Ultrasound Screening for Posterior Shoulder Dislocation in Infants with Brachial Plexus Birth Palsy: Level 4 Evidence

Abstract

▴This presentation will discuss Materialise computer planning in skeletally immature patients. Clinical examination may fail to detect posterior shoulder dislocation in infants with brachial plexus birth palsy (BPBP).1Pöyhiä T.H. Lamminen A.E. Peltonen J.I. Kirjavainen M.O. Willamo P.J. Nietosvaara Y. Brachial plexus birth injury: US screening for glenohumeral joint instability.Radiology. 2010; 254: 253-260Crossref PubMed Scopus (42) Google Scholar The purpose of this study was to determine the prevalence of shoulder dislocation in this population on ultrasound (US) and to determine whether physical examination (PE) measurements correlate with US findings. Infants presenting to our BPBP clinic receive serial shoulder US exams until age 1 year. We retrospectively reviewed data for infants with concurrent physical exam and US prior to 1 year of age, but before any surgical intervention. PE consisted of Active Movement Scale (AMS) and passive external rotation of the shoulder in adduction (PERAdd) and abduction (PERAbd). US measurements included percentage of humeral head displaced posterior to the axis of the scapula (PHHD) and the alpha angle (intersection of posterior scapular margin with a line tangential to the humeral head through the glenoid).2Vathana T. Rust S. Mills J. Wilkes D. Browne R. Carter P.R. et al.Intraobserver and interobserver reliability of two ultrasound measures of humeral head position in infants with neonatal brachial plexus palsy.J Bone Joint Surg Am. 2007; 89: 1710-1715Crossref PubMed Scopus (31) Google Scholar Shoulder dislocation was defined as both PHHD > 0.5 and alpha angle > 30 degrees. PE results were compared between infants demonstrating dislocation at some time versus infants with no evidence of dislocation. We used receiver operating characteristic (ROC) analysis to evaluate the association between PE and concurrent US results. Sixty-six infants contributed a total of 118 ultrasound examinations (mean 1.8, range 1-5). Nineteen (28.8%) demonstrated shoulder dislocation, first detected at a range of 2.1-10.5 months of age. Of these, 14 (74%) presented with a dislocated shoulder at their first ultrasound. Infants with a dislocated shoulder demonstrated significantly less mean PERAdd (mean 46 versus 71 degrees) and a greater difference between internal rotation and external rotation scores on the AMS scale (mean 5.5 point versus 3.3 point difference) than those with a reduced shoulder (Table 1). PERAdd was better able to discriminate between concurrent evidence of dislocation and no dislocation (area under ROC curve [AUC] 0.89) than was the shoulder rotation difference (AUC = 0.73). A cut-off of 60 degrees for PERAdd yielded a sensitivity of 94% and a specificity of 69% for predicting dislocation on US (Figure 1). •Twenty-nine percent of infants seen in a BPBP specialty clinic had a shoulder dislocation during their first year of life.•Limited PERAdd and a large internal rotation - external rotation (IR-ER) difference on the AMS were associated with dislocation.•US shoulder screening is recommended for infants with BPBP, especially those with limited PERAdd.•US screening when PERAdd is = 60 degrees would identify an estimated > 90% of dislocations with a false positive rate < 30%.View Large Image Figure ViewerDownload Hi-res image Download (PPT)