[Objective]To investigate the clinical effects of the internal fixation for fracture and dislocation of cervical spine with pedicle screws.[Method]Forty-one cases suffered from cervical fracture and dislocation were treated with Axis system.The patients all took X-ray,CT and MRI examinations before operations.Personal manipulation of every pedicle screw was attained according to the imaging measurement.[Result]All of the patients were followed up for six to twelve months postoperatively.One hundred and ninty-six of total 218 screws (90%) were in correct positon and 22 were incorrect.One nerve root injury and one doubtful blood vessel injury happened.Complete reduction and fracture union were obtained in 38 cases while inadequacy reduction and nerve root irritation existed in 3 cases,one of which suffered anterior approach operation on account of degeneration.Recovery didn't happen in the 6cases with complete spine injury.Ninteen cases with inadequacy spine injury recovered apparently even near normal level.[Conclusion]Cervical pedicle screw technique was identified to be safe and feasible for cervical fracture and dislocation.The key factors for a successful operation contain selection of patients,familiarity of the cervical anatomy,standard skill of manipulation and individuality of screw placement.

[Objective]To report the mid-term results and main points of modular femoral prosthesis in total hip revision surgery for Paprosky type Ⅲ bone defect of the proximal femur.[Method]Nine cases of Paprosky type Ⅲ bone defect of the proximal femur were treated with modular femoral prosthesis MP and ZMR from May 2003 to October 2006.There were 5 males and 4 females with the age range of 39-65 years(mean age 57 years).All the patients were followed up for 8-34 months(mean 19 months).Causes for revision included loosening and osteolysis of primary cemented prosthesis in 7,and coral face prosthesis sterile loosening in 2.The shortest time from the last operation to the revision was 4 years,and the longest was 12 years.There were 5 of type ⅢA and 4 of type ⅢB according to the Paprosky bone defect classification.[Result]The Harris score was 35 points(28-54) before operation and 85(70-90) after operation.Seven patients walked without the help of crutches,one had a mild pain in the thigh and a leg crispation of 2.5 centimeter,and the other having a medium pain in the thigh limping with a crutch.No significant loosening,infection or osteolysis of distal femur was found.One prosthesis sinking 12 mm in 1 case.[Conclusion]Total hip revision surgery for Paprosky type Ⅲ femoral bone defect using modular femoral prosthesis has optimal mid-term results.It offers stabilization both in the initial and late stages.Due to the separation of prosthetic stem from the proximal prosthesis,the implantation is easy to fix.Modular femoral prosthesis,which is benificial to control offset,anteversion angle,and limb length makes the total hip revision surgery simpler and safer.

BACKGROUND:Studies have demonstrated that the success rate of isolation of umbilical cord blood mesenchymal stem cells (UCB-MSCs)is low,which also lacks of unified identification method.OBJECTIVE:To modify the traditional in vitro isolation and culture method of UC8-MSCs to obtain a higher success rate and to observe its biological characteristics.DESIGN,TIME AND SETTING:In vitro observation of cytology.The study was performed at the Ninth People's Hospital of Shanghai Jiao Tong University Medical College between April 2006 and January 2007.MATERIALS:A totaI of 28 UCB samples were obtained from full-term normal delivery.Department of Matemity,Shanghai Red House Hospital.The written informed consent was obtained from the puerpera and their families.METHODS:NeonataI umbilical cord blood was collected under sterile condition.Mononuclear cells (MNCs) were separated from using lymphocyte isolation medium by centrifugation and suspended in α-minimum essential medium(α-MEM)containing 10% fetal bovine serum.The medium was half exchanged after 5-7 days of primary culture and then was totally exchanged every 3-4 days.The confluent cells were divided into 2 groups.In group 1.when the round megakaryocytes were confluent and fusiform fibroblast-like cells were fell off.the cell suspension was transferred to new culture dish;in group 2.when the round megakaryocytes dominated the majodty,the culture medium was replaced by α-MEM containing 15% calf serum,followed by culture in α-MEM containing 10% fetal bovine serum when the round megakaryocytes fell off.The fifth passage of UCB-MSCs was harvested for subsequent osteoinduction in vitro.MAIN OUTCOME MEASURES:The cell morphology was observed by microscopy;Flow cytometry was used to examine the surface antigen phenotype;alkaline phosphatase and oil red staining was performed to detect cell differentiation capacity.RESULTS:Of 28 samples of UCB,attaching cells were obtained from 20 samples(6/10 in group 1,14/18 in group 2),fibroblast-like cells that could passage steadily(4 samples in group 1,9 in group 2)were cultured from 13 0f 20 samples with success rate of 46.4%,among which MSCs were passaged steadily up to P22.UCB-MSCs were all positive for MSC-related antigens such as CD29 and CD105,but negative for CD34,CD45 and CD106.Incubation of UCB-MSCs under special condition resulted in a differentiation of osteoblast and adipocyte.CONCLUSIONMSCs exist in UCB,which have multi-differentiation capacity,and passage steadily.The modified in vitro culture method improves culture success rale of UCB-MSCs.

