Tendonitis, Tenosynovitis, and Enthesopathy (eSlide 11.2)

Tendonitis, tenosynovitis, and enthesopathy can all result from excessive repetitive movements or external stressors. The upper limb tendons most commonly involved are wrist extensors and the abductor pollicis longus and extensor pollicis brevis muscles of the thumb. The goal of splinting for these conditions is to immobilize the affected structures to facilitate healing and decrease inflammation. For example, the forearm-based thumb spica splint used for de Quervain stenosing tenosynovitis immobilizes the wrist, carpometacarpal (CMC) joint, and MCP joint of the thumb. The IP joint of the thumb needs no fixation because the affected tendons do not move this joint.

Lateral epicondylitis is a common enthesopathy of the upper limb, which can be treated with a tennis elbow orthosis. This is a forearm band that changes the lever arm against which the wrist extensors pull. In essence, it puts the origin of the extensor muscles at rest and decreases the microtrauma from overuse. This orthotic device is a firm strap against which the extensors press when contracting; it is placed approximately 2 fingerbreadths distal to the lateral epicondyle. A similar orthosis is used for medial epicondylitis.

Trigger finger causes a snapping sensation in the volar surface of the digits on release of the grasp. It is usually a result of trauma to the flexor tendon sheath of the fingers or thumb, producing thickened tendinous sheaths and restriction of motion. In advanced trigger finger, the digit can become “locked” in flexion. The goal of trigger finger treatment is to temporarily halt the repetitive motion to allow the sheath to heal. Functional use of the hand should be maintained, although the affected digit is immobilized. The splint for trigger finger covers the proximal phalanx and MCP joint of the involved digit. It decreases the tendinous excursion through the first annular pulley at the base of the MCP joint and allows the inflamed structures to rest.

Sprains (eSlide 11.3)

Sprains are defined as momentary subluxations with spontaneous reduction that result in torn ligamentous structures. Sprains require joint immobilization in a position of function to allow for healing as well as functional use. Common sprains include dislocation of the IP and MCP joints caused by hyperextension and are often seen in sports injuries.

Splints commonly used for digital sprains are finger extension splints that hold the PIP joint in extension but allow flexion of the DIP joint. This position keeps the oblique retinacular ligament and terminal extensor tendon lengthened, preventing boutonnière deformities during the healing phase. Ulnar collateral ligamentous injuries at the MCP joint of the thumb are treated with a hand-based thumb spica splint to immobilize the joint during the healing phase. Wrist splints that place the wrist in slight extension are used for wrist sprains. For mild sprains, splints with no spline (metal bar insert) permit some motion and avoid creating significant stiffness. They also limit available range to approximately 40 degrees of total motion. Elbow neoprene sleeves are helpful for mild sprains in the elbow because they limit the extremes of ROM but allow some functional movement.

Fractures (eSlide 11.4)

Most major fractures need total immobilization by casting, surgical intervention, or both. Some fractures, however, do not need total limb immobilization and can be treated with orthotic devices. These devices should immobilize the body part or the joint sufficiently to promote healing while also optimizing function. A gutter splint is used primarily for phalangeal and metacarpal fractures. These splints extend from the proximal forearm to beyond the DIP joint and can be radial (immobilizing the index and long fingers) or ulnar (immobilizing the ring and little fingers; also called a boxer splint). The splint should be wide enough to surround both fingers and the wrist. Other examples include traction-type splints that allow for very controlled motion during the healing phase of intraarticular finger fractures treated with pinning. Joint movement has been credited with enhancing cartilage nutrition and preventing intraarticular adhesions.

Arthritis (eSlide 11.5)

Joint diseases of the hand and wrist have the most significant impact on function. Orthotic devices can provide functional positioning to prevent further deformity and loss of use in arthritic diseases, as well as to protect the joints from further injury.

Rheumatoid arthritis is a chronic inflammatory disease that primarily affects synovial joints. The most frequently affected joints in the upper limb are the wrists, MCP joints, and PIP joints. Deformities include subluxation and ulnar deviation at the MCP joints, subluxation and radial deviation at the wrist, and swan neck and boutonnière deformities of the fingers. These deformities usually progress, especially if no attempt is made to rest and protect the affected joints from overuse. Several options are available for splinting the rheumatoid hand. Ulnar deviation splints that pull the MCP joints toward radial deviation and increase the functional use of the hand are now lightweight and permit full MCP joint motion in flexion and extension. Wrist splints that provide light support for the wrist are usually well tolerated. Swan neck and boutonnière splints can be made from thermoplastics but are often bulky and cosmetically unpleasing. The swan neck splint allows for flexion of the digit but blocks hyperextension. The boutonnière splint holds the DIP or PIP joint in extension.

Osteoarthritis most commonly involves the CMC joint of the thumb. A hand-based or forearm-based thumb spica splint can be prescribed for CMC joint osteoarthritis . By limiting motion at the base of the thumb, the splint decreases pain, especially with pinching-type activities.

