The Efficacy of Concave Rib Osteotomies in the Treatment of Idiopathic Thoracic Scoliosis

PURPOSE: To examine the effectiveness of concave rib osteotomies in improving the correction of idiopathic thoracic scoliosis.

METHODS: The authors retrospectively compared the degree of correction of idiopathic thoracic scoliosis in 22 patients treated with posterior instrumentation and fusion alone (group 1) versus 15 patients treated with concave rib osteotomies in addition to their posterior instrumentation and fusion (group 2). The osteotomies were performed in 12 of the 15 patients in group 2 in order to improve curve correction; in the other three, they were done in order to obtain bone graft elsewhere than the iliac crest. The fusions were performed between 1997 and 1999. The average age at the time of the index operation was 14, and 14 years, 1 month in groups 1 and 2, respectively, with the follow-up time averaging 3 years, 4 months and 3 years, 1 month in these 2 groups. The minimum follow-up time in either group was 2 years. Preoperative thoracic curves averaged 50 and 60 degrees in groups 1 and 2. The surgical technique for the concave osteotomies involved resection of 3-4 cm of rib on the concave side of the thoracic curve, beginning just lateral to the rib head. As few as 5 and as many as ten ribs were osteotomized, going through the same midline incision used for the posterior instrumentation.

RESULTS: The curve flexibility on preop sidebending films averaged 48% and 36% in groups 1 and 2, with the flexibility being only 30% in the 12 patients in group 2 who were osteotomized only for improved correction. Curve correction averaged 64% and 61% in groups 1 and 2. This represented an average of 24% improvement in curve correction over the preoperative bending films in group 1, and 39% in the osteotomy group. There were 4 complications in group 1, and no complications in group 2. The complications in group 1 included one extended postop ileus, 2 wound infections, and one proximal hook displacement which occurred twice.

CONCLUSION/SIGNIFICANCE: There are only a few articles in the orthopedic literature discussing the use of rib osteotomies in order to improve surgical correction of scoliosis. Our study demonstrates that the use of concave rib osteotomies is a safe and effective means of improving scoliosis correction in stiff curves, and may thereby obviate the need for anterior releases in patients with large or stiff curves. As an additional benefit, it may be a valid alternative for obtaining autograft bone for scoliosis surgery.