Comparative toxic effect of ammonia exposure on Mauremys sinensis and invasive species Trachemys scripta elegans.

As one of main pollutants, ammonia could cause adverse effects to aquatic animals. To explore the toxic effects of ammonia on Chinese striped-necked turtles (Mauremys sinensis) and invasive species red-eared slider (Trachemys scripta elegans), we compared the activities of antioxidant enzymes, the mRNA levels of genes involved in immune status, endoplasmic reticulum stress and apoptosis between T. s. elegans and M. sinensis under ammonia exposure for 30 days. The results showed that ammonia obviously increased the activities of SOD, CAT, GPX and T-AOC in both T. s. elegans and M. sinensis, especially CAT and GPX in T. s. elegans were higher than that in M. sinensis. The expression levels of JAK, RELA and Mcl-1 in T. s. elegans obviously increased, while IL-6 mRNA levels significantly increased in M. sinensis. In addition, Bip and IRE1 levels in M. sinensis showed a marked increase, and were significantly higher than that in T. s. elegans. Bcl-2 and Bcl-xL transcriptional levels in T. s. elegans showed an increase, especially Bcl-xL were significantly higher than that in M. sinensis. These results indicated that T. s. elegans exhibited more stronger antioxidant defense and immune function than M. sinensis under ammonia exposure. M. sinensis was more likely to occur endoplasmic reticulum stress and inflammation in ammonia environment. This research reveals the physiological response of turtles to ammonia, helps to understand adverse effects of environmental pressure on aquatic turtles, and further explains the tolerance of invasive species T. s. elegans to environmental pollution.

Comparative effects of modified rotary scarf osteotomy and traditional scarf osteotomy in treating moderate to severe hallux valgus: a retrospective cohort study.

BACKGROUND: Traditional Scarf osteotomy (TSO) is an effective procedure with a good record in moderate to severe hallux valgus (MSHV) surgery. In order to overcome shortcomings of TSO, Modified Rotary Scarf osteotomy (MRSO) was introduced in this study, which aimed to compare the clinical and radiological outcome in the patients treated with MRSO or TSO. METHODS: Of 175 patients (247 feet) with MSHV, 100 patients (138 feet) treated with MRSO and 75 patients (109 feet) treated with TSO were evaluated according to relevant indicators in twenty-four months follow-up. Pre-surgical and post-surgical HVA, IMA, DMAA, MTP-1 ROM, sesamoid grade and AOFAS (American Orthopaedic Foot and Ankle Society) scores and postsurgical complications were evaluated. RESULTS: Both groups manifested similar baseline characters. The mean follow-up was of 25.9 (range, 22-37) months. Significantly lower IMA, lower Sesamoid grade and higher DMAA at six months, twelve months and twenty-four months post-surgically had been showed in MRSO group compared to TSO group. There was no significant difference in HVA, MTP-1 ROM and AOFAS data at each follow-up time point post-surgically between the two groups. No major complications occurred in either group. CONCLUSION: MRSO showed comparable results to TSO, and improved IMA and sesamoid grade to a greater extent, with a lower probability of throughing effect. Although DMAA could be increased by MRSO, MRSO could still be a reproducible, non-dangerous and efficacious alternative procedure for treating HV patients which do not have severe DMAA.

Research on the clinical factors of cardiac iron deposition in children with beta-thalassemia major.

