Yanpeng Zhao

Comparison of lateral and posterior surgical approach in management of extra-articular distal humeral shaft fractures.

OBJECTIVE The objective of this study was to compare treatment results and complication rates between lateral and posterior approaches in surgical treatment of extra-articular distal humeral shaft fractures. MATERIAL AND METHODS Between June 2008 and May 2012, a total of 68 patients with extra-articular distal humeral shaft fractures were treated by lateral and posterior approaches. Of the patients, 30 were operated by a lateral approach (group I) and 26 patients were operated by a posterior approach (group II). There was no statistical significance between the two groups in sex distribution, age, the mechanism of the injury, injured arms, AO/ASIF (Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation) classification, and the time from injury to surgery (P>0.05). Operation time, intraoperative bleeding volume, hospitalisation, clinical outcomes, and complications were compared between the two groups. The elbow functional results were evaluated by the Mayo Elbow Performance Score (MEPS). RESULTS All patients were followed up. The average of follow-up in group I was 15.53±2.636 months (range, 12-22 months), and was 16.12±2.889 months (range, 12-22 months) in group II. There was no significant difference in the operation time, intraoperative bleeding time, and hospitalisation between the two groups (P>0.05). In group I, the mean time of bone union was 12.87±1.852 weeks (range, 10-16 weeks), the mean degrees of elbow flexion was 139.20°±3.274° (range, 134-146°), the mean degrees of elbow extension was 4.77°±1.906° (range, 0-8°), and the mean points of MEPS was 87.00±7.724 (range, 70-100 points). In group II, the mean time of bone union was 12.96±2.218 weeks (range, 10-16 weeks), the mean degrees of elbow flexion was 137.85°±4.076° (range, 130-145°), the mean degrees of elbow extension was 5.15°±2.327° (range, 0-9°), and the mean points of MEPS was 86.15±7.656 (range, 70-100 points). There was no significant difference in the bone union, range of elbow flexion, range of elbow extension and MEPS between the two groups (P>0.05). The overall complication rate in group I was lower than that in group II (P=0.041). CONCLUSIONS Both lateral and posterior surgical approaches acquired satisfied treatment results in the management of extra-articular distal humeral shaft fractures, and there was a lower complication rate using the lateral approach.

Intramedullary nailing versus plating for distal tibia fractures without articular involvement: a meta-analysis

BackgroundThe choice between intramedullary (IM) nailing or plating of distal tibia fractures without articular involvement remains controversial. A meta-analysis of randomized controlled trials (RCTs) and observational studies was performed to compare IM nailing with plating for distal tibia fractures without articular involvement and to determine the dominant strategy.Materials and methodsThe PubMed, Embase, Cochrane Library databases, Chinese Wan-Fang Database, and China National Knowledge Infrastructure were searched.ResultsTwenty-eight studies, which included 1863 fractures, met the eligible criteria. The meta-analysis did not identify a statistically significant difference between the two treatments in terms of the rate of deep infection, delayed union, removal of instrumentation, or secondary procedures either in the RCT or retrospective subgroups. IM nailing was associated with significantly more malunion events and a higher incidence of knee pain in the retrospective subgroup and across all the studies, but not significantly in the RCT subgroup, and a lower rate of delayed wound healing and superficial infection both in the RCT and retrospective subgroups relative to plating. A meta-analysis of the functional scores or questionnaires was not possible because of the considerable variation among the included studies, and no significant differences were observed.ConclusionsEvidence suggests that both IM nailing and plating are appropriate treatments as IM nailing shows lower rate of delayed wound healing and superficial infection and plating may avoid malunion and knee pain. These findings should be interpreted with caution, however, because of the heterogeneity of the study designs. Large, rigorous RCTs are required.

