cg-tower.com Bookshelf. A service of the national Library of Medicine, nationwide Institutes that Health.
You are watching: What does the clavicle articulate with
Anatomy, Shoulder and Upper Limb, Clavicle
Scott Hyland; Matthew Charlick; Matthew Varacallo.Author Information
The clavicle is a sigmoid-shaped long bone with a convex surface along the medial end when observed from cephalad position. It serves as a connection between the axial and appendicular skeleton in conjunction with the scapula, and each of this structures forms the pectoral girdle.<1> Though not as big as other supporting frameworks in the body, clavicular attachments enable for significant function and variety of movement of the top extremity and also protection the neurovascular frameworks posteriorly. Each part of this lengthy bone has actually a purpose in regards to its attachments the affects the as whole physiology of the pectoral girdle.
Medially, the clavicle articulates through the manubrial portion of the sternum, creating the sternoclavicular joint (SC joint). This joint, surrounded by a fibrous capsule, includes an intra-articular key in between the clavicle and also the sternum. Superiorly, the interclavicular ligament connect the ipsilateral and also contralateral clavicle, with each other providing more stability.<2>
Laterally, the clavicle articulates with the acromion, developing the acromioclavicular ligament (AC joint). The surrounding area provides an attachment because that the share capsule of the shoulder. This joint, prefer the SC joint, is likewise lined by fibrocartilage and contains one intra-articular disc. The three main ligaments to support this joint room the AC ligament, the coracoclavicular ligament (CC), and also the coracoacromial ligament (CA).<3>
The actual tower of the clavicle is clinically divided into two components clinically: medial two-thirds and lateral third. These locations are offered to properly determine where muscles are attached. The medial two-thirds has an attachment site for the sternocleidomastoid (SCM) muscle and also subclavius muscle follow me the subclavian groove superiorly and inferiorly, respectively. The anterior surface is one attachment because that the pectoralis major and the posterior because that the sternohyoid muscle. The costal tuberosity, i beg your pardon is where the costoclavicular ligament inserts and supports the SC joint, is likewise found ~ above the inferior surface.<4> The lateral third of the clavicle serves as attachments because that the deltoid and also trapezius muscles anteriorly and posteriorly, respectively. Inferiorly the conoid and trapezoid materials of the CC ligament administer stability in between the clavicle and also the coracoid procedure of the scapula.
The clavicle happens to be among the most commonly fractured bones in the person body; fracture can be as a result of direct call or force transmission from falling top top an outstretched hand. Depending on the level that displacement of the fracture, surgery may be indicated, and proper administration is established on an individual basis because of differentiating factors surrounding such injury.
Structure and Function
Although small, the clavicle permits for optimal role of the top extremity and also protects the top extremity by dispersing the quantity of pressure transmitted from direct contact. The placing of the clavicle also keeps the extremity far enough away native the thorax, enabling for the range of activity (ROM) of the shoulder to be unimpeded. The strut-like mechanics enable the scapula to glide smoothly along the posterior wall surface which is critical for full upper extremity motion.<5> The anatomical location additionally protects neurovascular structures, including the brachial plexus, subclavian artery, and also subclavian vein which, if disrupted, would certainly greatly increase morbidity.<6>
The clavicle, interestingly, is the very first bone to start ossification throughout embryologic advance and is a derivative of the lateral mesoderm. The medial and also lateral ends of the clavicle undergo various processes that ossification. The medial end undergoes formation via endochondral ossification. Endochondral ossification that a bony framework is came before by a cartilaginous model built by chondrocytes before mineralization and ossification. The lateral end, on the contrary, develops via intramembranous ossification i m sorry constitutes woven bone formed straight without cartilage. In both cases, the framework is remodeled in a method that the result is lamellar bone. Regardless of being one of the very first bones to begin ossification, it is one of the last to complete this process, and growth plates may not nearby until between the twenty to twenty-fifth year the life.<7><8>
Blood Supply and Lymphatics
Although classified together a long bone, the clavicle (in most cases) does not have actually a medullary cavity like its lengthy bone counterparts. Previous researches have presented periosteal arterial blood it is provided to the bony structure but no main nutrient artery (a.). The suprascapular a., thoracoacromial a., and the inner thoracic a. (mammalian a.) have all been found to carry out arterial supply to the clavicle.<9>
Controversy surrounding the main sensory innervation of the clavicle. Anesthetizing studies adhering to clavicular fracture have suggested there may be involvement individually or in a mix of the supraclavicular nerve (n.), subclavian n., and also long thoracic/suprascapular n.<10> A typical anatomical sport is a perforating branch the the supraclavicular n. The passes in the premium surface the the clavicle. Post-mortem studies have actually revealed insertion that the nerve in bony tunnels or grooves that would prove prone to injury and may describe entrapment neuropathy following clavicular fracture.<11>
The clavicle has multiple attachments because that musculature that should be taken into consideration anatomically.
