Spinal Orthotics



Spinal Orthotics


Ferne Pomerantz

Eva Durand



An orthosis is a mechanical device that applies forces to the body in an effort to support, limit, and stabilize moving parts, assist and improve motion, correct and align deformities, and prevent and protect susceptible areas. The location, direction, and magnitude of these forces vary with the components and design of the orthosis. The word orthotic is derived from the Greek word “orthos,” meaning straight, normal, or true. Orthotics, also called braces or splints, have been known since the ancient Egyptian era. Their use continues till today; however, changes and advances in materials and techniques of fabrication, interrelated with newer surgical procedures and medical treatments, have expanded their applications.

An orthotist is a professional who designs, makes, and, with the referring physician, helps prescribe the proper orthosis for a patient. Orthoses can be prefabricated to fit a large variety of patients or custom molded to a specific patient. Their effectiveness is directly dependent upon the proper fit and alignment of the components as well as proper use and compliance by the patient. The physician and orthotist should prepare a detailed prescription together in order to avoid delivering the wrong device. Once delivered each should be present to “check out” the device in order to ensure proper fit.

The prescription of an orthosis requires an understanding of the pathology of the disorder to be treated and must take into account the goals to be achieved. Knowledge of anatomy, biomechanics, and kinesiology, and an understanding of the indications (positive effects) and limitations (negative effects) of the orthosis are paramount when prescribing such devices.

One should not get confused by the myriad classifications and names for orthoses. Some are named for their founder, others for the location where they were developed, and still others for the parts of the body to which they are applied. The most standard way to name an orthosis is by the joints that it encompasses and the motion it controls (1). In this chapter we review the different types of spinal orthotics, indications for their use, positive and negative effects, and problems that may interfere with the ongoing rehabilitation of the patient. Braces for scoliosis and osteoporosis are not covered in this chapter (see Chapters 32 and 33, respectively).


MECHANISM OF ACTION

Spinal orthotics are prescribed for a variety of reasons (Table 77-1). They are designed to protect the spinal column and supporting structures (ligaments and muscles) from loads and stresses that can cause pain or progression of angular and translational deformity. The physiologic mechanisms responsible for this protection are control of motion, trunk support, and spinal alignment (2).


Control of Motion

The control of motion depends on the flexibility of the device. Numerous studies have attempted to quantify the degree of motion restriction. The most minimal limitation in gross movement likely occurs because the device acts as a physical and kinesthetic reminder to the patient not to move in harmful ways. Braces such as soft collars or lumbar corsets are examples of these. These types of devices also serve to provide warmth and heat to the patient, which may reduce spasm and pain. More restrictive braces act to limit intersegmental spinal motion and further, inhibit flexion-extension, lateral bending, and axial rotation.


Trunk Support

Trunk support is achieved by an increase in the intra-abdominal pressure. An increase in the thoracoabdominal pressure reduces the demand on the spinal extensor musculature and the vertical loading on the thoracolumbar spine and the intradiscal pressure.


Spinal Alignment

Spinal alignment is achieved by the application of the three-point force system inherent in all bracing. The corrective component ideally is located midway between the opposing forces above and below it. These systems shift forces from diseased areas to more healthy segments and prevent unopposed forces from causing deformity.

At each spinal level, orthoses require different designs to achieve their desired function. The desired physiologic effect must be decided upon when prescribing an orthosis so that the least restrictive device capable of completing the job is ordered. For example, if trunk support by thoracoabdominal containment is sufficient to reduce the compressive forces on the spinal column and stress on the musculature, then joint motion stabilization should not be required (2).

Before prescribing an orthosis, one must begin with the indication and develop a goal and then decide which orthosis will achieve the desired goal. Once that goal has been achieved and the device is no longer needed, the device should be
discarded. Considerable diversity and controversy can surround the choice of an orthosis and the length of time needed for immobilization. Specific guidelines are generally lacking.








TABLE 77.1 Indications for Spinal Orthotics











Stabilize the spine after fracture (with or without neurological deficit)


Limit spinal motion in cases of pain or sprain


Support posture and prevent deformity after paralysis


Postsurgical stabilization (with or without fracture)


Spinal orthotics are divided into groups by the joints they encompass. Within each group, there are many different designs (Table 77-2). They may further be differentiated by the motion they restrict or allow.

