Osteopathic Manipulative Treatment: HVLA Procedure - Cervical Vertebrae

Anatomy and Physiology

The cervical spine has 7 vertically stacked bones called vertebrae, labeled C1 (cervical 1) through C7 (cervical 7). C1 (called the atlas) connects the top of the cervical spine to the base of the skull, and C7 connects to the upper thoracic spine at about shoulder level. These uniquely shaped bones (the spinal column) protect the spinal cord, a cylindrical bundle of nerve fibers and associated nerve roots enclosed within the cervical vertebrae, connecting the body to the brain.

The upper cervical spine is unique. The atlas (C1) and axis (C2), functioning together, are primarily responsible for spinal rotation, flexion (bend forward), and extension (bend backward) and are the most mobile part of the entire spine. Roughly 50% of flexion and extension and 50% of neck rotation occur in the areas of C1 and C2. The remainder of the cervical vertebrae (C3-C7) are smaller than the thoracic and lumbar vertebrae. The vertebral bodies are round with a hollow center that continues from C1 and C2 and houses the spinal cord as it travels distally from the brainstem. The cervical intervertebral discs are "shock-absorbing pads" between each level starting below C2 (axis). The discs are strong yet flexible tissues composed of fibrocartilage. In the middle of each disc is a nucleus pulposus, a gel-like material surrounded by a strong protective outer layer called the annulus fibrosus.

At each vertebral level of the spinal column, the discs hold the vertebrae together and absorb shock to the spine. The discs also create spaces (called foramen) between each bony vertebrae, allowing nerves to exit the spinal cord.  Spinal nerve roots are bundles of nerve fibers that exit (or enter) the spinal cord in pairs from each side of the spinal cord and travel through the foramen to send and receive nerve impulses from the body. Each cervical nerve innervates or provides sensation and motor function to both sides of a corresponding part of the upper body. Muscles, tendons, and ligaments help support the cervical spinal column by limiting excessive movement in all directions.

Common disc disorders include degenerative disc disease and disc herniations ("ruptured disc") that can cause adjacent spinal nerve irritation. This can happen when a disc flattens or becomes deformed, as the space for a spinal nerve passing through the foramen is compromised. Nerve compression may cause pain radiating throughout the neck and into the head, back, and arms. Cervical spinal stenosis is a narrowing of the hollow center of the spinal canal. It can lead to spinal cord compression and impingement of the nerve roots exiting the spinal cord. Cervical trauma may affect the cervical spinal column by causing injury to bones, nerves, muscles, tendons, and ligaments. Trauma can disrupt nerve communication between the brain and various somatic and visceral systems, sometimes resulting in weakness, paralysis, and loss of sensation. Cervical strain is typically the result of a stretch injury to the muscles and ligaments of the cervical spine. Oftentimes, it is the result of trauma from sports-related injuries, falls, or motor vehicle accidents. Prolonged improper positioning (poor workplace ergonomics) can cause postural deviations, which may eventually result in neck pain even in younger patient populations.[7]

To be an adequate cervical HVLA OMT provider, the provider must have adequate knowledge of cervical spine and neck anatomy.[8]  It should be noted that all cervical vertebrae except C1 and C2 are composed of 2 portions: The body (an anteriorly situated central mass of bone) and a vertebral arch arising posteriorly off the body. The vertebral arch consists of the pedicles that connect the body to the articular processes and the lamina that connects the articular processes to the spinous process on the most posterior aspect of each vertebra. The paired articular processes on each vertebra articulate with an adjacent articular process of a contiguous vertebra to form zygapophyseal joints, allowing motion between the vertebrae in X, Y, and Z planes. 