Naringenin inhibits spinal cord injury-induced activation of neutrophils through miR-223

Naringenin (NR), a flavonoid abundant in citrus fruits has been reported to possess anti-inflammatory properties. The present study aimed to investigate the protective of naringenin in rats after spinal cord injury (SCI) and the underlying mechanisms associated with neuroinflammation. Adult male Sprague-Dawley rats were subjected to laminectomy at T9-T11 and compression with a vascular clip. The spinal cords spanning the injury site about 0.8cm were collected for testing. There were five groups (n=7 in each group): (a) Control group; (b) sham group group; (c) SCI+saline; (d) SCI+NR (50mg/kg, p.o.) group and (e) SCI+NR (100mg/kg, p.o.) group. Different doses of NR (50mg/kg, p.o. and 100mg/kg, p.o.) or saline were administered once daily for 11 consecutive days, from 3days prior to surgery to 7days after surgery. The expression level of miR-223, NLRP3 and IL-1β were measured by RT- qPCR. The accumulation of neutrophils at the site of compression, as evaluated by measuring the tissue myeloperoxidase activity, significantly increased with time following the compression, peaking at 24h post compression. The expression of miR-223 was significant elevated in (b). However, spinal cord myeloperoxidase activity and the expression of miR-223 did not increase in sham-operated animals. NR significantly inhibited a SCI-induced activation of neutrophils through repressed miR-223 in group (d) and (e). There was a better effect in group (e) than group (d). miR-223 is thought to act as a fine-tuner of granulocyte production and the inflammatory response. Our findings suggested that repeated administration of naringenin (100mg/kg, p.o) may provide the protective effect of the spinal cord injury in rats, possibly through inhibiting neuroinflammation.

Computer aided pelvic reduction frame for anatomical closed reduction of unstable pelvic fractures

Traditional closed reductions of unstable pelvic fractures are mainly performed by surgeons using manual manipulation and subjective verification based on intra‐operative roentgenography. It is difficult to perform an accurate closed reduction because of a lack of adequate knowledge of the displacement patterns and an inability to apply the reduction in correct direction. Using the concept of the remote center of motion mechanism and computer‐aided design software, we developed a pelvic reduction frame for use in anatomical closed reductions of unstable pelvic fractures. With three‐dimensional reconstruction technique and the matrix algorithm, the spatial orientation of the displaced hemipelvis can be calculated and deconstructed into several rotational and translational movements that can be completed with the frame. To verify the accuracy of this system, the rotations were repeated 10 times in arbitrary degrees and directions. After the matrix is calculated, the displaced hemipelvis can be reduced to the anatomical position using our frame. The maximum residual translational and rotational displacements were less than 5 mm and 4 degrees, which indicated the accuracy of this system. The maximum average residual translation and rotation were 1.87 mm in Z‐axis (ranging: 4.63–0.1 mm) and 1.1 degrees around Y‐axis (ranging: 3.81–0.13 degrees), respectively. Only the Z‐axial translation showed a statistically significant difference (p < 0.05). In conclusion, the proposed pelvic reduction frame could be a useful tool for the anatomical reduction of unstable pelvic fractures.

The Effect of Polymorphisms in SPP1 on Risk of Fracture: A Case-Control Study

Background The purpose of the study was to investigate the correlation between rs4754 and rs6840362 polymorphisms of secreted phosphoprotein 1 (SPP1) gene and fracture risk. Material/Methods rs4754 and rs6840362 were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 130 patients with fracture and 107 healthy controls matched with the former by age and sex. Hardy-Weinberg equilibrium (HWE) was assessed in the control group based on the genotype distributions of SSP1 poylmorphisms. The differences in genotype, allele, and haplotype frequencies between cases and controls were detected by the chi-square test, and the relative risk of fracture is expressed by odds ratio (OR) and 95% confidence interval (CI). The linkage disequilibrium (LD) and haplotype analyses were conducted with HaploView software. Results The TT genotype in rs4754 had significant difference in patients with fracture and controls (10.77% and 4.59%, P=0.04) and the results showed that people carrying TT genotype of rs4754 were more susceptible to fractures than CC genotype carriers (OR=3.00, 95%CI=1.02–8.89). The T allele also had 1.54 times higher risk of fractures (OR=1.54, 95%CI=1.04–2.30), but this was not true for the rs6840362 polymorphism. LD between the 2 polymorphisms and haplotype C-T (rs6840362-rs4754) increased the susceptibility to fracture (OR=2.01, 95%CI=1.23–3.28). Conclusions SPP1 rs4754 polymorphism may be related to risk of fracture, but not rs6840362.