Nerve Injuries (eSlides 11.6 and 11.7)

When a peripheral nerve is injured, the level and completeness of the injury determines the extent of the deficit incurred. For example, in a distal median nerve injury, a simian hand deformity may occur, and the functions most affected are thumb palmar abduction and opposition. The goal of an orthotic device is to help restore this function. The splint usually has a spring coil design that holds the MCP joints in slight flexion but permits MCP extension. This splint also has a portion to position the thumb in palmar abduction.

Radial nerve injuries distal to the humeral spiral groove commonly present with wrist drop and finger drop. The goal in these cases is to enhance wrist and finger extension. A radial nerve palsy orthosis is based on the forearm, with an outrigger holding the wrist, fingers, and thumb in extension and allowing flexion of the digits.

With a proximal ulnar nerve injury, the patient has a “benediction hand,” characterized by hyperextension of the fourth and fifth MCP joints and flexion of the PIP joints because of the loss of balance between the extrinsic and intrinsic hand muscles. Here the goal is to prevent fixed deformity of the fourth and fifth MCP joints and improve function. An ulnar nerve palsy orthosis holds the MCP joints of the fourth and fifth fingers in slight flexion by a spring coil or figure-of-eight splint design. The spring coil design assists MCP flexion and permits extension of the MCP joints but blocks hyperextension. This can also be accomplished with a static splint that uses a “lumbrical bar” to prevent hyperextension of the MCP joints of the fourth and fifth digits. Thumb position is most often compromised in low median and ulnar nerve injuries, which leave the patient with no or a weakened ability to place the thumb in opposition and palmar abduction.

Incomplete nerve injuries can be caused by compression without producing complete paralysis (for example, in median nerve injury from carpal tunnel syndrome). The purpose of the splint is to immobilize the wrist to minimize swelling from overuse of the tendons. Complete resolution of carpal tunnel syndrome can occur if wrist orthoses are applied early, when symptoms first appear. The splint is molded to the patient from a thermoplastic that offers excellent conformity to hold the wrist in 0-5 degrees of extension. The splint’s commonly used name, wrist cock-up splint, is misleading and should be avoided because it implies that the wrist should be placed in extension. The patient should be instructed to reduce activities that stress the wrist and to wear the splint all night.

A word of caution is in order regarding prefabricated wrist splints for carpal tunnel syndrome. Many of these splints have an angled metal bar to hold the wrist in 45 degrees of extension. This angle far exceeds the recommended 0-5 degrees of extension needed to decrease pressure in the carpal tunnel. Patients need to be instructed to remove the metal spline, flatten it, and then replace it in the fabric sleeve. Usually, this splint should be worn for 4-6 weeks, with gradual weaning from the splint and return to activity with workstation modifications.

Cubital tunnel syndrome (compression of the ulnar nerve at the elbow) can be treated with long arm splints that hold the elbow in 45 degrees of flexion, the forearm in neutral position, and the wrist in 0-5 degrees of extension, leaving the thumb and fingers free.

Brain Injury and Stroke (eSlide 11.8)

Depending on the area of brain injury and ensuing deficits, particularly if there is a change in muscle tone, orthotic devices should be designed to prevent deformities and help adjust muscle tone. Resting and positioning orthotic devices are also necessary to help prevent complications, such as distal edema, joint subluxation, and contracture formation. In upper limb paralysis, a resting hand splint is commonly used to position the wrist in slight extension, the MCP joints in slight flexion, and the IP joints in extension. The thumb is supported in a position between palmar and radial abduction. Full support of the first CMC joint prevents ligamentous stresses on the thumb, especially in the insensate hand. This thumb position uses a reflex-inhibiting posture to decrease tone in the hand. The antispasticity ball splint places the fingers and hand in a reflex-inhibiting position and serves to reduce tone.

A mobile arm support can be used to enhance function for patients with proximal upper limb weakness, especially when the weakness is profound and the outlook for recovery is guarded. A mobile arm support is particularly helpful when activities of daily living, such as eating and grooming, are performed. When attached to a wheelchair with a swivel joint, the mobile arm support is often called a balanced forearm orthosis.

Many types of slings are available for patients with decreased tone in the upper limb. Decreased tone can result in shoulder subluxation, and a sling can decrease this deformity. These slings restrict active motion of the shoulder by keeping the humerus in adduction and internal rotation and placing the elbow in flexion. They are designed to unload the weight of the arm on the shoulder, but they do not approximate the humeral head back into the glenoid fossa. Slings or half-arm trays do not completely correct shoulder subluxation. The arm trough or half-lap board is often preferred because it does not restrict use of the limb and places the humerus in a position that is more naturally approximated into the glenoid fossa.

