Cervical Strain (Whiplash)

CHAPTER 103

Cervical Strain

(Whiplash)

Presentation

The patient may arrive directly from a motor vehicle collision complaining of acute neck pain, arrive the following day (complaining of increased neck stiffness and pain), or arrive anytime afterward (to have the injuries “documented”). The injury was incurred when the neck was subjected to sudden extension and flexion when the car was struck from the rear, possibly injuring intervertebral joints, disks, and ligaments; cervical muscles; or even nerve roots.

Sports injuries are another source of neck injury and pain. As is common with other strains and sprains, the stiffness and pain tend to peak on the day after the injury.

What To Do:

Obtain a detailed history to determine the mechanism and severity of the injury. Was the patient wearing a seat belt? Was the headrest up? Were eyeglasses thrown into the rear seat? Was the seat broken? Was the car damaged? Was the car drivable afterward? Was the windshield shattered? Was there intrusion into the passenger compartment?

Did a sports injury include a worrisome mechanism of injury, such as axial loading with the neck flexed or hyperextended, or did it involve spear tackling (using the helmet as the point of impact when tackling)?

Historical red flags that suggest a serious spinal injury include any dangerous mechanism of injury (e.g., a fall from a height of more than 1 meter; an axial loading injury, as described above or a diving injury; high-speed [>60 m/hr or 100 km/hr] motor vehicle collision rollover or ejection; motorized recreational vehicle or bicycle collision) or the presence of paresthesias in the extremities, severe neck pain, or persistent patient apprehension.

To evaluate the possibility of head trauma, ask about loss of consciousness or amnesia, headache, and nausea or vomiting (see Chapter 10).

Examine the patient for involuntary splinting, point tenderness over the spinous processes of the cervical vertebrae, cervical muscle spasm or tenderness, and strength, sensation, and reflexes in the arms (to evaluate the cervical nerve roots).

Physical red flags that suggest a serious spinal injury include age of 65 years or older, inability of the patient to actively rotate his neck 45 degrees to the left and to the right, any focal neurologic findings, or midline cervical tenderness.

If there is any question at all of an unstable neck injury because of historical or physical red flags mentioned previously or if there is altered mentation, intoxication, or painful distracting injuries, start the evaluation with a cross-table lateral radiograph of the cervical spine while maintaining cervical immobilization with a rigid collar. If necessary, the anteroposterior (AP) view and open-mouth view of the odontoid can also be obtained before the patient is moved.

Use of plain films is adequate for low-risk patients, but there are no identifiable factors that predict false-negative cervical spine radiographs. Therefore a CT scan of the cervical spine should be obtained when plain films are inadequate or because of difficult clinical circumstances, such as obesity. A CT scan of the cervical spine should also be obtained when you are dealing with a high- or moderate-risk patient who is having CT scanning of other body parts.

Most minor neck injuries can be safely cleared without obtaining any radiologic studies. Using the “Canadian C-spine rule,” if there are no historical or physical high-risk factors (red flags noted previously), and the patient has low risk factors that allow a safe assessment of neck range of motion (e.g., simple rear-end motor vehicle collision, ability to sit at the time of the examination, ability to ambulate at any time after the injury, or delayed onset of neck pain) and is able to actively rotate his neck 45 degrees to the left and to the right, then he does not need radiographs or CT scanning.

Alternatively, the National Emergency X-ray Use Study (NEXUS) can be applied to safely clear the cervical spine without any imaging studies in patients who have normal alertness, are not intoxicated, have no painful distracting injuries, and, on examination, have no midline cervical tenderness or focal neurologic deficits.

If (1) the C-spine has been cleared clinically or if radiographs or CT scans show no fracture or dislocation, and (2) history and physical examination are consistent with mild to moderate stable joint, ligament, and/or muscle injury, explain to the patient that the stiffness and pain are often worse after 24 hours but usually begin to resolve over the next 3 to 5 days. Most patients are back to normal in 1 week, although some have persistent pain for 6 weeks.

When there is significant discomfort, provide 1 or 2 days of intermittent immobilization by fitting a soft cervical collar to wear when out of bed. Place the wide side of the cervical collar either anterior or posterior, based on the position of maximum comfort. When worn in reverse, the collar allows neck flexion and may be valuable, particularly when carrying out certain activities of daily living, such as driving. If neither position improves comfort, omit the collar. Under any circumstances, a collar should be used for as brief a time as possible, because early mobilization has been shown to speed recovery.

Instruct the patient to apply heat or cold if either is found to be beneficial, and take over-the-counter (OTC) acetaminophen or anti-inflammatory analgesics, such as ibuprofen or naproxen.

Have the patient begin gentle range-of-motion exercises as soon as possible. One exercise and mobilization protocol consists of small-range and amplitude rotational movements of the neck, first in one direction, then the other, to be repeated 10 times in each direction every waking hour. The movements should be performed up to a maximum comfortable range. These home exercises can be done in the sitting position, if symptoms are not too severe or in the unloaded supine position when the sitting position is too painful.

The athlete must demonstrate a full pain-free range of motion and at least 90% strength before return to play can be advised.

Arrange for follow-up for all patients, as necessary.

