Plain Radiography

Radiographs of the cervical spine can be a quick and cost-effective initial study in athletes with neck pain. In the setting of trauma, the utility of radiographs has largely been replaced by computed tomography. Adequate radiographs should include all seven cervical vertebrae, including the C7–T1 disk space. Multiple orthogonal views should be obtained: AP, lateral, open-mouth odontoid view, and oblique views to evaluate for foraminal stenosis. A swimmer’s view can aid in assessing the cervicothoracic junction. If there is concern for dynamic instability, flexion/extension views can be beneficial.

Computed Tomography

Computed tomography (CT) has largely superseded plain radiographs as the study of choice for the evaluation of cervical spine trauma. CT is the most efficient modality for detecting skeletal injuries and is almost 40% more sensitive than a single lateral radiograph [34]. In 2007, the American College of Radiology formulated an algorithm for cervical spine trauma: if NEXUS or CCR criteria indicate low risk, then no imaging should be performed. If NEXUS or CCR criteria indicate imaging, then a CT of the cervical spine with sagittal and coronal reformations is highly recommended [35]. CT imaging is relatively quick and provides more granular information of injury morphology; thus, many trauma centers opt for CTs of the cervical spine rather than initial plain radiographs.

Magnetic Resonance Imaging

Magnetic resonance imaging [1] is a noninvasive imaging technique that can differentiate between various soft tissues and bone based on water content. MRI is an excellent imaging modality for evaluating the neural elements, ligamentous structures, and intervertebral disks. Generally, MRI is a useful modality for evaluating athletes with neck pain and neurologic symptoms in the outpatient setting. MRI is highly sensitive at detecting degenerative changes, such as disk bulges and cervical spondylosis. However, in the general population, lifetime prevalence of degenerative changes in the cervical spine on MRI in asymptomatic patients younger than 40 years old is 25% [36]. Athletes who suffer repeated microtraumas to the cervical spine are at greater risk for degenerative disk disease compared to the general population [37]. Therefore, diagnostic imaging may frequently identify asymptomatic pathology and should be considered only as an adjunct to history and clinical examination.

Non-contrast MRI is the imaging modality of choice in athletes with clinically diagnosed radiculopathy that fails to improve with conservative therapy. If history and physical examination reveal concern for cervical myelopathy, MRI should be obtained to evaluate for the source of spinal cord compression. If an MRI is contraindicated (i.e., metallic implants), CT myelogram should be considered.

The role of MRI in acute cervical trauma is still debated. The American College of Radiology does not support the routine use of MRI for all trauma patients with neck pain. They recommend MRI in the setting of trauma only if NEXUS or CCR criteria are met, and there are clinical findings of myelopathy and neurologic deficit, clinical or imaging findings to suggest ligamentous injury, or clinical concern for an unstable spine [35].

Transient Spinal Cord Injury

Transient spinal cord quadriparesis , also known as cervical cord neuropraxia, is traditionally seen in contact sports, such as football or hockey, where collisions can impart sufficient force, leading to spinal cord injury. Transient paralysis in these situations is characterized by paresthesia +/− weakness in affected extremities, typically resolving within 30 min but may last up to 24–48 h. The most common pattern of this injury results in a combination of weakness, quadriplegia, and/or sensory deficits in all four extremities (~80% of cases) [42]. Numerous mechanisms have been proposed, including spinal cord concussion, failure of neural transmission, and selective vascular attenuation, which likely result from structural insults such as fractures/dislocations, ligamentous infolding, instability, syrinx, and/or herniated nucleus pulposus.

Athletes with congenital cervical stenosis and acquired cervical stenosis, typically secondary to degenerative osteophyte formation, are defined as having a spinal canal diameter of 14 mm or less. These athletes have a notably high incidence of spinal cord and peripheral nerve injuries, and return to play or clearance for athletic participation must entail a thorough discussion with the athlete/family/agent as to the risks of catastrophic injury. Return to play for athletes with known cervical stenosis is a controversial topic, but surgeons will generally broach the topic of return to play after full neurologic recovery and without ongoing insult. However, all parties must have a thorough understanding of the inherent risks.

Cervical Sprain/Strain vs Cervical Spondylosis

The athlete with a cervical sprain will primarily complain of neck soreness and tightness. It often occurs in association with a traumatic event. There are typically no neurologic manifestations, and paraspinal muscle tenderness is the hallmark finding.

Whereas, cervical spondylosis will not usually be associated with a traumatic event, the athlete will primarily complain of neck pain and stiffness. It often is not associated with a traumatic event. It will tend to be symptomatic in older athletes. Neurologic manifestations can be present from osteophyte compression on cervical roots or the spinal cord. Paraspinal muscle tenderness will be present less frequently than with a sprain/strain.

