TOS

• Thoracic outlet syndrome:

  • Thoracic outlet syndrome (TOS) is a complex presentation of a collection of diverse symptoms characterized by pain, paraesthesia, weakness and discomfort in the upper limbs (Watson et al., 2009)
  • Often aggravated through elevation of the arms and by related movements of the head and neck (Watson et al., 2009)
  • Due to the variety of presentation clinically it can make it a challenging one to manage

  
• Thoracic outlet syndrome - Prevalence:

  • Affects ~ 8% of the population
  • Female:male 4:1
  • Mean age: 30 - 40 years old
  • Due to Neurological structures affected: 95 - 98% (Polvsen & Polvsen., 2018)
  • Due to vascular structures affected: 2 - 5% (Polvsen & Polvsen., 2018)
• Thoracic outlet syndrome - Pathology/Anatomy:

  • Pressure on neurovascular structures (subclavian vein, artery or lower trunk of the brachial plexus) by upper ribs, clavicle or scalenes
  • Three possible sites for entrapment of neurovascular structures (shown in diagram):
  • 1: between the anterior and middle scalenes - interscalene space
  • 2: beneath the clavicle - costoclavicular space
  • 3: beneath the tendon of pectoralis minor - retropectoralis minor space

  
• Thoracic outlet syndrome - Aetiology & History:

  • Common causes: Bony pathology and soft tissue changes
  • Other causes:
  • Congenital abnormalities: enlarged first rib tubercle, cervical rib (Watson et al, 2009)
  • Traumatic: post fracture, changes to clavicle and first rib, AC joint
  • Occupational: Repetitive activities particularly overhead increase risk (Barkhordarian., 2007)
  • Posture that reduces the thoracic outlet space - increased kyphosis, increase CT junction flexion (Watson et al)
  • Muscle length changes along the pathway of the neurovascular structures – Scalenes and Pecs (Watson et al)
• Thoracic outlet syndrome - Classification:

  • Arterial
  • Venous
  • Neurogenic - most common (95% to 98%)
• Thoracic outlet syndrome - Special Test - Neural Tissue Provocation Test:

  • looks at the sensitivity of the nervous system to movement
  • does this by applying a load onto the brachial plexus
  • also known as upper limbs tension tests
  • not specific to TOS
• Thoracic outlet syndrome - Special Test - EAST/ROOS/Fatigue:

  • Specific to TOS
  • 76% specificity
  • The scalene triangle is narrowed by abducting the arms to 90 degrees with elbows flexed
  • The repetitive opening and closing of the fist may reproduce symptoms causing a reduction in radial pulse volume
• Thoracic outlet syndrome - Special Test - Adson's Test:

  • Specific to TOS
  • 30% specificity
  • Radial pulse is palpated whilst the patient’s neck is in extension and ipsilateral rotation (rotate to affected side) and the arm is held at about 30 degrees abduction, whilst holding a deep inspiration
  • Positive test: reproduce the symptoms and/or loss of radial pulse
• Thoracic outlet syndrome - Special Test:

  • In isolation 58% of asymptomatic volunteers are positive
  • Combining (EAST & Adson’s) specificity increases to 82%
• Thoracic outlet syndrome - Investigations:

  • All – X-ray of cervical spine and chest may show cervical rib or elongated C7 Transverse process
  • Arterial TOS – Duplex ultrasound, arteriography, haemodynamic testing, CT/MR arteriography
  • Venous TOS – Duplex ultrasound, CT/MR venography
  • Neurogenic TOS – nerve conduction studies (conduction deficits might not be visible in early stages), EMG
• Thoracic outlet syndrome - Conservative Management:

  • Advice & education:
  • explain diagnosis and encourage compliance with exercises and recommendations for task modification, particularly those that aggravate/exacerbate symptoms
  • Address fears and unhelpful beliefs
  • Symptom Control:
  • Modify postures and positions that aggravate symptoms
  • Avoid carrying heavy objects on affected upper limb in order to help prevent decrease in thoracic outlet and load onto neurovascular structures. This is important early on to help reduce symptoms and sensitivity of neurovascular structures
• Thoracic outlet syndrome - Conservative Management - Build Capacity:

  • Improve Thoracic outlet container
  • Increase muscle length of reduced length structures: Scalenes, Pecs
  • Manual therapy: 1st rib mobilisations – never in isolation
  • Posture: Tsp Kyphosis, shoulder girdle, lower cervical spine
  • Restore deficits in strength
  • Exercises to improve muscle strength and endurance
  • Depressed & protracted scapula: Deltoids, upper traps, rhomboids. Post shoulder  cuff
  • Exercises to improve Scapulo-thoracic control
  • Serratus anterior, rhomboids, trapezius
• Thoracic outlet syndrome - Conservative Management - Build Capacity:

  • Improve neural tissue mobility - Flossing/Sliders/gliders
  • •https://www.youtube.com/watch?v=gdKldyXgkgs&t=252s
  • Postural control and advice
  • Thoracic spine Kyphosis, depressed shoulder girdle, and if the lower cervical spine is in excessive flexion
• Thoracic outlet syndrome - Conservative Management - Return to function:

  • Advanced rehabilitation to build strength and conditioning in order for sufficient strength, mobility and control towards specific goal/function/sporting activity
  • Increase load and resistance particularly into previously identified impairments – ensure capacity is there
  • Graded return to activity particularly those that are above head and put tension on the neurovascular structures
  • Hooper et al., 2010
• Thoracic outlet syndrome - Surgical Management:

  • Large % TOS will improve conservatively
  • Surgical management indicated if there is a structural cause to their problem:
  • Cervical rib, enlarged first rib tubercle, fibrous bands
  • Surgery indicated especially in those with arterial and venous TOS due to high level of symptoms they present with but also seriousness of vascular compromise as well as the need to rule out presence of thrombosis or emboli
  • Decompression surgery of structures compressing the neurovascular bundle helps to restore normal vascular and neural function
  • Hooper et al., 2010