295. Should selective thoracic fusion be reserved for nonstructural compensatory lumbar curves? Radiographic and clinical results from propensity score matched patients at minimum 5-year follow-up

BACKGROUND CONTEXT For adolescent idiopathic scoliosis (AIS) Lenke Type 1-4C curves, controversy exists whether selective thoracic fusion (STF) is sufficient or non-selective fusion (NSF) should be used to treat the associated lumbar curves. PURPOSE In this multicenter study with minimum 5-year follow-up, we performed propensity score matching to compare patients treated with selective thoracic fusion and non-selective fusion for Lenke 1-2C curves vs 3-4C curves. STUDY DESIGN/SETTING Retrospective analysis of multicenter, prospectively collected data using propensity score matching PATIENT SAMPLE A total of 74 patients with Type 1-2C curves and 36 patients with 3-4C curves OUTCOME MEASURES Radiographic parameters (such as main thoracic and compensatory lumbar Cobb angles) and SRS-22 scores METHODS A prospective, multicenter database was queried for Lenke 1-4C curves (min 5-yr follow up). Patients were dichotomized to STF (fusion L1 or above) vs NSF (fusion below L1). We analyzed two subgroups: 1) non-structural lumbar curves (1-2C), and 2) structural lumbar curves (3-4C). After propensity score matching within each subgroup for age and preop thoracic and lumbar Cobb angles, we conducted within and between group comparisons of radiographic data and SRS-22 scores. RESULTS Of 124 patients with 1-2C curves, 74 matched (37 STF, 37 NSF). At 5 years postop, both STF and NSF led to improvement in main thoracic (MT) and compensatory lumbar (CL) Cobb angles as well as coronal balance (C7-CSVL), but NSF values were better than STF (p CONCLUSIONS In propensity score matched patients treated for Lenke Type 1-2C curves, STF results in slightly less radiographic correction but similar patient reported outcomes as NSF at 5 years. In contrast, matched patients treated for Lenke Type 3-4C curves with NSF have both better radiographic and patient reported outcomes when compared to STF. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.