What Not To Do:

Do not forget to tell the patient her symptoms may well be worse the day after the injury.

Do not refer the patient for chiropractic manipulation of the cervical spine. There is risk for cervical myelopathy, cervical radiculopathy, and vertebral basilar artery strokes, with little chance of any improvement.

Do not be slack in recording the history and physical examination. This sort of injury may end up in litigation, and a detailed record can obviate the physician being subpoenaed to testify in person.

Do not check neck movement by using passive range-of-motion testing. This has the potential for causing serious neurologic injury.

Do not obtain a radiograph of every neck. A thousand negative cervical spine radiographs are cost effective if they prevent one paraplegic from an occult unstable fracture, but with the Canadian C-spine rules and NEXUS establishing a standard of care for the evaluation of neck injuries, not all patients need radiography just because they were in a motor vehicle collision, fell, or hit their head.

Do not remove shoulder pads and helmets in football and hockey players until the cervical spine has been cleared, unless there is airway compromise or the helmet prevents cervical immobilization. To safely remove this equipment, the patient’s torso, head, and neck are elevated about 30 to 40 degrees by a four-person team. With manual stabilization of the neck, the helmet and shoulder pads are removed simultaneously, and the patient is lowered to the supine position.

Discussion

Most injuries to the cervical spine are minor. The most commonly encountered injuries are soft tissue trauma and include ligament sprains, muscle strains, and soft tissue contusions. Fortunately, these injuries generally heal without producing long-term problems.

The cervical spine is made up of seven specialized vertebrae, which together provide a wide range of motion to the head. As with other joints, the large range of motion afforded by the cervical spine comes at the cost of stability, because the cervical region has relatively little intrinsic bony stability and relies on ligament restraints to avoid excessive or pathologic mobility.

The primary static stabilizers of the neck include the anterior longitudinal ligament, intervertebral disk, posterior longitudinal ligament, ligamentum flavum, facet capsules, and interspinous and supraspinous ligaments. Important dynamic stabilizers consist of the sternocleidomastoid, trapezius, strap, and paraspinal muscles. This muscular envelope functions as a dynamic splint and protects the cervical spine during the full range of motion, whereas the ligamentous structures act as a check rein, limiting motion at the end points.

Strains are defined as stretch injuries occurring at the musculotendinous junction or within the muscle substance. Sprains involve a stretch injury to a ligamentous structure. Cervical contusions involve a blunt-force injury to the soft tissues. Sprains occur with a spectrum of ligamentous disruptions, ranging from mild pain without instability to gross ligamentous disruption. Injuries to the facet joints and capsular ligaments have been blamed for chronic neck pain following forced flexion injuries, such as whiplash.

Typically, patients who have sustained a cervical sprain, strain, or contusion present with painful, limited cervical motion and tenderness over the involved structure. The management of cervical sprains, strains, and contusions is similar, although ligament injuries usually take more time to heal.

Whiplash, in contrast with most other injuries, has a female preponderance of 2:1. Some have speculated that this gender difference reflects a woman’s smaller, less muscular neck. Most patients presenting for evaluation at some point after the injury have less specific symptoms, however, and few “hard” signs on examination. Localized neck pain, neck stiffness, occipital headache, dizziness in all of its forms, malaise, and fatigue are common whiplash symptoms. Localized paracervical tenderness to palpation, reduced range of neck motion, and weakness of the upper extremities secondary to guarding are common findings.

Although most patients with myofascial symptoms recover in several months, 20% to 40% complain of debilitating symptoms for extended periods, sometimes years.

When litigation is involved, some patients exaggerate or lie about persisting symptoms to help make their legal cases. Most plaintiffs who have persistent symptoms at the time of settlement of their litigation, however, are not cured by a verdict. The clinician should evaluate the merits of each case individually. The available evidence does not support bias against patients just because they have pending litigation.

The term whiplash is probably best reserved for describing the mechanism of injury and is of little value as a diagnosis. Because of the many undesirable legal connotations that surround this term, it may be advisable to substitute “flexion/extension injury.”

Brachial plexus injuries, which are commonly referred to as “stingers” or “burners,” are a common occurrence in athletics, especially in football. Either traction on the brachial plexus or compression of the dorsal nerve roots can cause these injuries.

When the neck is flexed laterally and the contralateral shoulder is depressed, a traction force is created on the brachial plexus. Conversely, extreme lateral flexion of the neck can cause cervical nerve root compression by narrowing the neural foramen. Both types of stingers usually result in transient neuropraxia, manifested in the injured athlete as a burning sensation down the affected arm and weakness of C5-6–innervated muscles (deltoid, biceps, supraspinatus, infraspinatus). The athlete is usually seen coming off the field or mat shaking his arm, which may be hanging limply at the side, and leaning toward the side of injury.

Usually, a stinger is a self-limited injury that does not require anything more than keeping the athlete out of the game until the neurologic symptoms have resolved. (Pain usually resolves in less than 15 minutes; strength returns in 24 to 48 hours.)

The athlete should not return to play if there is any cervical pain, limited cervical range of motion, bilateral limb involvement, or persistent neurologic deficits.