Dynamics of Benthic Nitrate Reduction Pathways and Associated Microbial Communities Responding to the Development of Seasonal Deoxygenation in a Coastal Mariculture Zone.

Intensive mariculture activities result in eutrophication and enhance coastal deoxygenation. Deoxygenation profoundly influences nitrate reduction processes and further the fate of nitrogen (N) in coastal systems. Herein, 15N isotope labeling, real-time PCR, and high-throughput sequencing techniques were jointly used to investigate the participation and seasonal dynamics of sediment nitrate reduction pathways and the succession of functional microbial communities during the development of seasonal deoxygenation in a coastal aquaculture zone. Denitrification dominated benthic nitrate reduction (46.26-80.91%). Both denitrification and dissimilatory nitrate reduction to ammonium were significantly enhanced by summer deoxygenation (dissolved oxygen levels fell to 2.94 ± 0.28 mg L-1), while anammox remained unchanged. The abundance of the nitrous oxide reductase gene nosZ increased during deoxygenation. The community of the nosZ gene was sensitive to deoxygenation, with Azospirillum and Ruegeria accounting for the majority. Pelobacter was overwhelming in the nrfA gene (encoding dissimilatory nitrite reductase) community, which was less affected by deoxygenation. The variations of benthic nitrate reduction processes were driven by bottom water oxygen combined with temperature, chlorophyll a, and microbial gene abundances and community compositions. Our results implicated that seasonal oxygen-deficient zones could be substantial N sinks of coastal ecosystems and important for N balance. Effective management measures need to be developed to avoid further exacerbation of coastal deoxygenation and maintain the sustainable development of mariculture.

Comparison of clinical effects between microscopic surgery and conventional surgery in children with penile hypospadias and difference analysis of postoperative urodynamics.

Objective: To compare and analyze the clinical effects of microscopic surgery and conventional surgery in children with penile hypospadias and the differences in postoperative urodynamic indexes. Methods: It was a clinical comparative study. A total of 80 children with penile hypospadias admitted to Beijing Children's Hospital Affiliated to Capital Medical University Baoding Hospital from July 2018 to September 2022 were selected and randomly divided into two group. The experimental group were treated with microscopic urethroplasty, while the control group were treated with traditional urethroplasty. The operative effect, operation time, total intraoperative blood loss, postoperative hospital stay and incidence of surgical complications were compared and analyzed between the two groups. All the children were followed up for two years, and the changes in urodynamic parameters including maximum urine flow rate (Qmax), average urine flow rate (Qavc), urine flow time (FT), peak time (TQmax) and residual urine (PVR) were compared before, two weeks after, six months after and two years after surgery. Results: The efficacy of the experimental group was significantly higher than that of the control group (p=0.013). The intraoperative blood loss and postoperative hospital stay in the experimental group were significantly better than those in the control group (p=0.000). The incidences of urinary leakage and urethral stricture in the experimental group were lower than those in the control group (p<0.05). The Qmax level in the experimental group was higher than that in the control group at six months and two years after surgery, while the FT level was lower than that of the control group (p<0.05). Conclusion: Microscopic surgery is a method with significant clinical value in the treatment of penile hypospadias.

Krüppel-like Transcription Factor 7 Is a Causal Gene in Autism Development.

BACKGROUND: Autism spectrum disorder (ASD) is a complex neurodevelopmental disease. To date, more than 1000 genes have been shown to be associated with ASD, and only a few of these genes account for more than 1% of autism cases. Klf7 is an important transcription factor of cell proliferation and differentiation in the nervous system, but whether klf7 is involved in autism is unclear. METHODS: We first performed ChIP-seq analysis of klf7 in N2A cells, then performed behavioral tests and RNA-seq in klf7+/- mice, and finally restored mice with adeno-associated virus (AAV)-mediated overexpression of klf7 in klf7+/- mice. RESULTS: Klf7 targeted genes are enriched with ASD genes, and 631 ASD risk genes are also differentially expressed in klf7+/- mice which exhibited the core symptoms of ASD. When klf7 levels were increased in the central nervous system (CNS) in klf7+/- adult mice, deficits in social interaction, repetitive behavior and majority of dysregulated ASD genes were rescued in the adults, suggesting transcriptional regulation. Moreover, knockdown of klf7 in human brain organoids caused dysregulation of 517 ASD risk genes, 344 of which were shared with klf7+/- mice, including some high-confidence ASD genes. CONCLUSIONS: Our findings highlight a klf7 regulation of ASD genes and provide new insights into the pathogenesis of ASD and promising targets for further research on mechanisms and treatments.

