Thoracic Outlet Syndrome (TOS) is characterized by neurovascular symptoms in the upper limb due to compression of nerves and blood vessels in the thoracic outlet area. This condition is often misdiagnosed or undiagnosed. The specific structures compressed are usually the nerve bundle known as the brachial plexus and occasionally the subclavian artery or subclavian vein. Similar to Spondylolisthesis, which involves the displacement of a vertebra, leading to nerve compression and back pain, TOS significantly impacts daily activities and quality of life. Both conditions affect the musculoskeletal and nervous systems, making accurate diagnosis and treatment essential for symptom management and functional improvement.
Types Of TOS:
- Depending upon exact site (structure) OR injury (functional) TOS is divide into three subgroup.
- Neurological TOS(compression of brachial plexus nerves)
- Arterial TOS(compression of subclavian artery)
- Venous TOS(compression of subclavian vein)
Anatomy Involved:
The anatomy of the thoracic outlet is defined by the bony circle of the sternum in front, connected to the first rib laterally, which attaches to the vertebra posteriorly. The clavicle attaches to the first rib and sternum anteriorly.
It consists of three spaces:
- Interscalene triangle space
- Costoclavicular Space
- Pectoralis Minor space
Interscalene Triangle:
Most commonly Involved. This Space is Bordered medially 1st rib, Anteriorly Clavicle and scalenus Anterior and posteriorly by Scalenes medius. Anterior and middle scalene muscles have their insertion in the first rib. The brachial plexus and Subclavian artery passes through this space.
Costoclavicular Space/Triangle:
Involvement is Common but majorly seen as progression of scalene triangle (or left untreated). The space is bordered by anteriorly by Middle third of Clavicle and subclavius Muscles, Posteromedial wall is formed by 1st rib and posterolateral aspect is covered by superior border of scapula. The subclavian Vein, artery and brachial Plexus Passes through this space. Congenital abnormalities, trauma to clavicle or first
rib and postural changes in subclavian muscle can cause compression of structure passing by.
Subcorocoid Space/ Pectoralis Minor Space:
Last passage, just beneath the coracoid process just under Pectoralis minor tendon. The border contains superiorly by Coracoid process superiorly, Anteriorly by Pectoralis minor and posteriorly by Ribs 2nd to 4th. Shortening of Pectoralis major can lead to compression and Narrowing of space. Which is seen in hyper abduction of GH joint.
Etiology:
- Bony Abnormalitylike Cervical extra rib, Long C7 transverse process, tight bands or ligament or exostosis (osteoma- benign growth of bone). Clavicle hypermobility.
- Tumors
- Muscle Abnormality, Anomalous insertion of Scalene, Hypertrophy, Brachial plexus Pass through muscles, a broaden insertion of Middle scalene on the first rib.
- Trauma like Whiplash Injury
- Posture,Forward Head posture or Depressed shoulder.
- Repetitive strain injury, Typing, swimming or in sport.
- Obesity
X-Ray Showing Extra Rib:
Clinical Features:
Neurogenic TOS:
- Paresthesia
- Pain in shoulder, arm, forearm and fingers
- Occipital headache
- Weakness of UE.
Cervical outlet or Upper thoracic outlet Syndrome
- Upper nerve roots of C5, C6 and C7 is affected/ compressed
Lower TOS
- In costoclavicular space lower roots like C8 and T1 is compressed
Arterial TOS:
- Weakness
- Numb or cold limbs
- Claudication
- In Progressive stage gangrene or Thrombosis which leads to several Disease like Raynaud’s discoloration in UE generally in distal area.
Venous TOS:
- Edema
- Cyanosis
- Venous distension
- Paget-Schroetter syndrome-uncommon DVT
Diagnostic Special Test:
Adson Maneuver:
One of the most common test of TOS. The examiner locates the Pulse. Rotates head towards affected/test side shoulder. Then ask patient to extend head while Therapist laterally rotates and extends
the patient’s shoulder. The patient is instructed to deep breathe and hold it.
Positive Test: Disappearance of Pulse.
Military Brace Test:
The Examiner palpates the radial pulse and then draws patients shoulder down and back. A Positive test Indicates Absence of Pulse. Effective on patient who carry heavy bag pack or coat.