Magnetic resonance imaging (MRI) T2* is the gold standard for detecting iron deposition in cardiac tissue, but the technique has limitations and cannot be fully performed in paediatric thalassemia patients. The aim of this study was to analyse clinical data to identify other predictors of cardiac iron deposition. A retrospective analysis was performed on 370 children with ß-TM. According to the cardiac MRI results, patients were allocated to a cardiac deposition group and noncardiac deposition group. Multivariate analysis revealed that genotype and corrected QT interval were associated with cardiac iron deposition, indicating that the-ß0/ß0 genotype conferred greater susceptibility to cardiac iron deposition. Receiver operating characteristic curve (ROC) analysis was performed, and the area under the curve (AUC) of genotype was 0.651. The AUC for the corrected QT interval was 0.711, at a cut-off value of 418.5 ms. ROC analysis of the combined genotype and corrected QT interval showed an AUC of 0.762 with 81.3% sensitivity and 64.7% specificity. Compared to patients with the ß+/ß+ and ß0ß+ genotypes, ß0ß0 children with ß-TM were more likely to have cardiac iron deposition.  Conclusion: The genotype and QTc interval can be used to predict cardiac iron deposition in children with ß-TM who are unable to undergo MRI T2 testing.

Butylparaben disordered intestinal homeostasis in Chinese striped-necked turtles (Mauremys sinensis).

Butylparaben (BuP) is regarded as a widespread pollutant, which has potential risk to aquatic organisms. Turtle species are an important part of aquatic ecosystems, however, the effect of BuP on aquatic turtles is not known. In this study, we evaluated the effect of BuP on intestinal homeostasis of Chinese striped-necked turtle (Mauremys sinensis). We exposed turtles to concentrations of BuP (0, 5, 50, and 500 µg/L) for 20 weeks, then investigated the composition of gut microbiota, the structure of intestine, and the inflammatory and immune status. We found BuP exposure significantly changed the composition of gut microbiota. Specially, the unique genus in three concentrations of BuP-treated groups mainly was Edwardsiella, which was not present in control group (0 µg/L of BuP). In addition, the height of intestinal villus was shortened, and the thickness of muscularis was thinned in BuP-exposed groups. Particularly, the number of goblet cells obviously decreased, the transcription of mucin2 and zonulae occluden-1 (ZO-1) significantly downregulated in BuP-exposed turtles. Meanwhile, neutrophils and natural killer cells in lamina propria of intestinal mucosa increased in BuP-treated groups, especially in high concentration of BuP (500 µg/L). Moreover, the mRNA expression of pro-inflammatory cytokines, especially IL-1ß showed a significant upregulation with BuP concentrations. Correlation analysis indicated the abundance of Edwardsiella was positively correlated with IL-1ß and IFN-γ expression, whereas its abundance was negatively correlative with the number of goblet cells. Taken together, the present study demonstrated BuP exposure disordered intestinal homeostasis through inducing dysbiosis of gut microbiota, causing inflammatory response and impairing gut physical barrier in turtles, which emphasized the hazard of BuP to health of aquatic organism.

Effect of ammonia stress on AMPK regulating-carbohydrate and lipid metabolism in Chinese striped-neck turtle (Mauremys sinensis).

In aquatic organisms, ammonia is one of the major factors that affect energy levels when it exceeds its optimal concentration. Numerous studies have examined the effects of ammonia on aquatic animals, but its effect on metabolism is still unknown. The effect of ammonia on carbohydrates and lipid metabolism in the Chinese striped neck turtle (Mauremys sinensis) was investigated in this study by exposing the turtle to two different ammonia concentrations (A100: 1.53 mg L-1) and (A200: 2.98 mg L-1) for 24 and 48 h, respectively. Our results showed that the mRNA expression of adenosine monophosphate-activated protein kinase α1 (AMPKα1) significantly increased only in A100 at 24 h, whereas its activity increased in both ammonia-exposed groups. The two AMPK-regulated transcription factors responsible for carbohydrate metabolism also exhibited changes in ammonia-treated groups, as hepatocyte nuclear factor-4-alpha (HNF4α) increased and forkhead box protein O1 (FoxO1) decreased. The expression of phosphofructokinase (PFK) and glucose-6-phosphatase (G-6-PAS) was subsequently downregulated. In addition, transcription factors, carbohydrate-responsive element-binding protein (ChREBP), and sterol regulatory element-binding protein 1c (SREBP-1c), which are known to be involved in lipogenesis, were suppressed. These downstream genes include fatty acid synthase, stearoyl CoA desaturase, and acetyl-CoA carboxylase (FAS, SCD-1 and ACC). Moreover, the glucose content decreased, whereas the triglyceride content increased significantly in A200 at 24 h. We concluded that AMPK signaling inhibits gluconeogenesis and lipogenesis, and promotes glycolysis to meet energy demand under stressful conditions in M. sinensis.

