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

Arm rotated medially with supination – the ARMS variant: description of its surgical correction

<p>Abstract</p> <p>Background</p> <p>Patients who have suffered obstetric brachial plexus injury (OBPI) have a high incidence of musculoskeletal complications stemming from the initial nerve injury. The presence of muscle imbalances and contractures leads to typical bony changes affecting the shoulder, including the SHEAR (Scapular Hypoplasia, Elevation and Rotation) deformity. The SHEAR deformity commonly occurs in conjunction with Medial Rotation Contracture (MRC) of the arm. OBPI also causes muscle imbalances at the level of the forearm, that lead to a fixed supination deformity (SD) in a small number of patients. Both MRC and SD will cause severe functional limitations without surgical intervention.</p> <p>Methods</p> <p>Fourteen OBPI patients were diagnosed with MRC of the shoulder and SD of the forearm along with SHEAR deformity during a 16 month study period, with eight patients available to long-term follow-up (age range 2.2 – 18 years). Surgical correction of the MRC was performed as a triangle tilt or humeral osteotomy depending on the age of the child, after which, the patients were treated with a radial osteotomy to correct the fixed supination deformity. Function was assessed using the modified Mallet scale, examination of apparent supination and appearance of the extremity at rest.</p> <p>Results</p> <p>Significant functional improvements were observed in patients with surgical reconstruction. Mallet score increased by an average of 5.2 (p < 0.05). Overall forearm position was not significantly changed from an average of 5° to an average of 34° maximum apparent supination after both shoulder rotation and forearm rotation corrective surgeries.</p> <p>Conclusion</p> <p>The simultaneous presence of two opposing deformities in the same limb will visually offset each other at the level of the wrist and hand, giving the false impression of neutral positioning of the limb. In reality, the neutral-appearing position of the hand indicates a fixed supination posture of the forearm in the face of a medial rotation contracture of the shoulder. Both of these deformities require surgical attention, and the presence of concurrent MRC and SD should be monitored for in OBPI patients.</p