Abstract
Background: Congenital anomalies of the chest wall and Sprengel’s shoulder are often associated with congenital deformities of the spine. It has been suggested that extensive rib fusions on the concavity of a congenital scoliosis may adversely affect progression of the spine deformity, thoracic function and growth of the lungs, which can lead to a thoracic insufficiency syndrome.
Methods: This is a retrospective study of the medical records and spine radiographs of 620 consecutive patients with congenital spine deformities. The rib anomalies were classified into simple and complex and the presence of a Sprengel’s shoulder was recorded.
Subjects: There were 497 patients (80%) with scoliosis, 88 patients (14%) with kyphoscoliosis, and 35 patients with kyphosis (6%). The mean rate of scoliosis deterioration without treatment, age and curve size at surgery was compared for the different types of vertebral abnormalities in patients with and without rib anomalies.
Results: Rib anomalies occurred in 124 patients. The rib anomalies were simple in 97 patients (78%) and complex in 27 (22%). The most common simple rib anomaly (70 patients; 72%) was a fusion of two or three ribs. The most common complex rib anomaly (20 patients; 74%) was a fusion of multiple ribs associated with a large chest wall defect. Rib anomalies were most commonly associated with a congenital scoliosis (116 patients; 93.6%), and much less frequently with a congenital kyphoscoliosis or kyphosis (8 patients). In those patients with a scoliosis, the rib anomalies were simple in 91 patients (78.5%) and complex in 25 patients (21.5%). Eighty-eight of the 124 patients (76%) with rib abnormalities had a scoliosis due to a unilateral unsegmented bar with or without contra-lateral hemivertebrae at the same level, and 8 patients had mixed unclassifiable vertebral anomalies. In contrast, only 17 patients with a scoliosis and rib anomalies had hemivertebrae alone. The rib anomalies were most frequently associated with a thoracic or thoracolumbar scoliosis (107 patients; 92.2%) and occurred on the concavity in 81 patients (70%), convexity in 27 patients (23%), and were bilateral in 8 patients. Sprengel’s deformity occurred in 45 patients; 43 patients with congenital scoliosis (8.6%), and 2 with kyphoscoliosis or kyphosis. A Sprengel’s shoulder occurred most frequently in association with a thoracic scoliosis due to a unilateral failure of vertebral segmentation (28 patients). The elevated shoulder was on the concavity of scoliosis in 26 patients and on the convexity in 16 patients. We compared the mean rate of curve progression without treatment, the age and curve size at spine surgery for the different types of spine deformities in patients with and without rib anomalies either simple or complex and found no significant difference (p> 0.05); the only statistical difference was that the mean age at surgery was higher for patients with a unilateral unsegmented bar without rib anomalies (p=0.005).
Conclusion: Congenital rib anomalies and Sprengel’s shoulder occur most commonly on the concavity of a thoracic or thoracolumbar congenital scoliosis due to a unilateral failure of vertebral segmentation. However, these anomalies do not have an adverse effect on curve size or rate of progression.
The abstracts were prepared by Mr Colin E. Bruce. Correspondence should be addressed to Colin E. Bruce, Consultant Orthopaedic Surgeon, Alder Hey Children’s Hospital, Eaton Road, Liverpool, L12 2AP.
