

Ligaments

Superior Glenohumeral Ligament:

· Limits external rotation and inferior translation of the humeral head.

· Arises from the glenoid and inserts on the anatomical neck of the humerus.

Middle Glenohumeral Ligament:

· Limits external rotation and anterior translation of the humeral head.

· Arises from the glenoid and inserts on the anatomical neck of the humerus.

Inferior Glenohumeral Ligament:

· Limits external rotation and superior and anterior translation of the humeral head (anterior portion);

· Limits internal rotation and anterior translation (posterior portion).

· Arises from the glenoid and inserts on the humerus just beyond the lesser tuberosity.

Coracohumeral Ligament:

· Split into anterior and posterior divisions by the biceps tendon.

· Anterior portion limits extension while the posterior portion limits flexion.

· Both divisions limit inferior and posterior translation of the humeral head.

· Helps to support the weight of the resting arm against gravity.

· Runs laterally from the coracoid process to the humerus, covering the superior Glenohumeral Ligament and blending with the Superior Joint Capusle and Supraspinatus Tendon superiorly.

Transverse Humeral Ligament:

· This ligament serves to keep the tendon of the long head of the biceps in the bicipital groove.

3. SIGNS AND SYMPTOMS ARE

>Sagging of the shoulder downward and forward.

>Inability to lift the arm because of pain.

>A grinding sensation when you try to raise the arm.

>A deformity or "bump" over the break.

>Bruising, swelling, and/or tenderness over the collarbone.