Zhirui Li

A Systematic Review and Meta-Analysis of Ilizarov Methods in the Treatment of Infected Nonunion of Tibia and Femur.

Background Infected nonunion of tibia and femur are common in clinical practice, however, the treatment of these diseases has still been a challenge for orthopaedic surgeons. Ilizarov methods can eradicate infection, compensate bone defects and promote the bone union through progressive bone histogenesis. The objective of this systematic review was to review current available studies reporting on Ilizarov methods in the treatment of infected nonunion of tibia and femur, and to perform meta-analysis of bone and functional results and complications to evaluate the efficacy of Ilizarov methods. Methods A comprehensive literature search was performed from the SCI, PubMed, Cochrane Library; and Embase between January 1995 and August 2015. Some major data were statistically analyzed using weighted means based on the sample size in each study by SPSS 13.0, including number of patients, mean age, mean previous surgical procedures, mean bone defects, mean length of follow-up, bone union, complications per patient, external fixation time, and external fixation index(EFI). Bone results (excellent, good, fair and poor rate), functional results (excellent, good, fair and poor rate) and complications were analyzed by Stata 9.0. Findings A total of 590 patients from 24 studies were included in this systematic review. The average of bone union rate was 97.26% in all included studies. The poor rate in bone results and functional results was 8% (95%CI, 0.04–0.12; I2 = 44.1%, P = 0.065) and 10% (95%CI, 0.05–0.14; I2 = 34.7%, P = 0.121) in patients with infected nonunion of tibia and femur treated by Ilizarov methods. The rate of refracture, malunion, infectious recurrence, knee stiffness, amputation, limb edema and peroneal nerve palsy was respectively 4%, 7%, 5%, 12%, 4%, 13% and 13%. Conclusions Our systematic review showed that the patients with infected nonunion of tibia and femur treated by Ilizarov methods had a low rate of poor bone and functional results. Therefore, Ilizarov methods may be a good choice for the treatment of infected nonunion of tibia and femur.

Early application of negative pressure wound therapy to acute wounds contaminated with Staphylococcus aureus: An effective approach to preventing biofilm formation

Negative pressure wound therapy (NPWT) has been demonstrated to be effective at preventing biofilm-associated infections; however, its role in biofilm prevention is unknown. The present study evaluated the effect of NPWT on biofilm prevention when rapidly initiated following wound contamination. Full-thickness dermal wounds (8 mm) were created in rabbit ears and inoculated with green fluorescent protein-labeled Staphylococcus aureus (S. aureus). At 6 h following inoculation, continuous NPWT at −125 mmHg was initiated, with the wounds on the contralateral ear left untreated in order to serve as self-controls. S. aureus rapidly formed mature biofilms in the wound beds post-inoculation, with a persistent bacterial burden of ~105−107 colony-forming units (CFUs)/wound and impaired wound healing. Compared with the untreated group, NPWT resulted in a significant reduction in biofilm matrix, which was verified by scanning electron microscopy and epifluorescence. A reduction in bacterial counts followed (P<0.05) with ~103 CFUs/wound on postoperative day 13 and improvement in all healing parameters (P<0.05) relative to control wounds. The results of the present investigation suggest that NPWT is an effective strategy to impeding the formation of S. aureus wound biofilms when initiated rapidly following bacterial contamination. The early application of NPWT, aimed at biofilm prevention, may improve wound care.

The Effect of Teriparatide on Fracture Healing of Osteoporotic Patients: A Meta-Analysis of Randomized Controlled Trials

Purpose. This meta-analysis is to assess the effectiveness of teriparatide in fracture healing and clinical function improvement of the osteoporotic patients. Methods. We searched PubMed, Embase, Web of Science, and the Cochrane databases for randomized and quasi-randomized controlled trials comparing teriparatide to placebo, no treatment, or comparator interventions in the osteoporotic patients. Results. Five studies with 251 patients were included. Patients treated with teriparatide therapy had a significant shorter radiological fracture healing time compared with those in the control group (mean difference [MD] −4.54 days, 95% confidence interval [CI] −8.80 to −0.28). Stratified analysis showed that lower limb group had significant shorter healing time (MD −6.24 days, 95% CI −7.20 to −5.29), but upper limb group did not (MD −1 days, 95% CI −2.02 to 0.2). Patients treated with teriparatide therapy showed better functional outcome than those in the control group (standardized mean difference [SMD] −1.02, 95% CI −1.81 to −0.22). Patients with therapy duration over 4 weeks would have better functional outcome (SMD −1.68, 95% CI −2.07 to −1.29). Conclusions. Teriparatide is effective in accelerating fracture healing and improving functional outcome of osteoporotic women. However, more clinical studies are warranted in order to determine whether the results are applicable to males and the clinical indications for teriparatide after osteoporotic fractures.

