12-year survival analysis of 322 Hintegra total ankle arthroplasties from an independent center

Background and purpose — Total ankle arthroplasties (TAAs) have larger revision rates than hip and knee implants. We examined the survival rates of our primary TAAs, and what different factors, including the cause of arthritis, affect the success and/or revision rate.Patients and methods — From 2004 to 2016, 322 primary Hintegra TAAs were implanted: the 2nd generation implant from 2004 until mid-2007 and the 3rd generation from late 2007 to 2016. A Cox proportional hazards model evaluated sex, age, primary diagnosis, and implant generation, pre- and postoperative angles and implant position as risk factors for revision.Results — 60 implants (19%) were revised, the majority (n = 34) due to loosening. The 5-year survival rate (95% CI) was 75% (69–82) and the 10-year survival rate was 68% (60–77). There was a reduced risk of revision, per degree of increased postoperative medial distal tibial angle at 0.84 (0.72–0.98) and preoperative talus angle at 0.95 (0.90–1.00), indicating that varus ankles may have a larger revision rate. Generation of implant, sex, primary diagnosis, and most pre- and postoperative radiological angles did not statistically affect revision risk.Interpretation — Our revision rates are slightly above registry rates and well above those of the developer. Most were revised due to loosening; no difference was demonstrated with the 2 generations of implant used. Learning curve and a low threshold for revision could explain the high revision rate.

Arthritis in the ankle often develops earlier than in the hip or knee, and 70% have a traumatic etiology (Saltzman et al. 2005, Brown et al. 2006). Total ankle arthroplasty (TAA) can be indicated for severe arthritis in the ankle joint, but the anatomical preconditions, like a small surface area and high stress from compression and torque (Bouguecha et al. 2011, Kakkar and Siddique 2011), makes it less durable than hip and knee prosthetics. The Hintegra TAA, a 3-component mobile bearing, uncemented implant (Hintermann et al. 2004) is widely used and results from the development center demonstrate survival rates of 94% and 84% after 5 and 10 years’ follow-up (Barg et al. 2013). This is considerably more than the survival rates from national registries. Labek et al. (2011) demonstrated that development centers report only half of the revision rate that can be found in the few existing national registers. In a systematic review of primary Agility total ankle arthroplasty (DePuy Synthes Orthopedics, Warsaw, IN, USA), the author (Roukis 2012) found that the incidence of complications increased from 7% to 12%, in studies where the inventor was excluded. Similar results were found by Prissel and Roukis (2013), who found an increased incidence of complications from 6% to 13% in studies where the inventor or faculty consultants were excluded. These studies indicated the risk of selection (inventor) and publication (conflict of interest) bias.Planning and surgical technique, including significant experience, are mandatory for a successful outcome. The better result from development centers may reflect, besides the above-mentioned bias, that there is a long learning curve and that the indication for revision surgery varies.We examined the survival rates of primary Hintegra TAAs performed at Hvidovre Hospital, with revision rate as outcome. We report primary diagnosis for primary TAA and examine whether sex, generation of the implant, preoperative angles and implant position affect the revision rate.     

Image formation in vibro-acoustography with depth-of-field effects.

We study the image formation of vibro-acoustography systems based on a concave sector array transducer taking into account depth-of-field effects. The system point-spread function (PSF) is defined in terms of the acoustic emission of a point-target in response to the dynamic radiation stress of ultrasound. The PSF on the focal plane and the axis of the transducer are presented. To extend the obtained PSF to the 3D-space, we assume it is a separable function in the axial direction and the focal plane of the transducer. In this model, an image is formed through the 3D convolution of the PSF with an object function. Experimental vibro-acoustography images of a breast phantom with lesion-like inclusions were compared with simulated images. Results show that the experimental images are in good agreement with the proposed model.     

Critical study of hair growth analysis with computer-assisted methods

BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials.     

双波长紫外分光光度法测定贝母中腺苷和胸苷的含量

将4种贝母的甲醇提取物经薄层色谱法粗分离后,直接用双波长紫外分光光度法测定其含量。结果表明,该方法线性关系好,腺苷和胸苷标准曲线的相关系数均为0.9999,同时也发现平贝、炉贝和伊贝中腺苷都占核苷总量60%以上,而浙贝中仅占约40%,提示贝母生药的抗凝血活性可能与贝母中核苷类化合物的种类和含量的差别有关。     

Disappointing results and low tolerability of photodynamic therapy with topical 5-aminolaevulinic acid in psoriasis. A randomized, double-blind phase I/II study

BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile.     

Promutagenic methylation damage in bladder DNA from patients with bladder cancer associated with schistosomiasis and from normal individuals.

Radioimmunoassays (RIAs) have been used to detect the promutagenic lesion O6-methyldeoxyguanosine (O6-MedG) in DNA isolated from the bladder tissues of Egyptian patients presenting with bladder carcinoma and concomitant schistosomiasis (bilharziasis), a parasitic disease known to be associated with the presence of N-nitrosamines in the urine. Alkylation damage was present in the DNA of the majority of the samples (44/46, 96%); 38 samples were of tumour tissue and 8 from uninvolved bladder mucosa. Levels of O6-MedG ranged from undetectable (ND; i.e. less than 0.01 mumol O6-MedG/mol dG) to 0.485 mumol/mol dG with an overall mean of 0.134 +/- 0.10 mumol/mol dG, including the two samples that were below the limit of detection. In contrast, methylation damage was detected in only 4/12 (33%) of the DNA samples from normal bladder tissue of European origin. In these samples levels of O6-MedG ranged from ND to 0.225 mumol/mol dG with an overall mean of 0.046 +/- 0.082 mumol O6-MedG/mol dG. These results confirm that alkylation events can be detected in the DNA of schistosome-infected human bladder tissue. The methylation of uninvolved and tumour tissue DNA to similar extents suggests that the alkylating intermediate may have been present in the urine. These results indicate the need for further investigation to determine whether relationships exist between levels of DNA damage and the prevalence of schistosome infection and/or the extent and type of bacterial infection that frequently accompanies this disease.