User:Jackson P&O/C6 Spinal Cord Injury

This website outlines the upper limb orthotic treatment provided to a client with a C6 level spinal cord injury. Evidence used to develop an upper limb orthotic prescription is given, the design and manufacture of the prescribed orthosis is detailed, the fabricated orthosis critically assessed, and a referral letter and ongoing treatment plan provided.

Please note that this case study is fictional and the information provided is not a substitute for medical or professional care, and you should not use the information in place of the advice of your physician or other healthcare provider.

Case Study Description
The client is a 30 year old female who suffered a spinal cord injury during a motor vehicle accident. The vehicle she was driving was forcibly hit from behind, with the impact causing sudden forward movement of her head. The client was diagnosed as having incompletely severed the spinal cord at the C6 level, with the injury classified as ASIA impairment scale grade B i.e. some sensory but no motor function below the injury level (American Spinal Injury Association, 2002). She can flex her elbows and extend her wrists, but cannot actively extend her elbows, flex her wrists or move her fingers. The client experiences some hand pain and stiffness. The client is six months post injury and will soon begin outpatient rehabilitation. The client’s goals for rehabilitation are to become more independent and eventually be able to return to work as an accountant.

Upper Limb Orthotic Treatment of a Traumatic C6 Level Spinal Cord Injury
Rehabilitation after a traumatic spinal cord injury (SCI) will be multi-faceted, with upper limb orthotic treatment playing a role. The orthotic intervention will depend on the functional deficits, which are in turn dependent on the characteristics of the injury. The anatomy and pathology of SCIs are outlined, with a specific focus on C6 level injury. Orthotic treatment options for this injury are outlined and compared, and finally compared and contrasted with other treatments.

Anatomy and Pathology
The spinal cord, which is located within the vertebral column (Figure 1), facilitates the transmission of neural signals between the brain and the body. Nerves originate from the spinal cord and exit the vertebral column through openings between adjacent vertebrae, transmitting signals to the body (Moore, Dalley, & Agur, 2014). The nerves innervate the organs and limbs in a systematic manner; generally the more superior a limb or organ is within the body, the more superior the nerve that innervates it (Moore et al., 2014). A traumatic injury results in a lesion of the spinal cord, disrupting the flow of information between the brain and the body. The prognosis depends on the level and severity of the injury (Lin, 2010). Injury level is defined as “the most caudal segment of the spinal cord where sensory function and motor function on both sides are normal” (Lin, 2010, p. 90). Transmission of neural signals to nerves that originate below the level of the injury is compromised, and thus the functionality of organs and limbs that were innervated by these nerves is also compromised. Injury severity relates to whether the injury is complete, with no sensory or motor function below the injury level, or incomplete, where the individual may retain some sensory or motor function below the injury level, and is classified using the ASIA impairment scale (American Spinal Injury Association, 2002). There is variation between individuals and therefore within this discussion generally expected functional outcomes after a C6 level injury are considered.

The upper limbs will be substantially affected by a C6 level SCI. The biceps brachii, brachialis, and brachioradialis will remain innervated allowing elbow flexion, while wrist extension will also be possible due to innervation of the extensor carpi radialis longus and brevis. However, the triceps brachii, flexor carpi radialis and ulnaris, and hand musculature will be denervated, therefore active elbow extension, wrist flexion, and hand movement, will not be possible (Lin, 2010). Gravity may, however, be used to passively extend the elbow and flex the wrist. Moreover, some passive finger motion may be possible through tenodesis action, whereby as the wrist is extended the digits passively flex due to tension generated in the flexor muscles (flexor digitorum superficialis and profundus, and flexor pollicis longus) that cross the wrist joint (Davis, 2000).

Orthotic Treatment Options
For a person with a C6 level SCI the resulting loss of hand functionality will severely hamper their ability to complete routine tasks. Prehension, or grasping, facilitates many activities of daily living (Davis, 2000), and hence the main purpose of upper limb orthoses for persons with C6 level SCIs is to maintain or recover prehension of the hand (Knutson, Audu, & Triolo, 2006). Orthotic interventions for this purpose can be broadly split into two groups; static and dynamic orthoses. Static orthoses aim to maintain the hand in a functional posture such that prehension may be possible (Krajnik & Bridle, 1992), whereas dynamic devices aim to augment hand function such that forceful and/or sustained prehension is possible (Kang, Park, Lee, & Park, 2013).



