Shoulder dysfunction from "birth injury" is treatable

[mtomaino]

This week I saw a delightful 18 yo woman who had sustained an obstetrical brachial plexus injury which has impacted on both her shoulder and elbow function to this day. Sadly, despite travelling to Texas several years ago for surgical treatment, her function has not improved.

Obstetrical brachial plexus injuries refer to injuries sustained during birth to the nerves running from the neck to the arm. Though uncommon, the nerves may become become either stretched or ruptured, and depending on the extent, this can affect the shoulder, elbow, and hand. Numerous studies have shown that if elbow flexion does not return in the infant by 3 months (a proxy for recovery of the biceps muscle) then more aggressive surgical repair may be indicated. Why this approach in a baby?-----because if indeed recovery does not occur, significant functional impairment can last a lifetime.

When the injury affects only the shoulder, that is, the elbow and hand are normal, the functional limitations are often ellusive; and because it may go unnoticed until the toddler years and older, the opportunity to intercede before irreversible muscle atrophy occurs is missed. In such cases, attempts in subsequent years to lessen functional disability are directed to releasing contracture and transferring muscles that might restore the function no longer provided by a paralyzed motor unit. My patient this week had tendon releases, but for unknown reasons, no transfers.

In the case of birth-palsy related shoulder dysfunction, the "external rotators" are nonfunctional, but the "internal rotators" are working----and the net effect is that despite the ability to raise one's arm overhead, one loses the ability to optimally position the hand in space--to externally rotate the extremity. The photo below reveals such a lack of external rotation. Over the long term, the shoulder joint is affected because of abnormal loads on the socket, and a degree of capsular contracture prohibits even passive motion.

Surgical strategies, if employed early enough, include capsular release, and tendon transfer--most commonly transfer of the teres major and latissimus dorsi tendons to restore external rotation ("L'Episcopo procedure). Alternative treatment may include a derotational osteotomy of the humerus bone (cutting the arm bone and externally rotating the arm before fixing in the corrected position). This is more of a salvage procedure in cases when the shoulder joint itself has undergone changes that may make tendon transfers less successful. (See the xray attached with plate fixation)

This procedure is an option for the woman I saw this week, but in the final analysis, having quite successfully adapted to her functional disability over time, she may justifiably elect not to have additional surgery.