Dependence of tropical cyclone seeds and climate sensitivity on tropical cloud response.

Projections of future tropical cyclone frequency are uncertain, ranging from a slight increase to a considerable decrease according to climate models. Estimation of how much the Earth's surface temperature warms in response to greenhouse gas increase, quantified by effective climate sensitivity, is also uncertain. These two uncertainties have historically been studied independently as they concern different scales: One quantifies the extreme weather and the other the mean climate. Here, we show that these two uncertainties are not independent and are both influenced by the response of tropical clouds to warming. Across climate models, we show an anticorrelation between shortwave cloud radiative feedback and changes in the frequency of seed vortices, a prevalent type of tropical cyclone precursors. We further show an anticorrelation between effective climate sensitivity and tropical cyclone frequency changes, suggesting that global tropical cyclone frequency tends to decrease more substantially in models with larger temperature increase.

Circadian Rhythm-Dependent Therapy by Composite Targeted Polyphenol Nanoparticles for Myocardial Ischemia-Reperfusion Injury.

Myocardial ischemia-reperfusion (IR) injury is a severe rhythmic disease with a high prevalence in the early morning. IR injury has a significant circadian rhythm in reactive oxygen species (ROS) and inflammation levels. The development of rhythmic drugs has become a priority in myocardial IR injury. In this study, resveratrol (RES) and proanthocyanidins (OPC) were utilized to design nanoparticles (NPs), with hyaluronic acid (HA) as the core, grafted with MMP-targeting peptides to improve delivery to injured myocardial regions (HA-RES-OPC-MMP NPs). NPs significantly scavenged ROS, attenuated inflammation, and activated the rhythm gene. Notably, the difference in therapeutic effects on myocardial IR injury in mice at Zeitgeber time (ZT)1 and ZT13 confirms that NPs are rhythm-dependent drugs. At ZT13, echocardiographic and MRI confirm that IR injury in mice was not as severe as at ZT1, yet NPs were also less effective in treatment. Further, Per1/2 knockout mice confirmed the rhythm-dependent treatment of myocardial IR injury by NPs. Molecular studies have shown that rhythmic characteristics of inflammation and Sirt1 transcript levels are the main reasons for the different rhythmic therapeutic effects of NPs. Circadian rhythm-dependent treatment of HA-RES-OPC-MMP NPs has excellent potential for more precise treatment of myocardial IR injury in the future.

Correction: A novel nano delivery system targeting different stages of osteoclasts.

Correction for 'A novel nano delivery system targeting different stages of osteoclasts' by Bosong Zhang et al., Biomater. Sci., 2022, 10, 1821-1830, https://doi.org/10.1039/D2BM00076H.

Effect of Preventive Nursing on Male Children with Hypospadias in Preventing Postoperative Complications.