Static orthoses aim to maintain a functional hand posture by preventing or correcting any deformities that may otherwise occur as a result of the paralysis. This includes prevention of overstretching of musculature, prevention of contractures and resulting decreases in range of motion, stabilization of otherwise frail joints, and maintenance of thumb web space and palmar curvature (Krajnik & Bridle, 1992). There is no consensus within the literature about the optimal upper limb posture for static orthoses. Some aim to prevent contracture by holding the wrist and hand neutral with the thumb in slight opposition, while others promote natural tenodesis by holding the wrist extended and the metacarpophalangeal and proximal interphalangeal joints flexed (Harvey, 1996; Krajnik & Bridle, 1992). These are resting orthoses and therefore limited functionality is expected while wearing the devices.

Krajnik & Bridle (1992) surveyed medical practitioners about their use of upper limb orthoses after SCI and found it to be common practice to prescribe static orthoses. However, despite widespread clinical use, two systematic literature reviews reported no evidence to support the use of static orthoses (Harvey, Lin, Glinsky, & De Wolf, 2009; Kalsi-Ryan & Verrier, 2011). Studies that tested the efficacy of static orthoses for persons with SCI found no significant differences between use or not of the orthoses (DiPasquale-Lehnerz, 1994; Harvey et al., 2007).

Dynamic orthoses aim to augment the hand function of the wearer, by producing actions that otherwise would not be possible. For persons with a C6 level SCI the aim is to enhance natural tenodesis, such that sustained and/or forceful prehension is possible (Kang et al., 2013; Knutson et al., 2006). Wrist-driven dynamic orthoses (Figure 2) are often recommended for this purpose (Kang et al., 2013; Knutson et al., 2006; Lin, 2010). These orthoses couple the wrist and finger joints such that motion at the wrist causes and controls motion at the fingers. Wrist-driven orthoses consist of three components to: a) provide an attachment point on the forearm; b) stabilize the carpometacarpal joint of the thumb in slight opposition; and c) hold the interphalangeal joints of the second and third digits in a slightly flexed position (Kang et al., 2013). Active wrist extension moves a mechanical linkage between the forearm and finger components, passively flexing the fingers at the metacarpoplalangeal joint such that they oppose the thumb, while gravity assisted wrist flexion opens the hand (Kang et al., 2013). While wearing the device the user should have sufficient range of motion of the fingers to enable them to pick up and hold various objects.

Practitioners often prescribe wrist-driven dynamic splints after C6 level SCI (Krajnik & Bridle, 1992), and there is some evidence to support this practice. Davis (2000) compared the hand function of persons with SCIs who used wrist-driven flexor hinge orthoses to those who used natural tenodesis, or had had tendon transfer surgery. Both the wrist-driven orthosis and tendon transfer surgery “enabled greater functional use of the hand than tenodesis” (Davis, 2000, p. 80). Further, Kang et al., (2013) compared the pinch force of persons with a SCI with and without a wrist-driven orthosis and found the orthosis increased pinch force for all subjects.

Other Treatment Options
Complete recovery of functionality after a SCI is generally not anticipated, with any limited functional improvements expected to occur within a year (Lin, 2010). While orthotic interventions may be used after this time, other treatment options, such as electrical stimulation therapies and surgical interventions, are often considered to address the long-term deficits. A recent systematic review of the literature highlighted that there is evidence to support both of these treatment options (Kalsi-Ryan & Verrier, 2011).

Neuroprostheses restore limb movement through the use of electrical stimulation to activate the otherwise paralysed muscles acting about a joint (Peckham et al., 2001). The aims of upper extremity neuroprostheses for persons with C6 level SCIs are generally similar to those of wrist-driven dynamic orthoses; to facilitate prehension. The main difference is that finger movement is controlled by electrical signals rather than by motion at the wrist. Testing of persons with SCIs with and without neuroprostheses indicated that use of these devices improved hand function, increasing the ability to perform activities of daily living (Alon & McBride, 2003; Peckham et al., 2001).

Surgical interventions for persons with SCIs involve transferring the tendon of an active muscle to the insertion point of a paralysed muscle, to allow movements otherwise not possible (Kalsi-Ryan & Verrier, 2011). Again the purpose of the intervention is to facilitate prehension, however in this case through the permanent reconfiguration of a functional muscle-tendon unit. Persons with SCIs who underwent this treatment were found to have increased grip strength and hand functionality compared to before treatment (Lo, Turner, Connolly, Delaney, & Roth, 1998; Meiners, Abel, Lindel, & Mesecke, 2002). Moreover, when compared to those using passive tenodesis to achieve prehension, those who had received tendon transfer surgery had significantly higher pinch force (Davis, 2000). Although there is evidence supporting the use of dynamic orthoses, electrical stimulation, and surgery there is a scarcity of evidence comparing the various treatment options. The interventions have the same general goal, to facilitate prehension and thus enhance hand functionality, and each has been shown to address this goal. Other factors must therefore be considered. While recovery is continuing dynamic orthoses may be the best option as invasive interventions, such as tendon transfer surgery and implanted neuroprostheses, will generally not be prescribed until no further recovery is expected (Lin, 2010). Other considerations include the funding available, the permanency of the intervention, as invasive interventions are more difficult to modify or adjust than non-invasive treatments, and the ease of use. All such factors must be considered when deciding which intervention is best for a particular individual.

