Thoracic outlet

Most lesions causing Homer s syndrome involve the preganglionic neuron. Patients with such lesions may have an apical lung tumor (Pancoast tumor) or breast malignancy that has spread to the thoracic outlet. The patient may also have a history of surgery or trauma to the neck, chest, or cervical spine. Nonoperative injuries to... 

A risk factor is defined as an attribute or exposure that increases the probability of a disease or disorder (Putz-Anderson, 1988). Biomechanical risk factors for musculoskeletal disorders include repetitive and sustained exertions, awkward postures, and application of high mechanical forces. Vibration and cold environments may also accelerate the development of musculoskeletal disorders. Typical tools that can be used to identify the potential for development of musculoskeletal disorders include conducting work-methods analyses and checklists designed to itemize undesirable work site conditions or worker activities that contribute to injury. Since most of manual work requires the active use of the arms and hands, the structures of the upper extremities are particularly vulnerable to soft tissue injury. WUEDs are typically associated with repetitive manual tasks with forceful exertions, such as those performed at assembly lines, or when using hand tools, computer keyboards and other devices, or operating machinery. These tasks impose repeated stresses to the upper body, that is, the muscles, tendons, ligaments, nerve tissues, and neurovascular structures. There are three basic types of WRDs to the upper extremity tendon disorder (such as tendonitis), nerve disorder (such as carpal tunnel syndrome), and neurovascular disorder (such as thoracic outlet syndrome or vibration-Raynaud s syndrome). The main biomechanical risk factors of musculoskeletal disorders are presented in Table 22. 

Thoracic outlet syndrome A disorder resulting from compression of nerves and blood vessels between the clavicle and the first and second ribs at the brachial plexus. 

A musculoskeletal injury that arises gradually as a result of repeated microtrauma. CTDs are characterized by injuries to the tendons, nerves, or neurovascular system. Muscles and joints are stressed, tendons are inflamed, nerves are pinched, or the flow of blood is restricted. Examples of CTDs include tendinitis, tenosynovitis, carpal tunnel syndrome, thoracic outlet syndrome, and Raynaud s phenomenon (white finger disease). 

Assessment of the dynamic compression of the subclavian artery when it crosses one of the tunnels of the thoracic outlet has been performed with both CT and MR imaging (Fig. 24.16). With CT, the arterial compression seems better depicted with volume rendered reconstructions than with the 3D shaded surface images and with sagittal reformations (Remy-Jardin et al. 2000). With MR imaging, MIP or volume rendering can be performed (Demondion 2007). 

Fig. 24.16a,b. Bilateral thoracic outlet syndrome explored with CT imaging with the arms alongside the body (a) and after elevation of the arms (b). Compression of the subclavian artery in the entrance of the costoclavicular space (arrows) is well demonstrated after elevation of the arms... 

Remy-Jardin M, Remy J, Masson P et al (2000) CT angiography of thoracic outlet syndrome evaluation of imaging protocols for the detection of arterial stenosis. J Comput Assist Tomogr 24 349-361... 

Dale WA. Thoracic outlet compression syndrome critique. Arch Surg 1982 117 1437. 

Harding A, Silver D. Thoracic outlet syndrome. In Sabistan, Textbook of Surgery, 14th ed. Townsend CM, ed. Philadelphia W.B. Saunders, 1991, pp. 1757-1761. 

Parachuri R, Adaues EM. Entrapment neuropathies. Postgrad Med 1993 94 39-51. (Thoracic outlet syndrome in p. 45.)... 

The Musculoskeletal disorders more commonly seen in dental surgeons are Carpal Tunnel Syndrome Ulnar Nerve Entrapment Pronator Syndrome Tendinitis Tenosynovitis Extensor Wad Strain Thoracic Outlet Syndrome Rotator Cuff Tendonitis (Nield-Gehrig, 2008). 

The lirst rib is probably the rib most commonly involved in somatic dysfunction of all the ribs. It is affected by trauma, stress, and posture as well as by dysfunction ofthe C7-T1 complex. The patient may report "shoulder" pain, stiff neck, upper back or neck pain, and an inability to turn the head while driving. The first rib can impinge the neurovascular bundle as it passes between it and the clavicle through the costoclavicular space. The anterior and middle scalene muscles, which raise the first rib, may likewise compress the brachial plexus when they are in spasm and result in thoracic outlet syndrome symptoms. The patient s symptoms are then described as pain, numbness, or paresthesias ofthe arm or hand on the involved side. The physician needs to be aware that this may cause confusion should the patient demonstrate a herniated cervical disc on magnetic resonance imaging [MRO. The symptoms may be caused by the rib dysfunction rather than the herniated disc, so evaluation ofthe rib for normal motion and treatment of any dysfunction should be performed in these cases. Osteopathic manipulation may save the patient unnecessary surgery. 

This relatively gentle technique may increase intracranial venous drainage. The hand contact on the bone ofthe external cranium exerts an influence on the dura that comprises the venous sinuses. Before treatment is initiated, the thoracic outlet, cervical, and occipitoatlantal joint dysfunctions must be mobilized to allow drainage from the venous sinuses, out the internal jugular vein and into the thoracic cavity. 

Bursae and Gliding Spaces 199 Neurovascular Structures 202 Suprascapular Nerve 202 Axillary Artery and Nerve 202 Thoracic Outlet Structures 202 Brachial Plexus Nerves and Vertebral Anatomy 204... 

Rotator Cuff Pathology 206 Thoracic Outlet and Brachial Plexus Pathology 209... 

The thoracic outlet region includes the brachial plexus nerves and the subclavian artery and vein. These neurovascular structures traverse restricted spaces in which they can be compressed, the most important of which are the interscalene triangle, the costoclavicular space and the retropectoralis minor space (Fig. 6.16a) (Demondion et al. 2000). Both subclavian artery and brachial plexus nerves pass through the interscalene triangle, a space bordered by the anterior scalene musde anteriorly, the middle scalene muscle posteriorly and the first rib inferiorly. 

Generally speaking, the clinically relevant structures of the thoracic outlet region are the brachial plexus nerves, the subclavian artery and the subclavian vein. The causes of brachial plexopathy include trauma, intrinsic and extrinsic tumors, radiation plexopathy and Parsonage-Turner syndrome. The neurovascular structures of the thoracic outlet... 

Thoracic outlet syndrome is a range of disorders arising from the passage of the subclavian artery and... 

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