Factors Associated With Improved Quality of Life Outcomes in Patients Undergoing Surgery for Adult Spinal Deformity

Hideyuki Arima, MD, PhD; Tomohiko Hasegawa, MD, PhD; Yu Yamato, MD, PhD; Daisuke Togawa, MD, PhD; Go Yoshida, MD, PhD; Tatsuya Yasuda, MD, PhD; Tomohiro Banno, MD, PhD; Shin Oe, MD, PhD; Yuki Mihara, MD, PhD; Hiroki Ushirozako, MD, PhD; Tomohiro Yamada, MD; Yuh Watanabe, MD; Koichiro Ide, MD; Keiichi Nakai, MD; Yukihiro Matsuyama, MD, PhD


Spine. 2021;46(6):E384-E391. 

In This Article


This study examined factors that increase the likelihood of achieving post-surgical MCID for each SRS-22r domain in patients with ASD undergoing extensive spinal fusion. MCID represents a clinically significant change to PROM; achieving MCID after surgery is an important measure of treatment efficacy.[13] In this study, poor preoperative HRQOL score was a significant predictor of post-surgical achievement of MCID to all SRS-22r domains (Function, Pain, and Subtotal). This suggests that among patients with ASD, those with low baseline quality of life (QOL) were most likely to experience improvement as a result of surgery. Several previous studies have shown that conservative treatment is less effective than surgery in moderate and severe ASD cases;[5–7] in fact, surgical treatment has been shown as the only approach that can improve HRQOL in this patient group. Evidence that patients with severe ASD are likely to achieve MCID for the SRS-22r domains is encouraging to patients and surgeons alike, as this can be considered when selecting the most suitable treatment approach. If baseline HRQOL is poor, achieving MCID for the SRS-22r domains might be more likely given the relatively low point of departure. In this study, the cutoff values for the preoperative SRS-22r domain score for predicting achievement of MCID were also calculated. In contrast, relatively satisfactory baseline HRQOL might make it more difficult to achieve MCID, as there might be a limit to the extent of improvement that can be recognized by the patient. These effects, referred to as the "floor" and "ceiling" effect, respectively, are a limitation inherent to the concept of MCID.

Meanwhile, low postoperative SVA was associated with achieving MCID to SRS-22r Subtotal. Previous reports have shown that global sagittal alignment is associated with HRQOL.[25,26] In the present study, postoperative global sagittal alignment emerged as an important factor after adjusting for patient demographics, comorbidities, and preoperative spinal pelvic parameters. Nevertheless, Park et al[27] reported that acquisition of optimal alignment did not affect achievement of MCID. However, these authors did mention that clinical outcomes were associated with spinopelvic parameters. In the present study, postoperative PI-LL was not a significant factor; in contrast, postoperative SVA was a significant predictor of QOL-related outcomes. Yilgor et al[28] have suggested that overcorrection might increase the risk of complications and that it may not always be necessary to set PI-LL to the minimum value. Meanwhile, Lafage et al and Protopsaltis et al reported that the degree of correction should be selected based on a patient's age.[29,30]

Low postoperative SVA was associated with the likelihood of achieving MCID to SRS-22r Function; however, this association was not statistically significant. In many cases of ASD, spinal corrective fusion requires extensive fixation from the thoracic spine to pelvis, which reduces mobility around the waist.[4,31,32] However, despite these disadvantages, improvement of sagittal alignment tends to improve walking and ability to perform other activities of daily living.[20] Moreover, although not statistically significant, age affected the likelihood of achieving MCID for SRS-22r Function; in fact, the effect of treatment tends to be greater among younger than among older patients likely due to similar correction goals set for all age groups.[33] Yamato et al[34] reported that rigorous correction is necessary for extremely elderly patients. The present study may have involved insufficient correction for the oldest included adults, leading to relatively low rates of MCID SRS-22r Function achievement in this group.

To achieve MCID for SRS-22r Pain, preoperative poor SRS-22r Pain was the only relevant factor; postoperative sagittal alignment did not affect this outcome. Pain in patients with ASD cannot always be accounted for by alignment; indeed, previous studies have associated pain in ASD with psychological factors.[3,35] Nevertheless, in the present study, 46.1% of patients achieved MCID for SRS-22r Pain, which was a higher proportion of patients who experienced improvement than that reported for Function or Subtotal domains; this finding suggests that extensive corrective fusion from the thoracic spine to the pelvis might be an effective approach to pain management in patients with ASD.

Revision surgery did not affect outcomes assessed with SRS-22r Function and Subtotal socre; however, it tended to decrease the likelihood of achieving MCID. The majority of patients who require revision surgery experience mechanical complications such as rod breakage and PJF; efforts to minimize the incidence of these complications are required.[36–38] In this study, the rate of revision surgery was 29.8% at 2 years after the index surgery, which is consistent with previous reports;[39,40] nevertheless, such a revision surgery rate is not sustainable from either a clinical or an economic standpoint.

This study has some limitations. First, it was a single-center study; therefore, the present findings might have limited generalizability. Second, different types of ASD were included in this study, creating a sample of patients with heterogeneous disease etiology. Third, the follow-up period was short, and cases of revision surgery might have occurred after 2 years. Therefore, a long-term prospective study is required to replicate the present findings.