An Exceptional Avulsion Fracture Above the Medial Malleolus: A Retrospective Case Series.

The Lauge-Hansen classification does not cover all types of ankle injuries. The present report details three cases of exceptional fragment of the medial tibia that differed from the traditional Lauge-Hansen supination-external rotation and pronation-external rotation fracture patterns. The information obtained from this study will be helpful for conducting basic research of this condition and determining appropriate surgical approaches.

Chinese Consensus on Insertional Achilles Tendinopathy.

BACKGROUND: Insertional Achilles tendinopathy (IAT) is a common finding in the clinic. However, consensus on its mechanism, pathological process, diagnosis, treatment, and rehabilitation is lacking. Thus, the Chinese Society of Sports Medicine organized and invited experts representing the fields of ankle disease and tendinopathy to jointly develop an expert consensus on IAT. STUDY DESIGN: A consensus statement of the Chinese Society of Sports Medicine. METHODS: A total of 34 experts in the field of sports medicine and orthopaedics were invited to participate in the compilation of a consensus statement regarding IAT. Consensus was achieved according to the Delphi method. First, 10 working groups composed of 34 experts were established to compile draft statements about clinical problems related to IAT by reviewing and analyzing the available literature. An expert consensus meeting to discuss drafts was then arranged. Each statement was individually presented and discussed, followed by a secret vote. Consensus was reached when more than 50% of the experts voted in its favor. The strength of the proposed recommendation was classified based on the proportion of favorable votes: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimity, 100%. RESULTS: Of the 10 expert consensus statements on the clinical diagnosis and treatment of IAT, there was strong consensus for 8 statements and unanimity for 2 statements. CONCLUSION: This expert consensus focused on the concepts, causes, pathological process, clinical diagnosis, and treatment of IAT. Accepted recommendations in these areas which will assist clinicians in carrying out standardized management of related diseases.

Transfer of abductor hallucis tendon combined with scarf osteotomy versus single scarf osteotomy in moderate to severe hallux valgus deformity: a comparative retrospective cohort study.

BACKGROUND: Scarf osteotomy (SO) was broadly applied in moderate to severe hallux valgus (MSHV), and the results were satisfactory. However, due to the complicated pathologic changes in hallux valgus, the ideal surgical treatment is still controversial. Transfer of the abductor hallucis tendon combined with Scarf osteotomy (TAHTCSO) was an innovative alternative technique. This retrospective cohort study aimed to define if TAHTCSO mode resulted in improved outcomes as compared with the single SO in MSHV. METHODS: Of 73 patients (92 ft) with MSHV, 36 (45 ft) were treated through TAHTCSO and 37 ones (47 ft) through SO. The patients were assessed clinically and radiographically with a 24-month follow-up. They were assessed pre-operatively and post-operatively with intermetatarsal angle (IMA), hallux valgus angle (HVA), distal metatarsal articular angle (DMAA), first metatarsophalangeal joint range of motion (1#MTP ROM), as well as American Orthopaedic Foot and Ankle Society (AOFAS) forefoot scores and postoperative complications of surgery. RESULTS: Both cohorts had the same baseline feathures. All patients were followed up from 24 to 40 months, with a mean of 28.3 months. Patients in the TAHTCSO cohort had significantly decreased HVA at 6 months (p < 0.0001), 12 months (p < 0.0001), and 24 months (p < 0.0001) after surgery. 1#MTP had been increased slightly with non-statistic sense (p>0.05). IMA, DMAA and AOFAS also had not significantly difference at all followed time after surgery as compared with the SO cohort. The healing of osteotomies was observed within 8 weeks in the two cohorts. Two cases of hallus varus had been found in SO cohort and there were no cases of delayed healing and bone non-union in both cohorts. CONCLUSION: In this retrospective cohort study, TAHTCSO had sufficient maintenance of the correction and improved functional performance thereby was a good alternative for MSHV, though it did not display a better result for MSHV compared to SO.

