Physical therapists should stay current on splinting for upper extremity injuries and conditions.
Custom fabricated thermoplastic splints have a multitude of applications in the rehabilitation of upper extremity injuries and conditions. Therapists need to be familiar with the many types of splints which can aid in a patient’s recovery and the proper way to document and classify each specific splint.
Rehab professionals are continually developing new and improved methods to use thermoplastic splints.
Static splints, such as a wrist cock-up splint following wrist fracture, can be used to immobilize and protect tendons, bones, ligaments, nerves and joints. This category of splints is generally used to safely position injured or compromised joints to avoid injury, stiffness or deformity. These splints can also be used to rest and properly position an overused, painful or inflamed area. Other examples of static splints include a wrist extension splint for lateral epicondylitis, a safe position splint used for a burn and a resting splint for a spastic hand from a cerebral vascular accident.
Thermoplastic splints, such as a proximal interpahalangeal joint flexion splint, may be used to mobilize stiff joints. This type of splint is designed to treat joint stiffness for a diagnosis such as a healed proximal phalanx fracture. These splints are commonly referred to as dynamic or static progressive splints.
Dynamic splints apply a constant, active force. A spring or elastic band, for example, is often used to stretch a desired structure. Unlike dynamic splints, static progressive splints use a non-elastic component to apply traction or torque to a joint at maximal end range.
Turnbuckles, which can be incrementally adjusted, are often used for static progressive splints. Use of these mobilization splints are based on the Low Load Prolonged Stretch (LLPS) theories in which a gradual tension of relatively low force is applied to a joint’s connective tissue for a prolonged time period to produce a desired effect of increased joint range of motion (ROM).
These splints allow the therapist or patient to precisely control the tension. The tension and the wearing schedule are both dictated and monitored by the therapist. The therapist should continually monitor proper positioning of the target joints to be mobilized and any adjacent joints.
Other splints, such as a radial nerve palsy splint, are designed to increase specific upper extremity functions. The radial nerve palsy splint facilitates functional grasp and maintains ROM by using dorsal outriggers, elastic bands and finger slings. This splint works to overcome loss of active wrist and metacarpal (MCP) extension while the radial nerve attempts to recover. The patient can actively flex the wrist and digits to functionally grasp an object as the splint’s elastic component performs the task of extending the wrist and MCP joints to allow the patient to release the object.
Torque Transmission Splints
A torque transmission splint can be used to facilitate or isolate the completion of a specific exercise. A distal interphalangeal joint (DIP) blocking/exercise splint, for example, is designed to facilitate isolated active flexion of the DIP following a healed tendon repair.
Splint Classification System
The specific description and classification of these splints should be obtained and documented by using the splint classification system, or more specifically, the Expanded ASHT Splint/Orthosis Classification System (ESCS). This description system accurately notes the exact type, location and purpose of the given splint.
The six criteria of the ESCS are as follows: 1. Articular vs Non-articular: “Articular” is automatically assumed, and therefore, specific documentation of the criterion is only needed if the splint is non-articular. (A humeral fracture brace is an example of a non-articular splint). 2. Anatomic Focus: What are the primary joints affected by the splint? 3. Kinematic direction: What is the position of the primary joint(s) of this splint? 4. Primary purpose: Is the splint fabricated to mobilize or immobilize, restrict motion, or transmit torque to another joint for exercise? 5. Type: How many secondary joints are included in the splint? 6. Total number of joints included: All joints that are affected by the orthosis are tallied here.
Many hand therapists may initially find this system confusing and somewhat challenging. In the past, therapists simply described the common but very general term for various splints. However, the ESCS system is the most effective way to describe what type of splint the therapist is fabricating and the overall purpose of the splint.
A wrist splint for lateral epicondylitis, for example, is essentially a wrist cock-up splint. If the splint is not documented using the ESCS, however, a colleague may not be informed of the most essential aspects of the splint. The therapist must know: Is the purpose to protect an injury to the wrist, to rest the tendons in the carpal tunnel, function as the base for some sort of dynamic/static progressive splint, or to be used as an exercise splint to transmit torque to the digits? In this particular splint, the purpose is to rest the long wrist extensors and decrease stress and tension on these muscle tendon units.
