Yi-xin Chen

Early application of pulsed electromagnetic field in the treatment of postoperative delayed union of long-bone fractures: a prospective randomized controlled study

BackgroundPulsed electromagnetic field (PEMF) is reported to be an effective adjunct for the management of nonunion long-bone fractures. Most studies implement PEMF treatment after 6 months or longer of delayed union or nonunion following fracture treatment. Despite these variations in treatment, the early application of PEMF following a diagnosis of a postoperative delayed union has not been specifically analyzed. In this study, the outcomes of postoperative delayed union of long-bone fractures treated with an early application of PEMF were evaluated as compared with a sham-treated control group.MethodsIn this prospective, randomized controlled study, a total of 58 long-bone fracture patients, who presented with delayed union of between 16 weeks and 6 months, were randomly split into two groups and subjected to an early application of PEMF or sham treatment. Clinical and radiological assessments were performed to evaluate the healing status. Treatment efficacy was assessed at three month intervals.ResultsPatients in the PEMF group showed a higher rate of union than those in the control group after the first three months of treatment, but this difference failed to achieve statistical significance. At the end of the study, PEMF treatment conducted for an average of 4.8 months led to a success rate of 77.4%. This was significantly higher than the control, which had an average duration of 4.4 months and a success rate of 48.1%. The total time from operation to the end of the study was a mean of 9.6 months for patients in the PEMF group.ConclusionsFracture patients treated with an early application of PEMF achieved a significantly increased rate of union and an overall reduced suffering time compared with patients that receive PEMF after the 6 months or more of delayed union, as described by others.

Increased expression of insulin-like growth factor-1 receptor is correlated with tumor metastasis and prognosis in patients with osteosarcoma.

The aim of this study was to investigate the association of insulin‐like growth factor‐1 receptor (IGF‐1R) with metastasis and prognosis of osteosarcoma patients.

Lentivirus-mediated shRNA targeting insulin-like growth factor-1 receptor (IGF-1R) enhances chemosensitivity of osteosarcoma cells in vitro and in vivo

The overexpression of the type 1 insulin-like growth factor receptor (IGF-1R) has been reported to be associated with malignant transformation, tumor development and chemo- or radioresistance of tumor cells. Previously, we have reported that inhibition of IGF-1R could reverse the radioresistance of human osteosarcoma cells. However, whether inhibition of IGF-1R could enhance chemosensitivity of ostesosarcoma cells is unclear. In this study, lentivirus-mediated shRNA was employed to downregulate endogenous IGF-1R expression to study the function of IGF-1R in chemoresistance of osteosarcoma cells. Results showed that lentivirus-mediated shRNA targeting IGF-1R combined with chemotherapy (CDDP or DTX) could lead to growth suppression of osteosarcoma cells not only in vitro but also in vivo. Moreover, inhibition of IGF-1R gene combined with chemotherapy also synergistically enhanced Caspase-3-mediated apoptosis of osteosarcoma cells. The synergistical enhancement of apoptosis might be associated with downregulation of Bcl-2 and upregulation of Bax in osteosarcoma cells induced by IGF-1R inhibition. Therefore, the overexpression of IGF-1R gene might play important roles in chemoresistance of osteosarcoma cells, and lentivirus-mediated RNAi targeting IGF-1R would be an attractive anti-cancer strategy to chemosensitization of osteosarcoma cell.

Will the untreated ulnar styloid fracture influence the outcome of unstable distal radial fracture treated with external fixation when the distal radioulnar joint is stable