CircERCC2 ameliorated intervertebral disc degeneration by regulating mitophagy and apoptosis through miR-182-5p/SIRT1 axis.

The molecular mechanism of intervertebral disc degeneration (IVDD) remains unclear. This study aimed to investigate the role of circular RNAs (circRNAs) in the pathogenesis of IVDD. We sued nucleus pulposus (NP) tissues of patients, tert-butyl hydroperoxide (TBHP) stimulated NP cells (NPCs), and IVDD rat model to explore the interaction between circERCC2 and miR-182-5p/SIRT1 axis. The results showed that downregulation of circERCC2 increased the level of miR-182-5p and decreased the level of SIRT1 in degenerative NP tissues in vivo as well as in TBHP-stimulated NPCs in vitro. Treatment of SIRT1-si activated apoptosis and inhibited mitophagy. Moreover, miR-182-5p-si could regulate the mitophagy and the apoptosis of NPCs by targeting SIRT1. The effects of circERCC2 on NPCs and IVDD rat model were mediated by miR-182-5p/SIRT1 axis. In conclusion, this study provides the first evidence that circERCC2 could ameliorate IVDD through miR-182-5p/SIRT1 axis by activating mitophagy and inhibiting apoptosis, and suggests that circERCC2 is a potentially effective therapeutic target for IVDD.

Hypermethylation of Frizzled1 is associated with Wnt/ß-catenin signaling inactivation in mesenchymal stem cells of patients with steroid-associated osteonecrosis.

The Wnt/ß-catenin signaling pathway is associated with the pathogenesis of steroid-induced osteonecrosis. Our investigation studied whether aberrant CpG island hypermethylation of the FZD1 gene was present in patients with osteonecrosis of the femoral head (ONFH), which results in Wnt/ß-catenin signaling inactivation and subsequent cell dysfunction. Bone marrow was collected from the proximal femurs of patients with steroid-associated ONFH (n = 21) and patients with new femoral neck fractures (n = 22), and then mesenchymal stem cells (MSCs) were isolated. We investigated cell viability, the transcription and translation levels of Wnt/ß-catenin signaling-related genes, the extent of methylation at CpG islands of the FZD1 promoter, and the osteogenic and adipogenic differentiation abilities of MSCs from the control group and from the ONFH group treated with or without 5'-Aza-dC. According to the results, MSCs from the ONFH group showed a reduced proliferation ability, low transcription and translation levels of FZD1, inhibition of the Wnt/ß-catenin signaling pathway, weakened osteogenesis and enhanced adipogenesis ability. Aberrant CpG island hypermethylation of FZD1 was observed in the ONFH group. Treatment with 5'-Aza-dC resulted in de novo FZD1 expression, reactivation of the Wnt/ß-catenin signaling pathway and promotion of osteogenesis. Taken together, our study not only provides novel insights into the regulation of the Wnt/ß-catenin signaling pathway in this disease but also reveals potential for the use of demethylating agents for the treatment of GC-associated ONFH.

p53 mediated IFN-ß signaling to affect viral replication upon TGEV infection.

