Coracoid Abnormalities and Their Relationship with Glenohumeral Deformities in Children with Obstetric Brachial Plexus Injury

<p>Abstract</p> <p>Background</p> <p>Patients with incomplete recovery from obstetric brachial plexus injury (OBPI) usually develop secondary muscle imbalances and bone deformities at the shoulder joint. Considerable efforts have been made to characterize and correct the glenohumeral deformities, and relatively less emphasis has been placed on the more subtle ones, such as those of the coracoid process. The purpose of this retrospective study is to determine the relationship between coracoid abnormalities and glenohumeral deformities in OBPI patients. We hypothesize that coracoscapular angles and distances, as well as coracohumeral distances, diminish with increasing glenohumeral deformity, whereas coracoid overlap will increase.</p> <p>Methods</p> <p>39 patients (age range: 2-13 years, average: 4.7 years), with deformities secondary to OBPI were included in this study. Parameters for quantifying coracoid abnormalities (coracoscapular angle, coracoid overlap, coracohumeral distance, and coracoscapular distance) and shoulder deformities (posterior subluxation and glenoid retroversion) were measured on CT images from these patients before any surgical intervention. Paired Student t-tests and Pearson correlations were used to analyze different parameters.</p> <p>Results</p> <p>Significant differences between affected and contralateral shoulders were found for all coracoid and shoulder deformity parameters. Percent of humeral head anterior to scapular line (PHHA), glenoid version, coracoscapular angles, and coracoscapular and coracohumeral distances were significantly lower for affected shoulders compared to contralateral ones. Coracoid overlap was significantly higher for affected sides compared to contralateral sides. Significant and positive correlations were found between coracoscapular distances and glenohumeral parameters (PHHA and version), as well as between coracoscapular angles and glenohumeral parameters, for affected shoulders. Moderate and positive correlations existed between coracoid overlap and glenohumeral parameters for affected shoulders. On the contrary, all correlations between the coracoid and glenohumeral parameters for contralateral shoulders were only moderate or relatively low.</p> <p>Conclusions</p> <p>These results indicate that the spatial orientation of the coracoid process differs significantly between affected and contralateral shoulders, and it is highly correlated with the glenohumeral deformity. With the progression of glenohumeral deformity, the coracoid process protrudes more caudally and follows the subluxation of the humeral head which may interfere with the success of repositioning the posteriorly subluxed humeral head anteriorly to articulate with the glenoid properly.</p

Secondary gleno-humeral joint dysplasia in children with persistent obstetric brachial plexus palsy

The study aimed to evaluate the degree of gleno-humeral joint deformation in children with persistent obstetric brachial plexus palsy and its effect on limb function. Computer tomography was performed in 24 children in the mean age of 6.1 years. There were eight boys and 16 girls. Gleno-scapular angle, congruency of gleno-humeral joint and joint deformity according to Waters at all. criteria were measured. The mean functional score according to the Mallet classification system was 12.3 points. The joint was stabile in nine, subluxed in seven and dislocated in nine cases. Gleno-scapular angle in affected joints was 23.3° and in non-affected 4.5°. The glenoid was statistically more retroverted in older children. With more severe posterior incongruence there was statistically greater limitation of passive external rotation, active internal rotation and a poorer functional result according to Mallet. Abnormalities were found also in the humeral head, being deformed and smaller compared to the non-affected side in all cases. Glenoid retroversion, posterior subluxation/dislocation of humeral head and smaller humeral head size are the abnormalities, most often identified in CT examinations. Shoulder function and in particular, passive, external rotation are closely associated with the degree of deformity of the glenoid, as well as with the extent of posterior humeral head dislocation