The Putti Sign Following Residual Brachial Plexus Birth Injury: Prevalence and Significance

Background: The Putti sign, a common deformity and complaint in children with brachial plexus birth injury (BPBI), stems from a glenohumeral (GH) abduction contracture. Despite recent clinical studies offering insights into this deformity, none have explored the prevalence of the Putti sign or its correlation with GH abduction contractures. Methods: We conducted a prospective analysis of 238 patients (median age 7.5 years; range, 4.1-16.2) with residual BPBI seen in the clinic from December 2019 to December 2022. Epidemiological data, including demographics, palsy levels, modified Mallet scale sum, surgical history, and presence/absence of the Putti sign and glenohumeral adduction angle (GHADD), were collected. Patients were categorized into 4 age groups: 0 to 5 years (n=67), 6 to 10 years (n=102), 11 to 15 years (n=53), and 16 years and older (n=16). Results were expressed as medians (minimum-maximum), with frequency comparisons done using Pearson's chi-square analysis. Mann-Whitney U and Kruskal-Wallis tests were used for quantitative variable comparison, and receiver operating characteristic (ROC) analysis determined the threshold GHADD angle for Putti sign appearance. Results: Main findings included: (1) 27% of patients with residual BPBI exhibited the Putti sign, (2) confirmed correlation between the Putti sign and GH adduction contractures, (3) Putti sign manifestation with GHADD angle measuring less than -5 degrees because to abduction contracture, and (4) association between this deformity and reduced activities requiring external rotation. No significant differences in Putti sign prevalence were found across age groups. Conclusions: Our study underscores the common occurrence of the Putti sign in children with residual BPBI. It is important to note that we highlight its functional significance beyond cosmetic concerns. Contrary to prior literature, our analysis reveals functional impairment associated with the Putti sign. Although no age-based differences in Putti sign prevalence were observed, patients aged 0 to 5 years and 11 to 15 years showed more severe glenohumeral abduction contractures, possibly due to growth spurts. Level of Evidence: Diagnosis IV.