Leave it alone: the natural history of growth-friendly graduates without a final fusion

The natural history of growth-friendly graduates treated with growing instrumentation but no final fusion is unknown. Two previous reports exist with one analyzing 30 growin g rod patients with no definitive fusion and another including 10 patients with growing rod removal, but no comprehensive data exist in the literature.

A multi-center database was queried for patients treated with TGR or VEPTR and at least 2 years of follow-up from their index procedure. Patients met inclusion criteria if they had not undergone a final fusion procedure but had completed planned interventions for early onset scoliosis and had sufficient follow-up. Kaplan-Meier analysis was performed to model rates of UPROR and complications in patients with retained and removed implants over time.

Of 233 included patients, definitive treatment was implant maintenance in 203 (87%) and removal in 30 (13%). Patients with retained implants experienced 10 (5%) UPRORs and 41 (20%) complications after final lengthening. Patients with removed implants had 0 UPRORs and 10 (33%) complications after implant removal. Patients with available pre-definitive and follow-up measurements and whose implants were removed increased by a mean 14.3° of coronal curvature compared to 19.0° in those who retained implants at mean 3.8 and 3.7 year follow-up, respectively.

Growth-friendly graduates without final fusion demonstrate low rates of UPROR and complications following definitive lengthening or implant removal. However, those who undergo implant removal are more likely to experience complications. Coronal curve magnitude was moderately maintained in both cohorts, suggesting that avoidance of definitive fusion may be viable for some patients.