Introduction: The purpose of this study is to identify factors at an early age which reliably predict outcome in cases of obstetrical brachial plexus injury.

Currently, lack of spontaneous recovery of elbow flexion at three months of age is an indication for surgery in centres around the world. This has not been scientifically evaluated and currently no gold standard exists to predict which children will improve with conservative management and which children will benefit from surgery.

Methods: Six hundred and four children assessed at The Hospital for Sick Children brachial plexus clinic over the last ten years were evaluated prospectively in a retrospective review. Seventy nine children, all of whom underwent a brachial plexus physical exam at three months of age and had a minimum follow up of two years were analyzed in this study.

Four test scores, based on various combinations of validated physical examination maneuvers, were developed and calculated for children at their three month physical examination. One of the test scores was elbow flexion alone. The three month physical examination test scores were analyzed with respect to functional outcome. The ability of test scores to predict outcome was analyzed with logistic regression, receiver operating characteristic curves and tree based analysis.

Results: Two of four test scores were shown with logistic regression to predict benefit with statistical significance (p=0.01 and p=0.013). Elbow flexion alone did not predict outcome. ROC and tree based analysis support these findings.

Conclusions: Outcome in obstetrical brachial plexus injury can be predicted using two newly developed test scores. Elbow flexion alone does not predict outcome. Future studies will evaluate the test scores prospectively and ultimately derive a formula to calculate which child will benefit from conservative vs. surgical management.