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Chapter 23. Cervical spine. Overview. The cervical spine consists of 37 joints, which allow for more motion than any other region of the spine
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Chapter 23 Cervical spine
Overview • The cervical spine consists of 37 joints, which allow for more motion than any other region of the spine • However, this degree of mobility comes with a cost. With stability being sacrificed for mobility, the cervical spine is rendered more vulnerable to both direct and indirect trauma
Anatomy • Cervical curve • The cervical spine forms a lordotic curve that develops secondary to the response of an upright posture, which initially occurs when the child begins to lift the head at 3-4 months. • The presence of the curve allows the head and eyes to remain oriented forward, and provides a shock-absorbing mechanism to counteract the axial compressive force produced by the weight of the head
Anatomy • Cervicothoracic Junction • The cervicothoracic junction (CTJ) comprises the C 7-T 1 segment, although functionally it includes the seventh cervical vertebra, the first two thoracic vertebrae, the first and second ribs, and the manubrium • In addition, the CTJ forms the thoracic outlet, through which the neurovascular structures of the upper extremities pass
Anatomy • Vertebra • Compared with the rest of the spine, the vertebral bodies of the cervical spine are small and consist predominantly of trabecular (cancellous) bone • The third to sixth cervical vertebrae can be considered typical, while the seventh is atypical
Anatomy • Vertebra • Each pair of vertebrae in this region is connected by a number of articulations: a pair of zygapophyseal joints, the uncovertebral joints, and the IVD • The structure of the cervical vertebrae, combined with the orientation of the zygapophyseal facets, provides very little bony stability, and the lax soft tissue restraints permit large excursions of motion
Anatomy • Zygapophyseal joints • There are 14 zygapophyseal joints from the occiput to the first thoracic vertebra. These joints are typical synovial joints and are covered with hyaline cartilage • The average horizontal angle of the joint planes is approximately 45°, with the upper cervical levels closer to 35º, and the lower levels at approximately 65°
Anatomy • Uncovertebral Joints • Extend from C 3-T 1 there is usually a total of ten saddle-shaped, diarthrodial articulations • Formed between the uncinate process found on the lateral aspect of the superior surface of the inferior vertebra, and the beveled inferior-lateral aspect of the superior vertebra
Anatomy • Uncovertebral Joints • Penning and Wilmink highlighted a possible correlation between uncovertebral joint configuration and the coupled cervical segmental motion of side bending and axial rotation • A more recent study of the C 5-6 segment level by Clausen et al. found that both the zygapophyseal joints and Luschka joints are the major contributors to coupled motion in the lower cervical spine, and that the uncinate processes effectively reduce motion coupling and primary cervical motion
Anatomy • Intervertebral foramina • Serve as the principal routes of entry and exit for the neurovascular systems to and from the vertebral canal • This region is vulnerable to narrowing with certain motions, or with osteophyte growth • As the dimensions of the intervertebral foramen decrease with full extension and ipsilateral side bending of the cervical spine, uncovertebral osteophytes may compress the nerve root and cervical cord posteriorly
Anatomy • Ligaments • Both the function and location of the ligaments in this region are similar to that of the rest of the spine • Anterior longitudinal. This ligament is narrower in the upper cervical spine but is wider in the lower cervical spine than it is in the thoracic region • Posterior longitudinal. This ligament is broader and considerably thicker in the cervical region than in the thoracic and lumbar regions
Anatomy • Muscles • Trapezius • Most superficial back muscle • Traditionally divided into middle, upper, and lower parts according to anatomy and function • The innervation for the trapezius comes from the accessory nerve (CN XI) and fibers from the ventral rami of the third and fourth cervical spinal nerves
Anatomy • Muscles • Sternocleidomastoid (SCM) • Largest muscle in the anterior neck • Attached inferiorly by two heads, arising from the posterior aspect of the medial third of the clavicle and the manubrium of the sternum. From here it passes superiorly and posteriorly to attach on the mastoid process of the temporal bone • Motor supply is from the accessory nerve (CN IX), while the sensory innervation is supplied from the ventral rami of C 2 and C 3
Anatomy • Muscles • Levator scapulae • The levator is the major stabilizer and elevator of the superior angle of the scapula • With the scapula stabilized, the levator produces rotation and side bending of the neck to the same side; while acting bilaterally, cervical extension is produced
Anatomy • Muscles • Rhomboids • Although the rhomboid minor, with its attachment to the spinous processes of C 7 and T 1, has a slight association with the cervical spine, the rhomboid major, arising from the spinous processes of T 1 through T 5, is inactive during isolated head and neck movements
Anatomy • Muscles • Scalenes • The scalenes extend obliquely like ladders (‘scala’ means ladder in Latin) and share a critical relationship with the subclavian artery • Adaptive shortening of these muscles will affect the mobility of the upper cervical spine and, due to their distal attachments to the 1st and 2nd ribs they can, if in spasm, elevate the ribs and be implicated in the thoracic outlet syndrome