The transverse processes are small bony projections off each vertebra's right and left sides. The 2 transverse processes of each vertebra function as the site of attachment for muscles. The transverse foramen (foramen transversarium) of the cervical vertebrae is a hole or opening in the transverse process of a cervical vertebra for the passage of the vertebral artery and vein and the sympathetic nerve plexus. The paired vertebral arteries (1 on each side) are of particular importance because they provide blood to the brain and spinal cord, and they can be damaged during traumatic events involving the transverse processes. The spinous process is a bone projection off the posterior aspect of a vertebra. It arises from the neural arch at the junction of 2 laminae and provides attachment for muscles concerned with flexion, extension, and spine stability. Efficient and careful palpation of the cervical vertebral elements, particularly the spinous and transverse processes, is essential to establish an accurate diagnosis of cervical somatic dysfunction. Likewise, the same knowledge base is required to provide cervical HVLA OMT for the patient in the safest way possible. 

Indications

Many manual medicine practitioners use HVLA thrust techniques to treat spinal somatic dysfunction.  A common indication for HVLA OMT is "joint fixation," a condition where any 2 bones in a joint become misaligned or fixated (stuck). HVLA therapy in the cervical region may effectively resolve neck, shoulder, and head pain.[9] HVLA therapy of the cervical spine is indicated to treat motion loss with associated somatic dysfunction. It is hypothesized that fibrous adhesions develop in zygapophyseal joints during relative immobility periods, restricting joint motion. HVLA therapy is thought to improve symptoms consistent with musculoskeletal joint restriction due to cavitation and adhesions of the zygapophyseal joints.  HVLA is typically used for patients with local or radiating neck pain in non-acute phases.  To that extent, it is also used to treat patients with cervicogenic headaches. Studies suggest that mobilization or manipulation of the cervical spine may benefit individuals experiencing cervicogenic headaches.[10]

Contraindications

There are 2 types of contraindications in the cervical HVLA OMT: absolute and relative. Absolute contraindications include patients with a medical history of osteoporosis, active osteomyelitis, fractures in the cervical area, severe rheumatoid arthritis, and bone metastasis in the cervical region. Also included are patients with Down Syndrome, as HVLA therapy can lead to rupture of the transverse ligament of the dens process since this population may have increased laxity of the transverse ligament at baseline.[11]

Absolute Contraindications:[12][13]

• Acute fractures
• Acute soft tissue injury
• Acute myelopathy
• Ankylosing spondylitis
• Anticoagulant therapy
• Chiari malformation
• Connective tissue disease
• Dislocation
• Down syndrome
• Infection
• Instability
• Ligament rupture
• Osteoporosis
• Patient refusal
• Recent surgery
• Rheumatoid arthritis
• Surgical or pathologic fusion of a joint
• Tumor/bony malignancy
• Vertebral artery abnormalities
• Vascular disease

Relative Contraindications:[13]

• Acute herniated nucleus pulposis
• Acute whiplash
• Any symptom aggravated by movement of the neck
• Blurred vision
• Diplopia
• Dizziness/vertigo
• Drop attacks
• Dysarthria
• Dysphagia
• Facial/oral paresthesia
• Hypermobility syndromes
• Nausea
• Previous diagnosis of vertebrobasilar insufficiency
• Tinnitus
• Visual disturbances
• Worsening of symptoms with manipulations

Since a large number of the reported cases of serious adverse outcomes involved cervical HVLA OMT and "thrust" techniques involved vertebrobasilar accidents (VBA) and strokes, caution should be used when treating patients with suspected artery disease or vascular anomalies.[14][15][16]

Personnel

The technique requires practitioner training in OMT or hands-on spinal manipulation techniques. To have successful HVLA therapy outcomes, the patient must consent, be cooperative, and be relaxed and healthy enough to be placed in the proper position for treatment.

Preparation

It is encouraged that all practitioners who wish to use cervical manipulation should undertake a formal education program to decrease risks.[12] As with any therapy, awareness and knowledge are important factors in weighing the benefits, managing the risks, and recognizing early warning signs of adverse events.[17] Preparation should begin with a thorough history and complete head-to-toe assessment to minimize the likelihood of complications arising from cervical manipulation. Patients should be thoroughly screened for all potential contraindications and precautions, preferably through screening methods focused on identifying patients who have contraindications to HVLA therapy and may be at risk of adverse outcomes.[12][13]

