Publication At A Glance

Surgical Correction of the Medial Rotation Contracture in Obstetric Brachial Plexus Palsy

Quite often, individuals with obstetric brachial plexus injury (OBPI) have shoulder bones that are deformed. These deformities are caused by weakened muscles in combination with muscles that are too strong. This out-of-balance condition creates a situation where the stronger muscles get very tight and even shorter in length as time goes by. As this tightening and shortening (contracture) occurs, the humeral head is forced to unnaturally turn in the joint. This is called a "medial rotation contracture". This force may also cause the humeral head to push out of the joint and towards the back. This is called a "posterior glenohumeral subluxation" (dislocation).

The scapula is another area of possible deformity. This is called the "SHEAR Deformity". SHEAR is when your scapula is smaller in size (than the scapula on the other side) and it's elevated (so one corner actually sticks up and you can visually see it) and rotated into somewhat of a "sideways" position.

The Triangle Tilt surgery was created to address these types of out-of-balance conditions and deformities.

This particular study included 44 children who underwent the Triangle Tilt surgery between February and August, 2005. We found that after having the surgery, there was a definite improvement in the position and rotation of the scapula. We also found that the humeral head was located in a better position in the joint as well as the correction of the rotation of the humeral head. Better positioning and a correction in the rotation allowed for much improved shoulder function. We used the Mallet scale to chart the improvements.