Early Experience with Reduction of Unstable Pelvic Fracture Using a Computer-Aided Reduction Frame

Purpose The optimal closed reduction technique for unstable pelvic fractures remains controversial. The purpose of this study is to verify the effectiveness and report early experiences with the reduction of unstable pelvic fractures using a computer-aided pelvic reduction frame. Methods From January 2015 to August 2016, a total of 10 patients with unilateral unstable pelvic fractures were included in this study. The surgical reduction procedure was based on the protocol of the computer-aided pelvic reduction frame that we proposed in a previous work. The quality of the reductions achieved using this system was evaluated with residual translational and rotational differences between the actual and virtual reduction positions of pelvis. The duration of the operation was recorded for quality control. Results The mean times required to set up the frame, to complete the virtual surgery simulation, and to reduce the unstable pelvic fractures were 10.3, 20.9, and 7.5 min, respectively. The maximum residual translational and rotational displacements were less than 6.5 mm and 3.71 degrees, respectively. Conclusions This computer-aided reduction frame can be a useful tool for the speedy and accurate reduction of unstable pelvic fractures. Further clinical studies should be conducted with larger patient samples to verify its safety and efficacy.

A new hand-eye calibration approach for fracture reduction robot

Abstract Objective: The hand-eye calibration is used to determine the transformation between the end-effector and the camera marker of the robot. But the robot movement in traditional method would be time-consuming, inaccurate and even unavailable in some conditions. The method presented in this article can complete the calibration without any movement and is more suitable in clinical applications. Methods: Instead of solving the classic non-linear equation AX = XB, we collected the points on X and Y axes of the tool coordinate system (TCS) with the visual probe and fitted them using the singular value decomposition algorithm (SVD). Then, the transformation was obtained with the data of the tool center point (TCP). A comparison test was conducted to verify the performance of the method. Results: The average translation error and orientation error of the new method are 0.12 ± 0.122 mm and 0.18 ± 0.112° respectively, while they are 0.357 ± 0.347 mm and 0.416 ± 0.234° correspondingly in the traditional method. Conclusions: The high accuracy of the method indicates that it is a good candidate for medical robots, which usually need to work in a sterile environment.

PHYSICAL SYMMETRY AND VIRTUAL PLANE-BASED REDUCTION REFERENCE: A PRELIMINARY STUDY FOR ROBOT-ASSISTED PELVIC FRACTURE REDUCTION

Traditional pelvis fracture reduction suffers from some disadvantages. Robot-assisted pelvis fracture reduction offers some promise in solving these problems. However, the reduction reference to guide robot motion is a key issue that must be resolved. In this paper, we propose a physical symmetry and virtual plane-based reduction reference and adopt the method of registration to calculate the virtual plane for the reference, which were verified via experiments. The results of the position symmetry experiments of the original pelvis and virtual plane-based position symmetry experiments were similar; both showed that the symmetry errors of the pelvis were less than 4mm and 2.5∘. The results indicated that the proposed method could be used as a reference for robot-assisted pelvis fracture reduction.

Robot-musculoskeletal dynamic biomechanical model in robot-assisted diaphyseal fracture reduction.

A number of issues that exist in common fracture reduction surgeries can be mitigated by robot-assisted fracture reduction. However, the safety of patients and the performance of the robot, which are closely related to the muscle forces, are important indexes that restrict the development of robots. Though researchers have done a great deal of work on the biomechanics of the musculoskeletal system, the dynamics of the musculoskeletal system, particularly the aspects related to the function of the robot, is not well understood. For this reason, we represent the complex biological system by establishing a dynamic biomechanical model based on the Hill muscle model and the Kane method for the robot that we have developed and the musculoskeletal system. We analyzed the relationship between the motion and force of the bone fragments and the robot during a simulation of a robot-assisted fracture reduction. The influence of the muscle force on the robot system was predicted and managed. The simulation results provide a basis for a fracture reduction path plan that ensures patient safety and a useful reference for the mechanical design of the robot.