Analysis of factors affecting baseline SF-36 Mental Component Summary in Adult Spinal Deformity and its impact on surgical outcomes.

OBJECTIVES: To identify the factors that affect SF-36 mental component summary (MCS) in patients with adult spinal deformity (ASD) at the time of presentation, and to analyse the effect of SF-36 MCS on clinical outcomes in surgically treated patients. METHODS: Prospectively collected data from a multicentric ASD database was analysed for baseline parameters. Then, the same database for surgically treated patients with a minimum of 1-year follow-up was analysed to see the effect of baseline SF-36 MCS on treatment results. A clinically useful SF-36 MCS was determined by ROC Curve analysis. RESULTS: A total of 229 patients with the baseline parameters were analysed. A strong correlation between SF-36 MCS and SRS-22, ODI, gender, and diagnosis were found (p < 0.05). For the second part of the study, a total of 186 surgically treated patients were analysed. Only for SF-36 PCS, the un-improved cohort based on minimum clinically important differences had significantly lower mean baseline SF-36 MCS (p < 0.001). SF-36 MCS was found to have an odds ratio of 0.914 in improving SF-36 PCS score (unit by unit) (p < 0.001). A cut-off point of 43.97 for SF-36 MCS was found to be predictive of SF-36 PCS (AUC = 0.631; p < 0.001). CONCLUSIONS: The factors effective on the baseline SF-36 MCS in an ASD population are other HRQOL parameters such as SRS-22 and ODI as well as the baseline thoracic kyphosis and gender. This study has also demonstrated that baseline SF-36 MCS does not necessarily have any effect on the treatment results by surgery as assessed by SRS-22 or ODI. LEVEL OF EVIDENCE: Level III, prognostic study.

Does Surgery for Adult Spinal Deformity Affect the Cognitive Abilities in Patients over 50 Years of Age?

AIM: To analyze the cognitive abilities of older patients undergoing spinal deformity surgery so as to understand whether adult spinal deformity (ASD) surgery is associated with postoperative cognitive malfunction. MATERIAL AND METHODS: A prospective longitudinal study was performed on surgical patients older than 50 years, enrolled in a prospective multicenter database. Mini-mental state examination (MMSE) was performed to assess cognitive function in addition to the health-related quality of life (HRQOL) tests; (SF-36, ODI and SRS-22) at the pre-operative, post-operative 6 weeks and 6 months points. Demographics, preoperative health status, co-morbidities and surgical characteristics were also analyzed. Descriptive statistics and repeated measures of variance analysis were performed. RESULTS: A total of 90 patients with a mean age of 67.4±8.2 years were enrolled in the study; all had MMSE evaluations at 6 weeks follow-up and 58 patients had both 6 weeks and 6 months follow-up. Average (SD) surgical time, estimated blood loss, number of levels fused and hospital stay were 240.1 (111.9) minutes, 1621.2 (1058.7) ml, 11.2 (4.4) levels and 14.2 (11.45) days, respectively. On analysis, a slight increase in mean MMSE score (p > 0.05) between time points was found despite decreases of > 2 points (3 or 4) in 6 patients (6.7%) at both time points. CONCLUSION: Although ASD surgery in older patients is recognized as challenging, this study suggests that it is not necessarily associated with a significant deterioration in the cognitive abilities of patients undergoing surgery. This may be due to the relatively minor influence of ASD itself on the cognitive abilities of the patients involved as well as to the relatively stable hemodynamic conditions obtainable during modern ASD surgery.