OBJECTIVE: To determine the clinical impact of preventive nursing on children with hypospadias and the intervention effect on postoperative complications. STUDY DESIGN: Comparative study. Place and Duration of the Study: Department of Urology Surgery, Beijing Children's Hospital Affiliated to Capital Medical University Baoding Hospital, Hebei, China, from August 2019 to July 2021. METHODOLOGY: Children with hypospadias who received elective surgery were randomly divided into two groups of forty cases each. The control group received traditional specialised nursing care during the perioperative period, the study group administered preventive care on the control basis. The postoperative rehabilitation, VAS, anxiety and depression score, postoperative complications, and nursing satisfaction were compared between the two groups. RESULTS: The time of first bowel movement, extubation, and hospitalisation in the study group were significantly shorter than in the control group, with statistically significant value (p<0.001). After intervention, the SAS and SDS in the study group were significantly lower than those in the control group, and the difference was statistically significant (p<0.05). The incidence of complications in the study group was 7.50%, lower than the 25% of control group (p = 0.034). The postoperative VAS scores of the study group were significantly lower than those of control group at 6 and 24 hours (p<0.05). Besides, nursing satisfaction in the study group was 97.50%, higher than the 82.50% of the control group (p = 0.025). CONCLUSION: Preventive nursing had a reliable nursing effect on children undergoing hypospadias surgery, which can reduce postoperative complications, alleviate postoperative pain, improve postoperative anxiety and depression, enhance nursing experience, and promote postoperative recovery. KEY WORDS: Preventive care, Hypospadias in male children, Urethroplasty, Complication, Clinical effect.

Macromolecular nanoparticles to attenuate both reactive oxygen species and inflammatory damage for treating Alzheimer's disease.

Prevention and early intervention are the current focus of treatment for Alzheimer's disease (AD). An increase in reactive oxygen species (ROS) is a feature of the early stages of AD, thus suggesting that the removal of excess ROS can be a viable method of improving AD. Natural polyphenols are able to scavenge ROS and thus promising for treating AD. However, some issues need to be addressed. Among them, important are that most polyphenols are hydrophobic, have low bioavailability in the body, are easily degraded, and that single polyphenols have insufficient antioxidant capacity. In this study, we employed two polyphenols, resveratrol (RES) and oligomeric proanthocyanidin (OPC), and creatively grafted them with hyaluronic acid (HA) to form nanoparticles to address the aforementioned issues. Meanwhile, we strategically grafted the nanoparticles with the B6 peptide, enabling the nanoparticles to cross the blood-brain barrier (BBB) and enter the brain for AD treatment. Our results illustrate that B6-RES-OPC-HA nanoparticles can significantly scavenge ROS, reduce brain inflammation, and improve learning and memory ability in AD mice. B6-RES-OPC-HA nanoparticles have the potential to prevent and alleviate early AD.

The KLF7/PFKL/ACADL axis modulates cardiac metabolic remodelling during cardiac hypertrophy in male mice.

The main hallmark of myocardial substrate metabolism in cardiac hypertrophy or heart failure is a shift from fatty acid oxidation to greater reliance on glycolysis. However, the close correlation between glycolysis and fatty acid oxidation and underlying mechanism by which causes cardiac pathological remodelling remain unclear. We confirm that KLF7 simultaneously targets the rate-limiting enzyme of glycolysis, phosphofructokinase-1, liver, and long-chain acyl-CoA dehydrogenase, a key enzyme for fatty acid oxidation. Cardiac-specific knockout and overexpression KLF7 induce adult concentric hypertrophy and infant eccentric hypertrophy by regulating glycolysis and fatty acid oxidation fluxes in male mice, respectively. Furthermore, cardiac-specific knockdown phosphofructokinase-1, liver or overexpression long-chain acyl-CoA dehydrogenase partially rescues the cardiac hypertrophy in adult male KLF7 deficient mice. Here we show that the KLF7/PFKL/ACADL axis is a critical regulatory mechanism and may provide insight into viable therapeutic concepts aimed at the modulation of cardiac metabolic balance in hypertrophied and failing heart.

A novel nanoparticle system targeting damaged mitochondria for the treatment of Parkinson's disease.

Mitochondrial damage is one of the primary causes of neuronal cell death in Parkinson's disease (PD). In PD patients, the mitochondrial damage can be repaired or irreversible. Therefore, mitochondrial damage repair becomes a promising strategy for PD treatment. In this research, hyaluronic acid nanoparticles (HA-NPs) of different molecular weights are used to protect the mitochondria and salvage the mild and limited damage in mitochondria. The HA-NPs with 2190 k Dalton (kDa) HA can improve the mitochondrial function of SH-SY5Y cells and PTEN induced putative kinase 1 (PINK1) knockout mouse embryo fibroblast (MEF) cells. In cases of irreversible damage, NPs with ubiquitin specific peptidase 30 (USP30) siRNA are used to promote mitophagy. Meanwhile, by adding PINK1 antibodies, the NPs can selectively target the irreversibly damaged mitochondria, preventing the excessive clearance of healthy mitochondria.

