Prevalence and predictors of elbow flexion contractures during early childhood following brachial plexus birth injury

Background

Elbow flexion contracture development in school-age children with a brachial plexus birth injury (BPBI) is common. Reports indicate onset between 2 and 4 years; however, little is known about early childhood prevalence, development, and trajectory of these contractures.

Purpose

To determine the prevalence and predictors of BPBI elbow flexion contractures during early childhood.

Study Design

A retrospective cross-sectional study.

Methods

Demographic, diagnostic, treatment, and elbow contracture data were collected for children with a BPBI <4 years between 2015 and 2019 from a prospectively collected database. Spinal root motor contributions and injury were determined using Active Movement Scale (AMS) scores at 6 weeks of age and used to predict contracture development.

Results

Of the 171 children that met inclusion criteria, 87% (n = 149) had upper plexus injuries. The mean age at the time of evaluation for an elbow contracture was 21.4 ± 12.7 months. The prevalence of elbow flexion contractures was 22% (n = 38), with mean onset at 13.4 ± 11.0 months. Mean contracture degree was −10.8 ± −6.9 degrees with 76% (n = 29) <−10 degrees. AMS shoulder abduction, flexion, and external rotation; elbow flexion; forearm supination; and wrist extension scores at a mean 2.3 ± 1.4 months were significantly lower in children who developed elbow flexion contractures (p < 0.001). Logistic regression found that low AMS elbow flexion with high elbow extension scores were a significant (p < 0.003) predictor of elbow contracture development.

Conclusions

The prevalence of elbow flexion contractures in early childhood is greater than previously understood. These findings indicate that C5-C6 injury affecting elbow flexion with relative preservation of elbow extension is a predictor of contracture development. Further research is needed to investigate the nature and sequelae of C5-C6 injury and its effects on elbow flexion contracture development.