It is essential to be aware of the negative effects of bracing. Weakness, atrophy, and contracture may follow restriction of motion and muscular activity. Skin irritation from poor fit, hygiene, and pin site shear and pressure, can result in ulceration, pain, and infection. Impaired ambulation and balance can result from the limitation in motion and weight of the device such as with a halo device, which in turn, may make an individual more dependent in their activities of daily living. Eating and swallowing may become compromised due to the position of the head and neck. There can be a decrease in pulmonary capacity due to the restricted chest wall motion and an increase in energy consumption. Psychological dependence on the brace can also develop. This should all be taken into account when prescribing these braces because patients with certain medical conditions (e.g., neuromuscular disease), body types, and personalities may not be able to tolerate them.

Effective spinal bracing, therefore, is a complicated procedure and needs to take into account multiple factors. It is contingent upon correct fit, patient compliance, body habitus, the ability to restrict gross and segmental vertebral motion and the ability to minimize and prevent the negative side effects. Compliance is dependent on the patient’s understanding of the condition, willingness to tolerate a snug fitting appliance, and overall comfort. Discomfort may be related to strap tightness, complaints of confinement, or increased perspiration caused by the brace. With patients who can volitionally adjust the straps, the effectiveness of the brace may be compromised if they loosen the straps. Individuals with a short stout neck and no defined chin are harder to fit with a cervical collar. Pendulous breasts, short trunk, thoracic kyphosis, or an obese abdomen make it difficult to comfortably fit cervicothoracic or thoracolumbosacral appliances. Two braces may need to be given to the patient so that one can be washed on a regular basis in order to maintain hygiene. Skin under the brace needs to be checked and washed daily. While in the brace, an exercise program should be implemented, if possible. Once the brace is discontinued, a more aggressive strengthening and stretching program is initiated in order to prevent the negative effects of disuse. In addition, the patient or caregiver must be instructed in the donning and doffing of the orthosis, its wearing schedule, whether or not the patient needs to sleep and shower in the brace, and the length of time the orthosis is recommended. Follow-up of its continued use is required both for the physician and the patient.








TABLE 77.2 Categories of Orthoses













Cervical (CO)—soft or rigid head cervical (Philadelphia, Aspen, Miami, Newport)


Cervicothoracic (CTO)—Halo, SOMI, Minerva, any rigid collar with an anterior or posterior extension


Thoracolumbosacral (TLSO)—custom-molded body jacket, CASH, Jewitt


Lumbosacral (LSO)—chairback, Knight, corsets/binders


Sacroiliac (SO)—trochanteric belt, sacral belt, sacral corset



CERVICAL ORTHOSES (COs)

Cervical bracing can be categorized in several different manners. In general, these devices can be subdivided into two broad categories: cervical and cervicothoracic. Cervical devices encircle the cervical spine, whereas cervicothoracic braces extend into the thoracic spine. When adding a thoracic extension piece, the cervical orthosis (CO) provides greater motion control of the lower cervical spine. To limit extension and hyperextension of the cervical spine, an intimate fit under the occiput must be achieved.

With cervical appliances, the ability to control cervical motion varies significantly from the soft collar that provides minimal restriction to the halo that offers significant reduction in movement. Several studies have examined the effects of various orthoses on mean cervical range of motion (3—8). Many of these studies used different methods to quantify the amount of restriction (e.g., radiographic analysis, goniometric assessment, and computerized spinal motion analysis). In addition, the sample size and characteristics varied from study to study (i.e., cadaver models, healthy spines vs. injured spines). Table 77-3 outlines motion restriction (3, 4, 5, 6, 7, 8). For the orthotic to restrict motion adequately, it must fit properly and be worn correctly.


Cervical Biomechanics

The cervical spine is a highly mobile structure allowing flexion, extension, lateral flexion, and rotation; thus, motion occurs in three planes: sagittal, frontal, and transverse. The atlantooccipital joint primarily permits flexion and extension, with minimal axial rotation and lateral flexion. Functionally, this synovial joint enables an individual to nod their head. At the atlantoaxial (C1-2) joint, the predominant motion is rotation. Having no vertebral body or disc, the atlas rotates around the odontoid axis. Cervical rotation begins first at this articulation and then proceeds caudally. Approximately, 50% of the total rotation achieved by the cervical vertebral column occurs at C1-2. Between C4 and C7, maximum flexion and extension
occurs, with the greatest motion occurring at C5-6. During flexion the vertebral foramina open and with extension close. Lateral flexion (lateral side bending), however, occurs between C2 and C7 in the coronal plane. Given the configuration of the articulating facets, lateral flexion and rotation are coupled motions. As right rotation occurs, it initiates right lateral flexion and as left cervical rotation occurs, it initiates left lateral flexion. Sagittal motion occurring at C2-7 is uncoupled. The C2-4 region has the most side bending and rotation.