Conclusions
The primary goal of rehabilitation after a SCI is to maintain or recover hand functionality, as deficits in this area will substantially affect one's ability to complete activities of daily living. During the first year after a C6 level injury a wrist-driven dynamic orthosis is expected is improve prehension, and therefore facilitate many activities of daily living. Later in recovery surgery or neuroprostheses may be considered to permanently enhance functionality.

Orthosis Prescription
Considering the clinical evidence the ‘ideal’ prescription for the client who is currently six months post injury is a wrist-driven dynamic orthosis for the dominant hand, similar to that shown in Figure 2. This orthosis would allow the client to achieve prehension of the hand, facilitating many activities of daily living and assisting them to become more independent. Although the client has bilateral weakness the dynamic orthosis would be prescribed for just the dominant hand as optimal functionality is typically achieved using dynamic orthoses on just the dominant hand (Lin, 2010). However, due to limitations in materials/parts it is not possible to manufacture a dynamic orthosis for the client. Therefore the ‘current’ short term prescription for the client is a static low temperature thermoplastic orthosis, designed to maintain a functional hand posture whilst waiting for fabrication of a dynamic orthosis. As for a dynamic orthosis this orthosis is prescribed for the dominant hand, and is to be worn overnight as a resting orthosis.

Low Temperature Thermoplastic Device
The primary goals of the low temperature thermoplastic (LTT) orthosis are to maintain a functional hand posture to alleviate hand pain, and to maintain the client’s current level of functionality. As such the functional aims and goals of this resting orthosis are to:
 * Immobilize the wrist in 40-50° extension, to prevent wrist flexor contracture and overstretching of the wrist extensors (Harvey, 1996). This is because wrist extensor functionality is not only vital to allow future use of a dynamic orthosis but also to maintain passive tenodesis functionality (Davis, 2000).
 * Immobilize the wrist in neutral radial-ulnar deviation and rotation, to maintain normal angulation between the forearm and hand.
 * Immobilize the first carpometacarpal joint in 40-50° abduction and flexion, and the first metacarpophalangeal joint in slight flexion (0-10°), to maintain a functional thumb posture i.e. thumb opposition. Additionally, this immobilizes the flexor pollicis longus in a shortened position, encouraging adaptive shortening of the muscle, and therefore promoting passive tenodesis (Harvey, 1996).
 * Place no restriction on movement of the second to fifth metacarpophalangeal joints and the interphalangeal joints, to maintain the passive range of motion at these joints. Moreover, it is important that the fingers are not immobilized in an extended position as this would stretch the flexor muscles and as a result the passive tenodesis functionality may be compromised (Harvey, 1996).
 * Support the volar aspect of the palm, to prevent deformity of the hand and maintain the thumb web space and palmar arch (Krajnik & Bridle, 1992).

Plaster of Paris Casts
Two plaster casts were taken, replicating the limiting wrist/hand postures that the client would attain while wearing a wrist-driven dynamic orthosis. The purpose of these casts would be to guide fabrication of a dynamic orthosis. The functional aims and goals of the casts were the same as those of the low temperature thermoplastic orthosis, with the following exception: It should be noted that although the casts placed no restriction on the movement of the second to fifth metacarpophalangeal joints a wrist-driven dynamic orthosis would control these joints. When wearing a wrist-driven dynamic orthosis the finger posture resulting from a given wrist angle is tuned, by way of the mechanical linkage between the finger and wrist components, to allow varying grip strength. It was not aimed to replicate this adjustable relationship between wrist and finger posture within the casts.
 * The casts immobilized the wrist in 40-50° extension and 20-30° flexion respectively. These positions represent the limiting wrist postures the client would reach while using a dynamic orthosis. The hand and forearm components of a dynamic orthosis would need to be fabricated to allow the wrist to reach these postures.

