In order to evaluate the efficacy of low intensity ultrasound and tissue engineering technique to repair segmental bone defects, the rabbit models of 1.5-cm long rabbit radial segmental osteoperiosteum defects were established and randomly divided into 2 groups. All defects were implanted with the composite of calcium phosphate cement and bone mesenchymal stem cells, and additionally those in experimental group were subjected to low intensity ultrasound exposure, while those in control group to sham exposure. The animals were killed on the postoperative week 4, 8 and 12 respectively, and specimens were harvested. By using radiography and the methods of biomechanics, histomorphology and bone density detection, new bone formation and material degradation were observed. The results showed that with the prolongation of time after operation, serum alkaline phosphatase (AKP) levels in both groups were gradually increased, especially in experimental group, reached the peak at 6th week (experimental group: 1.26 mmol/L; control group: 0.58 mmol/L), suggesting the new bone formation in both two group, but the amount of new bone formation was greater and bone repairing capacity stronger in experimental group than in control group. On the 4th week in experimental group, chondrocytes differentiated into woven bone, and on the 12th week, remodeling of new lamellar bone and absorption of the composite material were observed. The mechanical strength of composite material and new born density in experimental group were significantly higher than in control group, indicating that low intensity ultrasound could not only effectively increase the formation of new bone, but also accelerate the calcification of new bone. It was concluded that low intensity ultrasound could evidently accelerate the healing of bone defects repaired by bone tissue engineering.

BACKGROUND: Bone defect is commonly treated in clinic with auto graft, allograft and artificial bone graft, but with the disadvantages to various extents. Therefore, how to better repair bone tissue in bone defect becomes the hot spot in surgical field.OBJECTIVE: The complex of marrow stromal stem cell (MSC) and calcium-phosphates artificial bone (CPAB) was prepared and the repair of bone defect was observed in animal experiment.DESIGN: Randomized controlled experiment was designed.SETTING: Department of Traumatic Surgery, Affiliated Hospital of Qingdao University Medical College.MATERIALS: The experiment was performed in Animal Experimental Center of Affiliated Hospital of Qingdao University Medical College from May 2002 to September 2003, in which, 24 New Zealand health normal big white adult rabbits were employed, aged varied from 6 to 14 months, mass weighted from 9 to 3.5 kg, of either sex.METHODS: (① Rabbit MSCs were differentiated and proliferated and CPAB was taken as carrier to prepare the complex of CPAB and MSCs. ②24 rabbits (48 laterals) were prepared as model of bone defect, divided into 3 groups, named complex group (24 laterals), in which, unilateral bone defect of 24 rabbits were implanted with cell + carrier complex; The rtificial bone group (12 laterals), in which, CPAB was implanted contralaterally;and blank control (12 laterals), in which, no any management was done contralaterally in bone defect of 12 rabbits. In 8, 16 and 24 weeks after surgery, 4 animals were collected at each time spot in each group for radionuclide monitoring; and the animals were sacrificed under anesthesia for X-ray picturing and histological staining analysis.MAIN OUTCOME MEASURES: ① Gross observation of bone defect in each group. ② Results of X-ray examination. ③ Results of histomorphologic observation. ④ Results of radionuclide monitoring.RESULTS: 24 rabbits all entered result analysis. ① Gross observation of bone defect in each group and results of X-ray examination: In complex group of 24 hours, the fractutred ends were connected partially, the bounder was not clear between the regenerated bone and material and reopened medullary cavity was not visible. In simple artificial bone group, the implanted material was integrated with the cross end and material volume did not change obviously compared with the initial implanting stage. In bland control, ununion fracture presented and medullary cavity was closed. ②Results of histomorphological observation: In 24 hours, the bone defect was smaller in size and the union happened on the defect area in complex group. In artificial bone group, the regenerated bone was integrated tightly with the material and grew inside partially. In blank control group,medullary cavity was closed and bones were not connected. ③ Results of radionuclide monitoring: It was remarkably distinguished with naked eye that radioactive concentration was in tendency of obvious increasing in both complex group and artificial bone group in 8-24 weeks.CONCLUSION: The complex of CPAB and MSCs regenerates bone tissue and repair radial defect in whole. In addition, the repair ability is superior remarkably to simple CPAB.

Objective To study the prevalence of cholelithiasis among spinal cord injured (SCI)male patients, and the correlation of cholelithiasis with the SCI patients′ age, weight,and the level of injury, severity and duration of the SCI. Methods One hundred male SCI patients including 58 patients with ASIA class A and B and 42 with ASIA class C and D,with aged 20-65 years old(average 46.5 years) were followed up.They suffered from a spinal cord injury more than one year. The control group consisted of 100 male volunteers without both SCI and biliary diseases, with aged 20-68 year old(average 42.6 years). All patients in the two groups underwent ultrasonographic imaging to evaluate the gallbladder and the biliary tract. Results The prevalence of cholelithiasis was 26.0% in the SCI group patients and 10.0% in the control group,the difference was statistical difference (P 0.05). Conclusions SCI represents a major risk factor for the development of cholelithiasis . There are no correlation of cholelithiasis with the SCI patients′ age , weight,SCI level,severity and duration of SCI.