Anatomy • Neurology • The cervical spine is the only region that has more nerve roots than vertebral levels • In general, structures supplied by the upper three cervical nerves can cause neck and head pain, whereas the mid to lower cervical nerves can refer symptoms to the shoulder, anterior chest, upper limb, and scapular area
Biomechanics • The only significant arthrokinematic available to the zygapophyseal joint is an inferior, medial and posterior glide of the inferior articular process of the superior facet during extension, and a superior, lateral and anterior glide during flexion • Segmental side bending is, therefore, extension of the ipsilateral joint and flexion of the contralateral joint • Rotation, coupled with ipsilateral side bending, involves extension of the ipsilateral joint and flexion of the contralateral
Examination • The examination of the acute and recently traumatized neck is necessarily different from the routine examination of a more chronic and less irritable condition, because of the potential for the examination itself to be harmful
Examination • Where possible, the patient should first be examined for central and peripheral neurological deficit, neurovascular compromise and serious skeletal injury such as fractures or craniovertebral ligamentous instability • The examination must be graduated and progressive so that the testing can be discontinued at the first signs of serious pathology
Examination • Clinical signs and symptoms of serious pathology include: • Unexplained weight loss • Night pain • Involvement of more than 1 nerve root • Expanding pain • Weak and painful resisted testing • 4 findings and their interpretations • Spasm with PROM • T1 palsy
Examination • History • The history often gives the clinician clues as to the source of the patient’s symptoms, the nature and location of the involved structure, the severity of the condition, and the activities or positions that appear to aggravate or improve the patient’s condition
Examination • Systems Review • Symptoms that show no predictable response to mechanical stimuli are unlikely to be mechanical in origin, and their presence should alert the clinician to the possibility of a more sinister disorder or one of central initiation, autonomic, or affective nature • The systems review must include questions that will elicit any symptoms that might suggest a central nervous system condition, or a vascular compromise to the brain
Examination Upper Quarter Scan • AROM, passive overpressure, resistance • C 1-4 • C 5 • C 6 • C 7 • C 8 • T 1 • DTR • Sensation
Examination • Tests and Measures • Observation • A major contributor to cervicogenic pain is a lack of postural control due to poor neuromuscular function • Static observation of general posture, as well as the relationship of the neck on the trunk, and the head on the neck, is observed while the patient is standing and sitting, both in the waiting area, and in the examination room
Examination • AROM • The clinical examination of the mobility of the cervical spine should consist of a comparison between active and passive ranges and coupled movements of the cervical spine • Active motion induced by the contraction of the muscles determines the so-called physiologic ROM • Passively performed movement causes stretching of non-contractile elements, such as ligaments, and determines the anatomic ROM
Examination • Key Muscle Testing • During the resisted tests, the clinician looks for relative strength and fatigability
Examination Specific key muscles for the various levels • C 2 • C 3 • C 4 • C 5 • C 6 • C 7 • C 8-T 1
Examination • Combined motion testing • Using a biomechanical model • A restriction of cervical extension, side bending and rotation to the same side as the pain is termed a closing restriction. This restriction is the most common pattern producing distal symptoms. However, a limitation in cervical flexion accompanied by the production of distal symptoms can also occur • A restriction of cervical flexion, side bending and rotation to the opposite side of the pain is termed an opening restriction
Examination Neurological examination • MOTOR LOSS • Spinal nerve root • Peripheral nerve • Long thoracic • Thoracodorsal • Subscapular • Suprascapular • Dorsal scapular • Medial pectoral • Lateral pectoral • Axillary • Musculocutaneous • Radial • Median • Ulnar
Examination Neurological examination • SENSORY LOSS • Spinal nerve root • Peripheral nerve • Musculocutaneous • Axillary • Radial • Median • Ulnar
Examination • Palpation • Palpation is performed to: • Check for any vasomotor changes such as an increase in skin temperature • Localize specific sites of swelling • Identify specific anatomical structures and their relationship to one another • Identify sites of point tenderness • Identify soft tissue texture changes or myofascial restriction • Locate changes in muscle tone resulting from, trigger points, muscle spasm, hypertonicity, or hypotonicity
Examination • Stability (Stress) testing • Transverse • Anterior - posterior • Torsion • Vertical • Lateral shear
Examination Special Tests • Foraminal compression • Axial distraction • Upper limb neural tension • Median • Ulnar • Radial
Examination Special Tests • Thoracic Outlet Syndrome • Vascular • Neurological • Traction
Intervention Strategies • Physical therapy interventions that have included postural re‑education, neck‑specific strengthening and stretching exercises, and ergonomic changes at work, have been shown to be beneficial in reducing neck pain and improving mobility
Intervention Strategies • Acute Phase • Goals: • To encourage patient involvement • To provide mechanoreceptor stimulation • To control pain and inflammation • To promote healing • To maintain the newly attained ranges • To provide neuromuscular feedback
Intervention Strategies • Functional Phase • Goals: • Correction of imbalances of strength and flexibility • Incorporate neuromuscular re-education • Strengthening of entire kinetic chain • Postural correction and retraining