Towards no-scar cardiac surgery - minimally invasive access through umbilicus for aortic valve replacement.

There is an ever-growing trend towards less-invasive procedures in all fields of medicine. We designed an animal study to prove the concept that trans-apical aortic valve replacement from an incision within the umbilicus through a single channel for instruments is feasible, which would be a major leap towards no-scar cardiac surgery. In three adult pigs, after creating a single 3-cm incision at a place where the human umbilicus would be, we introduced a 30F sheath through a tunnel created by an endoscopic vein-harvesting device up to the cardiac apex, through it and up to the left ventricle simulating the approach for trans-apical aortic valve replacement. We used a standard Amplatz nitinol occluder to seal the defect in ventricle wall later. The animals were followed up for 1h. Blood loss was minimal, and no tamponade occurred in any of the animals. In addition, we performed a test with water column static pressure to evaluate the impact of preclotting on the sealing properties of the occluders: 1 min flow-through was 2860+/-176 ml for the standard occluders and 348+/-56 ml for preclotted occluders (p<0.001).

Functional calibration procedure for 3D knee joint angle description using inertial sensors.

Measurement of three-dimensional (3D) knee joint angle outside a laboratory is of benefit in clinical examination and therapeutic treatment comparison. Although several motion capture devices exist, there is a need for an ambulatory system that could be used in routine practice. Up-to-date, inertial measurement units (IMUs) have proven to be suitable for unconstrained measurement of knee joint differential orientation. Nevertheless, this differential orientation should be converted into three reliable and clinically interpretable angles. Thus, the aim of this study was to propose a new calibration procedure adapted for the joint coordinate system (JCS), which required only IMUs data. The repeatability of the calibration procedure, as well as the errors in the measurement of 3D knee angle during gait in comparison to a reference system were assessed on eight healthy subjects. The new procedure relying on active and passive movements reported a high repeatability of the mean values (offset<1 degrees) and angular patterns (SD<0.3 degrees and CMC>0.9). In comparison to the reference system, this functional procedure showed high precision (SD<2 degrees and CC>0.75) and moderate accuracy (between 4.0 degrees and 8.1 degrees) for the three knee angle. The combination of the inertial-based system with the functional calibration procedure proposed here resulted in a promising tool for the measurement of 3D knee joint angle. Moreover, this method could be adapted to measure other complex joint, such as ankle or elbow.

Comparison of polyethylene wear in anatomical and reversed shoulder prostheses.

Wear of polyethylene is associated with aseptic loosening of orthopaedic implants and has been observed in hip and knee prostheses and anatomical implants for the shoulder. The reversed shoulder prostheses have not been assessed as yet. We investigated the volumetric polyethylene wear of the reversed and anatomical Aequalis shoulder prostheses using a mathematical musculoskeletal model. Movement and joint stability were achieved by EMG-controlled activation of the muscles. A non-constant wear factor was considered. Simulated activities of daily living were estimated from in vivo recorded data. After one year of use, the volumetric wear was 8.4 mm(3) for the anatomical prosthesis, but 44.6 mm(3) for the reversed version. For the anatomical prosthesis the predictions for contact pressure and wear were consistent with biomechanical and clinical data. The abrasive wear of the polyethylene in reversed prostheses should not be underestimated, and further analysis, both experimental and clinical, is required.

Cross-cultural adaptations of the Oxford-12 HIP score to the French speaking population.

BACKGROUND: An objective measurement of surgical procedures outcomes is inherent to professional practices quality control; this especially applies in orthopaedics to joint replacement outcomes. A self-administered questionnaire offers an attractive alternative to surgeon's judgement but is infrequently used in France for these purposes. The British questionnaire, the 12-item Oxford Hip Score (OHS) was selected for this study because of its ease of use. HYPOTHESIS: The objective of this study was to validate the French translation of the self-assessment 12-item Oxford Hip Score and compare its results with those of the reference functional scores: the Harris Hip Score (HHS) and the Postel-Merle d'Aubigné (PMA) score. MATERIALS AND METHODS: Based on a clinical series of 242 patients who were candidates for total hip arthroplasty, the French translation of this questionnaire was validated. Its coherence was also validated by comparing the preoperative data with the data obtained from the two other reference clinical scores. RESULTS: The translation was validated using the forward-backward translation procedure from French to English, with correction of all differences or mistranslations after systematized comparison with the original questionnaire in English. The mean overall OHS score was 43.8 points (range, 22-60 points) with similarly good distribution of the overall value of the three scores compared. The correlation was excellent between the OHS and the HHS, but an identical correlation between the OHS and the PMA was only obtained for the association of the pain and function parameters, after excluding the mobility criterion, relatively over-represented in the PMA score. DISCUSSION AND CONCLUSION: Subjective questionnaires that contribute a personal appreciation of the results of arthroplasty by the patient can easily be applied on a large scale. This study made a translated and validated version of an internationally recognized, reliable self-assessment score available to French orthopaedic surgeons. The results obtained encourage us to use this questionnaire as a complement to the classical evaluation scores and methods.

