O2077: Does Open Triradiate Cartilage Lead to Poor Outcomes Among Cerebral Palsy Patients Undergoing Spinal Fusion?

Background: The optimal timing for SF in patients with CP and scoliosis remains a subject of debate. This study investigates whether SF in skeletally immature patients during or before peak height velocity provides equivalent radiographic and clinical results versus those nearing skeletal maturity. We hypothesize spinal fusion (SF) yields equivalent radiographic and clinical results in skeletally immature patients with cerebral palsy (CP) compared to patients nearing skeletal maturity.

Methods: We identified patients with GMFCS 4 and 5 CP undergoing SF to the pelvis with a minimum 2-year follow-up. Patients were classified based on skeletal maturity at the time of surgery: open or closed triradiate cartilage (TRC). We compared perioperative clinical and radiographic outcomes and Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) scores.

Results: Of 127 patients with 2-year follow-up, 86(68%) had TRC-closed at the time of SF, and 41(32%) had TRC-open. TRC-open group mean age was 11.9y (range: 9.6-21) vs 15.4y (range: 8.47-17.2) (p < 0.001). TRC-open patients were more likely to be G-tube fed, 82.9% vs 47.7% (p < 0.001). Demographics were similar between the groups. The preoperative mean major curve was 77°, and the mean pelvic obliquity was 26°, which did not differ between the two groups. Two years postoperatively, there was an improvement in major curve magnitude by 65% and pelvic obliquity by 17°, which did not differ between the two groups or among the 46% of patients who had a 5-year follow-up. There was no significant difference in blood loss, length of hospital stay, infection, or medical complications. The TRC-open group had more instrumentation-related complications vs the TRC-closed group (24% vs 9% p< 0.03), often prominent implants, but this did not result in a higher reoperation rate. TRC-open group transiently improved in CPCHILD communication subdomain scores, but there were no other score differences at any time points between the groups. (Table 1)

Conclusion: CP patients aged 8.5-21 undergoing SF achieved similar perioperative outcomes and radiographic results at 2 and 5 years, regardless of open or closed TRC. Skeletally immature patients may have an increased risk of implant-related complications. These results suggest that definitive SF is a viable treatment option in CP patients approaching adolescence with open TRC.