Analysis of joint laxity after total ankle arthroplasty: cadaver study.

BACKGROUND: Clinical results of total ankle arthroplasty with early designs were disappointing. Recently-developed ankle prostheses have good mid-term results; however, limited information is available regarding effects of total ankle arthroplasty on ankle laxity. METHODS: Eight cadaveric lower extremities were tested with a custom device which enabled measurement of multi-axial forces, moments, and displacement during applied axial, shear, and rotational loading. Tests consisted of anterior-posterior and medial-lateral translation and internal-external rotation of the talus relative to the tibia during axial loads on the tibia simulating body weight (700 N) and an unloaded condition (5 N). Tests were performed in neutral, dorsiflexion, and plantarflexion. Laxity was determined for the intact ankle, and following insertion of an unconstrained total ankle implant, comparing load-displacement curve. FINDINGS: Laxity after total ankle arthroplasty did not approximate the normal ankle in most conditions tested. Displacement was significantly greater for total ankle arthroplasty in both posterior and lateral translation, and internal rotation, with 5 N axial loading, and anterior-posterior, medial-lateral translation, and internal-external rotation for 700 N axial loading. For the 700 N axial load condition, in the neutral ankle position, total anterior-posterior translation averaged 0.4 mm (SD 0.2 mm), but 6.0 mm (SD 1.5 mm) after total ankle arthroplasty (P<0.01). This study demonstrated more laxity in the replaced ankle than normal ankle for both unloaded and 700 N axially loaded conditions. INTERPRETATION: These data indicate the increased responsibility of the ligaments for ankle laxity after total ankle arthroplasty and suggest the importance of meticulous ligament reconstruction with total ankle arthroplasty operations.

Modified Blalock-Taussig shunt with compensatory properties.

Determination of the proper length of the tubular prosthesis is a major issue when performing a systemic-pulmonary artery shunt. The procedure is simplified by using a prosthesis with accordionlike properties. This was demonstrated in 7 consecutive infants with complex congenital heart defects, in whom systemic-pulmonary artery shunts were placed without early or late complications.

Lonkkaproteesi, varteenotettava hoitovaihtoehto lonkkavaivaiselle koiralle

Summary: Total hip prosthesis, a reasonable treatment for dogs with hip problems

La variabilité chirurgicale en Suisse : différences intercantonales observées pour trois interventions

En Suisse, la variabilité géographique de la consommation de soins chirurgicaux est un domaine encore inexploré. Ce rapport examine de manière descriptive trois interventions chirurgicales réalisées en Suisse entre 2003 et 2005 : la prothèse partielle ou totale de hanche, la prothèse de genou et la cure de hernie discale. Il se concentre sur les caractéristiques démographiques des patients opérés, leur diagnostic et les différences des taux d'intervention selon les cantons. Les résultats sont présentés sous forme de taux bruts, de taux standardisés et de cartes géographiques de distribution.

Darker eumelanic barn owls better withstand food depletion through resistance to food deprivation and lower appetite.

The intensity of selection exerted on ornaments typically varies between environments. Reaction norms may help to identify the conditions under which ornamented individuals have a selective advantage over drab conspecifics. It has been recently hypothesized that in vertebrates eumelanin-based coloration reflects the ability to regulate the balance between energy intake and expenditure. We tested two predictions of this hypothesis in barn owl nestlings, namely that darker eumelanic individuals have a lower appetite and lose less weight when food-deprived. We found that individuals fed ad libitum during 24 h consumed less food when their plumage was marked with larger black spots. When food-deprived for 24 h nestlings displaying larger black spots lost less weight. Thus, in the barn owl the degree of eumelanin-based coloration reflects the ability to withstand periods of food depletion through lower appetite and resistance to food restriction. Eumelanic coloration may therefore be associated with adaptations to environments where the risk of food depletion is high.

Infection after total ankle replacement : A 5-year retrospective analysis of 92 implanted ankle prostheses (2004-2008).

Objectives: Total ankle replacement (TAR) is increasingly used for treatment of primary or posttraumatic arthritis of the ankle joint, if joint movement is intended to be preserved. Data on characteristics and treatment of ankle prosthetic joint infection (PJI) is limited and no validated therapeutic algorithm exist. Therefore, we analyzed all infections, which occurred in a cohort of implanted ankle prostheses during a 5-year-period.Methods: Between 06/2004 and 12/2008, all patients with an implanted ankle prosthesis at our institution were retrospectively reviewed. All patients were operated by the same surgical team. Ankle PJI was defined as visible purulence, acute inflammation on histopathology, sinus tract, or microbial growth in periprosthetic tissue or sonication fluid of the removed prosthesis. The surgery on the infected ankle prosthesis and the follow-up were performed by the surgical team, who implanted the prosthesis. A specialized septic team consisting of an orthopaedic surgeon and infectious diseases consultant were included in the treatment.Results: During the study period, 92 total ankle prostheses were implanted in 90 patients (mean age 61 years, range 28-80 years). 78 patients had posttraumatic arthritis, 11 rheumatoid arthritis and 3 other degenerative disorder. Ankle PJI occurred in 3 of 92 TAR (3.3%), occurring 1, 2 and 24 months after implantation; the causative organisms were Enterobacter cloacae, Streptococcus pyogenes and Staphylococcus epidermidis, respectively. The ankle prosthesis was removed in all infected patients, including debridement of the surrounding tissue was debrided and insertion of an antibiotic loaded spacer. Provisional arthrodesis was performed by external fixation in two patients and by plaster cast in one. A definitive ankle arthrodesis with a retrograde nail was performed 6 to 8 weeks after prosthesis removal. One patient needed a flap coverage. All 3 patients received intravenous antibiotic treatment for 2 weeks, followed by oral antibiotics for 4-6 weeks. At follow-up visit up to 18 months after start of treatment, all patients were without clinical or laboratory signs of infection.Conclusions: The infection incidence after TAR was 3.3%, which is slightly higher than reported after hip (<1%) or knee arthroplasty (<2%). A two-step approach consisting of removal of the infected prosthesis, combined with local and systemic antibiotic treatment, followed by definitive ankle arthrodesis shows good results. Larger patient cohort and longer follow-up evaluation is needed to define the optimal treatment approach for ankle PJI.