Low Temperature Thermoplastic Device
In order to achieve the functional aims and goals a volar based wrist-thumb orthosis was designed (Figure 3). This orthosis will be worn overnight by the client as a short-term resting orthosis. Details of the design include:

Materials

 * The orthosis is fabricated from low temperature thermoplastic. This material is light-weight, easy to use and can be molded directly onto the arm, making it suitable for this temporary resting orthosis.

Positioning

 * The wrist is immobilized in 40-50° extension (Harvey, 1996), neutral radial-ulnar deviation and neutral rotation.
 * The first carpometacarpal joint is immobilized in 40-50° abduction and flexion, and first metacarpophalangeal joint in 0-10° flexion (Krajnik & Bridle, 1992).
 * The range of motion of all other joints is not restricted.

Trimlines

 * The distal palmar edge is just proximal to the distal palmar crease and the distal thumb edge is just proximal to the interphalangeal joint. These trimlines are rolled to provide smooth edges against the skin, ensuring comfort.
 * The proximal edge is approximately two thirds of the length of the forearm. This allows for a long lever arm to minimise the force required to immobilize the wrist, but also does not interfere with elbow motion (McKee & Morgan, 1998). This trimline is slightly flared to prevent excessive pressure along the edge.
 * The medial and lateral edges are such that the orthosis covers slightly more than ½ the circumference of the arm. This provides a large surface area which will reduce the pressure on the arm (McKee & Morgan, 1998). The medial trimline passes below the volar aspect of ulnar styloid, and the lateral trimline passes below the volar aspect of the radial styloid, to prevent pressure areas at the bony prominences.

Attachment

 * 2cm Velcro strap at the distal edge.
 * 4cm Velcro straps at the proximal edge and centered directly over the wrist joint.
 * Adjustable padding is included at each strap to maximise the distribution of the force and thereby enhance comfort.

General

 * The orthosis is volar based as the volar aspect of the arm is naturally more able to tolerate pressure than the dorsal aspect (McKee & Morgan, 1998).
 * The orthosis conforms to the contours of the hand.

Force Diagrams
Force diagrams for the orthosis are shown in Figure 4. Two three-force systems act on the upper limb. The forces F1, F2, and F3 act in combination to extend the wrist, while the forces F4, F5 and F6 act in combination to oppose the thumb. Thumb opposition is a triplanar motion which involves flexion, abduction and slight internal rotation about the 1st carpometacarpal joint, and as such these forces have been shown acting in the three anatomical planes. The force F1 is provided by the wrist strap, while the other forces are provided by the molded plastic. Note the following abbreviations are used; CMC – carpometacarpal joint, DIP – distal interphalangeal joint, IP – interphalangeal joint, MCP – metacarpophalangeal joint, PIP – proximal interphalangeal joint, W – wrist joint.







Plaster of Paris Casts
The overall design and trimlines of the plaster casts were very similar to those of the low temperature thermoplastic device with the following exceptions:

Materials

 * The casts are fabricated from plaster of paris.

Positioning

 * Two casts were made with differing wrist positions. The first immobilized the wrist in 40-50° extension, while the second immobilized the wrist in 20-30° flexion.

Low Temperature Thermoplastic Device
1. Position the client’s hand and forearm in pronation on a piece of paper and trace around. Mark distal palmar crease, wrist joint, 1st carpometacarpal joint, 1st metacarpophalangeal joint and 1st interphalangeal joint. 2. Join the marks for each edge of the distal palmar crease and for each side of the 1st interphalangeal joint. Add a tab approximately the same length as the thumb between these lines (Figure 5a).

3. Draw the medial and lateral edges of the pattern approximately 1-2 cm wider than the hand and 2-3 cm wider than the forearm, and the proximal edge approximately two thirds the length of the forearm. 4. Cut the pattern out (Figure 5b) and apply to the client’s limb to check the fit. 5. Trace onto LTT (Figure 5c) and then cut out.

19. Secure the orthosis onto the upper limb and check the fit (Figure 10). Cut the loop Velcro straps to the required length, rounding the ends for better aesthetics.



Plaster of Paris Casts
1. Prepare the consultation area for casting - place a plastic sheet on the floor, have a bucket of water, plaster and indelible pencil ready.

2. Position the client in a chair, and cover with a plastic sheet.

3. Cut a length of nylon stockinette approximately the length of the client’s forearm. Cut a hole for the thumb and place the stockinette over the forearm with the thumb through the hole. Tie off distally to the fingers and pull tight towards the elbow.