Spinal Cord Injury (eSlides 11.9 and 11.10)

In patients with spinal cord injury, orthotic devices are needed to enhance function, help with positioning, or both. The type of device depends on the level of injury and the extent of neurologic compromise. With spinal cord injury at the C1-C3 level, the goals are to prevent contractures and hold the wrist and digits in a position of function with a resting hand splint. In a C4-level injury, the goal is to use the available shoulder strength by providing mobile arm support to enhance function, as previously described. In a C5-level injury, the goal is to statically position the wrist in extension with a ratchet-type hinged orthotic device to hold devices and use the shoulder musculature for function. An orthotic device for a C6 tetraplegia patient can enhance finger flexion with a tenodesis flexion effect from wrist extension. For example, a Rehabilitation Institute of Chicago tenodesis splint, molded from thermoplastic materials, has several positioning components. A thumb post component positions the thumb in palmar abduction. A dorsal finger piece component, which is attached with a static line to a volar forearm component, holds the PIP joints of the index and long fingers in slight flexion. When the patient extends the wrist, the static line pulls the fingers toward the thumb post. This produces a three-point pinch, allowing the patient to grasp an object. When the patient relaxes the wrist, the fingers extend passively, releasing the object. The degree of pinch varies depending on the strength of the wrist extensors and the degree of finger flexion, extension, and opposition. This custom-made thermoplastic tenodesis device is mainly used in training and practice. If a patient finds the device useful, a light metal custom-made tenodesis orthosis achieves better functional restoration. An adaptive or functional use orthosis promotes functional use of an upper limb that is impaired because of weakness, paralysis, or loss of a body part. An example is the universal cuff, which encompasses the hand and holds various small items, such as a fork, pen, or toothbrush, to enhance independence.

Postsurgical and Postinjury Orthoses (eSlides 11.11, 11.12, and 11.13)

Many types of splints have been developed to help regain motion in stiff joints. Examples of such splints include dynamic elbow flexion and extension splints after upper arm or elbow fracture, dynamic wrist flexion and extension splints after a Colles fracture, and dynamic finger flexion and extension splints for stiffness after crush injuries to the hand. Similar splints can be fabricated with a static progressive approach. Joints that have a soft end feel do well with dynamic splints. Those with a rigid end feel typically respond better to a static progressive approach that will maintain a constant joint position while the tissue gently accommodates to the tension, without the influence of gravity or motion. Examples of static progressive splints are the Joint Jack or cinch straps and splints for PIP and DIP joint contractures with the MERiT components. Selection of forearm-based or hand-based splints is determined by the need for stabilization. In general, the goal is to immobilize as few joints as feasible. Forearm pronation–supination splints with both dynamic and static features are very helpful in regaining motion after fractures of the radius and ulna.

Several splint designs are currently used after repair of tendon injuries. The type of surgical procedure or injury level often dictates the type of splint used so that the splints cannot be used interchangeably. After flexor tendon repair, Kleinert and Duran splints are commonly used. The Kleinert splint features dynamic traction into flexion but allows active digit extension within the constraints of the splint. The Duran splint statically positions the wrist and MCP joints in flexion and IP joints in extension. The Indiana Protocol splint can also be used. This splint adds a tenodesis-type action splint to the Kleinert componentry for specific, active-assisted ROM exercises. It can be used only if a specific surgical suture technique has been used.

The type of extensor tendon repair splint depends on the level of injury. A mallet finger injury requires only a Stax splint, which is a static splint holding the DIP joint in full extension. A more proximal injury, however, needs a splint that holds the wrist statically in extension, with dynamic extension of the MCP and IP joints. Such a splint permits active flexion of the MCP joints within the constraints of the splint to an angle of approximately 30 degrees. Injuries to the thumb flexor or extensor tendons require more specific splinting that depends on the level of the injury.

Postoperative joint replacements for the PIP, DIP, or MCP joints of the hand require specific splints that promote healing or encapsulation of the joints while preserving ROM during the healing phases.

Orthoses for Burns (eSlide 11.14)

After burn injuries, body parts should be repositioned to prevent the development of expected deformities. For example, in burns of the dorsal surface of the hand, the wrist is placed in 15-20 degrees of extension, the MCP joints in 60-70 degrees of flexion, the PIP and DIP joints in full extension, and the thumb between radial and palmar abduction. If tendons are exposed, flexion of the MCP joints should be decreased to 30-40 degrees to keep some slack in the tendons until there is wound closure. Palmar hand burns require maximum stretching to counteract the contracting forces of the healing burn. The antideformity position of a palmar burn consists of 15-20 degrees of wrist extension, extension of the MCP and IP joints, digital abduction, and thumb abduction and extension. This has been referred to as an “open palm” or “pancake” position. For prevention of shoulder adduction deformity after axillary burns, the shoulder should be held in abduction with an airplane splint. The tendency toward hypertrophic scarring after a burn is addressed with a selection of compression garments, elastomer molds, facial splints, gel shell splints, and silicone gel sheeting.