Description of Intervention1-4
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 the stimulus required for collagen growth and reorganization. This will eventually facilitate the return of the joint’s passive ROM and directly effect AROM & functional improvements.
Dynamic splinting for flexion assist is indicated when there is stiffness or extension contracture of the metacarpophalangeal (MP), proximal interphalangeal (PIP), and/or distal interphalangeal (DIP) joints. The MP joints are more prone to extension contractures, while the PIP and DIP joints are more likely to develop flexion contractures. This is due to both the overpull of the more powerful flexor tendons and the flexed posture of the IP joints. Thus, dynamic splints for flexion assist are more frequently used to address MP joint extension contracture, but are also utilized for PIP or DIP joint extension contracture when indicated.
Contractures of these joints may be caused by collateral ligament shortening, and continuous stretching through dynamic splinting is therefore indicated to help patients regain joint flexion and hand functionality. When dynamic splints are applied appropriately and in a timely manner, it leads to successful outcomes with less joint stiffness.
Indications for Intervention
A dynamic splint for flexion assist is for patients with extensor contracture of the MP, 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.5,6
- If extension contracture is identified in one or more MP, PIP, and/or DIP joints, consider prescribing a dynamic splint for flexion assist.
Orthoses Guidelines1-5,7-9
When a dynamic splint for flexion assist 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 that require a dynamic splint for flexion assist. 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 flexion 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 or NSAIDS 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. For example, when fabricating a dynamic splint for DIP flexion assist, the following protocol may be used:
- Mold the thermoplastic material around the PIP joint while leaving the DIP and MP joints free
- The PIP joint should be in enough flexion to allow for a 90° pull on the DIP
- Ensure the seam is on the dorsolateral surface
- Attach a Velcro hook and loop to form the strap on the dorsal surface
- Create an outrigger by clipping one end of a paper clip and bend its midportion to approximately 90°
- Heat the outrigger and attach it to the volar surface of the PIP portion of the splint
- Attach the finger sling and rubber band—which should be equal the distance between the finger sling and outrigger—then loop the rubber band around the outrigger
The duration and frequency for wearing the splint is also largely dependent on patient-related variables. For the example provided above, patients should begin by wearing the splint for 10–15 minutes intervals, about 6 times per day. Regardless of the initial duration, patients should then be instructed to gradually increase the amount time spent wearing the splint and keeping the affected joint(s) held at the end of its available ROM each day. 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.
