Clinical Diagnosis of the Infantile Shoulder Subluxation in Residual Brachial Plexus Birth Injury and Its Correlation With Ultrasound Diagnosis

Abstract

Introduction and aims of study: Timely detection of shoulder subluxation in infants with brachial plexus birth injury (BPBI) is essential to prevent the progression of glenohumeral deformity. Shoulder ultrasonography (USG) is routinely used to detect an infantile subluxation/dislocation, but its use is limited because of the paucity of expert radiologists in developing countries. The aim of this study was to determine the clinical examination predictors to determine shoulder subluxation in patients with BPBI correlating with ultrasound confirmation. Methods: We prospectively studied children who presented to our hospital between 2017 and 2021 diagnosed as brachial plexus birth injury. In patients developing internal rotation contracture of the shoulder, we looked for 3 standard clinical signs: reduced passive external rotation <60 degrees, deep anterior crease (DAC) and relatively short arm segment. Shoulder subluxation was defined as USG measurement of alpha angle>30 degrees and ossific nuclei of the humerus lying behind the dorsal scapular line. Sensitivity and specificity were used to assess their efficacy in clinical diagnosis of shoulder subluxation in different groups. The predicted probability of shoulder subluxation from each prediction rule was compared with actual distributions based on USG confirmation. Results: Of the 58 BPBI infants who developed PER<60 degrees at the shoulder, 41 had USG confirmed shoulder subluxation. The 2 independent predictors of shoulder subluxation (PER<45 degrees and DAC) were identified in the current patient population based on data analysis. The presence of short arm segment is a very specific marker of shoulder subluxation but not sensitive. The predicted probability of shoulder subluxation from the prediction rule combining all the 3 markers were similar to the actual distributions in the current patient population. Conclusions: PER<45 degrees and presence of deep anterior crease are clinical markers indicating shoulder dislocation in patients with BPBI developing reduced external rotation at the shoulder. On the basis of the proposed clinical diagnosis algorithm, the above markers along with the selective use of USG can help in early detection and treatment of infantile shoulder dislocation.

Brachial plexus birth injury: advances and controversies

“…Advances in USG technology have enabled very detailed images to be obtained in locomotor system problems and offer the possibility of imaging without the need for anaesthesia. In addition to imaging the injured nerves (Gunes et al., 2018), structural changes in the shoulder that may develop as early as the fourth month secondary to birth paralysis may be detected by USG (Shah et al., 2023) or MRI. Posterior subluxation of the shoulder was found in 15 (44%) of 34 children who underwent MRI (Grahn et al., 2019).…”

“…If recognized early by experienced therapists, stretching exercises, orthoses, if necessary, and botulinum toxin applications may help to achieve better functional results (Grahn et al., 2022). Shoulder subluxation can be investigated using ultrasound, with an alpha angle greater than 30° and the proximal humeral ossification centres being behind the dorsal scapular line (Shah et al., 2023).…”