Description of Intervention1-5
Hand therapists often request for the hand surgeon to prescribe dynamic splints to restore the passive range of motion (ROM) of one or more stiff joints. These orthoses utilize traction devices like rubber bands, springs, cords, and/or Velcro strips to hold the stiff joint(s) at the end of their available ROM under light tension for intermittent periods. Applying this prolonged, low-load stretch to joints provides a stimulus for collagen growth and reorganization, which will eventually facilitate the return of the joint’s passive ROM and directly effect AROM & functional improvements.
Dynamic splinting is indicated for flexion contracture of the proximal interphalangeal (PIP) and/or distal interphalangeal (DIP) joints to increase IP extension. Flexion contractures are more common in the PIP and DIP joints than the metacarpophalangeal (MP) joints, which is due to both the overpull of the more powerful flexor tendons and the flexed posture of the IP joints. PIP joint trauma typically ruptures the joint’s stabilizing structures, most commonly the volar plate and collateral ligaments, which produces flexion contracture. The subsequent lack of passive extension also precludes active extension and leads to various functional deficits.
The longer flexion contracture is left untreated, the stiffer the joint becomes, which highlights the need for expedient intervention. Therefore, dynamic splinting is strongly recommended in these cases, and when applied appropriately and in a timely manner, it can lead to successful outcomes of less IP joint stiffness.
Indications for Intervention
A dynamic splint for IP extension is indicated for patients with flexion contracture of one or more PIP and/or DIP joints.
Evaluation
- Ask the patient to describe their medical history, with a focus on the injury to the digit(s) and if any surgical procedure was performed.
- Ask if the patient has any comorbidities, including diabetes, osteopenia/osteoporosis, cardiovascular issues, or a history of smoking.
- Perform a physical examination of the hand and wrist. Measure the active and passive ROM of the joints involved and compare these values with those of the contralateral side.
- Ask the patient to rate their pain on the visual analogue scale (VAS) or a similar pain scale.
- Consider using the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, which is used to assess impairment of the upper extremity.
- Other parameters that may be evaluated include task performance with a hand function test, power grip with a hand dynamometer, pinch grip with a hydraulic pinch gauge, and dexterity with a pegboard.6,7
- If flexion contracture is identified in the PIP and/or DIP joints, consider prescribing a dynamic splint for IP extension.
Orthoses Guidelines1-6,8-10
When a dynamic splint for IP extension is indicated, you may choose to prescribe either a prefabricated, custom-fitted, or custom-fabricated splint:
- Prefabricated splint: these splints are made by a manufacturer and can be purchased over the counter at pharmacies or with a prescription from orthopedic supply stores; therefore, prefabricated splints are not individualized for the patient and do not require any special fitting services; however, patients can make minimal adjustments with Velcro straps to ensure the splint fits properly, and the therapist will also adjust the dynamic components of the splint depending on the specific indication
- Custom-fitted splint: this is a type of prefabricated splint that requires bending, cutting, or molding the splint to fit the patient’s hand properly; it may be necessary to apply heat to manipulate the splint
- Custom-fabricated splint: these splints are individualized for each patient by taking castings, measurements, tracings, and images of the injured area that are used to create a specialized splint; you will then fabricate the splint by molding, drilling, sewing, or bending the splint material before fitting and applying it to the patient
Custom-fitted and custom-fabricated splints are strongly recommended for most patients requiring a dynamic splint for IP extension. Dynamic splints can be constructed with a variety of materials, including plaster, fiberglass, padding, ace wraps, metal, cloth, leather, or thermoplastic. Traction devices like rubber bands, springs, cords, or Velcro strips are then added to the orthotic to apply a passive extension force to the joint(s) involved. When fabricating the splint, ensure that it fits comfortably. The splint should also allow for maximal sensory perception, and the pressure of the splint should be distributed equally. It should not challenge the normal contours of the hand and forearm. Pain medications may be needed before and during the splinting process.
The configuration and splinting position for each joint depends on the location and severity of the injury and, if applicable, the surgical procedure performed. One popular design that may be used is an outrigger splint with rubber bands for traction, which can be fabricated with thermoplastic material, rivets, wire frame, hoop-and-loop Velcro strips, rubber bands, finger slings, and Theraband straps. When fabricating a dynamic splint for the PIP joint, the thermoplastic component should be secured over the MP joints and the DIP joint should be stabilized with a finger sling or Theraband straps while the PIP joint is left free. Once all elements of the splint are in place, a gauge should be used to ensure that a passive extension force of 200–250 gm/cm2 is being applied to the distal end of the middle phalanx of the involved joint(s). It’s preferred that the MCP’s be held/splinted in some flexion when looking to achieve IP extension to emphasize and facilitate optimal IP extension results.
The duration and frequency for wearing the splint is also largely dependent on patient-related variables. For the outrigger splint described above, patients should wear the splint for 8–12 hours daily for 8 weeks, primarily for several hours while awake. Extension splints for flexion contractures are especially useful at night because fingers assume a flexed posture during sleep. Static extension splinting is preferred for night time. Patients can then be weaned from the splint over 2–3 weeks. When the splint is not being worn, patients should perform active flexion and extension exercises for the joints involved every day to reduce the risk for tightening and shortening of the tissues. In some cases, dynamic splints may need to be worn for up to 4–5 months. Static splinting should be integrated for night/sleeping to ensure no undo forces are placed on the tissues at rest/sleep. It’s very important for the hand therapist and hand surgeon to collaborate and emphasize the importance of patient involvement in the rehabilitation process.
Splint use must be supplemented by a comprehensive hand therapy treatment program, with sessions at least once per week. The basis of hand therapy rehabilitation programs is passive and active ROM exercises, and the therapist should check the biomechanics and tension of the splint at each visit and adjust these parameters if necessary. Advise patients to slowly return to activities as they regain their hand and finger function. Edema and scar management—when applicable—are also essential throughout the entire rehabilitation program.
