1Predicament and challenge of spinal surgery for elderly patientsLU Shi-baoEditorial801-8032The surgical treatment and preliminary postoperative outcomes of degenerative lumbar spinal stenosis combined with sagittal imbalance syndromeZHU Wei-guo, LU Shi-bao, KONG Chao, WANG Yu, WANG Wei, HU Hai-liang, WANG Bao-baoSpine surgery804-8103Role of paraspinal muscle degeneration in degenerative lumbar scoliosis with different drum tower classificationsLI Dong-yue, LIU Zhen, HU Zong-shan, Abdukahar Kiram, LI Jie, WANG Bin, QIU Yong, ZHU Ze-zhangSpine surgery811-8194Logistic regression analysis on risk factors of osteoporotic vertebral compression fracture 2 years after percutaneous kyphoplastyWEI Yi, LI Xing, ZHAO Jing-wei, CHEN Si, LIU BoSpine surgery820-8245A new method to evaluate spine-pelvis sagittal balance based on pelvic and thoracic compensationHOU Ying, LI Xiang-Yu, KONG Chao, WANG Yu, ZHU Wei-Guo, WANG Dong-Fan, SHI Bin, LU Shi-Bao, LU JieOriginal article825-8306Effectiveness of Roussouly classification in predicting mechanical complications after long-segment fixation in the treatment of adult degenerative scoliosisLI Li-xin, LIU Ying, FAN Guo-feng, LU Bo, SUN Xiang-yao, HAI YongOriginal article831-8367Application and research status of health economics evaluation in elderly orthopedic diseasesWANG Jia-lin, KONG Qiong, ZHU Wei-guo, WANG Yu, KONG Chao, WANG Wei, LU Shi-baoReview837-8418Osteotomy patterns for the treatment of patellofemoral instabilityWANG Zhi-xue, JI Zhen-wei, WU Peng, ZHANG Zhi-xiang, FANG Huan-ming, FENG Chong-yang, DING YongReview842-8479Research progress of hip arthroplasty in patients with osteoporosisSUN Chang-jiao, YU Peng, XU Ping-ping, LI Hui-min, XIE Lan-lan, YANG Kai, CAI XuReview847-85310Bilateral total knee arthroplasty: progress in simultaneous versus staged surgeriesXU Gu-jun, SONG Ping, GUO Ren-wen, KONG Xiang-peng, CHAI WeiReview854-85811The relationship between circular RNA and osteosarcomaLIU Qian-zheng, LIN Hao, HUANG Jing, CAI Yi-xiaReview859-86212Modified Delphi study on building Chinese experts'consensus on cortical bone trajectory fixation for lumbar spine surgeryZHANG Yi-qi, HAI Yong, LIU Yu-zeng, LIU Jing-weiClinical research and practice863-86713Study of risk factors and prognosis of osteosarcoma metastasis and the development and validation of clinical prediction modelsLUO San-tong, LIANG Wei-mingClinical research and practice868-880 