[Objective]To observe the bone repairing efficacy of large segmental femur defects in rabbits with calcium phosphate cement(CPC)combined with bone morphogenetic protein(BMP)and massive bone allograft,which may benefit the clinical application of large segmental bone allograft transplantation.[Method]Fifty-four New Zealand white rabbits were divided into three groups and a 2 cm femur defect was created on one side of each rabbit,followed by implantation with:CPC combined with BMP and massive bone allograft(Group A),bone allograft only(Group B)and autograft transplantation(Group C).Intramedullary nails with a 3 mm diameter fixed all the grafts transplanted.The bone defect repair efficacy was evaluated by radiology and histology exam at 4,8 and 12 weeks after operation.[Result]The bone reparation capacities of allograft with CPC/BMP complex was better than that of the allograft alone after 4 ~8 weeks of transplantation,which were similar to the result of autograft transplantation.Complete bone union was achieved for all the groups after 12 weeks of operation,with better bone remodeling for group A and group C transplantation.The healing process of CPC/BMP combined with allograft transplantation was featured with large amount of bone callus forming surrounding the graft-host bone union area and the surface of allograft,which composd the extra cortical bone bridge and ingrowth(EBBI).Bone invasion,resorption as well as new bone genesis were seen in the surface of bone allograft at early stage,companied by expansion of Haversians canal,with more lanner cells,osteoblasts,osteoclasts and blood cells inside the allograft.CPC was slowly biodegraded with the bone graft resorption and new bone regeneration.[Conclusion]CPC combined with BMP can improve the bone reparation and substitution process in massive bone allograft transplantation for the treatment of large segmental bone defects.

Objective To introduce the technique of OCM hospital (Orthopadische Chirurgie Munchen) in total hip arthroplasty (THA). Methods From January 2005 to January 2006, 20 cases of THA were done in our department with the technique of OCM hospital. The operative approach was through the anterior interval of gluteus medius, and a "V" shaped capsulatomy and a twice-osteotomy of femoral neck were conducted. Specialized acetabular saws and positioners of cup were applied to fix the prosthesis and a table was used to allow the posterior part to be removed. The affected femur was then further externally rotated so that the lower extremity could be placed in the sterilized bag beside the table. In order to achieve better position of the femoral stem, an extensive capsule release was done. Results BMI (body mass index) averaged 27. 4% , the length of skin incision 9. 3 cm, and blood transfusion two units for all the patients. The blood loss and the drainage were 130 mL and 80 mL respectively. In the mean follow up of 4. 3 months, 15 cases recovered completely but five still needed crutches. The mean VAS (visual analog scale) evaluation decreased from the preoperative 5. 1 to 3. 6 (one month later), 1. 7 (three months later ) and 0. 8 (six months later). The mean Harris scores of hip for all the cases increased from the 45. 4 to 88. 4 postoperatively. Conclusions OCM THA owns many advantages, such as small skin incision, less injury to gluteus medius and rapid recovery of patients, but compared with a conventional THA it needs a long learning and special instruments. Its indications are patients who are not over-weighted and have their first THA. Therefore, it is suggested that only qualified hospital and surgeons are allowed to perform the operation.

0.05). 3)ALP assay showed that the 7th,14th and 28th day of bBMP implantation, the ALP activities of bBMP in implantation groups were relatively higher than that of the control group (P0.05). 4)Histologically,after the 7th day implantation, a large quantity of mesenchymal cells differentiated with active chondrogenesis. The 14th day later, a large amount of cartilage and woven bone formed, and laminar bone and bone marrow were seen on day 28 after implantation. Conclusion The bBMP possesses active bone induction properties even after 10 years storage in 4℃ . The low-level antibodies of the recipient mice can be detected after implanted with bBMP, but the bone inducing activities are not affected. This may be a reference data for purification and clinical application of native BMP.