TABLE 77.3 Effects of Cervical Collars on Percent Mean Motion Permitted
























































































































Flexion/Extension


Lateral Flexion


Rotation


Source


Soft collar


74.2


92


83


Johnson (3)



91


91


89


Sandler (4)



92


92


91


Carter (5)


Philadelphia


29


67


44


Johnson



58/53


78


52


Lunsford (6)



60


89


73


Sandler


Miami J


41



20


Richtera (7)



52/62


65


52


Lunsford (6)



40/46




Gavin (8)


Malibu


47/43


59


39


Lunsford


Newport


63/62


73


51


Lunsford


Aspen


31/48




Gavin


Aspen 2 post CTO


16/39




Gavin


Aspen 4 post CTO


12/20




Gavin


Minerva


46



14


Richtera


SOMI


28


66


34


Johnson



39


82


82


Sandler


Halo


4


4


1


Johnson


a Richter only studied the upper cervical spine.



Soft Cervical Collars

A soft cervical collar is prefabricated foam rubber with a cotton stockinette covering and Velcro closures (Fig. 77-1). These closures are worn posteriorly. Depending on the patients dexterity and upper extremity range of motion, some can only fasten the closures anteriorly and rotate the collar around their neck while others leave the Velcro closures in the front. The manufacturer’s intention was to have these collars worn with the closures facing posteriorly. Collars range in size from small to extra large. To identify the correct size, circumferential neck measurements are taken. This measure corresponds with pre-determined sizes. Patients tolerate this device very well. Carter and associates reported that the degree of motion restriction achieved with the soft collar was dependent on the velcro closure position (5). If the intent is to limit flexion, then the collar should be worn in the reverse position with the tabs facing anteriorly. The explanation for this is a function of the starting position of the head. Given its soft material construction, the soft collar can only provide warmth, psychological reassurance, and kinesthetic reminders to limit cervical range of motion; it cannot provide structural support. Essentially, this orthoses reminds the patient not to move. Its use may be appropriate to treat mild muscular spasms associated with arthritic changes and mild soft-tissue injuries.






FIGURE 77-1. Soft cervical collars.

Soft collars are often prescribed for the early management of whiplash injuries. The effectiveness of its therapeutic use is under scrutiny. A study evaluating whether or not a soft collar reduced the duration and intensity of the patient’s pain following a whiplash (9) showed that test patients wearing a soft collar and control patients not wearing a soft collar reported persistent pain for at least 6 weeks postinjury. Hence, wearing a collar did influence the patients’ pain. In a randomized prospective study (10), comparing the effect of early mobilization wearing a soft collar versus not wearing a soft collar, a significant finding was the number of days it took the group with the collar to return to work. Those who wore the collar took twice as long to return to work (mean 34 days) whereas the mobilization group without the collar returned to work sooner (mean was 17 days). In another randomized controlled study (11), examining the effect of early mobilization versus the use of a collar in patients sustaining a whiplash injury, found that those patients who participated in early mobilization rated their pain and disability less than those wearing a soft collar at 6 weeks after injury. At 6 weeks, the exercise group rated their pain less in the neck and shoulder and had fewer headaches. The early mobilization group was seen by a physical therapist for exercise instruction. In 2006, the same group of researchers published their findings using the same cohort except the patients were 6 months out and the results were the same. Patients who engaged in physical therapy with active exercises had less pain at 6 months than those treated with a soft collar (12). Considerations regarding the negative effects of brace wearing (i.e., psychological dependency, muscle atrophy, etc.) should be weighed under this condition.


Hard Cervical Collars

These rigid prefabricated COs are used for either prehospital trauma immobilization or long-term management in patients who sustained a cervical injury. Examples of collars used for prehospital emergency stabilization are the Philadelphia, Stifneck, Ambu, and the NecLoc. These collars are either a one- or two-piece design. Each of these devices is radiolucent and also CT
and magnetic resonance imaging (MRI) compatible. With the exception of the Philadelphia collar, these extrication collars are used for short-term use. The purpose of these prehospital collars is to aid the rescuer in maintaining spinal alignment and stabilization in patients with potential or actual cervical injuries during transport. Using six fresh cadaver geriatric spines, Bednar concluded that the Stifneck and Philadelphia collars did not provide significant mechanical immobilization in the unstable cervical spine and may be ineffective in preventing displacement (13). This study questioned the effectiveness of these collars during field use. The results have to be considered carefully in light of the sample size and population studied. Nevertheless, the prehospital standard of care is to immobilize the cervical spine with a rigid collar with sandbags or foam blocks anchored to both sides of the head on a back board.