Since HVLA OMT is considered a procedure, proper consent should be obtained before the initiation of treatment.[18]  Providing information about HVLA and assessing the patient's understanding of HVLA is essential to positive outcomes and patient relaxation during the procedure. The practitioner's duty includes the safe and appropriate performance of HVLA therapy and providing pertinent information and advice to enable the patient to make an informed decision regarding their treatment. Failure to inform the patient of the potential risks and benefits and failure to obtain informed consent is a breach of duty. Preparation starts with localizing the correct region in which a cervical somatic dysfunction exists. To establish this diagnosis, it is necessary to identify the specific cervical spine level at which the segment is causing severe pain on palpation or a restriction of motion. Once identified, the practitioner engages that cervical level in both flexion and extension. The provider then tests the patient's ability to rotate and side-bend each segment to the right and left. Once identifying the restricted barrier, for example, a C4 vertebra that is flexed, rotated left side bent left, the physician would take the restricted barrier into the opposite orientation. For this example, you would engage C4 extended rotated right and side bent right. 

Patient positioning is ideal for optimal procedural outcomes. The patient should be supine, and the operator (physician) should be at the head of the table. Patients need to be as relaxed as possible during physical assessment. This is an essential component of treatment for patients to have optimal results and prevent any adverse outcomes. A satisfactory patient-physician relationship and a foundation of trust are imperative to positive outcomes.

Technique or Treatment

A Step-by-step organized procedural pathway is paramount to an ideal outcome for this procedure. The first step is diagnosing the patient's cervical somatic dysfunction. Then, verifying that there are no existing contraindications ensures that the patient is a candidate for HVLA therapy. Diagnosing cervical somatic dysfunction involves a careful manual examination of the atlantooccipital joint with the patient in the supine position, comparing the depths of the occipital sulci. The atlantoaxial joint is examined by flexing the patient's cervical spine and locking the atlantooccipital and C2-C7 joints. The range of motion of the atlantoaxial joint is then evaluated by slowly rotating the cervical spine from right to left, noting any restricted movement when comparing the rotation to each side.  C2-C7 are also evaluated with the patient in the supine position, with careful attention directed to the freedom of movement of each segment with palpation to the right and left.  With the cervical spine positioned in the neutral, flexed, and extended positions, the practitioner should determine which segments are rotationally translated (manually displaced) more easily from 1 side versus the contralateral side.  A lack of equality at any translation level of an individual vertebra indicates a restriction.

HVLA techniques are most successful when the patient is relaxed. Myofascial techniques may be instituted before HVLA therapy to relax muscle groups further. This is achieved by applying a slow and gentle force to loosen hypertonic muscles. By delivering perpendicular and parallel traction and stretching motions with the fingertips, the muscles and soft tissues "release." When the restricted barrier is identified (for example, C4 flexed rotated left, side bent left), the practitioner takes the restricted barrier into the opposite orientation. In this example, the practitioner would engage C4 in the extended, rotated right, and side-bent right position. 

The patient is instructed to relax. If the patient does not adequately relax, the treatment will fail, and the corrective thrust cannot be executed appropriately. The physician should instruct the patient to take multiple deep breaths, further engaging the restrictive barrier in the exhalation phase. The physician then executes a short, effective thrust to move the dysfunctional segment through the restriction barrier. The ability to perform a successful adjustment with HVLA therapy sometimes elicits a "popping" sound. The restrictive barrier should be engaged entirely before applying the thrust. Finally, after executing the HVLA technique, the practitioner should reassess the range of motion and the somatic dysfunction treated. A successful result would lead to approximately 70% or greater return in the restricted range of motion and/or relief of pain.  Patients are discharged after thirty minutes of observation with instructions to hydrate appropriately. They follow up in 1 week for further evaluation and reassessment. 

