Shoulder external rotation contracture following neonatal brachial plexus injury.

BACKGROUND: Glenohumeral posterior external rotation contractures and scapular winging are frequently overlooked problems in residual neonatal brachial plexus injury (NBPI). Recent attention has emphasized their impact on vital functions such as feeding and hygiene. This study aims to present the epidemiology of posterior glenohumeral contractures in a significant pediatric NBPI population and explore contributing factors. METHODS: We conducted a retrospective analysis of data collected from January 2019 to November 2022, involving a case series of 262 children with residual NBPI. The data included demographics, palsy level, prior surgical history, and the modified Mallet scale. Glenohumeral passive internal rotation in abduction and cross-body adduction angles were measured bilaterally. Subjects were categorized into "Belly-" (Mallet hand-to-belly <3) and "Belly+" (Mallet hand-to-belly ≥3) groups. RESULTS: The median participant age was 7.9 years (range: 3.5-21 years). Extension injury patterns included Erb's palsy (56.5%), extended Erb's palsy (28.6%), and global palsy (14.9%). Contractures exceeding 10°, 20°, and 30° were prevalent in both internal rotation in abduction and cross-body adduction angles. The "Belly-" group (9.5%) demonstrated a significant reduction in both angles compared to the "Belly+" group. Weak correlations were found between internal rotation in abduction (r = 0.390, P < .0001) or cross-body adduction (r = 0.163, P = .0083) angles and Mallet hand-to-abdomen item. Glenohumeral reduction and Hoffer procedures led to a notable decrease in cross-body adduction angle, without affecting "Belly-" prevalence. Global injuries exhibited decreased angles compared to Erb's group. CONCLUSIONS: External rotation glenohumeral contractures are prevalent in residual NBPI, impacting midline access. Surprisingly, the history of glenohumeral procedures or extensive injuries did not increase the likelihood of losing the ability to reach the belly. Receiver operating characteristic analysis suggests specific thresholds for maintaining this ability.

Shoulder extension impairment with residual neonatal brachial plexus injury.

BACKGROUND: Impairment of both shoulder extension and behind-the-back function are common in patients with residual neonatal brachial plexus injury (NBPI), but have scarcely been studied or reported in the literature. Behind-the-back function is classically evaluated using the hand-to-spine task used for the Mallet score. Angular measurements of shoulder extension with residual NBPI have generally been studied utilizing kinematic motion laboratories. To date, no validated clinical examination method for this has been described. METHODS: Intraobserver and interobserver reliability analyses of 2 shoulder extension angles-passive glenohumeral extension (PGE) and active shoulder extension (ASE)-were performed. Afterwards, a retrospective clinical study was conducted on prospectively collected data on 245 children with residual BPI treated from January 2019 through August 2022. Demographic characteristics, level of palsy, previous surgical procedures, modified Mallet score, and bilateral PGE and ASE data were analyzed. RESULTS: All inter- and intraobserver agreements were excellent, ranging from 0.82 to 0.86. The median patient age was 8.1 years (3.5-21). Among the 245 children, 57.6% had Erb's palsy, 28.6% extended Erb's palsy, and 13.9% global palsy. One hundred sixty-eight (66%) of the children could not touch their lumbar spine, among whom 26.2% (n = 44) had to swing the arm to reach it. Both the degrees of ASE and PGE achieved correlation significantly with the hand-to-spine score, the ASE strongly (r = 0.705) and the PGE weakly (r = 0.372) (both P < .0001). Significant correlations also were found between lesion level and the hand-to-spine Mallet score (r = -0.339; P < .0001) and ASE (r = -0.299; P < .0001), and between patient age and the PGE (P = .0416, r = -0.130). A statistically significant decrease in PGE and incapacity to reach the spine were found in patients who underwent glenohumeral reduction, shoulder tendon transfer, or humeral osteotomy, relative to those who had microsurgery or no surgery. Receiver operating curves showed that, for both PGE and ASE, the minimum extension angle required to successfully perform the hand-to-spine task was 10°, with sensitivity levels of 69.9 and 82.2, and specificity levels of 69.5 and 87.8 (both P < .0001), respectively. CONCLUSIONS: Glenohumeral flexion contracture and lost ASE are extremely common in children with residual NBPI. Both the PGE and ASE angles can be measured reliably with a clinical exam, with at least 10° of PGE and ASE necessary to perform the hand-to-spine Mallet task.