Ross Test/ Elevated Arm Stress Test:
Also known As Positive abduction and external Rotation (AER), the Hands up test and EAST. The patient stands and abducts the arm to 90*. Laterally rotates the shoulder and flexes elbow to 90*. The patient open-close hand slowly for 3 minutes. If the patient is unable to keep the arms in the starting position for 3 minutes or suffers from ischemic pain, heaviness or profound weakness of the arm or numbness and tingling of hand during the 3 minute, the test is considered as positive. Minor fatigue and distress is common and taken as Negative test.
Wright Test or Maneuver:
Palpate the Radial pulse, Hyper abduct shoulder with lateral rotation. Test can vary in siting and supine as well as with holding breathe. This test is used to detect costoclavicular compression.
Modification-Allen maneuver: examiner flexes the patients elbow to 90* while the shoulder is extended horizontally and rotated laterally. The patient then rotates the head away from the test side. Absence of radial pulse Is indication of Positive test.
Differential Diagnosis:
- CTS
- Spinal canal tumors
- Epicondylitis
- Angina Pectoris
- Raynaud’s disease
- Shoulder myositis
- Cervical IVDP
- Cervical Myelopathy
Physiotherapy Management:
Goals:
- Pain Control and Decrease symptoms of TOS
- Facilitating return to work and improving function.
- Postural correction
- Patient education
- Overcome weakness by stretching tight structure and strengthen the weak muscles.
Stage I:
- Ice pack in starting of exercise and ending of exercise.
- TENS to relive pain
- Correction of sleeping and working posture (Reeducation)
- Breathing technique: diaphragmatic breathing will lessen the work load on scalene muscle.
- Scapular setting exercise.
- Serratus anterior Activation
Cyriax Release Maneuver:
- Elbows flexed to 90°
- Towels create a passive shoulder girdle elevation
- Supported spine and the head in neutral
- The position is held until peripheral symptoms are produced. The patient is encouraged to allow symptoms to occur as long as can be tolerated for up to 30 minutes, observing for a symptom decrescendo as time passes.
Scapular Setting Exercises:
Stage II:
- Massage
- Strengthening of the levator scapulae, sternocleidomastoid and upper trapezius (This group of muscles open the thoracic outlet by raising the shoulder girdle and opening the costoclavicular space)
- Stretching of the pectoralis, lower trapezius and scalene muscles (These muscles close the thoracic outlet)
- Postural correction exercises
- Relaxation of shortened muscles
- Aerobic exercises in a daily home exercise program
Exercises:
- Shoulder exercises to restore the range of motion and so provide more space for the neurovascular structures.
Exercise: Lift your shoulders backwards and up, flex your upper thoracic spine and move the shoulders forward and down. Then straighten the back and repeat 5 to 10 times.
- ROM of the upper cervical spine
Exercise: Lower your chin 5 to 10 times against your chest, while you are standing with the back of your head against a wall. The effectiveness of this exercise can be enlarged by pressing the head down by hands
- Activation of the scalene muscles is the most important exercises. These exercises help to normalize the function of the thoracic aperture. Exercises are Anterior scalene (Press your forehead 5 times against the palm of your hand for a duration of 5 seconds, without creating any movement), Middle scalene (Press your head sidewards against your palm), Posterior scalene (Press your head backwards against your palm
- Stretching exercises
Manipulative Technique:
Posterior Glenohumeral Glide with Arm Flexion:
The patient is supine. The mobilization hand contacts the proximal humerus avoiding corocoid process. The force is directed posterolaterally (direction of thumb).
Anterior Glenohumeral Glide:
The patient is prone. The mobilization hand contacts the proximal humerus avoiding acromion process. The force is directed anteromedially.
Inferior Glenohumeral Glide:
Patient prone. Stabilizing hand holds proximal humerus. Mobilizing hand contacts axillary border of scapula. Mobilize scapula in craniomedial direction along ribcage.
About Authors
Dr. Muhammad Mahmood Ahmad is a Spinal as well as an Orthopedic Surgeon with over 14 years of experience currently practicing at Razia Saeed Hospital, Multan.