BackgroundThe ulnar styloid is an important supportive structure for the triangular fibrocartilage complex. However, it remains inconclusive whether or not a fractured ulnar styloid should be fixed in an unstable distal radius fracture (DRF) with a stable distal radioulnar joint (DRUJ). The purpose of this study is to evaluate the effect of an untreated ulnar styloid fracture on the outcome of unstable DRF treated with transarticular external fixation when the DRUJ is stable.Methods106 patients with an unstable DRF and a stable DRUJ were included in this study following external fixation. The patients were divided into the non-fracture, the tip-fracture and the base-fracture groups according to the location of the ulnar styloid fracture at the time of injury. Postoperative evaluation included the range of wrist motion, the radiological index, the grip strength, the PRWE-HK scores, the wrist pain scores, and the instability of DRUJ at the external fixator removal time, three months postoperatively and the final follow-up visit.ResultsThe patients were followed for 12 to 24 months (15 months in average). Sixty-two of 106 patients (58%) had ulnar styloid fracture and 16 patients (26%) showed radiographic evidence of union of ulnar styloid fractures at the final follow-up visit. No significant difference in the radiological findings, the range of wrist motion, the grip strength, the PRWE-HK scores, and the wrist pain scores among three patient groups was detected at the external fixator removal time, three months postoperatively, or the final follow-up visit. Six of the 106 patients (5.7%) complained of persistent ulnar-side wrist pain during daily activities. One patient (0.9%) showed a positive sign in a stress-test, three patients (2.8%) showed a positive sign in a provocative-test, and five patients (4.7%) showed a positive sign in a press-test. There was no significant difference in the percentages of patients who complained of persistent ulnar-side wrist pain or showed a positive sign in the physical examination of the distal radioulnar joint among the three groups at the final follow-up time points.ConclusionWhen the DRUJ is stable, an untreated ulnar styloid fracture does not affect the wrist outcome of the patient with an unstable DRF treated with external fixation.

Haploinsufficiency of endogenous parathyroid hormone-related peptide impairs bone fracture healing

Previous studies have demonstrated that endogenous parathyroid hormone‐related peptide (PTHrP) plays a central role in the physiological regulation of bone formation. However, it is unclear whether endogenous PTHrP plays an important function in enhancing bone fracture healing. To determine whether endogenous PTHrP haploinsufficiency impaired bone fracture healing, closed mid‐diaphyseal femur fractures were created in 8‐week‐old wild‐type and Pthrp+/− mice. Callus tissue properties were analysed 1, 2 and 4 weeks after fracture by radiography, histology, histochemistry, immunohistochemistry and molecular biology. The size of the calluses was reduced 2 weeks after fracture, and the fracture repairs were poor 4 weeks after fractures, in Pthrp+/− compared with wild‐type mice. Cartilaginous callus areas were reduced 1 week after fracture, but were increased 2 weeks after fracture in Pthrp+/− mice. There was a reduction in the number of ostoblasts, alkaline phosphatase (ALP)‐positive areas, Type I collagen immunopositive areas, mRNA levels of ALP, Runt‐related transcription factor 2 (Runx2) and Type I collagen, Runx2 and insulin‐like growth factor‐1 protein levels, the number of osteoclasts and the surface in callus tissues in Pthrp+/− compared with wild‐type mice. These results demonstrate that endogenous PTHrP haploinsufficiency impairs the fracture repair process by reducing cartilaginous and bony callus formation, with downregulation of osteoblastic gene and protein expression and a reduction in endochondral bone formation, osteoblastic bone formation and osteoclastic bone resorption. Together, the results indicate that endogenous PTHrP plays an important role in fracture healing.

Distal Femoral Fractures in Post-poliomyelitis Patients Treated with Locking Compression Plates

Treatment of distal femoral fracture in post‐polio patients is difficult because the bone is usually osteopenic, small and deformed. This retrospective study aimed to investigate the outcomes of distal femoral fracture in post‐polio patients treated by locking compression plates (LCP).

Mechanical property and biological performance of electrospun silk fibroin-polycaprolactone scaffolds with aligned fibers.

