STUDY DESIGN: Retrospective review. OBJECTIVE: To compare the results of spinal fusion in patients with open triradiate cartilages (OTRC) and closed triradiate cartilages (CTRC). SUMMARY OF BACKGROUND DATA: Patients with OTRC at the time of spinal fusion may be at increased risk of developing postoperative changes related to growth. METHODS: From a database of patients with adolescent idiopathic scoliosis, we identified 44 patients with OTRC (mean age, 11.6 years) and 450 patients with CTRC (mean age, 15.6 years) and a minimum follow-up of 2 years. Patients in both groups were treated with anterior-only, posterior-only, or combined anterior and posterior spinal fusion; none had all-pedicle screw posterior instrumentation. RESULTS: In the OTRC group, anterior or posterior instrumentation, but not the combined approach, resulted in a significant mean late increase in the main curve (4.4 degrees and 7.3 degrees vs. 0 degrees , respectively; P = 0.002), an approach-related difference not seen in the CTRC group. Significantly more OTRC patients had proximal levels added on after surgery than did CTRC patients (18% vs. 8%, respectively; P = 0.02), and there was a trend toward this phenomenon distally (29% vs. 19%, respectively; P = 0.10). Proximal and distal junctional kyphosis was not significantly different between the 2 groups. Reoperation rate was 11% and 7% for OTRC and CTRC patients, respectively. For the selectively fused Lenke 1C curves in OTRC and CTRC patients, there was a trend in the uninstrumented lumbar curve toward a smaller lumbar curve before surgery (36 degrees and 41 degrees , respectively; P = 0.07) and a larger curve after surgery (27 degrees and 24 degrees , respectively; P = 0.07). CONCLUSION: Patients with scoliosis and OTRC have a greater risk of adding-on proximally and of loss of correction with anterior-only instrumentation; they may also have less predictable lumbar correction from selective thoracic fusion. However, after combined surgery, they have results similar to those of more skeletally mature patients.
STUDY DESIGN: Retrospective review. OBJECTIVE: To compare the results of spinal fusion in patients with open triradiate cartilages (OTRC) and closed triradiate cartilages (CTRC). SUMMARY OF BACKGROUND DATA: Patients with OTRC at the time of spinal fusion may be at increased risk of developing postoperative changes related to growth. METHODS: From a database of patients with adolescent idiopathic scoliosis, we identified 44 patients with OTRC (mean age, 11.6 years) and 450 patients with CTRC (mean age, 15.6 years) and a minimum follow-up of 2 years. Patients in both groups were treated with anterior-only, posterior-only, or combined anterior and posterior spinal fusion; none had all-pedicle screw posterior instrumentation. RESULTS: In the OTRC group, anterior or posterior instrumentation, but not the combined approach, resulted in a significant mean late increase in the main curve (4.4 degrees and 7.3 degrees vs. 0 degrees , respectively; P = 0.002), an approach-related difference not seen in the CTRC group. Significantly more OTRC patients had proximal levels added on after surgery than did CTRC patients (18% vs. 8%, respectively; P = 0.02), and there was a trend toward this phenomenon distally (29% vs. 19%, respectively; P = 0.10). Proximal and distal junctional kyphosis was not significantly different between the 2 groups. Reoperation rate was 11% and 7% for OTRC and CTRC patients, respectively. For the selectively fused Lenke 1C curves in OTRC and CTRC patients, there was a trend in the uninstrumented lumbar curve toward a smaller lumbar curve before surgery (36 degrees and 41 degrees , respectively; P = 0.07) and a larger curve after surgery (27 degrees and 24 degrees , respectively; P = 0.07). CONCLUSION:Patients with scoliosis and OTRC have a greater risk of adding-on proximally and of loss of correction with anterior-only instrumentation; they may also have less predictable lumbar correction from selective thoracic fusion. However, after combined surgery, they have results similar to those of more skeletally mature patients.