Collecting and deactivating TGF-ß1 hydrogel for anti-scarring therapy in post-glaucoma filtration surgery.

Scar formation can lead to glaucoma filtration surgery (GFS) failure, wherein transforming growth factor (TGF)-ß is the core regulator. To reducing scar formation, this paper presents our study on the design of hydrogels to deactivate TGF-ß1. We hypothesized that excess TGF-ß1 can be removed from aqueous humor through the addition of oxidized hyaluronic acid (O-HA) hydrogels that are seeded with decorin (O-HA â€‹+ â€‹D). Immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) were performed to demonstrate the adsorption properties of O-HA â€‹+ â€‹D hydrogel, thus reducing the TGF-ß1 concentration in aqueous humor. In the light that collagen contraction in human Tenon's capsule fibroblasts (HTFs) and the angiogenesis of human umbilical vein endothelial cells (HUVECs) can be activated by TGF-ß1 and ß2, we performed the quantitative analysis of polymerase chain reaction to determine the effect of O-HA â€‹+ â€‹D on the type I collagen, fibronectin, and angiogenesis. Our results illustrate that O-HA â€‹+ â€‹D can inhibit the increase of α-SMA expression in HTF induced by TGF-ß1 and that O-HA â€‹+ â€‹D can inhibit the production of collagen I and fibronectin in HTF treated with TGF-ß1. Furthermore, we performed in vivo studies by employing a rabbit model, where rabbits were treated with hydrogels post GFS. Our results demonstrate that, as compared with other groups, the rabbits treated with O-HA â€‹+ â€‹D had the greatest reduction in inflammatory cells with reduced level of collagen in wounds. Taken together, the present study paves the way toward the treatment of post-glaucoma fibrosis following surgery.

Enhanced hydrological cycle increases ocean heat uptake and moderates transient climate change.

The large-scale moistening of the atmosphere in response to increasing greenhouse gases amplifies the existing patterns of precipitation minus evaporation (P-E) which, in turn, amplifies the spatial contrast in sea surface salinity (SSS). Through a series of transient CO2 doubling experiments, we demonstrate that surface salinification driven by the amplified dry conditions (P-E < 0), primarily in the subtropical ocean, accelerates ocean heat uptake. The salinification also drives the sequestration of upper-level heat into the deeper ocean, reducing the thermal stratification and increasing the heat uptake through a positive feedback. The change in Atlantic Meridional Overturning Circulation due to salinification plays a secondary role in heat uptake. Consistent with the heat uptake changes, the transient climate response would increase by approximately 0.4 K without this process. Observed multi-decadal changes in subsurface temperature and salinity resembles those simulated, indicating that anthropogenically-forced changes in salinity are likely enhancing the ocean heat uptake.

[The diagnosis and treatment of rotational unstable nonunion of femoral shaft fracture after interlocking nailing].

OBJECTIVE: To evaluate the principle and treatment of rotational unstable nonunion of the femoral shaft fracture after interlocking nailing. METHODS: From April 2003 to June 2007, 18 cases of rotational unstable nonunion of femoral shaft fractures after interlocking nailing were treated with exchanged reamed nailing and/or LCP fixation and iliac bone graft. The average age was 40 years old (from 22 to 52). RESULTS: All patients were followed up for an average time of 28 months (from 12 to 58). All the fractures were united in an average time of 7 months (from 6 to 8). There were no perioperative complications occurred and no wound infection were observed. No loosening was found around the implant till the last follow-up. CONCLUSIONS: Rotational instability is one of the reasons of nonunion of femoral shaft fracture after interlocking nailing. Reaming and nail exchanging or LCP fixation with iliac bone graft are the appropriate methods which can achieve a great clinic results.