BACKGROUND: The characteristics of cervical anatomy and pedicle screw, operational specification, and individual screw implantation are the key factors of a successful implantation treatment.OBJECTIVE: This study was designed to investigate the cervical pedicle screw and host response as well as the recovery of spinal nerve functions during the surgery and follow-up period of cervical spine fracture-dislocation.DESIGN: A case analysis.SETTING: Department of Orthopaedics, General Hospital of Shenyang Military Area Command of Chinese PLA, Shenyang, Lianning Province, China.PARTICIPANTS: A total of 41 patients with cervical spine fracture-dislocation, who have complete follow-up data, were admitted to the Department of Orthopaedics, General Hospital of Shenyang Military Area Command of Chinese PLA between February 2002 and February 2006. Of the included patients, 18 were complicated by spinal cord injury (according to Frankel classification system, 6 were graded as A, 1 as B, 4 as C, and 7 as D.METHODS: Forty-one patients with cervical spine fracture-dislocation were treated by implanting a screw through the cervical pedicle and fixing it. Prior to surgery, all patients were subjected to X-ray, CT and MRI examinations. According to measurements, each cervical pedicle screw was individually implanted. The entire surgery was accomplished by Xiang Liang-bi, chief physician, whose qualification corresponds to the responsibilities.MAIN OUTCOME MEASURES: Material and host response during and after screw implantation as well as in the follow-up period. Recovery of spinal nerve function after screw implantation.RESULTS: All patients were followed up for 6-12 months and all incisions were healed primarily. Material and host response during the process of screw implantation: A total of 218 screws were implanted. After initial implantation, 12 screws were loosened, and such a phenomenon disappeared in 11 screws by adjusting inserting point and inserting direction or/and increasing screw diameter or length. The remaining 1 screw was stabilized by increasing the fixed segments. After drilling, poles of 10 screws bled much and treated by hemostasis. C1-2 venous plexus hemorrhage was caused in 3 patients and stopped by compression, and Apofix internal fixation was used in 1 of 3 patients due to unclear surgical visual field. Material and host response after surgery and during the follow-up: A total of 218 screws were inserted. Of the 218 screws, 196 were in correct position, and 22 were deviated to different degrees. Deviation of 1 screw caused injury to nerve root and that of another screw led to injury to blood vessel. Thirty-eight patients acquired satisfactory reduction and bone union. Three patients presented with symptoms of nerve root irritation due to incomplete reduction in the old fracture-dislocation. Among the 3 patients, 1 was subjected to anterior approach due to screw removed, and neither injury to vertebral artery, spinal cord, and nerve root nor internal fixation destroy was found in any other patients. Recovery of spinal nerve function after implantation: Among the 18 patients complicated with spinal cord injury, 6 patients, who were assessed as grade A spinal cord injury, did not exhibit improvement in spinal cord function, while the remaining 12 presented with 1 or 2 grades of improvement.CONCLUSION: There is a lower probability for biocompatibility reaction, and spinal nerve function recovers better after implantation of cervical pedicle screw. So implantation of a cervical pedicle screw system is an effective and relatively safe method for treatment of cervical spine fracture-dislocation.