What is an extension block splint (EBS)?

From the Guidelines

An extension block splint should be worn at night as part of a treatment plan for specific hand conditions, with the splint being a rigid rest orthosis that covers the base of the thumb and the thenar eminence but not the wrist. This recommendation is based on the study by D. Moher et al. 1, which discusses the use of custom-made neoprene splints in patients. The study highlights the importance of proper adjustment and fitting of the splint to ensure patient comfort and effectiveness of treatment.

Key Considerations for Extension Block Splint Use

• The splint should be worn at night, as specified in the study 1, to provide continuous support and immobilization of the affected area.
• The splint should be adjusted by a trained occupational therapist to ensure proper fit and to allow for opposition of the thumb with the first long finger.
• Patients should be encouraged to contact the occupational therapist if they experience any discomfort, pain, or adverse effects while wearing the splint.
• The use of an extension block splint is part of a comprehensive treatment plan that may include usual care at the discretion of the patient's physician.

Importance of Proper Splint Use

The study by D. Moher et al. 1 emphasizes the need for careful consideration of treatment options for patients with hand conditions. While the study does not specifically address the use of extension block splints for finger injuries, it highlights the importance of proper immobilization and support in the treatment of hand conditions. By wearing an extension block splint at night, patients can receive the necessary support and immobilization to promote proper healing and prevent complications.

From the Research

Extension Block Splint

• An extension block splint is a type of splint used to treat mallet finger injuries, which involve a flexion deformity of the finger resulting from injury to the extensor mechanism at the base of the distal phalanx 2.
• The splint is designed to keep the fingertip straight and immobilize the distal interphalangeal joint (DIPJ) in extension, allowing the tendon injury or fracture to heal 3.
• The use of an extension block splint is a common treatment option for closed mallet finger injuries, particularly for Doyle type I injuries, which can be managed non-surgically with external splints 3.
• Studies have shown that splinting can be an effective treatment for mallet finger injuries, with good results and minimal morbidity in the majority of patients 4, 5.
• However, surgical management may be considered for acute and chronic mallet lesions in patients who have failed nonsurgical treatment, are unable to work with the splint in position, or have a fracture involving more than one third of the joint surface 5.
• A randomized clinical trial compared nonoperative splinting versus extension-block pinning of bony mallet fingers and found that splinting was safe and efficient in restoring joint motion, but did not sufficiently prevent secondary subluxation of the joint 6.

Treatment Duration

• The typical treatment duration for mallet finger injuries using an extension block splint is 6 to 8 weeks 4, 2, 5.
• During this time, the splint should be worn full-time to keep the fingertip straight and allow the tendon injury or fracture to heal 3.
• Radiographic follow-up during splinting may be necessary to monitor the healing process and prevent secondary subluxation of the joint 6.

Patient Compliance

• Patient compliance is essential for successful treatment of mallet finger injuries using an extension block splint 2.
• Patients should be instructed to wear the splint full-time and avoid activities that may cause further injury to the affected finger.
• Regular follow-up appointments with a healthcare professional are necessary to monitor the healing process and make any necessary adjustments to the treatment plan.