Abstract The mechanical strength, biocompatibility, and sterilizability of silk fibroin allow it to be a possible candidate as a natural bone regenerate material. To improve mechanical character and reinforce the cell movement induction, silk fibroin (SF)–polycaprolactone (PCL) alloy was fabricated by electrospinning techniques with a rotating collector to form aligned fibrous scaffolds and random-oriented scaffolds. The scanning electron microscope image of the scaffold and the mechanical properties of the scaffold were investigated by tensile mechanical tests, which were compared to random-oriented scaffolds. Furthermore, mesenchymal stem cells were planted on these scaffolds to investigate the biocompatibility, elongation, and cell movement in situ. Scanning electron microscopy shows that 91% fibers on the aligned fibroin scaffold were distributed between the dominant direction ±10°. With an ideal support for stem cell proliferation in vitro, the aligned fibrous scaffold induces cell elongation at a length of 236.46 ± 82 μm and distribution along the dominant fiber direction with a cell alignment angle at 6.57° ± 4.45°. Compared with random-oriented scaffolds made by artificial materials, aligned SF-PCL scaffolds could provide a moderate mesenchymal stem cell engraftment interface and speed up early stage cell movement toward the bone defect.

Effect of Chemical Thromboprophylaxis on the Rate of Venous Thromboembolism After Treatment of Foot and Ankle Fractures

Background: Venous thromboembolism (VTE) is a well-documented complication in patients with lower limb fractures, but management guidelines for its prevention in isolated foot and ankle fracture patients are conflicting. The aim of this study was to conduct a multicenter, prospective cohort study to define the prevalence of VTE in patients with isolated foot and ankle fractures and determine whether routine prophylaxis is necessary in these patients. Methods: In a double-blind, placebo-controlled study, consecutive patients in 3 hospitals who met our criteria were enrolled. After randomization, patients received either thromboprophylaxis with low-molecular-weight heparin units (LMWH group) or placebo (placebo group) for a period of 2 weeks. All patients underwent routine ultrasonography 1 day preoperatively, 1 week postoperatively, and 1 month postoperatively. Demographic parameters were then collected and compared. Results: Of the 814 patients who met our criteria, 19 patients (2.3%, 95% confidence interval [CI], 0%-31.9%) were found to have objectively confirmed VTE, but none of the patients were symptomatic. Of the 411 patients in the LMWH group, 2 developed VTEs preoperatively and 4 postoperatively; of the 403 patients in the placebo group, 5 developed VTEs preoperatively and 8 postoperatively. The overall incidence of asymptomatic postoperative deep vein thrombosis (DVT) was 0.98% (95% CI 0%-20.3%) in the LMWH group and 2.01% (95% CI 0%-29.5%) in the placebo group without significant difference. Advanced age (odds ratio [OR] 1.050, 95% CI 1.014-1.088, P = .007) and high body mass index (OR 1.201, 95% CI 1.034-1.395, P = .016) were identified as risk factors in predicting occurrence of DVT. No fatal pulmonary emboli or major bleeding complication occurred in either group. Conclusion: Routine anticoagulant prophylaxis was not found to be necessary for patients with foot and ankle fractures, although further investigation with a properly powered study design is required to definitively determine which foot and ankle patients are best served by anticoagulation and which ones are not. Level of Evidence: Level II, prospective comparative study.

Anatomical Study of the Clavicles in a Chinese Population

Background. A reemergence of interest in clavicle anatomy was prompted because of the advocacy for operative treatment of midshaft clavicle fractures. Several anatomical studies of the clavicle have been performed in western population. However, there was no anatomical study of clavicle in Chinese population. Patients and Methods. 52 patients were included in the present study. Three-dimensional reconstructions of the clavicles were generated. The length of the clavicle, the widths and thicknesses of the clavicle, curvatures of the clavicle, the areas of the intramedullary canal, and sectional areas of the clavicle were measured. All the measurements were compared between genders and two sides. Results. The mean length of the clavicles was 144.2 ± 12.0 mm. Clavicles in males were longer, wider, and thicker than in females; also males have different curvatures in both planes compared with females. The mens intramedullary canals and sectional areas of the clavicle were larger than those of women. No significant difference between the sides was found for all the measurements. Conclusion. This study provided an anatomical data of the clavicle in a Chinese population. These clavicle dimensions can be applied to the modifications of the contemporary clavicle plate or a new development for the Chinese population.