Objective To investigate the incidence and risk factors of surgical site infection(SSI) in patients with internal fixation surgery for limb fracture.Methods Medical data of patients with internal fixation surgery for limb fracture in a hospital from January 2013 to January 2016 were collected, 39 patients with SSI following internal fixation was as infection group, according to the 1:2 ratio, 78 patients without SSI following operation during the same period were randomly selected as the control group, risk factors of SSI were analyzed.Results Among 4 125 patients undergoing internal fixation surgery, incidence of SSI was 0.95% (n=39), the positive rate of bacterial culture in infection group was 87.2% (34/39), a total of 38 strains of pathogenic bacteria were isolated, among which 22 were gram-positive strains (57.9%), 15(39.5%)were gram-negative strains,1(2.6%) was fungi,Staphylococcus aureus was the main pathogenic bacteria (47.4%), and there were 20 isolates of multidrug-resistant organisms.Univariate analysis showed that infection group and control group was significantly different in the following aspects: combined underlying diseases, time from injury to operation≥8 hours, open fracture, multiple fracture, duration of operation≥180 minutes, intra-operative blood loss≥400 mL, allogeneic blood transfusion, duration of postoperative indwelling drainage tube≥5 days, and average length of hospital stay≥14 days (all P<0.05).Multivariate logistic regression analysis showed that the following factors were risk factors for SSI following internal fixation surgery for fracture: time from injury to operation≥8 hours, open fracture, duration of operation≥180 minutes, duration of postoperative indwelling drainage tube≥5 days, and average length of hospital stay≥14 days (all P<0.05).Conclusion Risk factors for SSI in patients with internal fixation surgery for limb fracture are multiple, reducing risk factors has a positive effect on decreasing the incidence of SSI and improving the cure rate.

Objective To evaluate the safety of Renaissance spine robot assisted system in spinal injury.Methods From March 2014 to May 2016,38 patients with spinal disease received spinal surgery assisted by spine robot system.They were 20 males and 18 females,with an average age of 42 years (range,from 12 to 69 years).There were 10 lumbar fractures,8 thoracic fractures and 20 spinal deformities.Pedicle screw implantation was conducted in 30 patients (PS group) and percutaneous vertebroplasty in 8 (PV group).One side was chosen randomly to use Mazor spine robot assisted system (assisted group) and the opposite side the conventional method (non-assisted group).The anteroposterior and lateral X-rays and CT scan of the lumbar and/or thoracic spine were performed in all patients after surgery.The precision of pedicle screws implantation in PS group was evaluated by the Abul-Kasimhierarchy grading system;location of the puncture trajectory,time used for puncture and radiation exposure time in PV group were evaluated.Results 208 pedicle screws were implanted in PS group,including 120 lumbar ones and 88 thoracic ones.For lumbar pedicle screw implantation,the excellent to good rate was 95.0％ (57/60) in the assisted group,significantly higher than that in the non-assisted group (80.0％,48/60) (P ＜ 0.05).For thoracic pedicle screw implantation,the excellent to good rate was 95.5％ (42/44) in the assisted group,significantly higher than that in the non-assisted group (77.3％,34/44) (P ＜ 0.05).There were 24 puncture trajectories in 8 patients in PV group,showing no pedicle penetration or cement leaking in any case.The mean time used for puncture was 5.5 ± 1.4 min in the assisted group,significantly shorter than that in the non-assisted group (17.8 ± 7.5 min) (P ＜ 0.05);the X-ray exposure time was 14.0 ± 4.0 s in the assisted group,significantly shorter than that in the non-assisted group (22.4 ± 6.0 s) (P ＜ 0.05).Conclusions Renaissance spine robot-assisted system deserves more clinical application,because in spinal surgery it can make pedicle screw implantation more precise and safer,and can reduce operation time and X-ray exposure time in percutaneous vertebroplasty.