4. Using an indelible pencil mark the styloids, distal palmar crease and approximate trimlines.

5. Wrap a thin layer of padding around the thumb, to facilitate later removal of the cast.

6. Make a slab of plaster 4 layers thick and approximately the same length as the forearm. The pattern for the LTT can be used as a guide. Also prepare another short slab to be used to wrap around the thumb.

7. Position the client’s hand and forearm. Check the wrist extension angle using a goniometer and ensure the thumb is in opposition to the 3rd digit.

8. Wet the long slab of plaster in the bucket of water, remove any excess water and mold to the clients arm ensuring that the distal end is just proximal to the distal palmar crease and that the edges of the slab cover the medial and distal trimlines.

9. Wet the short slab of plaster and wrap around the thumb. Smooth the edges well to ensure they adhere to the main section (Figure 11).



10. Using the indelible pencil draw vertical lines on the thumb so the two sections can be realigned if they separate.

11. When the plaster is set cut the stockinette along the dorsal surface of the forearm/hand and then gently remove the cast from the client’s forearm. 12. Check the cast and cut each edge to the trimlines which will have transferred onto the inside of the cast from the indelible pencil marks on the stockinette.

13. Apply to the client’s limb to check the fit. Make any required adjustments to the trimlines (Figure 12).

14. Repeat to make the second cast in wrist flexion (Figure 13).



Critique of Orthosis
A video critique of the device can be viewed using the following link:

Critique video

Outcome Measures
Standard outcome measure tests were completed, both at initial assessment and also after four weeks of use of the LTT wrist-hand orthosis. Details of the tests completed are given.

Disabilities of the Arm, Shoulder and Hand Questionnaire
The Disabilities of the Arm, Shoulder and Hand Questionnaire (DASH) was completed (Institute for Work & Health, 2013). This questionnaire evaluates disorders of the upper limb in terms of both function and symptoms. This questionnaire has been shown to be a valid and reliable measure of upper extremity disability (Beaton et al., 2001). The DASH was chosen as it is easy to administer and as it considers both function and symptoms, changes in both of these aspects of the client’s condition can be assessed.

At initial assessment the client’s DASH score was 96 (minimum score 0, maximum 100, lower score represents less disability). After four weeks use of the LTT orthosis the DASH score reduced to 84. This represents a change of 12 which is within the values of 10 - 15 reported for the minimum clinically important difference for the DASH questionnaire (Beaton et al., 2001; Roy, MacDermid, & Woodhouse, 2009). Therefore use of the orthosis can be considered to have provided a clinically important improvement in arm and hand disability. Changes were seen only in items 24 through 29 of the questionnaire, indicating that improvement had only been seen in symptoms and not in functionality. However, as the current prescription is a resting orthosis, aimed at maintaining the current functionality of the hand and preventing deformity, functional improvements were not expected.

Capabilities of Upper Extremity Instrument
The Capaibilities of Upper Extremity Instrument (CUE) was also completed at initial assessment (Marino, Shea, & Stineman, 1998). This questionnaire aims to measure limitations in upper extremity functionality and has been specifically designed for persons with tetraplegia. This questionnaire has been shown to be reliable and repeatable (Marino et al., 1998) and is easy to administer. The CUE was chosen as it is specific to tetraplegia, allowing a more detailed assessment of the client’s functionality level/functional deficits to be obtained than was possible with the DASH. This information was important to guide prescription of the orthotic intervention.

At initial assessment the client scored 110 (minimum score 32, maximum 224, lower score represents greater functional limitation). This score is in line with those reported in the literature for a C6 level SCI (Marino et al., 1998). The client generally scored lower on the questions about use of the hands and fingers, and therefore recovering prehension was highlighted as important for the client. This questionnaire was not repeated at the second assessment as the ‘current’ prescription has not addressed functional deficits.

Referral Letter and Ongoing Treatment Plan
Although some improvement in symptoms has been seen with the current orthosis there has been no improvement in functionality. The client has therefore been referred to another clinic for the manufacture of a wrist-driven dynamic orthosis. A copy of the referral letter has been included below. While awaiting the dynamic orthosis the client will continue to wear their current device overnight and will continue working with an occupational therapist during the day to maintain their passive range of motion.



Annexe: Search Strategy
The MEDLINE, CINAHL and Cochrane Library databases were searched using the terms ‘spinal cord injury’, SCI, quadriplegi*, tetraplegi*, orthos*, splint*, brace, bracing and 'upper extremity'. The references identified were checked for relevance, with systematic reviews and controlled clinical trials preferentially selected. Finally, the references and citations of the relevant articles were checked recursively for other potentially relevant references.