Description of Intervention
A hand-based thumb splint is a type of splint that keeps the thumb immobilized while allowing the other fingers to move freely. These splints are prescribed for musculoskeletal conditions involving the thumb and its supporting structures to provide stabilization and restrict motion, thereby facilitating the healing process. Many thumb including lacerations, fractures & sprains of the MCP and IP injuries distal to the wrist can benefit from hand-based thumb splints.1-3
Hand-based thumb splints may be favored over casts as an initial, temporary measure for certain acute injuries to accommodate for the anticipation of swelling in addition to hygiene or wound care cases. Although there may be some variations in the design of each device, nearly every hand-based thumb splint is essentially a hand brace with added support for the injured thumb, usually in the form of a spica.1 Splints may be prefabricated, custom-fitted, or custom-fabricated, and are available in many types of materials, including fiberglass, neoprene, and thermoplastic.1,3,4
These types of splints are considered a key tool in the armamentarium of hand therapists and physical therapists for several reasons, including their cost-effectiveness and simplicity. Hand-based splints are easy to apply, easy to manipulate—for both providers and patient—and easy to remove to assess the extent and progression of the injury.1
Indications for Intervention
A hand-based thumb splint is indicated for patients with musculoskeletal injuries involving the thumb including sprains, fractures, UCL injuries, and degenerative conditions, as well as during conservative management in addition to the recovery period of surgery.
- Ask the patient to describe their medical history, with a focus on any recent injuries to the hand or wrist. Ensure the patient describes their symptoms and the duration of these symptoms in detail.
- Ask if the patient has any comorbidities, including diabetes, osteopenia, cardiovascular issues, or a history of smoking.
- Perform a physical examination of the hand and wrist. If range of motion (ROM) is impaired, measure the active and passive ROM of the joint(s) involved and compare these value(s) with 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.4,5
- Assign a diagnosis based on the patient’s history, symptomatology, and examination findings, and prescribe a hand-based thumb splint if the presentation is appropriate.
Orthoses Guidelines1-3,5-8
If the initial evaluation indicates that the patient is a good candidate for a hand-based thumb splint, you may select 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, but patients can make minimal adjustments with Velcro straps to ensure the splint fits properly
- 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, but a prefabricated splint may be sufficient for some patients with only minor symptoms. Hand-based thumb splints can be constructed with a variety of materials, including plaster, fiberglass, padding, ace wraps, metal, cloth, plastic, or leather. If fitting or fabricating the splint, ensure that it fits comfortably. Pain medications may be needed before and during the splinting process. 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.
After the splint is applied, provide the patient with wear and care instructions, including cleaning directions, which vary by splint. The frequency and duration of use depend on the type and severity of the condition and the patient’s comfort level. In many cases it’s appropriate to recommend wearing the splint with daily activities and at night if the patient experiences interrupted sleep. Patients with carpal tunnel syndrome may be told to wear the splint with activities that trigger flare-ups, but excessive use of the splint can limit ROM and other physical abilities. The duration of use also varies, but usually begins with a period of 4–8 weeks, which may be extended if indicated and tolerated by the patient. When the splint is not worn, encourage patients to continue moving their affected wrist normally to keep muscles flexible and strong.
A hand-based thumb splint is only one component of a treatment program and should be supplemented with other interventions during and after their use, particularly stretching and strengthening exercises, manual therapy, therapeutic modalities, and functional training.
