Abstract: Objective  The aim of this study was to explore the effects of lumbar lordosis on spinal sagittal balance after Roussouly type Ⅱ spinal lumbar fusion.Methods In the experiment,96 patients undergoing Roussouly type Ⅱ spinal lumbar fusion in Laohekou First Hospital were enrolled as the research objects between January 2022 and December 2023.According to random number table method,they were divided into control group (intraoperative maintaining of the original lumbar lordosis,n=48) and study group (intraoperative increasing of lumbar lordosis by 5°,n=48).The clinical symptoms [numerical rating scale (NRS),Oswestry disability index (ODI)],spinal and pelvic sagittal parameters [pelvic incidence (PI),sacral slope (SS),pelvic tilt (PT),lumbar lordosis (LL),thoracic kyphosis (TK)],rehabilitation status [Japanese Orthopaedic Association (JOA),Berg balance scale (BBS)] and postoperative complications were compared between the two groups.Results The experiment results showed that at 6 months after surgery,scores of NRS and ODI were decreased in both groups,which were lower in study group than control group (P<0.05).At 6 months after surgery,PI,SS,PT and LL in study group were (48.48±1.62) °,(35.42±5.39) °,(16.75±1.84) ° and (39.36±3.72) °,higher than those in control group [(47.51±2.32) °,(28.83±4.46) °,(13.95±1.77) °,(30.78±3.64),P<0.05],while TK was lower than that in control group [(11.72±1.08) °vs. (14.26±1.23) °,P<0.05].At 6 months after surgery,scores of JOA and BBS were increased in both groups,which were higher in study group than control group (P<0.05).There was no significant difference in incidence of postoperative complications between study group and control group (12.50% vs.14.58%,P>0.05).Conclusion It can be concluded that appropriate increase of lumbar lordosis can significantly improve spinal sagittal balance,promote the remission of clinical symptoms and rehabilitation process in patients after Roussouly type Ⅱ spinal lumbar fusion.

Key words: lumbar lordosis, Roussouly type Ⅱ, spinal lumbar fusion, spinal sagittal balance, postoperative recovery