Publication At A Glance

SURGICAL NORMALIZATION OF THE SHOULDER JOINT IN OBSTETRIC BRACHIAL PLEXUS INJURY

Individuals with obstetric brachial plexus injuries (OBPI) have bony issues of the shoulder joint.

The issues include:

1) The humeral head (upper arm) not sitting correctly in the joint socket. Usually it sits too far back in the socket or it might even be dislocated out the back. (posterior humeral head subluxation)

2) The "socket" (joint) should have a circular rim in it to keep the humeral head in place. But in the cases of OBPI, the socket may be too flattened (glenoid retroversion) so that there is no rim at the back of the joint and this is one of the reasons the humeral head dislocates.

3) In many cases, the bony changes involve the scapula with the SHEAR deformity (Scapular Hypoplasia, Elevation And Rotation -- a smaller and thinner scapula, a scapula that is elevated and rotated)

4) The joint just can't function correctly with all these partial or complete dislocations (joint incongruity)

5) The child's arm hangs inward with a bent elbow. A child showing this type of arm and shoulder position probably has a partial or complete shoulder dislocation.

The purpose of this study was to see what kind of effect the Triangle Tilt surgery has on the anatomy of the shoulder joint. We studied 100 OBPI patients. CT & MRI scans were taken 12-38 months after having the Triangle Tilt surgery.

Patients who were completely dislocated (complete posterior glenohumeral dislocation) improved significantly after surgery. The shape of the shoulder joint (glenoid) also improved. Before surgery, 53% of the patients had a concave or flat glenoid and after surgery, 81% had a concave or flat glenoid with an improved rim of the shoulder joint.

Triangle tilt surgery was successful for both the positioning of the humeral head in the socket and for improving the shape of the socket itself (to hold the humeral head better in place). These post surgery improvements have been shown to be associated with improving the shoulder function and the quality of life for OBPI patients.