Proximate basis of the covariation between a melanin-based female ornament and offspring quality.

In contradiction to sexual selection theory, several studies showed that although the expression of melanin-based ornaments is usually under strong genetic control and weakly sensitive to the environment and body condition, they can signal individual quality. Covariation between a melanin-based ornament and phenotypic quality may result from pleiotropic effects of genes involved in the production of melanin pigments. Two categories of genes responsible for variation in melanin production may be relevant, namely those that trigger melanin production (yes or no response) and those that determine the amount of pigments produced. To investigate which of these two hypotheses is the most likely, I reanalysed data collected from barn owls ( Tyto alba). The underparts of this bird vary from immaculate to heavily marked with black spots of varying size. Published cross-fostering experiments have shown that the proportion of the plumage surface covered with black spots, a eumelanin composite trait so-called "plumage spottiness", in females positively covaries with offspring humoral immunocompetence, and negatively with offspring parasite resistance (i.show $132#e. the ability to reduce fecundity of ectoparasites) and fluctuating asymmetry of wing feathers. However, it is unclear which component of plumage spottiness causes these relationships, namely genes responsible for variation in number of spots or in spot diameter. Number of spots reflects variation in the expression of genes triggering the switch from no eumelanin production to production, whereas spot diameter reflects variation in the expression of genes determining the amount of eumelanin produced per spot. In the present study, multiple regression analyses, performed on the same data sets, showed that humoral immunocompetence, parasite resistance and wing fluctuating asymmetry of cross-fostered offspring covary with spot diameter measured in their genetic mother, but not with number of spots. This suggests that genes responsible for variation in the quantity of eumelanin produced per spot are responsible for covariation between a melanin ornament and individual attributes. In contrast, genes responsible for variation in number of black spots may not play a significant role. Covariation between a eumelanin female trait and offspring quality may therefore be due to an indirect effect of melanin production.

eComment: Everyday clinical practice consequences?

Comment on : "Type A aortic dissection involving the carotid arteries: carotid stenting during open aortic arch surgery by Salvatore Lentini, Fabrizio Tancredi, Filippo Benedetto, and Roberto Gaeta in Interactive CardioVascular and Thoracic Surgery 2009 8: 157-159

Cutaneous benign mixed tumor (chondroid syringoma) of the eyelid: clinical presentation and management.

PURPOSE: To describe the clinical presentation of cutaneous benign mixed tumor of the eyelid and its management options. METHODS: Periocular cases of cutaneous benign mixed tumor were gathered from members of an oculoplastics specialty Internet discussion group. A total of 9 patients are described in this retrospective, interventional case series. The clinical presentation, histopathology, and management of these lesions is reviewed. RESULTS: Patients were typically asymptomatic, presenting with a slowly enlarging, nontender nodule of 2 to 8 years' duration. The lesions ranged from 4 mm to 17 mm in greatest dimension. Four of the lesions were on the eyelid margin, three in the sub-brow area of the upper eyelid, and two in the central lids. All six cases not involving the brow were fixed to the tarsus; one brow lesion was believed to be adherent to the skin. None of the lesions was associated with significant changes of the overlying epidermis, although one lesion showed overlying pigmentation. All patients underwent excisional biopsy for diagnostic or cosmetic reasons. On histopathologic examination, the tumors were biphasic, with an epithelial component exhibiting apocrine or hair follicle differentiation and a myxoid, adipocytic, chondroid, and/or fibrous stroma. The pathologic diagnoses were all consistent with cutaneous benign mixed tumor (chondroid syringoma, pleomorphic adenoma). Follow-up ranged from 2 weeks to 12 months, although several patients failed to keep scheduled follow-up appointments. No clinical recurrences were identified. CONCLUSIONS: Cutaneous benign mixed tumor may occur in the eyelid, and, although uncommon, should be included in the differential diagnosis of firm, nodular eyelid tumors. The histopathologic features are similar to those seen in this tumor type arising in other areas of the body. Preoperative consideration of this diagnostic possibility may allow the surgeon to plan for complete excision, thereby reducing the possibility of recurrence or malignant transformation.

