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 To To To To To encourage patient involvement provide mechanoreceptor stimulation control pain and inflammation promote healing maintain the newly attained ranges 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