Many infants with birth-related nerve injuries show early shoulder joint changes, study finds

A new study in PM&R found that shoulder joint problems in infants with birth-related nerve injuries may be much more common than previously understood. The article, “Prevalence of shoulder subluxation diagnosed via ultrasound screening in infants with birth brachial plexus injuries,” was co-authored by Assistant Professor Gabrielle Goodlin, MD; Teaching Associate Sarah Lewis, PT, DPT, PCS; and Associate Professor Marisa Osorio, DO; along with colleagues from Seattle Children's Hospital and UW Medicine.

The researchers studied 114 infants with birth brachial plexus injuries, a type of nerve injury that can occur during delivery and affect movement and strength in the arm and shoulder. The team used ultrasound imaging to look for shoulder subluxation, a partial dislocation of the shoulder joint, during the infants' first year of life. It is important to identify potential problems early, because there is a time-sensitive window for surgical intervention. 

The authors found that more than 83 percent of patients had signs of shoulder subluxation at their first screening around three months of age. More than half had more severe changes in the shoulder joint.

The study also found that many infants with shoulder subluxation had normal shoulder movement during a physical examination. Nearly 75 percent of infants with normal range of motion still showed shoulder joint changes on ultrasound, suggesting that imaging may identify problems that are not visible during a routine exam.

The authors conclude that shoulder joint changes in infants with birth brachial plexus injuries are more common than previously reported. More research is needed to determine whether earlier detection through ultrasound screening could help guide treatment and protect long-term shoulder function.