I did a search on your words- "cervical pain associated with TOS"
I'm just posting as I find them - so I haven't read everything.

[Thoractic Outlet Syndrome (TOS)

• Mayo clinic performed 120 procedures in 32 year period.

• Roos describes performing over 1400 procedures in less than 15 years!

• Some confusion exists over what constitutes this particular entity.

Surgical Anatomy

• An opening bordered laterally by the 1st rib, medially by the vertebral column and anteriorly by the claviculomanubrial complex. Though often described, the mere presence of an accessory rib does not always lead to TOS. Instead, the basic common anatomical denominator is compression of the neurovascular bundle (subclavian artery and lower brachial plexus) through several narrow spaces by a variety of physiological and anthropomorphic factors.

Narrow Straits Traversed by the Neurovascular Bundle

1) Interscalene triangle

Anteriorly scalene anticus, posteriorly scalene medius, and inferiorly medial border of first rib. Scalene anticus originates from the transverse processes of C3-C6 and inserts into the scalene tubercle. The scalene medius extends from all of the cervical transverse processes to the rough area of the 1st rib behind the subclavian groove. The triangle is narrowly based caudally, with an apex pointing toward the angle of the jaw.

The interscalene hiatus transmits all trunks of the brachial plexus, but only the lower trunk and the subclavian artery are related to the first rib.

2) Costoclavicular triangle

After leaving the interscalene hiatus, the neurovascular bundle immediately enters a second triangular space bounded anteriorly by the middle third of the clavicle and the subclavius, superoanteriorly by the under surface of the clavicle, posterolaterally by the upper border of the scapula and the subscapularis muscle, and posteromedially by the anterolateral border of the first rib. The boundaries of this triangle are movable with movement of the clavicle. The subclavian vein courses in front of the scalene anticus, and enters this triangle in its medial angle. It may be subject to compression or thrombosis.

3) Subcoracoid space

Distally, the neurovascular bundle passes beneath the coracoid process just deep to the pectoralis minor tendon. Here, the bundle is closely related to the stout clavipectoral fascia. This fascia forms a tight ligament travelling from the costomanubrial joint to the coracoid process (costocoracoid ligament). This ligament can compress the neurovascular structures through the subcoracoid space during shoulder abduction.

Predisposing Factors

Anthropomorphic Factors

• Quadruped to biped state.

• Descent of the acromioclavicular apparatus.

• Typical patient with TOS is postpubertal, asthenic female with a slender neck and poorly developed shoulder musculature.

• Not common amongst healthy muscular men.

Postural/dynamic Factors

• Hyperabduction and external rotation of the arm (painting, car repair).

• Wearing shoulder strap to carry heavy object.

• This causes costoclavicular compression and bowing of the axillary artery and the cords in the subcoracoid space.

Traumatic Factors

• In full arm abduction, the humeral head comes forward from the glenoid fossa and may traumatize the axillary vessels and cords of the plexus.


Structural Anomalies of the Thoracic Outlet

1) Anomalous Ribs

• Incidence of cervical ribs on routine thoracic films: 0.002 - 0.5%.

• Anomalous first thoracic ribs also seen as commonly as cervical ribs.

• Patients with anomalous ribs are symptomatic in only 10%.

• Cervical ribs may be familial.

• Left side most often symptomatic for unclear reasons.

• Role of pre- and post-fixation of the brachial plexus:

In the standard plexus (formed from C5-T1) the obliquely coursing cervical roots inhibit full development of the cervical rib anlages below each exit foramen. The first root that comes out horizontal enough to permit subjacent rib development is the C8 root. The first true (thoracic) rib therefore articulates with the 8th vertebral body. In complete prefixation, the relationships between the roots and the developing ribs is exactly analagous to the standard arrangement except for upward shifting of the first true rib by one vertebral body level. There is no neurovascular compromise.

In incomplete prefixation, continued contribution of T1 fibers to the lower trunk demands that the T1 root ascend and acutely hook across the developing C7 rib, thereby preventing complete ossification of its anterior portion, which subsequently becomes a fibrous band.

• Pathogenesis of symptoms with anomalous ribs:

The abnormal rib raises the level of the thoracic outlet. The neurovascular bundle must therefore ascend to a much higher level and then acutely angulate over the rib or its ligament. This becomes a site of chronic, low grade trauma producing neuritis, axonal degeneration and symptoms. The clinically significant portion of a cervical rib is its anterior portion.

The anterior portion of a cervical rib may force the lower trunk and the subclavian artery against the scalene anticus. If the rib is sufficiently long to fuse to the rib below anteriorly, this will invariably reduce the costoclavicular space so that limb movements will repeatedly slam the clavicle against the pinched artery and nerve.



2. Anomalous Fibrous Bands

• May be more common than ribs as cause of TOS.

• Types:

A) Bands originating from a cervical or rudimentary 1st thoracic rib.

• A short anomalous rib may indicate a fibrous ligament from its tip.

• These represent the anterior portion of the rib anlage that has been prevented from ossifying.

• Invariably attached to the medial border of the 1st rib below, and elevate the subclavian artery and lower trunk toward the clavicle.

B) Bands originating from the C7 vertebra.

• An elongated C7 transverse process represents an abortive attempt to form a cervical rib whose cartilaginous anlage subsequently transforms into a fibrous band that inserts on the T1 rib posterior to the scalene tubercle

C) Bands arising from the 1st thoracic rib.

D) Bands associated with the scalene muscles.

• A sharp tendinous expansion continuous with the anteromedial border of the scalene medius passes to the first rib.

• Lifts the neurovascular structures up and forward.