In order to evaluate the efficacy of low intensity ultrasound and tissue engineering technique to repair segmental bone defects, the rabbit models of 1.5-cm long rabbit radial segmental osteoperiosteum defects were established and randomly divided into 2 groups. All defects were implanted with the composite of calcium phosphate cement and bone mesenchymal stem cells, and additionally those in experimental group were subjected to low intensity ultrasound exposure, while those in control group to sham exposure. The animals were killed on the postoperative week 4, 8 and 12 respectively, and specimens were harvested. By using radiography and the methods of biomechanics, histomorphology and bone density detection, new bone formation and material degradation were observed. The results showed that with the prolongation of time after operation, serum alkaline phosphatase (AKP) levels in both groups were gradually increased, especially in experimental group,reached the peak at 6th week (experimental group: 1.26 mmol/L; control group: 0.58 mmol/L), suggesting the new bone formation in both two group, but the amount of new bone formation was greater and bone repairing capacity stronger in experimental group than in control group. On the 4th week in experimental group, chondrocytes differentiated into woven bone, and on the 12th week, remodeling of new lamellar bone and absorption of the composite material were observed. The mechanical strength of composite material and new born density in experimental group were significantly higher than in control group, indicating that low intensity ultrasound could not only effectively increase the formation of new bone, but also accelerate the calcification of new bone. It was concluded that low intensity ultrasound could evidently accelerate the healing of bone defects repaired by bone tissue engineering.

Objective To compare the clinical outcomes between open reduction and fixation with cannulated screws via the modified Burks-Schaffer approach versus arthroscopic EndoButton plating for avulsion fracture of the tibial attachment of the posterior cruciate ligament(PCL).Methods From February 2013 to August 2017,41 patients with acute displaced avulsion fracture of the tibial PCL attachment were treated operatively at Department of Trauma Surgery,The Affiliated Hospital to Qingdao University.They were 24 men and 17 women,aged from 18 to 65 years (average,39 years).The lefi knee was injured in 22cases and the right knee in 19.They were divided into 2 groups according to their different fixation methods.The open reduction and fixation group (23 cases) received open reduction and fixation with cannulated screws via the modified Burks-Schaffer approach while the arthroscopic group (18 cases) arthroscopic Endobutton plating.The 2 groups were compared in terms of operation time,bleeding,objective knee scores and knee range of motion (ROM) after operation.Results All the 41 patients were followed up from 23 to 40months (average,27.2 months).Their follow-up revealed no incision infection,malunion,nonunion or loosening of the implants.Their knee X-ray films at the final follow-ups showed bony union of all the avulsion fractures.There were significant differences between the open reduction and fixation group and the arthroscopic group in operation time (52.6±7.3 min versus 86.8±9.2 min) and bleeding (63.9±12.7 mL versus 19.7 ± 10.2 mL) (P ＜ 0.05).There was no significant difference in the objective knee scores or knee ROM between the 2 groups (P ＞ 0.05).Conclusions Both open reduction and cannulated screw fixation via the modified Burks-Schaffer approach and arthroscopic EndoButton plating can achieve satisfactory clinical outcomes in the treatment of avulsion fracture of the tibial PCL attachment.Although the 2 methods make no significant differences in stability of the knee joint or in clinical scores,the latter leads to less bleeding and the former shorter operation time.

Objective:To compare the therapeutic efficacy between femoral neck system (FNS) and cannulated compression screws (CCS) in the fixation of femoral neck fractures in the elderly patients aged 65 to 75 years old.Methods:A retrospective study was conducted to analyze the data of 39 patients aged 65 to 75 years old who had been treated for femoral neck fractures at Department of Trauma Surgery, Hospital Affiliated to Qingdao University from January 2015 to September 2022. The patients were divided into 2 groups according to their internal fixation methods. In the FNS group of 18 cases subjected to FNS fixation, there were 8 male and 10 females with an age of (71.1±2.8) years. In the CCS group of 21 cases subjected to CCS fixation, there were 7 males and 14 females with an age of (70.1±2.9) years. The 2 groups were compared in terms of intraoperative fluoroscopy frequency, surgical time, intraoperative bleeding, hospitalization costs, fracture healing time, internal fixation failure, and Harris hip score, changes in neck shaft angle, and femoral neck shortening at 1 year after surgery.Results:The differences were not statistically significant in the preoperative general data or follow-up time between the 2 groups, indicating comparability ( P>0.05). In the FNS group, the intraoperative fluoroscopy frequency [(15.1±2.3) times] was significantly lower than that in the CCS group [(19.5±3.5) times], the surgical time [(49.2±5.2) minutes] was significantly shorter than that in CCS group [(62.4±11.2) minutes], and the intraoperative bleeding [(74.2±15.6) mL] and hospitalization costs [(39,928.7±1,438.3) yuan] were significantly higher than those in the CCS group [(53.1±17.3) mL and (23,527.9±2,126.3) yuan] (all P<0.05). The difference in fracture healing time was not statistically significant between the 2 groups ( P>0.05). In the FNS group, the decreased neck shaft angle (2.65°±1.66°) and femoral neck shortening (3.9±1.3 mm) were significantly smaller than those in the CCS group [4.18°±2.13° and (6.3±2.5) mm] at 1 year after surgery, and the Harris hip score [(82.2±7.2) points] was significantly higher than that in the CCS group [(76.4±5.9) points] (all P<0.05). Internal fixation failure occurred in 1 case in the FNS group and in 4 cases in the CCS group, respectively, showing no statistically significant difference ( P>0.05). Conclusions:Compared with CCS fixation, FNS fixation may lead to better therapeutic efficacy in patients with femoral neck fracture aged 65 to 75 years old. However, the risk of internal fixation failure should also be taken into consideration.