Objective:To evaluate the hip C-arm fluoroscopy at primary position in internal fixation of femoral neck fracture.Methods:A retrospective study was conducted of the 69 patients with femoral neck fracture who had been treated from August 2015 to August 2018.They were divided into a primary position group ( n=35) subjected to C-arm hip fluoroscopy at primary position under symmetry traction of bilateral lower limbs for reduction of femoral neck fracture and a control group ( n=34) subjected to C-arm hip fluoroscopy at frog’s position on the healthy side for traction and reduction of the injured hip. The 2 groups were compared in terms of fluoroscopy frequency, times of resetting guide pin, intraoperative blood loss and total operation time. Results:The 2 groups were comparable due to insignificant significances between them in the preoperative general data like gender, age, fracture type, injury cause, or interval from injury to operation ( P>0.05). Compared with the control group, the primary position group showed less intraoperative fluoroscopy (7.2 times ± 0.5 times versus 16.1 times ± 1.2 times), fewer times of resetting guide pin (2.1 times ± 0.31 times versus 4.7 times ± 0.8 times), less intraoperative blood loss (96.8 mL ± 18.6 mL versus 198.1 mL ± 13.2 mL), and shorter total operation time (1.2 h ± 0.2 h versus 1.6 h ± 0.3 h). All the differences were statistically significant ( P<0.05). Conclusions:C-arm hip fluoroscopy at primary position may protect the stability after fracture reduction because bilateral lower limbs are under symmetrical traction and the hip position needs no alteration. Operation of C-arm fluoroscopy is easy and convenient and produces clear images. Therefore, this new mode of fluoroscopy has advantages of less intraoperative fluoroscopy and guide pin resetting, leading to significantly reduced intraoperative blood loss, ineffective operation time and anesthesia time.

Objective:To explore the significance of digital orthopedic technology in surgical plan for spinal tumor and the preliminary outcomes of 3D printed vertebral bodies in spinal tumor surgery.Methods:The clinical data of 2 patients were retrospectively analyzed who had had a 3D printed vertebral body implanted at Center of Orthopaedics, Shenzhen Hospital from June 2018 to December 2019. One was a 32-year-old male, diagnosed with cervical neurinoma; the other was a 27-year-old female, diagnosed with giant cell tumor of lumbar bone. 3D virtual reconstruction of tumor and surrounding structures was established via Mimics software for surgical plan. Virtual osteotomy was simulated, their disease models and guide templates were 3D printed, and their metal artificial vertebral bodies were 3D printed after personalized design of the vertebral body diameter, porosity and procedures of reconstruction and fixation. Lesion resection and prosthesis implantation were carried out in accordance with the preoperative plan. After operation, the motor function of cervical or lumbar vertebrae, tumor recurrence, and spinal stability reconstructed were regularly observed.Results:Resections and reconstructions went uneventfully in both cases. The 2 patients were followed up for 21 and 13 months respectively. Their postoperative images showed that their 3D printed vertebral bodies fitted the neighboring vertebral bodies well. The spinal stability was reconstructed without any loosening or periprosthetic osteolysis, and the tumors were removed completely with no recurrence in both cases. Their spinal motor function was satisfactory.Conclusions:Digital orthopedic technology can offer accurate guidance in the treatment of spinal tumors. It is necessary to consider local physiological anatomy in personalized design of a metal vertebral body 3D printed. Clinical application of 3D printed metal vertebral bodies is a new strategy for spinal reconstruction following spinal tumor resection.

Osteoporotic vertebral compression fracture (OVCF) can lead to lower back pain and may be even accompanied by scoliosis, neurological dysfunction and other complications, which will affect the daily activities and life quality of patients. Vertebral augmentation is an effective treatment method for OVCF, but it cannot correct unbalance of bone metabolism or improve the osteoporotic status, causing complications like lower back pain, limited spinal activities and vertebral refracture. The post-operative systematic and standardized rehabilitation treatments can improve curative effect and therapeutic efficacy of anti-osteoporosis, reduce risk of vertebral refracture, increase patient compliance and improve quality of life. Since there still lack relevant clinical treatment guidelines for postoperative rehabilitation treatments following vertebral augmentation for OVCF, the current treatments are varied with uneven therapeutic effect. In order to standardize the postoperative rehabilitation treatment, the Spine Trauma Group of the Orthopedic Branch of Chinese Medical Doctor Association organized relevant experts to refer to relevant literature and develop the "Guideline for postoperative rehabilitation treatment following vertebral augmentation for osteoporotic vertebral compression fracture (2022 version)" based on the clinical guidelines published by the American Academy of Orthopedic Surgeons (AAOS) as well as on the principles of scientificity, practicality and advancement. The guideline provided evidence-based recommendations on 10 important issues related to postoperative rehabilitation treatments of OVCF.