Retrospective analysis of 514 cases of tibial plateau fractures based on morphology and injury mechanism.

BACKGROUND: Tibial plateau fractures remain a clinical challenge due to the complexity of the fracture patterns which have been repeatedly categorized by many researchers. However, limitations do exist in some respects. So we aimed to reclassify tibial plateau fractures based on injury mechanism and morphological characteristics. METHODS: Five hundred fourteen cases of tibial plateau fractures were enrolled. The X-rays and CT scans were analyzed. RESULTS: According to our observation and analysis, tibial plateau fractures can be categorized into the following six types: (1) Lateral condylar fractures (axial force applied while knee extending in valgus position). Two hundred fifty-one cases were included (48.83%). (2) Fracture dislocation (multiple forces especially rotational stress while knee extending). Fifty-five out of 514 cases belong to this pattern (10.70%). Correction of the subluxation remains primary and crucial during surgical procedures. (3) Simple medial condylar fractures (axial force applied while knee extending in varus position). One third of which were associated with an avulsion fracture of fibular head. Fifteen cases were included (2.92%). (4) Bicondylar fractures (axial forces applied while knee extending). One hundred twelve cases were included (21.79%). Surgical algorithm greatly depends on soft tissue conditions. (5) Posterior condylar fractures (axial stress applied while knee flexing). Sixty-five cases were seen in our study (12.65%), most of which were associated with an avulsion fracture of the intercondylar eminence (49/65, 75.38%). The fracture of posteromedial part, posterolateral part, and intercondylar eminence forms a unique pattern of injury defined as "Posterior Condylar Triad." (6) Anterior condylar compression fractures (axial, varus, or valgus forces applied while knee overextending). Posterior structural complexes, crucial ligaments, or even popliteal arteries are prone to be damaged. Sixteen cases were identified (3.11%). CONCLUSION: Our classification system has instructive significance in overall preoperative evaluation of fracture features and soft tissue problems as well as guiding clinical management for better functional outcomes.

[Clinical study on the rotational deformity after interlocking nailing in femur shaft fracture].

OBJECTIVE: To explore the approach to accurately judge the degree of rotational deformity in femur shaft fracture. METHODS: 110 patients with femur shaft fracture were divided into 3 groups: Group A (n = 62) with the distal end of the fractured femur at the traumatic side at neutral position so as to fix the fracture, Group B (n = 27), with both the distal and proximal ends of the fractured femur at the neutral position so as to fix the femur at an antiversion angle of 15 degrees d, and Group C (n = 21), with the degree of antiversion angle to be controlled to that on the intact side. X ray examination and CT scanning were conducted 3 days after intramedullary nailing to measure the degree of the antiversion angle on both sides. The difference between the degrees of antiversion angle at the 2 sides was considered the rotational deformity of the femur shaft after the nailing. The antiversion angles of the femurs at both sides of 11 healthy persons were measured as controls. RESULTS: The biggest value of antiversion angle was 26 degrees , the smallest value was 8 degrees , the average value at the left side was 12.8 degrees , and the average value at the right side was 12.45, and the biggest difference between the 2 side was 7 degrees in the control group. The average antiversion angle of the femur was 14.67 degrees , the biggest value was 51 degrees , and the smallest value was -24 degrees at the traumatic side; and the average antiversion angle of the femur was 14.27 degrees , the biggest value was 40 degrees , and the smallest value was -23 degrees at the intact side in the treatment groups. 53% and 52% of the patients in Groups A and B showed a rotational deformity < 10 degrees , and 9% and 11% of them showed a rotational deformity > 20 degrees , significantly different from those in the control group (all P < 0.05). The rotational deformity was < 10 degrees in all patients of Group C, not significantly different from that of the control group (P > 0.05). CONCLUSION: Clinically about half of the femur shaft fractures are fixed in the position of rotational deformity > 10 degrees after nailing. The rotational deformity of femur shaft fracture should be prevented by comparing the antiversion angle on the intact side so as to achieve more reliable adequate reduction.

