Summary: Posterior‐only fusion with Pedicle Screws is commonly practiced for patients with open TRC. It lowers OR time, EBL and hospital stay but may lead to modest loss of correction and of kyphosis at 2‐yr follow up.
Introduction: Open Triradiate Cartilages (OTRC) indicate significant growth remaining. Patients with significant scoliosis and OTRC had traditionally been treated with anterior and posterior fusion. There is increasing use of posterior‐only fusion with pedicle screws (PSF/PS), but no series to compare these outcomes. Clinical outcomes were studied.
Methods: Outcomes of three groups of patients were compared: (1) OTRC, age ≤11 having PSF/PS (20 pts), (2) OTRC, age ≤ 11 having APSF (9 pts) and (3) CTRC/Risser 4‐5 matched for curve size with group 1 having PSF/PS (20 pts). All had minimum 2 yr follow up.
Results: Preop curve averaged 58° for (1) & (3) and 54° for (2). Each group was fused a mean of 11 levels. EBL averaged 585 cc for (1) and 1255cc for (2). Hospital stay averaged 5.3 days for (1), 6.6 days for (2) (p=0.02), and 5.8 days for (3). Patients in (1) & (2) grew 7 cm between postop and final follow‐up, vs 0.5 cm for (3) (p=0.005). First postop curves were similar at 12‐18°. By 2 year follow up, (1) lost significantly more correction than (2) and (3) ( 8.8°, 1.6° and 1.3° respectively, p=0.002). Progression >10° occurred in 35% of (1), 0% of (2) and 5% of (3) (p=0.015)(fig 1). There was no significant difference in lower compensatory curve change between groups. Group 2 gained 8° of kyphosis within the instrumented thoracic curve vs loss of 6° for (1) and (3) (p=0.01). There was a significant difference in final clinically‐measured rib prominence in (1) vs (2) (10° vs 6°, p=0.03) but not in SRS scores. Only one patient has required reoperation (for pseudarthrosis, in group 3).
Conclusion: Patients with OTRC fused posteriorly with PS have less OR time, blood loss and hospital stay but more loss of main curve correction postoperatively than those fused circumferentially and than mature patients. They also have less thoracic kyphosis within the fused region. None have required reoperation at 2 yr F/U.
Significance: Further monitoring of these cohorts and caution in PSF/PS for larger curves may be indicated.