Effect of Negative Pressure on Proliferation, Virulence Factor Secretion, Biofilm Formation, and Virulence-Regulated Gene Expression of Pseudomonas aeruginosa In Vitro

Objective. To investigate the effect of negative pressure conditions induced by NPWT on P. aeruginosa. Methods. P. aeruginosa was cultured in a Luria–Bertani medium at negative pressure of −125 mmHg for 24 h in the experimental group and at atmospheric pressure in the control group. The diameters of the colonies of P. aeruginosa were measured after 24 h. ELISA kit, orcinol method, and elastin-Congo red assay were used to quantify the virulence factors. Biofilm formation was observed by staining with Alexa Fluor® 647 conjugate of concanavalin A (Con A). Virulence-regulated genes were determined by quantitative RT-PCR. Results. As compared with the control group, growth of P. aeruginosa was inhibited by negative pressure. The colony size under negative pressure was significantly smaller in the experimental group than that in the controls (p < 0.01). Besides, reductions in the total amount of virulence factors were observed in the negative pressure group, including exotoxin A, rhamnolipid, and elastase. RT-PCR results revealed a significant inhibition in the expression level of virulence-regulated genes. Conclusion. Negative pressure could significantly inhibit the growth of P. aeruginosa. It led to a decrease in the virulence factor secretion, biofilm formation, and a reduction in the expression level of virulence-regulated genes.

Combination therapy of anabolic agents and bisphosphonates on bone mineral density in patients with osteoporosis: a meta-analysis of randomised controlled trials

Objective We aimed to determine whether the concomitant combination therapy of anabolic agents and bisphosphonates produces more effects on bone mineral density (BMD) than anabolic agents alone in patients with osteoporosis. Methods We searched MEDLINE, EMBASE and the Cochrane Library for publications from 1 January 1980 to 1 August 2016 to identify all the randomised controlled trials (RCTs) and quasi-RCTs. The primary outcome was the mean per cent changes in BMD at the lumbar spine, the total hip and the femoral neck with an optimal period of treatment (6 to 12 months). The secondary outcome was the mean per cent changes in BMD at the same sites with the full period of recommendation (18 to 24 months). A random-effects model was used to estimate the standardised mean differences (SMDs) and the 95% CIs. Results Seven studies, with 747 patients, were included. With the optimal period, the concomitant combination therapy demonstrated a significant advantage over a monotherapy in BMD improvement at the total hip (SMD 0.42; 95% CI 0.26 to 0.58) and the femoral neck (SMD 0.30; 95% CI 0.14 to 0.46), but not for the spine BMD (SMD 0.13; 95% CI −0.17 to 0.43). With the full period, the concomitant combination therapy did not improve the BMD at the lumbar spine (SMD −0.06; 95% CI −0.71 to 0.59), the total hip (SMD 0.05; 95% CI −0.71 to 0.82) and the femoral neck (SMD −0.32; 95% CI −1.15 to 0.50). Conclusions Compared with anabolic monotherapy, the concomitant combination therapy of anabolic agents and bisphosphonates significantly improved the BMD at the total hip and femoral neck with a shorter term (6 to 12 months) and produced similar benefits on BMD for the longer term (18 to 24 months). Also, the effect of concomitant combination therapy might be affected by the dose of anabolic agents. PROSPERO registration number CRD42016041335.

Establishment of a rat model of chronic thoracolumbar cord compression with a flat plastic screw

Previous studies of animal models of chronic mechanical compression of the spinal cord have mainly focused on cervical and thoracic lesions, but few studies have investigated thoracolumbar injury. The specific pathophysiological mechanism of chronic thoracolumbar cord injury has not yet been elucidated. The purpose of this study was to improve animal models of chronic thoracolumbar cord compression using the progressive screw. A custom-designed flat plastic screw was implanted in the spinal cord between thoracic vertebrae 12 and lumbar 1 of rats. The screw was tightened one complete turn (0.5 mm) every 7 days for 4 weeks to create different levels of chronic spinal cord compression. Following insertion of the screw, there was a significant decline in motor function of the hind limbs, and severe stenosis of micro-computed tomography parameters in the spinal cord. Cortical somatosensory evoked potential amplitudes were reduced remarkably, and latencies were prolonged at 30 minutes after surgery. The loss of motor neurons in the gray matter was marked. Demyelination and cavitation were observed in the white matter. An appropriate rat model of chronic thoracolumbar cord compression was successfully created using the progressive screw compression method, which simulated spinal cord compression injury.

Ipsilateral fibula transport for the treatment of massive tibial bone defects

OBJECTIVE The objective of the study was to evaluate the effectiveness of the treatment of massive tibial bone defects by ipsilateral fibula transport. MATERIALS AND METHODS Nine patients with massive tibial bone defects were retrospectively reviewed. There were 7 males and 2 females with an average age of 32.22 years. The mean length of bone defect was 15.67cm (range 13-25cm). RESULTS All patients were followed up and the mean time of follow up was 40.11 months (range 26-60 months). All the patients achieved bone union and the average external fixation time was 11.67 months (range 9-14 months). The mean degrees of knee extension were 2.2°(range 0-5°) and the mean degrees of knee flexion were 131.7° (range 120-140°). The mean degrees of ankle dorsiflexion were 8.9° (range 0-15°) and the mean degrees of ankle plantar flexion were 30° (range 20-40°). CONCLUSION Our study suggested that ipsilateral fibula transport in the treatment of massive tibial bone defects acquired satisfying functional results. It may be a better choice for the patients without suitable proximal or distal tibia remnant to transport.

