Introduction: Adult spinal deformity treatment approaches vary due to a lack of treatment algorithms. A Classification of Adult Spinal Deformity (“Classification”) has been established but validation of treatment has been limited. The purpose of this study is to evaluate outcomes following surgery for thoracic major deformity based upon a consensus algorithm developed by the Spinal Deformity Study Group.
Methods: Multi‐center analysis of consecutive adult patients. Type 1,11,111 curves (thoracic only/major) treated surgically included: 164 patients 1 yr, 98 with 2yr follow up (radiographs, health related quality of life (HRQOL) data and operative details). The consensus treatment algorithm calls for fusion 2 levels above and below the end vertebrae of the thoracic curve, 50% correction of the coronal Cobb angle and apical derotation (2 grades by Nash‐Moe). Statistical comparison of outcomes (reaching minimal clinically important difference, MCID) was made between groups dependant upon adherence with algorithm guidelines.
Results: 119 patients (76%) had fusion levels per algorithm. Only 38% reached MCID threshold for ODI, 41% for SRS activity at one year (31%, 49% respectively two year). Patients treated per algorithm were significantly more likely to reach MCID thresholds at one and two years post‐op (p=0.02–0.03). At two years patients treated per algorithm were more likely to also reach SRS appearance MCID (p=0.03). By coronal Cobb, 37% of patients reached 50% or more correction (per algorithm), and those were more likely to reach MCID for SRS appearance (p=0.002 year one, p=0.04 year two). Correction of axial rotation of 2 grades was noted in 26%, and was not correlated with reaching any MCID thresholds.
Conclusion: Adult thoracic major spinal deformity treatment has had little guidance from outcomes. Combining Classification and treatment algorithm (2 levels above and below coronal end levels of a curve, 50% Cobb reduction) showed adherence to guidelines lead to significantly improved outcome.
Significance: The Classification of adult spinal deformity can be combined with a treatment algorithm. In the setting of thoracic major curves the algorithm effectively guides ideal treatment for best outcome based upon HRQOL measures.