Complications

Although rare, the risk of catastrophic adverse effects has been associated with manual therapy of the cervical spine. The most serious associated adverse events include cervical artery dissection, vertebrobasilar insufficiency, and artery spasm, all of which can lead to stroke.[19] It is suggested that all practitioners perform a Vertebral Artery Test (Wallenberg test), a physical exam for vertebral artery insufficiency before neck manipulation. The Wallenberg test involves motion in the cervical spine in the position of rotation, extension, and a combination of both. If the patient has vertebral artery insufficiency symptoms during the test (lightheadedness, visual disturbance, or ocular nystagmus), it is considered a positive result, and cervical manipulation should be avoided.[20] 

Controversy surrounds the dependability of vertebral artery testing before manipulation, with studies concluding that it is impossible to conclude the accuracy of pre-manipulative tests. Studies may indicate that pre-manipulative tests are unreliable screening procedures.[21]  Nevertheless, the possibility of vertebral artery disease must be entertained before performing cervical manipulation. Vertebral artery injury is a major complication, usually occurring when cervical HVLA is performed with the neck in the extended position.[22] Vertebral artery dissections may occur due to intimal damage resulting from over-stretching the artery during rotational maneuvers.[23] Intimal injury can lead to bleeding into the wall of the artery, pseudoaneurysm formation, thrombosis, and embolism.[24]

Additional complications of this procedure, mainly performed by providers without sufficient experience, can include minor soreness or muscle pains. Complications are rare, but the chance of adverse events increases with contraindications. Additional complications can include fractures of cervical vertebrae, spinal cord injury, and other soft tissue injuries.[25] In some cases, subjective pains may be made worse following an HVLA therapy. It is also hypothesized that dural tears may infrequently occur following HVLA treatment and central retinal artery occlusions from patients with atherosclerotic disease of the carotid arteries and spinal cord contusion (Brown-Sequard syndrome).[26][27][28]

Clinical Significance

Various professions frequently use the HVLA, including physicians, chiropractors, physical therapists, and other manual medicine practitioners. HVLA therapy is also called the "thrust" technique since it directs a quick, short thrust through a joint, typically in the spine. The goal of HVLA OMT of the cervical spine is the resolution of symptoms (reduced pain, increased range of motion). The frequently cited therapeutic mechanism of HVLA treatment centers on restoring joint mobility and/or correcting a joint's malalignment.[29] With this in mind, some believe that the therapeutic effect of HVLA therapy is the result of a reduction of pain from some underlying painful biomechanical dysfunction (a corrective treatment of a painful biomechanical lesion).[30]

Controversy exists since evidence suggests that treating the asymmetrical movement of a single vertebral segment or multiple segments is unlikely to have a therapeutic effect and that treating spinal segments only produces a "minor movement" already observed in the pre-treatment segments.[29][31] In attempting to describe the mechanism of action of HVLA, researchers propose that HVLA provides relief through a complex reflexive pathway involving afferent and efferent neurons and their effects on local paraspinal regions. Furthermore, HVLA may help decrease pain by triggering serotonin and noradrenaline release on a systemic level.[32] Studies have suggested that osteopathic manipulative treatment, in general, is as efficacious as intramuscular ketorolac in providing pain relief.[33] To that extent, it was concluded that OMT is a reasonable alternative to parenteral nonsteroidal anti-inflammatory medications for patients with acute neck pain. Nevertheless, there is a need for further osteopathic trials with specific outcome measures related to the HVLA technique to define the therapeutic effect better and define what combination therapies might best benefit the patient.[34]

Enhancing Healthcare Team Outcomes

The patient-physician relationship is built on trust, allowing a physician to provide an accepted standard of care within the practitioner's scope of practice and training.[35][36][37] To that extent, communication between the physician providing HVLA OMT and the patient is pivotal for optimizing results. The physician's responsibility is to educate, provide adequate information about the risks and benefits of treatment, and obtain informed consent before this procedure to alleviate anxiety.  This allows maximal relaxation and comfort, which are essential to proper performance. Successful communication in the patient-physician relationship ensures trust and allows for shared decision-making.

Collaboration amongst the interprofessional team to understand and interpret somatic dysfunctions and HVLA therapy is paramount to guide further diagnostics, therapeutics, and consultations for the patient's overall benefit. Collaboration with other members of the healthcare team (other physicians, as well as physical therapists, occupational therapists, social workers, acupuncturists, counselors, etc) may ensure complementary healthcare modalities, such as dietary changes, nutritional supplements, therapeutic exercises, and medicinal regimes as part of the overall treatment plan.