TGEV can induce IFN-ß production, which in turn plays a vital role in host antiviral immune responses. Our previous studies showed that TGEV infection activated p53 signaling to induce host cell apoptosis, which might influence virus replication. However, whether there be an interaction between p53 and IFN-ß signaling in the process of TGEV infection is unknown. In the present study, we used low dose of TGEV to infect p53 wild-type PK-15 cells (WT PK-15 cells) and p53 deficient cells (p53-/- PK-15 cells), to investigate the modulation of IFN signaling and virus replication by p53. The results showed that the IFN-ß expression and production were notably inhibited in p53-/- PK-15 cells compared with that in WT PK-15 cells at early stage of TGEV infection. In addition, TGEV-induced the changes in mRNA levels of TRIF, TRAM, MDA5, RIG-I, IPS-1, IRF9, IRF3, ISG15 and ISG20 were notably hindered in p53-/- PK-15 cells before 36 h post infection (p.i.). Moreover, TGEV genomic RNA and sub genomic mRNA (N gene and ORF7) levels showed significant increase in p53-/- PK-15 cells compared with WT PK-15 cells after TGEV infection. And viral titers were observably enhanced in p53-/- PK-15 cells. Furthermore, exogenous IFN-ß and polyinosinic-polycytidylic acid (poly (I:C)) treatment markedly inhibited the mRNA levels of TGEV gRNA, N and ORF7 in WT PK-15 cells and p53-/- PK-15 cells compared to control. Taken together, these results demonstrated that p53 may mediate IFN-ß signaling to inhibit viral replication early after TGEV infection.

p53- and ROS-mediated AIF pathway involved in TGEV-induced apoptosis.

We previously demonstrated that transmissible gastroenteritis virus (TGEV) could induce apoptosis through caspase signaling. However, apoptosis was not completely prevented by caspases inhibitors, suggesting that there may be a caspase-independent pathway involved in TGEV-induced cell apoptosis. In this study, we investigated the regulation of apoptosis-inducing factor (AIF) on TGEV-induced apoptotic pathway. Results indicated that AIF translocated from the mitochondria to nucleus during TGEV infection, and the AIF inhibitor, N-phenylmaleimide (NP), significantly attenuated the apoptosis. In addition, the translocation of AIF was inhibited by Veliparib (ABT-888), an inhibitor of poly (ADP-ribose) polymerase (PARP). And the reactive oxygen species (ROS) scavenger, pyrrolidinedithiocarbamic (PDTC), redistributed AIF in the mitochondria and nucleus in TGEV-infected cells. Moreover, the protein levels in nucleus and the mRNA levels of AIF were inhibited in the presence of the p53 inhibitor, pifithrin-α (PFT-α) or in TGEV-infected p53-/-cells. Furthermore, TGEV-induced apoptosis was blocked by combination of three or more inhibitors, such as pan caspase inhibitor Z-VAD-FMK, NP, ABT-888, PDTC, PFT-α, to treat PK-15 cells. Taken together, these results suggest that the p53- and ROS-mediated AIF pathway and caspase-dependent pathway were involved in TGEV-induced apoptosis.

Manipulation of visible-light polarization with dendritic cell-cluster metasurfaces.

Cross-polarization conversion plays an important role in visible light manipulation. Metasurface with asymmetric structure can be used to achieve polarization conversion of linearly polarized light. Based on this, we design a quasi-periodic dendritic metasurface model composed of asymmetric dendritic cells. The simulation indicates that the asymmetric dendritic structure can vertically rotate the polarization direction of the linear polarization wave in visible light. Silver dendritic cell-cluster metasurface samples were prepared by the bottom-up electrochemical deposition. It experimentally proved that they could realize the cross - polarization conversion in visible light. Cross-polarized propagating light is deflected into anomalous refraction channels. Dendritic cell-cluster metasurface with asymmetric quasi-periodic structure conveys significance in cross-polarization conversion research and features extensive practical application prospect and development potential.

Locking compression plate distal ulna hook plate fixation versus intramedullary screw fixation for displaced avulsion fifth Metatarsal Base fractures: a comparative retrospective cohort study.