inferior surface: The subclavius muscle stays in the subclavian groove the the clavicle and also functions to boring the shoulder and also pull the clavicle anteroinferiorly. The coracoacromial ligament is located laterally and also provides support from the coracoid residing below. The medial component of the CA ligament is the conoid ligament i m sorry inserts onto the conoid tubercle, and also the lateral component is the trapezoid ligament which inserts top top the trapezoid line.
Anterior surface: The clavicular component of the pectoralis significant muscle originates native the medial clavicle anteriorly. The clavicular head contributes to flexion, horizontal adduction, and inward rotation that the humerus.
Posterior surface: as mentioned, the trapezius inserts posterosuperior on the clavicle. The clavicular head the the sternocleidomastoid (SCM) additionally has a comparable location yet is found along the medial third of the clavicle. The SCM, as soon as contracting alone, reasons the head to rotate to opposing side and laterally next bend ipsilaterally. As soon as both SCM contract, this causes head flexion.
The sternohyoid muscle has actually fibers originating inferomedially along the posterior surface of the clavicle in enhancement to the manubrium and also posterior sternoclavicular ligament. Contraction of the sternohyoid causes hyoid bone depression.
Compared come other long bones, the clavicle has shown to exhibit varying features. Thickness and also length have the right to both vary relying on the sex, through males having actually longer and thicker bone morphology than females. Males likewise have a greater level of curvature in the bone contrasted to females. Cadaveric studies additionally revealed left clavicles were substantially longer than the contralateral.<13> A rare, but clinically relevant hereditary disease, cleidocranial dysplasia, can current with absent or partially lacking clavicles bilaterally. Dental abnormalities, delay fontanel closure, and cranial sutures that have actually failed to fuse are other attributes that can be existing in this disease.<14>
One of the most usual fractures to take place is a clavicular fracture, much more typically in the middle third of the bone. While most medial and also lateral fractures deserve to be managed non-operatively if they stay stable, mid-shaft fractures have the right to potentially have a higher degree of displacement with an boosted incidence the malunion or non-union. Relying on the displacement and also possible shortening of the connected fragments, surgery might be warranted. Additionally, neurovascular deteriorate may additionally be an indication for operative management. Pediatric injury generally occurs in physeal regions of the clavicle, and due come the healing potential of this regions, non-operative treatment can be pursued.<15>
Operative administration has displayed to enhance short-term functional outcomes; however, permanent shoulder role difference contrasted to non-operative management has actually proven unremarkable. Open reduction with internal fixation making use of plate and screws and intramedullary nails have been provided to mitigate these fractures.<16> Increased patient satisfaction and earlier return to physical activity have to be seen through surgical monitoring when contrasted to the non-operative approach. Cost-effectiveness was additionally surprisingly advantageous for operative patients. Current recommendations suggest a patient-tailored technique when considering surgical procedure which may involve multiple parameters.<17>
The mid-clavicular line is a landmark ~ above the clavicle that is offered for lot of reasons. This landmark provides a basic location because that cardiac apex beat as well as appreciating the liver size. It likewise can be provided to locate the gallbladder i m sorry is located in between the mid-clavicular line and also transpyloric plane. Accurate ar assessment can vary, however, depending ~ above the user.<18>
AC share (ACJ) dislocation is typical in call sports and represents 9% of all traumatic shoulder girdle injuries <20>. The joint injury can be appreciated via X-ray imaging and also is classified into six types. The injury severity increases with injury type and also is dependence on the lot of gapping in between acromioclavicular articulation.
See more: What Was The Protagonist Of An Epic Myth Is Tics & Examples, What Is The Protagonist Of An Epic Myth
Type I and also II injuries are managed nonoperatively. The previous manifest solely as ACJ tenderness but no instability. type II injuries exhibit horizontal instability only, together the ACJ is disrupted and coracoclavicular distance is enhanced by less than 25% contrasted to the contralateral extremity.