Axial Neck Pain/Referred Pain vs Cervical Radiculopathy

Axial neck pain is a common complaint among athletes, especially those participating in contact sports. The cervical spine is a multifaceted region composed of neural elements, discoligamentous complexes, bone, facet and uncovertebral joints, and paraspinal musculature. The interaction of these complex cervical components can represent a spectrum of disorders with each specific component serving as a potential site of pathology. Instability, malalignment, intervertebral disk degeneration, disk herniation, and spinal stenosis can all present as neck pain [43]. The characteristic clinical findings associated with axial neck pain are deep-seated aching pain, painful range of motion, and pain with palpation of paraspinal musculature.

Cervical radiculopathy secondary to traumatic events results from traction, compression, laceration, or ischemia of the involved nerve [44]. Patients with cervical radiculopathy can exhibit loss of motor function within specific myotomes in addition to inconsistent sensory deficits at the affected level. Clinically, this can manifest as unilateral or bilateral numbness, paresthesia, pain, and loss of motion function within specific nerve distributions. Classically, patients report improvement in radicular symptoms with shoulder abduction or what is known as the hand on head position or Bakody’s sign. Patients can report worsening pain with distinct movement or positioning of the cervical spine. It is important to note that when differentiating radiculopathy from musculoskeletal neck pain, radicular symptoms should outweigh axial symptoms.

Rotator Cuff Tears vs Glenoid Labrum Injuries

Rotator cuff injuries present chronically as progressive pain and weakness with overhead activity; however, acutely, these injuries are more likely to be associated with dislocations or subluxations. Paresthesia and numbness are typically not present, although patients can present with radiating neck pain usually exacerbated with active shoulder motion. Weakness is apparent with initiation of shoulder abduction and further elucidated with strength testing using the Jobe’s test and resisted internal and external rotation of the shoulder. Further C5 weakness, specifically biceps and deltoid function, is absent in isolated rotator cuff tears.

Glenoid labrum injuries are often associated with shoulder instability. Patients may have a history of shoulder dislocation. The typical pain can be reproduced with abduction and external rotation (anterior instability) or shoulder adduction and axial loading (posterior instability). SLAP tears are associated with pain with overhead activity and are characterized by a deeper pain when compared to rotator cuff pathology.

C5 Radiculopathy vs Suprascapular Nerve Entrapment vs Traumatic Upper Brachial Plexus Injury

C5 radiculopathy can result from traumatic disk herniations, facet dislocations, fractures, or chronic degenerative changes [38]. Acute and rapid rotation of the cervical spine and chronic axial loads serve as the most common mechanisms of injury associated with C5 radiculopathies among athletes. Weakness and atrophy can be clinically evident when assessing the biceps, supraspinatus/infraspinatus, or deltoid. Shoulder range of motion has limited association with cervical pathology; however, as previously mentioned, shoulder abduction (hand on head position) typically relieves symptoms.

Suprascapular nerve entrapment typically involves isolated weakness and atrophy of the supraspinatus and/or infraspinatus depending on the site of compression, i.e., suprascapular notch. Other muscles innervated by C5 are spared, and radicular pain does not follow classic C5 dermatomal patterns. EMG and nerve conduction velocity tests can be helpful in assessing sites of distal compression.

Brachial plexus injuries most commonly present as burners/stingers and signify a relatively benign insult on the spectrum of traumatic brachial plexus injuries. Athletes with severe brachial plexus injuries present after forceful lateral deviation away from the affected upper extremity or after a traumatic fall onto the shoulder, neck, or head. Typically, upper brachial plexus injuries have preserved function of long thoracic nerve (i.e., lack of scapular winging) and variable involvement of the suprascapular nerve depending on the level of insult.

C6 and C7 Radiculopathy vs Median Nerve Entrapment (Pronator Syndrome/Carpal Tunnel Syndrome)

C6/C7 radiculopathy can result from rotational cervical spine injuries or axial loads (i.e., spear tackling technique) leading to weakness in muscles innervated by C6 and C7. Paresthesias and numbness follow dermatomal distributions of C6 (thenar eminence and thumb) and C7 (middle finger). Assessing thenar strength can be a differentiating exam maneuver since motor innervation is primarily provided by C8; thus, it should be normal with an isolated C6/C7 insult.

C8 Radiculopathy vs Ulnar Nerve Compression

C8 radiculopathies result from flexion and compression forces across the cervicothoracic junction. At the C7 to T1 junction, the mobile and lordotic cervical spine rapidly transitions to the rigid and kyphotic thoracic spine. Initial radiographic triage of injuries at this level has been largely replaced by CT imaging in addition to MRI. Patients present with weakness in finger flexion in addition to paresthesias in the fifth digit and along the medial border of the forearm. One clinical pearl is to assess opposition and abduction of the thumb (medial nerve) which distinguishes C8 radiculopathy from an ulnar nerve compression (i.e., cubital tunnel syndrome) [45]. Ulnar nerve compression can be elicited by compressing the medial side of the elbow (Tinel’s sign) with resulting paresthesias. Paresthesias from compression at the elbow are evident in the hand but not in the forearm due to innervation of the medial antebrachial nerve, which serves as another distinguishing clinical exam finding.