E) Bands associated with Sibson's fascia.

• Sibson's fascia (suprapleural membrane) is a semi-cone shaped sheet of dense connective tissue that forms a tentlike suspension system for the pleural dome.

• The lower trunk may pass behind the strong posterior border which will hook the lower nerve trunk like a knife edge.



3. Anomalous Muscle Insertions

A) Fused scalene anticus and medius insertions (10% humans)

B) Split scalene medius insertions

C) Scalene minimus hypertrophy

D) Subclavius hypertrophy

4. Anomalous Vessels

• Superficial cervical artery (thyrocervical trunk).

5. Malunited Clavicular Fracture and Other Osseous Lesions

• Callus around the pseudoarthrosis narrows the costoclavicular space.





Clinical Features

The diverse anatomical and physiological factors associated with TOS led to the description of a number of syndromes which are of historical interest.

1) Ochsner 1935 - scalene anticus syndrome (+ve Adson test)

2) Falconer 1943 - costoclavicular syndrome

3) Wright 1945 - hyperabduction syndrome

4) Sunderland - cervical rib syndrome

5) Droopy shoulder syndrome (women with long necks)

Neurological Component

Sensory Disturbance

1) The neurological disturbances are due to involvement of C8-T1 fibers. Rarely, the C7 fibers of the middle trunk are involved. Not an upper trunk lesion.

2) Sensory disturbances appear in advance of motor signs.

3) The initial sensory disturbances are almost always subjective (pain, paresthesiae in 95%).

4) NB:

The pain may not respect the C8-T1 dermatomes.

Paresthesiae may be segmental (inner hand and arm).

Symptoms may be preceded or precipitated by trauma.

Symptoms worsened by postural maneuvers.

Objective signs of C8-T1 sensory impairment occur with time.

Motor Disturbance

1) Weak, stiff, clumsy hands.

2) Weakness of the finger flexors and the intrinsics of the hand.

3) Muscle wasting in severe cases.

4) Common pattern is of thenar wasting with preservation of the hypothenar and interossei. A peculiar predilection for wasting of the abductor pollicis brevis and the opponens pollicis to give a characteristic guttering along the lateral aspect of the thenar pad. Flexor pollicis brevis is curiously spared. Therefore, lateral thenar wasting and ulnar sensory loss. This tends to separate TOS from carpal tunnel or ulnar nerve entrapment.

Vasomotor Disturbances and Trophic Changes

• The majority of sympathetic fibers to the upper limb are in the C8-T1 roots with lesser numbers in the C7 root. The sympathetic fibers are well mixed with the somatic fibers by the level of the first rib, so it is rare to see sympathetic changes before sensory or motor changes. Occasionally, however, a purely vasomotor syndrome will be occur.

1) Usually preceded by sensory and motor complaints. Consists of blanching and coldness of the fingers during exposure to cold; purplish red discoloration of the hand and distal forearm when the arm is dependent, and alternate blanching and red discoloration when the patient is upset.

2) Vasomotor symptoms may be independent of arm movement or position.

3) May see smooth, shiny skin with hair loss and curling of the nails.



Vascular Component

Subclavian Artery Injury

• Symptoms are a function of degree of vascular compression.

1) Ischemic pain of the hand, claudication

2) May get arterial thrombus formation and distal emboization (digit necrosis)

3) Rarely, a fusiform aneurysm will form from repeated trauma

Subclavian Vein Thrombosis

• Occurs at site where the vein passes between the costocoracoid ligament anteriorly and the first rib posteriorly.

1) Aching pain in extremity with signs of venous congestion.





Diagnosis

• Suspected in asthenic postpubertal women with long necks with arm pain associated with paresthesia and numbness in ulnar digits and forearm.

• Paradoxical thenar wasting and ulnar sensory loss strongly suggest diagnosis.

• No test is pathognomic for TOS!

• Real differential is between C8-T1 radiculopathy caused by TOS and cervical spondylosis.

Nerve Conduction Studies

1) Low amplitude median motor responses - most consistent

2) Low amplitude ulnar sensory action potentials

3) Relatively low or normal amplitude ulnar motor responses

4) Normal median sensory NCS

EMG

• Abnormalities most severe in the intrinisics of the hand muscles

Stress Tests

1) Pulse obliteration (may be a normal finding in most patients).

2) Ninety degree abduction external rotation test (head turned to opposite side). Probably best and most reliable test.

3) Exaggerated military maneuver: chest thrust.

4) Adson test - deep breath, head turned toward affected side.

5) Hyperabduction test.

Radiography

• Plain films. Anomalous rib or elongated C7 transverse process. Pancoast tumor, callus from fracutre, neurofibroma etc.

• C Spines films.

• Subclavian arteriography and venography.





Management

Conservative

• Avoid postures and movements exacerbating condition. Between 50-90% can be managed conservatively.

Surgery

Absolute Indications

1) threatened ischemia

2) vascular occlusion

3) peripheral emboli

4) progressive neurological deficit, wasting

Approaches

1) Posterior subscapular approach

• Good accessibility, but technically demanding and leaves patients with painful shoulder, and possible winging of the scapula.

2) Anterior subclavicular approach

• Infraclavicular incision. Poor visualization of the nerve trunks and great vessels.

3) Transaxillary approach

• Transverse incision over third rib in axilla.

• Exposes whole first rib without extensive muscle transection, but allows visualization of only the distal neurovascular bundle.

4) Anterior supraclavicular approach.

• Best approach for visualization of entire plexus and thoracic outlet.

Updated 25/01/97] http://www.ucsf.edu/nreview/09.2-Per...cicOutlet.html