Congenital Anomalies of the Ribs and Chest Wall Associated with Congenital Deformities of the Spine. A Study of 620 Patients

Summary: A retrospective study of 620 consecutive patients with congenital deformities of the spine was performed. The rib anomalies were classified into simple and complex and the presence of a Sprengel's shoulder was recorded. Congenital rib anomalies occurred most commonly on the concavity of a thoracic or thoracolumbar congenital scoliosis due to a unilateral failure of vertebral segmentation and did not appear to have an adverse effect on curve size or rate of progression.

Methods: This is a retrospective study of 620 consecutive patients with congenital deformities of the spine. Rib anomalies were classified into simple and complex and Sprengel's shoulder was recorded.

Results: Rib anomalies occurred in 119 patients. These were mostly associated with a scoliosis (111 patients), and much less with a kyphoscoliosis or kyphosis (8 patients). The rib anomalies were simple in 94 and complex in 25 patients. Eighty-five patients had scoliosis due to a unilateral failure of segmentation. Only 16 patients had scoliosis due to a hemivertebra alone. The rib anomalies were mostly associated with a thoracic or thoracolumbar scoliosis (102 patients), and occurred on the concavity in 82, convexity in 22, and bilaterally in 7 patients. Sprengel's deformity occurred in 45 patients; 43 with scoliosis, and 2 with kyphoscoliosis or kyphosis. Sprengel's shoulder occurred mostly in association with a thoracic scoliosis due to a unilateral failure of segmentation. The elevated shoulder was on the concavity of scoliosis in 26 and on the convexity in 16 patients. There was no significant difference in the rate of curve progression without treatment, the age, and curve size at surgery for the different types of congenital scoliosis in patients with and without rib anomalies either simple or complex (p>0.05). The only exception was the mean age at surgery, which was higher for patients with a unilateral unsegmented bar without rib anomalies (p=0.005). In addition, there was no significant difference with regard to any tethering effect due to the site of the rib fusions on the concavity of the scoliosis whether they were in close approximation to the spine or more lateral (p>0.05).

Conclusions: Congenital rib anomalies occur most commonly on the concavity of a thoracic or thoracolumbar congenital scoliosis due to a unilateral failure of segmentation and do not have an adverse effect on curve size or rate of progression.