[Measurement of fracture malrotation after interlocking intramedullary nailing of femoral shaft fracture].

OBJECTIVE: To study the quantitative measurement of the extent of malrotation after interlocking intramedullary nailing of femoral shaft fracture. METHOD: CT scan ("routine method") applied in 36 femoral shaft fractures that had been treated with close reduction and interlocking intramedullary nailing. For the judgement of the extent of malrotation, the anteversion of both fracture side and contralateral side were measured and the difference between the 2 sides was evaluated. The increase of anteversion represented internal rotation of the distal fragment, whereas the decrease of anteversion represented external rotation. RESULTS: The maximum anteversion of the fracture sides, whereas 48 degrees, the minimum anteversion -10 degrees, the mean value, 15.04 degrees, and the standard error is 11.34 degrees. The maximum anteversion of the contralateral side, whereas 31.3 degrees, minimum -4.8 degrees, the mean value was 13.96 degrees and the standard error was 10.20 degrees (P < 0.001). Compared with the contralateral side, half of the 36 cases showed increased anteversion and the other half decreased anteversion. The mean value of internal rotation is 11.56 degrees, and external rotation 9.39 degrees. The maximum internal rotation was 37 degrees, the minimum 0.9 degrees. Eight cases had internal rotation less than 8 degrees, 6 between 10 degrees - 15 degrees, and 4 over 15 degrees. The maximum external rotation was 24.3 degrees, and the minimum 1.8 degrees. Eleven cases had external rotation less than 10 degrees, 4 between 10 degrees - 15 degrees and 3 over 15 degrees. The incidence of malrotation more than 10 degrees was 47% (17/36), and more than 15 degrees 19.4% (7/36). CONCLUSION: The incidence of malrotation after femoral shaft fracture treated with close reduction and interlocking intramedullary nailing is high. Attention should be paid to clinical management and strict control for rotational reduction intra-operatively.

[Surgical treatment of shotgun injuries of the sciatic nerve].

OBJECTIVE: To explore the clinical characteristics and the effect of surgical therapy for shotgun injuries of the sciatic nerve. METHODS: From 1996 to 2000, 19 sciatic nerve injuries resulted from shotgun were observed. Among 19 cases of shotgun sciatic nerve wounds, the gluteal wound was in 2 cases, thigh wound in 15 cases, and knee wound in 2 cases. The firing distance was between 0.5-9 m. According to Shermen classification of shotgun injury, 4 cases belonged to type I injury, 11 cases type II, 4 cases type III. The time from injury to admission was between 2 months-14 months except 1 patient who underwent emergency operation 4 hours after injury, and 1 patient was treated with debridement and epineurial neurorrhaphy, 7 cases with nerve trunk grafting, 6 cases with nerve cable grafting, 4 cases with neurolysis, 1 case with arthrodesis of ankle. RESULTS: Nineteen cases were followed-up for 0.8-3.5 years (mean, 19 months). The excellent and good nerve functional recovery was found in 52.6% according to MCRR. CONCLUSIONS: Shotgun injuries of the sciatic nerve are very severe and complicated, and injuries in most patients were usually complicated by open fracture, vascular injury, soft-tissue loss and infection; the character of nerve injury was classified as 4-5 degree according to Sunderland Standard, nerve transfer is effective in the treatment of shotgun injuries of the sciatic nerve, but outcome is poor; the recovery of the sciatic nerve should be observed continually after injury; selecting correct initial treatment after injury, strict minimally invasive surgical procedure, physical therapy and reasonable preoperative and postoperative medication can improve the surgical results.

[Comparative study of antegrade and retrograde intramedullary nailing for the treatment of humeral shaft fractures].

