This is a retrospective review of patients treated for shoulder dysfunction and internal rotation contracture for obstetrical brachial plexus palsy with either arthroscopic release of the subscapularis alone or release and latissimus dorsi transfer. The authors generally performed an arthroscopic contracture release in patients below the age of 4 not responding to 3 months of dedicated stretching exercises exhibiting a positive hornblowers sign and/or a palpable humeral head posteriorly. In patients over the age of 4, they generally performed an arthroscopic release of the subscapularis and a latissimus dorsi tendon transfer.
Nineteen children with a mean age of 1.5 years underwent arthroscopic contracture release alone and 14 children with a mean age of 6.7 years were treated with both release and latissimus dorsi tendon transfer. Preoperative passive external rotation averaged -2 degrees for the children in the first group and -24 degrees for those in the second group. Arthroscopic release achieved a marked increase in passive external rotation and a centered position of the glenohumeral joint at the time of surgery in all but the oldest child in the series who had severe deformity. The contracture recurred in 4 children who had isolated release. These children were subsequently treated with a repeat arthroscopic release and a secondary latissimus dorsi transfer. None of the children who had a primary latissimus dorsi tendon transfer had recurrence of the contracture.
At 2-year follow-up, the mean passive external rotation was increased by 67 degrees in the first group and by 81 degrees in the second group. Internal rotation was not measured consistently preoperatively but was found to have decreased substantially postoperatively. MRI imaging performed prior to the surgery showed a pseudoglenoid deformity in 18 shoulders. At 2 years, MRI scans in 12 of 15 available showed marked remodeling of the deformity.
This study adds to the growing evidence that arthroscopic release of the subscapularis may significantly improve passive rotation of the shoulder and is the first study to indicate a potential benefit to allow for remodeling of the glenohumeral joint. Unfortunately, active external rotation was not reported in this series and still leaves open the question of subscapularis release alone versus release and muscle transfer to be performed simultaneously. In addition, many of the patients in this study did not significantly improve active elevation of the shoulder even with latissimus transfer. The authors did not indicate the specific insertion site of the latissimus tendon; one could surmise that their insertion point is at the infraspinatous closer to that described by L’Episcopo. The Hoffer insertion at the rotator interval has been shown to increase not only external rotation but forward flexion as well. Further studies are necessary to identify the ideal age for latissimus transfer in addition to subscapularis release. Finally, this study did not indicate any adverse effects (e.g. anterior dislocation) from the subscapularis release further providing evidence for the benefit of early intervention in these patients.
Journal of Bone and Joint Surgery