Ilizarov bone transport for the treatment of fibular osteomyelitis: a report of five cases

BackgroundThe objective of this study was to evaluate the effectiveness of the treatment of fibular osteomyelitis by Ilizarov bone transport.MethodsWe retrospectively reviewed 5 patients with fibular osteomyelitis treated by Ilizarov bone transport. Our study included 4 males and 1 female with a mean of age 29.2 years. The average length of the bone defects after radical debridement was 7.6 cm (range 6.5-10 cm).ResultsThe mean follow-up was 24.8 months (range 14–34 months). No patient was lost to follow-up. All the patients had bone union and no recurrence of infection was observed. The mean external fixation time was 8.8 months (range 8-10 months), and the mean external fixation index was 1.18 months/cm (range 0.90-1.43 months/cm). There was no sign of knee or ankle instability by clinical examination in all the patients. According to Association for the Study and Application of the Method of Ilizarov (ASAMI) classification, bone results were excellent in 3 patients, good in 2 patients; functional results were excellent in 3 patients, good in 2 patients.ConclusionsOur study suggested that Ilizarov bone transport may be a good choice for the treatment of fibular osteomyelitis, especially for the patient with distal fibular loss.

Negative-Pressure Wound Therapy in a Pseudomonas aeruginosa Infection Model

Background Negative-pressure wound therapy (NPWT) is an effective strategy for the management of contaminated wounds, including those infected by Pseudomonas aeruginosa. We hypothesized that NPWT would reduce virulence factors as well as biofilm components and inhibit virulence-regulated gene expression in a model of P. aeruginosa wound infection. Methods Wounds were created in anesthetized rabbits and P. aeruginosa was inoculated to the wound surface for 24 h. Wounds were treated with either NPWT or a sterile gauze dressing. Virulence factors including exotoxin A, rhamnolipid, and elastase were quantified by the enzyme-linked immunosorbent assay, orcinol, and elastin-Congo red methods, respectively. A biofilm component, eDNA, was quantified using a commercial kit. Virulence-regulated genes were determined by quantitative real-time polymerase chain reaction (RT-PCR). Biofilms were observed in vivo by staining with concanavalin A conjugated to Alexa Fluor® 647. Results NPWT was more effective than the control treatment in reducing virulence factors and bacteria counts in vivo. A biofilm component, eDNA, was less abundant in the NPWT group. The results of the RT-PCR indicated that the expression levels of P. aeruginosa virulence-regulated genes and quorum-sensing population density-dependent systems were significantly inhibited by NPWT treatment. Conclusion NPWT reduced bacteria counts, virulence factors, and eDNA in a P. aeruginosa wound infection model in vivo. These beneficial effects are likely to be related to the reduced expression of virulence-regulated genes and the drainage induced by NPWT treatment. These findings may help clinicians to obtain a better understanding of the mechanism of NPWT for the treatment of infected wounds.

The effects of low-intensity pulsed ultrasound on fresh fracture: A meta-analysis

Background: Low-intensity pulsed ultrasonography (LIPUS) is a form of mechanical stimulation that is delivered via a special device to the fracture site for the acceleration of fracture healing. We conducted a meta-analysis to assess the effect of LIPUS for fresh fractures in adults. Methods: MEDLINE, EMBASE and the Cochrane Library searched between Jan 1980 and Nov 2016. Studies should be quasi-randomized and randomized controlled trials (RCTs) comparing treatment with LIPUS to placebo or no treatment in adults with fresh fractures, reporting outcomes such as function; time to union; delayed union or non-union. Summary standard mean difference (SMD) and the risk ratio (RR) with their 95% confidence interval (CI) calculated with a random effects model. I2 statistic was used to assess the heterogeneity. Risk of bias was assessed by the Cochrane risk-of-bias tool. The GRADE system was used to evaluate the evidence quality. Results: A total of 12 trials with 1099 patients were included. The pooled results showed that LIPUS significantly reduced the time to fracture union (SMD: 0.65, 95% CI: 1.13 to 0.17), improved the quality of life (SMD: 0.20, 95% CI: 0.03–0.37) without affecting the time to full weight bearing (SMD: 0.76, 95% CI: 1.92 to 0.4), the time to return to work (SMD: 0.06, 95% CI: 0.14 to 0.27), or the incidence rate of delayed union and nonunion (RR: 1.02, 95% CI: 0.60–1.74). Conclusions: Moderate-to-high quality evidence shows that LIPUS treatment reduces the time to fracture union and improves the quality of life without affecting functional recovery and incident rate of delayed union and nonunion, suggesting that LIPUS treatment may be a good treatment modality for adults with fresh fractures. However, there are some methodological limitations in the eligible trials, further studies are needed to determine the clinical circumstances under which LIPUS is truly valid and to examine the optimal approach for the use of this adjunctive therapy.