OBJECTIVE: To compare therapeutic effects between antegrade intramedullary nailing and retrograde intramedullary nailing for the treatment of humeral shaft fractures. METHODS: From March 1999 to October 2006, 105 patients with humeral shaft fractures were treated with locked intramedullary nail and were adequately followed up. There were 82 antegrade nailing and 23 retrograde nailing. The follow-up parameters included operation time, blood loss,fracture healing rate, healing time, complications, Constant-Murley shoulder score and Mayo elbow performance score. RESULTS: The mean follow-up period was 31.2 months. Antegrade intramedullary nailing had significantly less blood loss than that in retrograde intramedullary nailing (P=0.002). The differences in operation time, complications, healing time and bone healing rate between he two groups had no statistical significance. Complications in the antegrade intramedullary nail group included 4 patients with nonunions, 1 patient with radial nerve palsy, and 8 patients with shoulder pains and decrement in shoulder range of motion. Complications in the retrograde intramedullary nail group included 1 patient with radial nerve palsy and 3 patients with iatrogenic fractures. For shoulder joints,the difference in the average Constant-Murley shoulder score between the two groups was statistically significant (P=0.04). For elbow joints, the average postoperative Mayo elbow performance score between these two approaches did not differ significantly. CONCLUSION: Both the antegrade intramedullary nailing and the retrograde intramedullary nailing are good alternatives for the treatment of humeral shaft fractures. Because of higher incidence of iatrogenic fractures, the insertion point of retrograde intramedullary nailing should be carefully prepared. With antegrade insertion, it important to bury the humeral nail below the rotator cuff to prevent the subacromial impingement, and the rotator cuff should be carefully repaired to avoid shoulder pain and improve shoulder function.

[Antibiotic-PMMA beads combined with external fixator for treating the infected fracture nonunion].

OBJECTIVE: To investigate the effects of antibiotic-PMMA (polymethyl-methacrylate) beads combined with external fixator in treatment of infected fracture nonunion. METHODS: Twenty-two cases of infected fracture-nonunions were reviewed involving 20 male and 2 female with an average age of 34.68 years (ranging 21 to 74 years). The data consisted of 9 cases of tibial fractures, 2 distal fractures of the femur, 6 femoral shaft fractures, 3 intertrochanteric fracture of the femur and 2 humeral shaft fractures. The procedure included thorough debridement to wipe out dead bone and granulation tissue, then antibiotic-PMMA bead chains imbedded into the dead space. One week later, secondary debridement was performed, antibiotic-PMMA bead chains were changed according to result of bacterial culture and susceptibility test, and fractures were stabilized with external fixator. Three months after debridement, antibiotic-PMMA bead chains were taken out and bone graft with autogenous iliac cancellous bone chips was performed. RESULTS: The mean follow-up period was 19.98 months (ranging 15 to 28 months). Infection was controlled in 20 cases. One tibial fracture and 1 intertrochanteric fracture of the femur needed repeated debridement 2 and 3 months after bone grafting respectively,because of infection recurrence and sinus formation. All 22 cases achieved bony union averaged 15.09 weeks after bone grafting with a range of 8 to 24 weeks. CONCLUSION: Thorough debridement, imbedding antibiotic-PMMA bead chains combined with external fixator and staged bone grafting has proven to be effective and simple for treatment of infected fracture nonunion. The antibiotic bead delivers high tissue levels,obliterates dead space, aids bone repair.

Hip arthroplasty for failed internal fixation of intertrochanteric fractures.

Nineteen patients who had hip arthroplasties for complications of internal fixation of intertrochanteric fractures were reviewed. There were 6 males and 13 females. The mean age was 64.1 years (range, 21-87 years) at the time of the fracture. The average interval from fracture to arthroplasty was 40.3 months (range, 2-288 months). The prosthesis types included 16 total hip arthroplasties and 3 bipolar hip arthroplasties. A standard femoral stem was used in every patient, and although the stem length did not extend well beyond the most distal screw holes, there was no stress fracture. Complications such as intraoperative fracture of the greater trochanter and postoperative dislocation were common. The Harris Hip Score significantly improved from 38.4 points before the conversion to 79.8 points after an average follow-up of 7.4 years (range, 2-18 years). There was no revision for mechanical failure.