Authors (including presenting author) :
Poon PH, Lui WY, Wong MF, Hui N
Affiliation :
Occupational Therapy Department, United Christian Hospital
Introduction :
Proximal interphalangeal joint (PIPJ) flexion contractures are a common clinical problem seen after various types of injury to the finger such as fracture, tendon injury, joint dislocation, synovitis etc. After the injury, periarticular structures can shorten if a joint is unable to move through its full range for a prolonged period of time. Splinting techniques to remodel shortened soft tissue structures are well described, static progressive stretch (SPS) finger extension splint is one of these. The SPS makes use of biomechanical principles for graded stress relaxation of the shorten structures.
Current commercial SPS finger extension splint composed of a volar base to support the finger and a screwing part on top to create progressive three-point pressure to the finger joint. The one-size, single design SPS finger extension splint cannot accommodate post-trauma enlarged finger joints and different degrees of PIPJ flexion contracture, making outcome unsatisfactory and causing patient discomfort. Thus, UCH Occupational Therapist (OT) had designed tailor SPS finger extension splint but precise fabrication of the dynamic parts was time and manpower consuming.
In view of the limitations, UCH OT incorporated 3D-print technology to design a SPS finger extension splint for PIPJ flexion contractures, aimed at improving treatment effectiveness, efficiency and accommodating patient’s needs.
Objectives :
To study the effectiveness and efficiency of a new SPS finger extension splint using 3D-print technology for PIPJ flexion contractures.
Methodology :
Our SPS finger extension splint prototype was finalized by assembling 3D printed dynamic parts and thermoplastic splint material as the base. It effectively combined nature of time-efficiency with premade parts and custom-made by allowing OT to adjust the three-point pressure timely. The advantages of the splint include: (1) Three sizes available to accommodate enlarged finger joints; (2) Thermoplastic base allows timely adjustment of splint angle according to patient’s flexion contracture, with precise three-point pressure point; (3) Short assembling time.
Result & Outcome :
The splint effectively applied progressive three-point pressure to the PIPJ without hyperextending the distal interphalangeal joint (DIPJ), thus a precise correctional force was created without causing patient discomfort. Patients reported good compliance and adherence to the regime. Reduction of flexion contractures was also noted after application of the splint for relatively short period of time and raised patient satisfaction. Therapist can serially adjust the splint simply by altering the contour of the thermoplastic base which significantly reduce the splint fabrication time.
Incorporating 3D-print technology into OT splinting design is highly recommended in the future to improve both treatment efficiency and effectiveness.
