Lower Satisfaction after Adult Spinal Deformity Surgery in Japan than in the US Despite Similar SRS22 Pain and Function Scores: A Propensity-Score Matched Analysis.

STUDY DESIGN:A multicenter retrospective case series OBJECTIVE.: The purpose of this study was to compare the clinical outcomes of a surgical treatment for ASD in the United States (US) with those in Japan (JP) in a matched cohort. SUMMARY OF BACKGROUND DATA:Surgical outcomes of thoracic-lumbar-sacral (TLS) spinal fusions in adult spinal deformity (ASD) patients who live in Asian countries are poorly understood. METHODS:A total of 300 surgically treated ASDs of age > 50yr with the lowest instrumented vertebra at the pelvis and a minimum follow-up of 2y were consecutively included. Patients were propensity-score matched for age, gender, levels fused, and 2y postop sagittal spinal alignment. Demographic, surgical, and radiographic parameters were compared between the US and JP groups. RESULTS:A total of 186 patients were matched by propensity score and were almost identical within these parameters: age (US vs. JP: 66 ± 8 vs. 65 ± 7y), gender (females: 90 vs. 89%), levels fused (10 ± 3 vs. 10 ± 2), 2y C7SVA (5 ± 5 vs. 5 ± 4 cm), 2y PI-LL (9 ± 15° vs. 9 ± 15°), and 2y PT (25 ± 10° vs. 24 ± 10°). ODI scores and SRS-22 function and pain scores were similar at 2y between the US and JP groups (ODI: 27 ± 19 vs. 28 ± 14%, p = .72; SRS-22 function: 3.6 ± 0.9 vs. 3.6 ± 0.7, p = .54; SRS-22 pain: 3.6 ± 1.0 vs. 3.8 ± 0.8, p = .11). However, significantly lower satisfaction was observed in JP than in the US (SRS-22 satisfaction: 4.3 ± 0.9 vs. 4.0 ± 0.8, p < .01). CONCLUSIONS:Surgical treatment for ASD was similarly effective in patients in the US and in JP. However, satisfaction scores were lower in JP compared to the US. Differences in lifestyle and cultural expectations may impact patient satisfaction following ASD surgery. LEVEL OF EVIDENCE:3.