Clinical results of autologous infrainguinal revascularization using grafts originating distal to the femoral bifurcation in patients with mild inflow disease.

AIM: Chronic critical limb ischemia (CLI) often requires venous bypass grafting to distal arterial segments. However, graft patency is influenced by the length and quality of the graft and occasionally patients may have limited suitable veins. We investigated short distal bypass grafting from the superficial femoral or popliteal artery to the infrapopliteal, ankle or foot arteries, despite angiographic alterations of inflow vessels, providing that invasive pressure measurement at the site of the planned proximal anastomosis revealed an inflow-brachial pressure difference of <or=10 mmHg. METHODS: Four hundred and twenty-three consecutive infrainguinal bypass grafts were performed for CLI between June, 1999 and November, 2002 at our institution. All patients underwent preoperative clinical examination, arteriography and assessment of the veins by duplex ultrasound. The study group are patients in whom the proximal and distal anastomoses of the bypass are below the femoral bifurcation and the popliteal artery, respectively. Invasive arterial pressure measurements were recorded at the level of the planned proximal anastomosis which was performed at that level if the difference of the inflow-brachial pressure was <or=10 mmHg, irrespective of angiographic alterations of the inflow vessels proximal to the planned anastomosis. All patients had a clinical follow-up included a duplex examination of their graft, at 1 week, 3, 9 and 12 months and, thereafter, annually. No patient was lost to follow-up. RESULTS: Sixty-seven patients underwent 71 short distal bypass grafts in 71 limbs with reversed saphenous vein grafts in 52, in situ saphenous veins in 11, reversed cephalic vein in 1 and composite veins in 7, respectively. Surgical or endovascular interventions to improve inflow were required in 4 limbs (5.6%). The mean follow-up time was 22.5 months and the two-year survival was 92.5%. Primary and secondary patency rates at 2 years were 73% and 93%, respectively, and the limb salvage rate was 98.5%. CONCLUSION: In appropriately selected patients, short distal venous bypass grafts can be performed with satisfactory patency and limb salvage rates even in the presence of morphologic alterations of the inflow vessels providing that these are not hemodynamically significant, or can be corrected intraoperatively.

Which available transapical transcatheter valve fits into degenerated aortic bioprostheses?

The transapical transcatheter aortic valve implantation (TA-TAVI) in degenerated aortic bioprosthesis is an emerging therapy for surgically non-amenable patients. However, the presence of different types of aortic bioprostheses (stented and stentless), available in different sizes (19-27 mm), can be at the origin of important mismatches between the malfunctioning, degenerated aortic valves and the inner stent-valves implanted through transapical accesses (23 and 26 mm Edwards Sapien transcatheter stent-valves). We report an emergency TA-TAVI treatment of a severely regurgitant degenerated 23 mm Mitroflow aortic bioprosthesis (Sorin Group, Milano, Italy) implanted seven years earlier in an 80-year-old lady, and we reviewed the current available literature about transapical 'valve-in-valve' procedures to analyze the hemodynamic results and the ideal 'prosthesis-to-prosthesis' match.

Enhanced biodegradation of hexachlorocyclohexane (HCH) in contaminated soils via inoculation with Sphingobium indicum B90A.

Soil pollution with hexachlorocyclohexane (HCH) has caused serious environmental problems. Here we describe the targeted degradation of all HCH isomers by applying the aerobic bacterium Sphingobium indicum B90A. In particular, we examined possibilities for large-scale cultivation of strain B90A, tested immobilization, storage and inoculation procedures, and determined the survival and HCH-degradation activity of inoculated cells in soil. Optimal growth of strain B90A was achieved in glucose-containing mineral medium and up to 65% culturability could be maintained after 60 days storage at 30 degrees C by mixing cells with sterile dry corncob powder. B90A biomass produced in water supplemented with sugarcane molasses and immobilized on corncob powder retained 15-20% culturability after 30 days storage at 30 degrees C, whereas full culturability was maintained when cells were stored frozen at -20 degrees C. On the contrary, cells stored on corncob degraded gamma-HCH faster than those that had been stored frozen, with between 15 and 85% of gamma-HCH disappearance in microcosms within 20 h at 30 degrees C. Soil microcosm tests at 25 degrees C confirmed complete mineralization of [(14)C]-gamma-HCH by corncob-immobilized strain B90A. Experiments conducted in small pits and at an HCH-contaminated agricultural site resulted in between 85 and 95% HCH degradation by strain B90A applied via corncob, depending on the type of HCH isomer and even at residual HCH concentrations. Up to 20% of the inoculated B90A cells survived under field conditions after 8 days and could be traced among other soil microorganisms by a combination of natural antibiotic resistance properties, unique pigmentation and PCR amplification of the linA genes. Neither the addition of corncob nor of corncob immobilized B90A did measurably change the microbial community structure as determined by T-RFLP analysis. Overall, these results indicate that on-site aerobic bioremediation of HCH exploiting the biodegradation activity of S. indicum B90A cells stored on corncob powder is a promising technology.