Oestrogen replacement treatment and the risk of endometrial cancer : an assessment of the role of covariates

The relationship between oestrogen replacement treatment and the risk of endometrial cancer was analysed in a case-control study of 158 histologically confirmed incident cases below the age of 75 and 468 controls in hospital for acute, non-neoplastic, non-hormone-related conditions conducted in the Swiss Canton of Vaud in 1988-1992. Overall, 60 (38%) cases vs. 93 (20%) controls had ever used oestrogen replacement treatment: the corresponding multiple logistic regression relative risk (RR) was 2.7 (95% confidence interval, CI: 1.7-4.1). The risk was directly related to duration of use, and rose to 5.1 (95% CI: 2.7-9.8) for > 5 year-use. The RR was still significantly elevated 10 or more years after stopping use (RR = 2.3, 95% CI: 1.2-4.5). When the role of covariates was considered, a significant interaction was observed with body mass index (RR for long-term oestrogen use = 6.0 for lean or normal weight women vs. 2.4 for overweight women). There was also a hint of a negative interaction with oral contraceptive (OC) use, since the RR for oestrogens was higher (or restricted) to women who had never used OC (RR = 5.4, for long-term oestrogen use), as compared with those who had used OC, who showed no significant evidence of association with oestrogens (RR = 0.9 for long-term use). There was no significant interaction with cigarette smoking. Thus, this study confirms the presence of a strong association between oestrogen replacement treatment and endometrial cancer risk, since in the late 1980s or early 1990s about 25% of cases could be attributed to oestrogen replacement treatment in this Swiss population. Further, it confirms the presence of significant negative interactions of oestrogen use with obesity, and, possibly, with OC as well.

Influence of preoperative leg pain and radiculopathy on outcomes in mono-segmental lumbar total disc replacement: results from a nationwide registry.

PURPOSE: Currently, many pre-conditions are regarded as relative or absolute contraindications for lumbar total disc replacement (TDR). Radiculopathy is one among them. In Switzerland it is left to the surgeon's discretion when to operate if he adheres to a list of pre-defined indications. Contraindications, however, are less clearly specified. We hypothesized that, the extent of pre-operative radiculopathy results in different benefits for patients treated with mono-segmental lumbar TDR. We used patient perceived leg pain and its correlation with physician recorded radiculopathy for creating the patient groups to be compared. METHODS: The present study is based on the dataset of SWISSspine, a government mandated health technology assessment registry. Between March 2005 and April 2009, 577 patients underwent either mono- or bi-segmental lumbar TDR, which was documented in a prospective observational multicenter mode. A total of 416 cases with a mono-segmental procedure were included in the study. The data collection consisted of pre-operative and follow-up data (physician based) and clinical outcomes (NASS form, EQ-5D). A receiver operating characteristic (ROC) analysis was conducted with patients' self-indicated leg pain and the surgeon-based diagnosis "radiculopathy", as marked on the case report forms. As a result, patients were divided into two groups according to the severity of leg pain. The two groups were compared with regard to the pre-operative patient characteristics and pre- and post-operative pain on Visual Analogue Scale (VAS) and quality of life using general linear modeling. RESULTS: The optimal ROC model revealed a leg pain threshold of 40 ≤ VAS > 40 for the absence or the presence of "radiculopathy". Demographics in the resulting two groups were well comparable. Applying this threshold, the mean pre-operative leg pain level was 16.5 points in group 1 and 68.1 points in group 2 (p < 0.001). Back pain levels differed less with 63.6 points in group 1 and 72.6 in group 2 (p < 0.001). Pre-operative quality of life showed considerable differences with an 0.44 EQ-5D score in group 1 and 0.29 in group 2 (p < 0.001, possible score range -0.6 to 1). At a mean follow-up time of 8 months, group 1 showed a mean leg pain improvement of 3.6 points and group 2 of 41.1 points (p < 0.001). Back pain relief was 35.6 and 39.1 points, respectively (p = 0.27). EQ-5D score improvement was 0.27 in group 1 and 0.41 in group 2 (p = 0.11). CONCLUSIONS: Patients labeled as having radiculopathy (group 2) do mostly have pre-operative leg pain levels ≥ 40. Applying this threshold, the patients with pre-operative leg pain do also have more severe back pain and a considerably lower quality of life. Their net benefit from the lumbar TDR is higher and they do have similar post-operative back and leg pain levels as well as the quality of life as patients without pre-operative leg pain. Although randomized controlled trials are required to confirm these findings, they put leg pain and radiculopathy into perspective as absolute contraindications for TDR.

Clinical results of enzyme replacement therapy in Fabry disease: a comprehensive review of literature.