BACKGROUND: Intramedullary screw (IMS) fixation was wildly used in fifth metatarsal base fractures (FMBFs) and the results were satisfactory. However, in the comminuted osteoporosis or small displaced avulsion FMBFs, anatomical reduction and stable fixation could not be achieved with IMS. The Locking Compression Plate (LCP) distal ulna hook plate fixation was a novel alternative fixation method. The aim of this retrospective cohort study was to determine if LCP distal ulna hook plate fixation resulted in improved outcomes compared to the traditional IMS fixation in displaced avulsion FMBFs. METHODS: Of 43 patients with displaced avulsion FMBFs, 18 patients were treated with LCP distal ulna hook plate fixation and 25 were treated with IMS fixation. The patients were evaluated clinically and radiographically and followed up to 12 months. The surgery time, time for hospital stay, time for weight-bearing, time for bony union, time for return to daily life, pain relief, functional outcome and complications after treatment with LCP distal ulna hook plate fixation or IMS fixation were compared. The functional outcome was assessed by the AOFAS (American Orthopedic Foot and Ankle Society) mid-foot score at 3, 6, 9, and 12 months after surgery. Meanwhile, pain scores were obtained at 3, 6, 9, and 12 months after surgery. RESULTS: The two cohorts had similar baseline characteristics. Surgery time was less in LCP distal ulna hook plate fixation cohort compare to IMS fixation cohort (p < 0.0001). Time for partial weight-bearing (p < 0.0001) and full weight-bearing (p < 0.0001) also demonstrated significant improvements in patients with LCP distal ulna hook plate fixation compared to IMS fixation. Patients in the LCP distal ulna hook plate fixation cohort had significantly increased AOFAS at 9 months (p < 0.0001) and 12 months (p < 0.0001) after surgery compared to the IMS fixation cohort. CONCLUSION: In this retrospective cohort study, LCP distal ulna hook plate fixation as an alternative fixation method was better therapy for the displaced avulsion FMBFs compared to IMS fixation. LCP distal ulna hook plate fixation had a short surgery time and improved functional performance.

Membrane complement regulatory protein reduces the damage of transplanting autologous bone marrow mesenchymal stem cells by suppressing the activation of complement.

There are few studies on the interaction of transplanting autologous bone marrow mesenchymal stem cells (BMSCs) and complement. In order to further explore the effect of complement on BMSCs, BMSCs were obtained from bone marrow of 20 cases clinical patients, and then experimented in vitro. The cytotoxicity of complement on the mesenchymal stem cells in autologous human serum (AHS) was measured by Europium cytotoxicity assay. The complement membrane attack complex (MAC) deposited on the membrane surface was detected by flow cytometry. Finally, the cytotoxicity on BMSCs was measured after mCRPs overexpression or knockdown. We found that more than 90% of cells derived from bone marrow were identified to be mesenchymal stem cells through detection of cell membrane surface markers by flow cytometry. BMSCs harvested from the 20 patients all had cytotoxicity after incubated with AHS, and the cytotoxicity was significant higher than that incubated with complement inactivated autologous human serum (iAHS). Complement attack complex (MAC) could be detected on the BMSCs incubated with AHS, which implied the complement activation. We also found that mCRPs CD55 and CD59 overexpressions can resist the cytotoxicity induced by complement activation, while mCRPs CD55 and CD59 knockdown can enhance the cytotoxicity. Thus, the results indicated that mCRPs could effectively protect BMSCs from attacking by complement by suppressing the activation of complement.

Targeted osteosarcoma chemotherapy using RGD peptide-installed doxorubicin-loaded biodegradable polymeric micelle.

