Spinal sagittal balance status affects postoperative actual falls and quality of life after decompression and fusion in-situ surgery in patients with lumbar spinal stenosis.

OBJECTIVES: It has been reported that good spinal sagittal alignment reduces the risk of fall and positive sagittal balance is the radiographic parameter that is most highly correlated with adverse health outcomes. However, no reports have demonstrated a change in risk of falling in patients with lumbar spinal stenosis (LSS) according to sagittal balance status.

PATIENTS AND METHODS: From September 2013 to October 2014, 141 patients who underwent lumbar spine surgery, including decompression and fusion in-situ for LSS, were enrolled in this study. Based on sagittal balance status, patients were divided into sagittal balance (SB) and sagittal imbalance (SI) groups. Four functional mobility tests were used to evaluate the risk of falling, and a fall diary, Oswestry disability index (ODI), and the Euro-QoL 5D(EQ-5D) visual analogue scale (VAS) were utilized to assess clinical improvement.

RESULTS: The mean patient age was 70.1 years in the SB group (N=46) and 70.9 years in the SI group (N=95) (not significant). The mean C7PL was 7.9mm in the SB group and 66.1mm in the SI group preoperatively (p<0.05). Among the four functional tests, only postoperative SMT and STS improved significantly in the SB group (p<0.05). Patients in the SI group showed significantly improved scores for all four functional tests during postoperative follow-up (p<0.05), but their performance was still worse than patients in the SB group. Average number of falls per individual during the follow-up period was 1.1±2.5 in the SB group and 1.9±3.2 in the SI group (p<0.05). There was a significant difference in the distribution of non-fallers and fallers (single and multiple fallers) between the two groups postoperatively(p<0.05). ODI and the EQ-5D VAS showed greater improvement in the SB group than the SI group. Multiple regression analysis revealed that sagittal balance during follow-up significantly affected ODI, EQ-VAS, functional mobility tests. (p<0.05).

CONCLUSION: Therefore, when fusion surgery is planned in patients with LSS, careful consideration of sagittal balance status might be important to attain better surgical and functional outcomes and decrease the incidence of actual falls after surgical treatment.