Background: Persistent muscle imbalance and soft-tissue contractures
can lead to progressive glenohumeral joint deformity in patients with brachial
plexus birth palsy. The objective of this investigation was to determine the
effects of correction of external rotation weakness and internal rotation
contractures with tendon transfers and extra-articular soft-tissue releases on
glenohumeral development in patients with brachial plexus birth palsy.
Methods: Twenty-five patients with brachial plexus birth palsy who
underwent latissimus dorsi and teres major tendon transfers to the rotator
cuff—with or without concomitant musculotendinous
lengthenings—were evaluated clinically and radiographically before the
operation and at a minimum of two years (average, forty-three months)
postoperatively. Shoulder function was prospectively assessed with use of the
modified Mallet classification system, in which aggregate shoulder function is
assigned a score of 5 to 25 points. Glenoid version and humeral head
subluxation were quantified with magnetic resonance imaging or computed
tomography, and glenohumeral deformity was graded.
Results: Clinically, all patients demonstrated improved global
shoulder function, with the mean aggregate Mallet score improving from 13
points preoperatively to 18 points postoperatively (p < 0.01). As seen
radiographically, the mean glenoid retroversion improved from 22°
preoperatively to 16.5° postoperatively (p = 0.012). The mean posterior
humeral head subluxation improved from 30% to 37% (p = 0.03). No patient had
progressive worsening of the glenohumeral deformity.
Conclusions: Latissimus dorsi and teres major tendon transfers to
the rotator cuff, combined with appropriate extraarticular musculotendinous
lengthenings, significantly improved global shoulder function but led to only
modest improvements in glenoid retroversion and humeral head subluxation. No
profound glenohumeral remodeling occurs after these extra-articular
rebalancing procedures, even when they are performed in patients of a young
age. While the long-term clinical and radiographically apparent effects at
skeletal maturity are uncertain, soft-tissue rebalancing procedures alone were
found to have halted the progression of, but not to have markedly decreased,
glenohumeral dysplasia at the time of a two to five-year follow-up.
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.