Clavicle anatomy

• The clavicle (collarbone) is one of the most fractured bones in the body. • Symptoms of a broken collarbone include severe pain and swelling at the site of the fracture and with visible deformity in some cases. • A clavicle fracture is diagnosed through a physical examination and • Clavicle fractures are classified into three types based on the location of the fracture: 1) near the sternum (least common), 2) near the AC joint (second most common), or 3) in the middle of the bone between the sternum and AC joint (most common). • Immobilization using a sling is often used to treat a clavicle fracture along with cold therapy and medication for pain relief. • In most cases of a fractured collarbone, there are no limitations once the fracture heals. Where is the clavicle? The clavicle is the bone that connects the breastplate (sternum) to the shoulder. It is a very solid bone that has a slight S-shape and can be easily seen in many people. It connects to the sternum at a joint with cartilage called the sternoclavicular joint. At the other end, the bone meets the shoulder area at a part of the shoulder blade (scapula) called the acromion. The joint at that end of the bone containing cartilage is called the acromioclavicular joint. The collarbone acts as a strut to connect the sternum to the shoulder blade. Because of the critical location of the clavicle, any severe force on the shoulder, such as falling directly onto the shoulder or falling on an outstretched arm, transfers f...

Subclavius muscle (musculus subclavius) The subclavius muscle is a short, triangular muscle of the thoracic wall that lies underneath the The main function of the subclavius is to stabilize the clavicle during This article will describe the Key facts about the subclavius muscle Origin Costal cartilage, sternal end of rib 1 Insertion Anteroinferior surface of middle third of clavicle Innervation Subclavian nerve (C5-C6) Blood supply Clavicular branch of thoracoacromial artery, suprascapular artery Function Sternoclavicular joint: Anchors and depresses clavicle Synonyms: costa prima, os costale primum The subclavius muscle originates by a strong tendon from the sternal end of the 1st rib, near its articulation with the costal cartilage. The tendon spreads superolaterally into a muscle belly that inserts into the lower surface of the middle third of the body of clavicle (groove for subclavius muscle). The subclavius is enclosed by the clavipectoral fascia, which is a fibrous connective tissue that spans the interval between the clavicle and Innervation The subclavius is innervated by the subclavian nerve (C5-6), a small branch that arises from the superior trunk of brachial plexus. Blood supply The subclavius muscle receives arterial blood from the clavicular branch of Synonyms: Nerve to subclavius muscle, Nervus musculi subclavius Function The main function of the subclavius muscle is the active stabilization of the clavicle at the depression of the sternal end of the clavic...

The standard AP view of the clavicle is taken with the patient upright or sitting, with arms at the sides, chin raised, and looking straight ahead. The posterior shoulder should be in contact with image receptor (IR) or tabletop, without rotation of body. In this position, the central ray (CR) should be perpendicular to the mid-shaft of the clavicle. The collimation border should be visible with the entire clavicle visualized, including both AC and SC joints (Fig. The standard axial view of the clavicle is taken with the patient in a similar position; however, the CR should be angled 15–30° cephalic to the patient. Note is made that in thinner patients, a greater angle may be needed. Correct angulation of CR will project most of the clavicle above the scapula and ribs . It should be noted that only the medial portion of the clavicle will be superimposed by the first and second ribs. Both posteroanterior (PA) and PA axial views of the clavicle can also be obtained if the patient is unable to tolerate the AP position. In this position, the patient’s chest should be pressed against the IR or tabletop. CT scanning is of little diagnostic value in an acute clavicle injury and is often reserved for cases of suspected neurovascular and/or visceral injury ; CT angiogram is indicated in the setting of a distal vascular deficit following a clavicle fracture. The other utility of CT lies in the evaluation of delayed union or non-union of a clavicle fracture. The patient is placed in ...

• 1 Anatomical Structure • 1.1 Articulating Surfaces • 1.2 Joint Capsule • 1.3 Ligaments • 2 Movements • 3 Mobility and Stability • 4 Blood Supply • 5 Innervation • 6 Clinical Relevance: Dislocation of the Sternoclavicular Joint The sternoclavicular joint is an articulation between the It is a saddle-type synovial joint which acts to link the upper limb with the trunk. In this article, we will examine the anatomy of the sternoclavicular joint – its structure, neurovascular supply, and clinical considerations. Anatomical Structure Articulating Surfaces The sternoclavicular joint is formed by an articulation between three structures: • Sternal end of the clavicle • Manubrium of the sternum • First costal cartilage (cartilage associated with the first rib) The articular surfaces are covered with fibrocartilage (as opposed to hyaline cartilage, present in the majority of synovial joints). The joint is separated into two compartments by a fibrocartilaginous articular disc. By Fig 1 – The articulating surfaces of the sternoclavicular joint. Joint Capsule The joint capsule of the sternoclavicular joint extends to the borders of the articular surfaces. It is lined internally by a synovial membrane, which produces synovial fluid to reduce friction between the articulating structures. Ligaments The ligaments of the sternoclavicular joint provide much of its stability. There are four main ligaments: • Sternoclavicular ligaments (anterior and posterior) – reinforces the joint capsule ...

• Acromioclavicular (AC) joint: The acromioclavicular joint forms between the acromion of the scapula and clavicle at the top of the shoulder, held together by the acromioclavicular ligament. • Sternoclavicular joint: The sternoclavicular joint forms between the sternum and clavicle at the front of the chest, and is supported by the costoclavicular ligament. The relative size of the clavicle leaves it particularly susceptible to fracture. Fracture of the clavicle can occur from a fall landing on an outstretched hand or through a direct blow to the shoulder. The middle third of the clavicle is most commonly fractured, accounting for about 80% of all cases of clavicle fractures. The subclavius, which means “beneath the clavicle,” is the primary muscle that controls the clavicle. It originates at the first rib, and attaches to the underside of the clavicle. When contracted, the subclavius, controlled by the subclavian nerve, causes the clavicle to depress, or move downwards. Acromioclavicular (AC) Joint Sprain or Separation Trauma to the acromioclavicular joint, such as a direct blow to the front of the shoulder or falling and landing on an outstretched hand, can injure the ligaments holding the acromion and clavicle together. This can result in either an acromioclavicular joint sprain or separation of the joint. Symptoms include pain localized specifically at the acromioclavicular joint at the top of the shoulder. Distal Clavicle Osteolysis (Weightlifter’s Shoulder) The end ...