The ESCS would note this wrist splint as a “wrist extension immobilization orthosis type 0 (1).” This notation essentially encompasses the six criteria. Criterion one is left blank since we can assume the splint is articular. Criterion two is the wrist since this is the primary joint of focus for the splint. Criterion three is the position of wrist extension, since we are purposely placing the wrist in extension to rest the long wrist extensors. Criterion four is to immobilize since we are in fact immobilizing the wrist. Criterion five is zero because there are no secondary joints included in this splint. Criterion six is one because there is a total of one joint included in this splint.
If the fabricating therapist merely documents that they made a wrist cock-up splint, the colleague would not know essential data relating to the splint. Therapists should become familiar with the ESCS’ detailed explanation of the most appropriate manner to document and refer to specific types of splints.
Evolution of Splinting
Improvements in surgical techniques, more specifically suture and fixation techniques, along with an increased knowledge and understanding of how injured or repaired structures heal, have resulted in a constant evolution regarding the mobilization and subsequent splinting of injured areas.
Essentially, surgeons and therapists have found that many repaired structures are stronger than originally thought, and they can handle more stress earlier in the healing process. In the past, patients remained in casts for extended periods to allow for adequate healing and strength of repaired or injured structures to occur. This prolonged immobilization resulted in stiffness, scarring and/or adaptive shortening of tendon and ligament which became difficult, painful or impossible to overcome in the post-immobilization rehabilitation period, leaving the patient with a permanent ROM loss and subsequent functional deficit.
Surgeons and therapists have adopted early protective mobilization of repaired or immobilized structures with the use of custom splints rather than long extended immobilization in plaster or fiberglass casts. Modern fracture fixation techniques using rigid plates and screws, for example, allow a patient following wrist fracture to be transferred from a cast to a wrist splint in two to three weeks in some cases, rather than six to eight weeks in a cast. A removable wrist splint can be beneficial to allow early protective/gentle ROM.
Communication between surgeons and therapists is essential to determine the appropriate timeframe for splinting based on the strength of repair or fixation and stability of the injured area for each specific patient case. For the compliant patient, this can result in increased ROM, decreased scarring, post-operative pain and stiffness and a better overall functional outcome. Early protective ROM is monitored closely by the therapist to avoid any motion that may disrupt the fixation or repair.
New suture techniques and materials, along with a better understanding of how tendons heal along with the increased knowledge of the tensile strength of repaired tendon has also changed the way therapists and surgeons treat post-operative tendon repairs in the hand. Following repair of a flexor or extensor tendon in the hand, a custom splint can be fabricated to allow for early protective ROM. The custom splint can position the wrist and hand in a manner that safely allows gentle glide of the repaired tendon. This approach reduces or prevents scar tissue from becoming established on the tendon and surrounding tissue/bone.
Proper positioning of the hand and wrist in the protective splint is critical because scar tissue formation on newly repaired tendons can significantly inhibit ROM and subsequent hand function. Gently gliding the tendon as soon as the repair can handle some stress can greatly decrease the scar tissue from binding to the tendon. In some cases, a tendon repair can be passively mobilized in a controlled, supervised manner as soon as 1.5 to 2 weeks post-operatively.
There is continued discussion and debate about how soon a tendon can be mobilized both passively and actively within a protected early ROM protocol. New and progressive protocols show evidence that a repaired tendon can be actively mobilized as soon as two weeks. Not all surgical patients are appropriate candidates for the early mobilization and splinting protocol. The patient must have a solid understanding of the rehab protocol and demonstrate good compliance with the protective ROM program. Children and patients with decreased cognition, for example, are generally poor candidates for these early ROM protocols.
If a patient deviates, even slightly, from the prescribed exercise protocol, rupture or gaping of the repair can result, causing disruption or failure of the surgical procedure. As the tendon repair gains strength, the splint can be modified and eventually discharged to allow increased and gradual unrestricted ROM and subsequent strengthening of the repaired tendon.
Custom splinting has and will continue to evolve as clinicians learn new and improved methods for using splints to best serve our patients. New types, modifications and variations of splints are continually being developed. All therapists practicing in a setting where patients can benefit from custom splints should be aware of these developments and incorporate them into their own treatments.
Brian Knutsen is president of Buzzards Bay Hand Therapy LLC, located in Marion and Lexington, MA.