For long-term patient management, the Philadelphia, Miami J, Aspen, Newport, or Malibu orthoses have been used. The Newport orthoses was replaced by the Aspen collar. Each of these orthoses is available in pediatric and adult sizes. Typically, these devices are prescribed for mid-cervical bony or ligamentous injuries, postoperative stabilization, or post-halo removal. Some specific clinical conditions are anterior cervical fusion, anterior discectomy, and cervical strain. If spinal instability exists, these rigid devices are contraindicated. These appliances are being used as the first line of treatment instead of traditional halo devices for the conservative management of stable upper cervical fractures in adults (14—20). Examples of these fractures include: unilateral avulsion fracture of the transverse atlantal ligament (20), Jefferson fracture, (burst fracture of C1) (14,16), Hangman’s fracture (traumatic spondylolisthesis of the axis-C2 on C3) (15,16,18), isolated lateral mass fracture of the atlas (19), and certain types of odontoid fractures (15—17). Studies analyzing patient outcomes in the aforementioned situations showed stable fracture healing, and no increased disability or neurologic compromise on follow-up examination (14,16,18, 19, 20). In addition, these devices are cost-effective, easily applied, and do not have the increased risks associated with the use of the halo. Frequent diagnostic imaging to detect possible instability is strongly recommended. Each of these devices is radiolucent and CT and MRI compatible.

The Philadelphia collar is a two-piece design constructed from closed cell Plastazote foam with molded chin and occipital support. Anteriorly it extends from the mandible to the sternum and posteriorly it extends from the occiput to the upper thoracic spine. The Miami J, Newport, and Aspen collars are two-piece polyethylene shells with internal padding. The Miami J collar offers greater customization; the anterior and posterior shells permit angle adjustability around the chin and occiput allowing for individual differences in bony anatomy. The Newport collar has superior and inferior adjustable supporting tabs that distribute the load along the occiput, upper thoracic spine, sternum, and upper trapezius. Each of these collars has an anterior opening to accommodate a cricothyrotomy/tracheotomy. Given the increasing prevalence of latex sensitivity, physicians may want to consider this when prescribing COs; the Philadelphia, Miami J, Aspen, and Malibu collars are latex free.

According to Goutcher and Lochhead, some patients while wearing a hard cervical collar, Stiffneck, Philadelphia, or Miami J, exhibit a significant decrease in maximal mouth opening (21). In their study evaluating the above listed collars, 51 male and female volunteers’ inter-incisor distance was measured with and without a collar. In an unpredictable manner, several subjects displayed a reduced inter-incisor distance that was less than or equal to 20 mm. This reduced excursion could obstruct a physician’s visualization of the glottis with a laryngoscope. For some patients, their results suggest that attempting tracheal intubation with a collar in place could be difficult. Should a patient require an emergency tracheal intubation, the authors recommend maintaining manual cervical stabilization with the removal of the anterior shell of the collar before attempting intubation.

When prescribing cervical collars with removable padding such as with the Miami J and Aspen, a second set of replacement pads should be included. The patient needs a second set to replace soiled and odorous pads, to allow moist pads to air dry after patient showering or perspiring, and when the pads show wear. Since these pads can be cleaned, it is not necessary to discard them. For specific cleaning directions, have the patient consult the manufacturer’s guide. Proper cleaning prevents skin irritation. Patients with long hair should be advised to wear their hair outside the collar to prevent irritation.

When assessing fit or proper donning of the COs, look at the patient’s face to determine if the chin is centered in the anterior piece. If the chin extends beyond the collar edge, it is too small. If the chin falls inside the collar it is too large. These visual markers indicate whether or not the device is sized or donned correctly. Patients should be familiar with proper donning and doffing procedures.

Furthermore, patients and caregivers should be educated regarding its effects on ambulation. Since the collar forces the patient to look straight ahead, patients should be warned that they will not be able to look down to see their feet or what is below them. As a result the patient must be alert to tripping hazards, that is toys on the floor, cracks in the sidewalk, pets, loose rugs, etc. Since geriatric patients are prone to tripping and falling, the physician should consider ordering the home care therapist to evaluate the home environment for potential environmental hazards and to formulate safety recommendations.

Barry and associates found that wearing a cervical collar affects the driving performance in healthy men and women (22). In a prospective randomized study, 23 volunteers wore a Philadelphia collar while driving and the following parameters were measured: velocity, acceleration, cervical rotation, and driver’s blind spot. Their results showed that drivers were able to stop, turn, and control the vehicle but drove slower. The driver’s blind spot was larger with the collar on than without it. A larger blind spot does affect merging and lane change. Overall, the researchers found that the drivers’
exhibited greater caution. Based on their design and sample size, the authors could not conclude that wearing a collar leads to an increased incidence in motor vehicle accidents. Patients should be advised about the increased blind spot associated with wearing a collar.