Osteosarcoma is the most common primary malignant bone tumor in the pediatric age group, and chemotherapy directed by targeted nanoparticulate drug delivery system represents a promising approach for osteosarcoma treatment recently. Here, we designed and developed a novel DOX-loaded targeted polymeric micelle self-assembled from RGD-terminated poly(ethylene glycol)-block-poly (trimethylene carbonate) (RGD-PEG-PTMC) amphiphilic biodegradable block copolymer, for high-efficiency targeted chemotherapy of osteosarcoma. Notably, the RGD-installed DOX-loaded biodegradable polymeric micelle (RGD-DOX-PM) with drug loading efficiency of 57%-73% displayed a narrow distribution (PDI=0.05-0.12) with average sizes ranging from 46 to 73nm depending on the DOX loading content. The release amount of DOX from RGD-DOX-PM achieved 63% within 60h under physiological condition. Interestingly, MTT assays in MG-63 and MNNG/HOS osteosarcoma cells exhibited that half-maximal inhibitory concentration (IC50) value of RGD-DOX-PM was much lower than its non-targeted counterpart (DOX-PM), implying RGD decorated nanoparticles had enhanced cell targeting ability and led to more effective anti-tumor effect. Furthermore, the targeting ability of RGD-DOX-PM was confirmed by in vitro flow cytometry and confocal laser scanning microscopy (CLSM) imaging assays, where the results showed more RGD-DOX-PM were taken up by MG-63 cells than that of DOX-PM. Therefore, this RGD decorated DOX-loaded polymeric micelle is promising for targeted chemotherapy of osteosarcoma.

Poly-(acryl amine-co-dimethyldiallyl ammonium chloride) graft starch flocculant for cleaning-up of wastewater.

Graft starch flocculant (GSF) was synthesized by copolymerization of carboxymethylated soluble starch, acryl amine and dimethyldiallyl ammonium chloride using ceric ammonium nitrate (NH4)2Ce(NO3)6 as the polymerization initiator. The morphology was observed by scanning electron microscope, the structure was characterized by Fourier transform infrared spectroscopy and the surface area was measured by the Brunauer-Emmett-Teller method. The experimental results showed that the GSF had huge pore volume, high specific area and proper reaction groups, which could enhance its ability to adsorb heavy metal ions. The adsorption behavior was investigated through batch experiments in simulated Cu(2+)and Pb(2+) ions wastewater, and adsorption characteristics were affected by many factors, such as flocculant concentration, pH of the solution and adsorption time. Finally, the optimal adsorption parameters were gained, with GSF density of 0.024 mg·L(-1), pH of 8 and a reaction time of 30 min. Application experiments adequately demonstrated that the removal ratio of Cu(2+) and Pb(2+) ions for the local wastewater reached about 50% based on the above optimized condition.

Tibiotalocalcaneal arthrodesis using a retrograde intramedullary nail with a valgus curve.

OBJECTIVE: Many different techniques have been described for performing tibiotalocalcaneal arthrodesis (TTCA) in patients with severe hindfoot disorders such as failed ankle arthroplasty and failed ankle joint arthrodesis with subsequent subtalar arthritis. The use of straight retrograde intramedullary nails is extremely limited because they may interfere with normal heel valgus position and risk damaging the lateral plantar neurovascular structures. Curved retrograde intramedullary nails have been designed to overcome these shortcomings. The purpose of this single surgeon series was to investigate the outcomes of TTCA using a curved retrograde intramedullary nail. METHODS: From June 2009 to January 2012, 22 patients underwent TTCA using intramedullary nails with a valgus curve by the same senior surgeon. All patients were available for analysis, the mean follow-up being 22.3 months (range, 6.8-38 months). The main outcome measurements included EQ-5D functional scores, the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale, radiologic assessment and clinical examination. RESULTS: Bony union and a plantigrade foot were achieved in 100% of subjects, the mean time to union being 3.9 months (range, 2.4 to 6.2 months). Structural bone graft was used in all patients. Postoperative radiologic results showed a good hindfoot alignment in all patients. The only complication was one case of delayed wound healing without deep infection. The mean postoperative EQ-5D functional and AOFAS ankle-hindfoot scores were 69.33 (range, 20 to 90) and 69.9 (range, 45 to 85) points, respectively. No revision surgery was necessary in our cohort. CONCLUSION: The results of the present study indicate that TTCA using a short, retrograde, curved intramedullary nail is an acceptable technique for obtaining solid fusion and good hindfoot alignment inpatients with severe hindfoot disorders.