Fabrication of the external rotation abduction thermoplastic shoulder orthosis for infants and children with birth-related brachial plexus injuries

Abstract

Introduction Birth-related brachial plexus injuries occur between 0.5 and 5.8 per 1000 live births worldwide.1 During early life, secondary deformities of the shoulder develop due to muscle imbalances that create functional consequences despite expected neurological improvements.2 Orthosis fabrication with the shoulder in external rotation and abduction allows for secondary releases and soft tissue lengthening for infants with fixed glenohumeral joint contractures undergoing primary nerve surgery, while removing any tension on the transferred or grafted nerves.Purpose of this orthosis Our clinic team found that the arm can be safely and comfortably supported in this style of orthosis after primary nerve surgery, and secondary shoulder surgeries, without compromising the integrity of the surgical intervention while reinforcing the positive effects of positioning the shoulder in external rotation and abduction.Design Fabrication of the external rotation abduction thermoplastic shoulder orthosis (ERATSO) uses near-identical designs for the different surgeries. The differences are the position of the infant/child in sitting/standing, the position of the affected arm in molding, and the attachment of the arm/body piece to the body component.Arm position For primary nerve surgeries, position the arm in external shoulder rotation, 30° of horizontal abduction, forearm pronation, elbow flexion, and with the palm facing forward. For secondary procedures, the position is the same except with the shoulder in 90° of horizontal shoulder abduction, forearm supination, with the palm facing the ear.Measurement See Figure 1 for patterns and required measurements for the body piece, and the arm/body piece.Fabrication See Figures 1 and 2 for an overview of the fabrication process of the orthosis.