Pressure ulcer formation is a potential complication of rigid collar use. Fragile or insensate skin is particularly vulnerable to ulceration. Common areas susceptible to damage are the occipital protuberance, mental protuberance of the mandible (chin), clavicles, and ears. These wounds may be the result of pressure, shear, or moisture accumulation. A poorly fitting orthotic could exert an external pressure greater than the acceptable skin pressure of 25 to 32 mm Hg; when this occurs tissue ischemia ensues, resulting in an ulcer. In addition, shearing forces can arise due to facial hair and skin sliding over the collar surface, or from positional changes. For example, when a patient moves from supine to a semi-Fowler position in preparation for getting out of bed, or if the patient slides down toward the foot of the bed, shear forces can develop. Since beards increase the shear forces, it is suggested that patients shave regularly. Since constant collar wearing increases the local skin temperature, excessive perspiration in and around the area can occur. Constant moisture macerates the skin, inducing breakdown. Jirika et al. found that patients with moist skin were four times more likely to develop skin breakdown compared to those with dry skin (23). Provisions should be made to keep the skin clean, dry, and cool.

To assess for skin breakdown, remove the anterior shell to inspect the chin and clavicles, then refasten the straps before log rolling the patient onto his or her side. Remove the posterior portion and inspect the occipital protuberance and ear lobes. When removing or applying the collar or a portion of it, the physician must maintain proper neck alignment to prevent injuring the cervical spine. Prior to discharge, patients should be advised to contact their physician if they notice any redness or pressure sores.

Plasier et al. conducted a study to evaluate the craniofacial pressures when using different hard cervical collars: Stifneck, Philadelphia, Newport, and Miami J (24). The study found that the Newport and Miami J collars had lower skin capillary closing pressures, and their open-cell foam material prevented moisture accumulation. In supine and upright positions, the Philadelphia collar exerted high capillary closing pressures leaving the tissues susceptible to injury. In another study, occipital pressure, skin temperature, and humidity were compared when wearing the Philadelphia and Aspen collars (25). Measurements were taken at two separate time intervals, zero and 30 minutes. Using paired t-tests the authors found no difference in pressure or skin temperature with the two collars. Skin humidity, however, was higher when wearing the Philadelphia collar. Skin humidity relates to perspiration and perhaps the closed cell materials used in the Philadelphia collar caused the subjects to perspire more. For patients predisposed to excessive perspiration, the materials used in the collar’s construction should be considered in order to optimize patient comfort, compliance, and minimize ulcer formation. Additional but uncommon complications associated with the use of hard collars have included marginal mandibular nerve palsy (26), dysphagia (27), changes in intracranial pressure (28), reduction in tidal volume (29), and incomplete tetraplegia (30).


Cervicothoracic Orthosis (CTO)

Several prefabricated hard collars (i.e., Philadelphia, Miami, and Aspen) can be made with an extension piece placed anteriorly and/or posteriorly to transform a CO into a CTO. For bedridden patients, devices without a posterior piece are better tolerated. CTOs restrict middle and lower cervical motion. Other examples of CTOs include the SOMI and Minerva. The SOMI is named for its body attachments: sternum, occiput, mandible immobilizer (Fig. 77-2). If the mandibular support interferes with the patient’s ability to chew, or a pressure sore develops, or the patient has a prominent chin, a forehead strap attaching to the occipital support can be substituted. Since this device lacks posterior thoracic support it cannot limit extension; it does limit flexion, however. Furthermore, it may be an appropriate option for bedridden patients since it lacks posterior thoracic coverage. Because the SOMI limits flexion it may be used in cases of atlantoaxial instability with an intact dens, such as in patients with rheumatoid arthritis and in C2 neural arch fractures.

The Minerva is a total contact orthosis with fixation points at the chin, occiput, sternum, thorax, and the forehead. The jacket is made of polyethylene and lined with an open cell material. In addition to controlling the middle and lower cervical spine it can be used for the upper cervical spine below C2. In a study examining the effects of mastication on cervical motion in patients wearing a cervical orthotic, it was found that chewing while wearing a brace with a chin device increased motion above C4 (31). This has implications for patients wearing a Minerva brace while eating. Benzel et al. found that when comparing the halo to the Minerva, the average movement from flexion to extension was 3.7 degrees ± 3.1 for the halo and 2.3 degrees ± 1.7 for the Minerva, suggesting that the Minerva could be considered over the halo in injuries below C2 (32). Between the occiput and C1 the halo provided

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May 25, 2016 | Posted by in PHYSICAL MEDICINE & REHABILITATION | Comments Off on Spinal Orthotics

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