Upper limb kinematics after Latissimus Dorsi transfer in children with brachial plexus birth palsy

Background: Brachial plexus birth palsy remains a frequent condition and one of its treatments is to transfer the Latissimus Dorsi tendon to the infraspinatus muscle. The aim of this study was to analyse, for the first time, the three-dimensional kinematic effects of this operation on the upper limb joints during the five Mallet tasks and their correlation with clinical parameters. Methods: Kinematic analysis was performed using an electromagnetic device. An Index of Improvement taking into account the angle in preop and postop, the reproducibility and the angle of a control group was developed. Three groups of patients were analysed: sixteen patients (mean: 10,5 years) for the reproducibility, thirty children (mean: 9,5 years) for the control group and ten patients (mean: 8 years 7 months) who were operated. Findings: The humerothoracic and glenohumeral external rotations improved during the external rotation, the neck and the abduction tasks and worsened during the spine task. The glenohumeral external rotation worsened during the mouth task. The Humerothoracic abduction improved during the abduction and the neck tasks. The elbow flexion improved for the neck task. Differences were observed between patients and correlations were obtained between the Index of Improvement and clinical parameters. Interpretation: Using kinematics allows to better analyse the evolution of joint angles after the latissimus dorsi transfer. The Index of Improvement allows to quickly analyse the effect of the operation for each angle and each patient. This effect depends on clinical parameters