1Application of 3D printing technology in spinal surgery:status quo and futureBAI Bo, BAI Xue-ling, ZHAO Xiao-wen, SANG Hong-xunEditorial321-3252Reconstruction with 3D-printed endoprostheses after type Ⅱ or Ⅱ+Ⅲ pelvic tumor resection: a retrospective case-control studyLIANG Hai-jie, GUO Wei, ZHANG Yi-dan, JI Tao3D printing326-3333A comparative study of 3D printed navigator for total knee arthroplasty based on groove guide plate technique and screw positioning guide techniqueLIU Shuai, YAO Qing-qiang, TIAN Shu-chang, HU Jun, ZHOU Jin, WEI Bo, GU Qiang-rong, XU Yan, WANG Li-ming3D printing334-3394Assistant function of 3D printing technology in the repair of complex scapular fractureLU Bing, XIAN Ai-ming, LIU Pan, WANG Yue3D printing340-3445Application of 3D printing technology in the teaching of complex traumatic orthopedicsCAO Bo, MA Chuang, CHENG Xin-chun, Alimujiang·Abulaiti, REN Peng, TANG Dan-dan, CAO Li, YANG Guang-zhong3D printing345-3476Research progress of application of 3D printing technology in orthopedics and hand surgeryLU Peng, TIAN WenReview348-3517Surgical site infection after pediatric spine surgery:a review of current literaturesSUN Xiang-yao, HAI YongReview352-3568Research progress of Schwann cell transplantation for spinal cord injuryQIAN Long, ZHANG Xiao-lei, HUANG Liang-jie, LIU Yan, TANG Jia-guangReview357-3619Early clinical observation of stand-alone zero-profile interbody fusion system in the surgical treatment of cervical spine diseaseLI Zhong-hai, TANG Jia-guang, REN Dong-feng, WANG Hua-dong, GUO Ji-dong, LI Li, WU Wen-wen, HOU Shu-xunOriginal article362-36810Pedicle screws combined with vertebroplasty for lumbar spinal stenosis complicated with osteoporotic vertebral compression fractureWU Xue-yuan, CHANG Yan-hai, JIN Zhan-kui, CHEN Ming, YANG Bo, SUN Zheng-ming, LING MingOriginal article369-37411Influence of operation mode and operation time on the incidence of postoperative deep venous thrombosis for the aged patients with hip fracturesLI Ming-dong, WANG Dan, GAO Xing, QIN Jun-jun, LIU JianOriginal article375-37812A meta-analysis of the clinical outcomes of arthrodesis in situ or after reduction for low-grade lumbar isthmic spondylolisthesisCHEN Jia-hai, BAI Xue-dong, LIU Li-yang, WANG Jing, LIN Ling-han, WANG De-li, HE Qing, RUAN Di-keMeta-analysis379-38513A correlative study of imaging features between lumbar disc herniation and lumbar Scheuermann's disease as well as Scheuermann's signsWANG Zhen, LI Yu-qian, WANG Xiao-dong, LI Hong-bin, ZHANG Jian-huaClinical research and practice386-38914Research on Unloader? One knee brace in the treatment of medial knee osteoarthritisZHOU Feng, ZHANG Fei, WANG Hui-xiang, DENG Guo-ying, WU Xiao-ming, WANG Qiu-gen, WANG Qian, WANG Jian-dongClinical research and practice390-39715Femoral head necrosis Ficat stage Ⅲ complicated with synovial chondromatosis: 1 case reportWANG Ya-kang, QIN Si-qing, JIANG Ren-qi, ZHANG Yu-minCase report398-400 