Midterm Outcomes of Shoulder Dislocations in Brachial Plexus Birth Injuries Treated With Injection Botulinum Toxin A.

Abstract

Background: Shoulder dislocation can be seen early in infancy and can be diagnosed by shoulder ultrasound. Botulinum toxin injection in the internal rotators of the shoulder can be used to as an adjunct to relieve the internal rotation contracture. The aim of this study was to evaluate the intermediate-term outcomes of shoulder dislocations treated with injection botulinum toxin and to identify the factors determining the outcomes of the procedure.

Methods: Eighty-six children with ultrasound diagnosed shoulder dislocation underwent injection BTX-A between 2011 and 2022. Children who underwent nerve surgeries and the ones with inadequate follow-up were excluded. Sixty-two children were followed up for a mean duration of 36 months. Injection botulinum toxin A 2 U/kg body weight was injected each into the subscapularis and the pectoralis major. After manual stretching of contracted anterior soft tissue and shoulder capsule, a shoulder spica was applied for 3 weeks. Hospital for Sick Children Active Movement Scale (HSC-AMS) score and active and passive shoulder was recorded before and after the procedure and the requirement for further interventions was noted.

Results: Outcomes were divided into 3 categories: group A-27 (44%) children who did not require any further surgery in our follow-up period; group B-27 (44%) needed further procedure for recurrence of IR contracture; and group C-8 (12%) developed external rotation contracture later. Children in group A had statistically significant higher preinjection HSC-AMS score for elbow flexion and shoulder abduction than the other groups. Children in group C had greater passive external rotation and weak elbow extension and wrist dorsiflexion as compared with the other 2 groups.

Conclusions: Injection botulinum toxin A is effective in treating shoulder dislocations in children with early recruitment of C5 to 6 muscles, while children with involvement of C7 muscles may develop an external rotation contracture subsequently, hence this procedure should be avoided.

Level of evidence: Level IV-therapeutic.