Enzyme replacement therapy (ERT) has been used to treat Fabry disease - a progressive lysosomal storage disorder - since 2001. Two preparations of the enzyme alpha-galactosidase A are available in Europe: agalsidase alpha, produced in a human cell line, and agalsidase beta, produced in Chinese hamster ovary cells. To review critically the published evidence for the clinical efficacy of these two enzyme preparations. A systematic literature search was undertaken to identify open or randomised controlled trials published on Fabry disease since 2001. Eleven trials fulfilled the criteria for inclusion in this review, of a total of 586 references on Fabry disease. To date, no direct comparisons exists between the two available enzyme preparations. Significant clinical benefits compared with placebo, however, have been demonstrated with ERT, with positive effects on the heart, kidneys, nervous system and quality of life. The quality of most of these publications was less than optimal. Further prospective studies are required to confirm the long-term clinical benefits of ERT. More studies are also needed on the effects of ERT in women and on the use of ERT early in the course of Fabry disease, to prevent organ damage. Large national and international outcomes databases will also be invaluable in evaluating treatment effects and safety.

Superior vena cava syndrome caused by invasive epidermoid carcinoma.

Lung cancer is the most frequent cause of superior vena cava (SVC) syndrome. Malignant SVC syndrome is generally considered a contraindication to curative resection, although palliative bypasses are done for symptoms that do not respond to medical therapy. However, a majority of patients with such advanced disease die of complications caused by the primary tumor rather than distant metastasis. We present the case of one patient with lung cancer invading the mediastinal structures. Combined resection and replacement of the SVC with a segment of Dacron vascular graft was performed. Postoperative survival time was 24 months.

Comparisons of preoperative three-dimensional planning and surgical reconstruction in primary cementless total hip arthroplasty.

Reconstruction of important parameters such as femoral offset and torsion is inaccurate, when templating is based on plain x-rays. We evaluate intraoperative reproducibility of pre-operative CT-based 3D-templating in a consecutive series of 50 patients undergoing primary cementless THA through an anterior approach. Pre-operative planning was compared to a postoperative CT scan by image fusion. The implant size was correctly predicted in 100% of the stems, 94% of the cups and 88% of the heads (length). The difference between the planned and the postoperative leg length was 0.3 + 2.3 mm. Values for overall offset, femoral anteversion, cup inclination and anteversion were 1.4 mm ± 3.1, 0.6° ± 3.3°, -0.4° ± 5° and 6.9° ± 11.4°, respectively. This planning allows accurate implant size prediction. Stem position and cup inclination are accurately reproducible.

Mechanical Properties of a Photopolymerizable Hydrogel for Intervertebral Disc Replacement.

We report on the modelling and experimental validation of a photopolymerizable hydrogel for a Nucleus Pulposus replacement.

Total knee arthroplasty - a clinical and numerical study of the micromovements of the tibial implant

Introduction The importance of the micromovements in the mechanism of aseptic loosening is clinically difficult to evaluate. To complete the analysis of a series of total knee arthroplasties (TKA), we used a tridimensional numerical model to study the micromovements of the tibial implant.Material and Methods Fifty one patients (with 57 cemented Porous Coated Anatomic TKAs) were reviewed (mean follow-up 4.5 year). Radiolucency at the tibial bone-cement interface was sought on the AP radiographs and divided in 7 areas. The distribution of the radiolucency was then correlated with the axis of the lower limb as measured on the orthoradiograms.The tridimensional numerical model is based on the finite element method. It allowed the measurement of the cemented prosthetic tibial implant's displacements and the microvements generated at bone-ciment interface. A total load (2000 Newton) was applied at first vertically and asymetrically on the tibial plateau, thereby simulating an axial deviation of the lower limbs. The vector's posterior inclination then permitted the addition of a tangential component to the axial load. This type of effort is generated by complex biomechanical phenomena such as knee flexion.Results 81 per cent of the 57 knees had a radiolucent line of at least 1 mm, at one or more of the tibial cement-epiphysis jonctional areas. The distribution of these lucent lines showed that they came out more frequently at the periphery of the implant. The lucent lines appeared most often under the unloaded margin of the tibial plateau, when axial deviation of lower limbs was present.Numerical simulations showed that asymetrical loading on the tibial plateau induced a subsidence of the loaded margin (0-100 microns) and lifting off at the opposite border (0-70 microns). The postero-anterior tangential component induced an anterior displacement of the tibial implant (160-220 microns), and horizontal micromovements with non homogenous distribution at the bone-ciment interface (28-54 microns).Discussion Comparison of clinical and numerical results showed a relation between the development of radiolucent lines and the unloading of the tibial implant's margin. The deleterious effect of lower limbs' axial deviation is thereby proven. The irregular distribution of lucent lines under the tibial plateau was similar of the micromovements' repartition at the bone-cement interface when tangential forces were present. A causative relation between the two phenomenaes could not however be established.Numerical simulation is a truly useful method of study; it permits to calculate micromovements which are relative, non homogenous and of very low amplitude. However, comparative clinical studies remain as essential to ensure the credibility of results.

Gonadotrophin replacement for induction of fertility in hypogonadal men.

Congenital hypogonadotrophic hypogonadism (CHH) is a rare form of infertility caused by deficient secretion or action of gonadotrophin-releasing hormone. There is no consensus regarding the optimal approach to fertility treatment in CHH men. In most cases, appropriate hormonal treatment with human chorionic gonadotrophin with or without follicle stimulating hormone will induce testicular development, spermatogenesis and fertility. Recent studies have examined sequential treatment with FSH pre-treatment to optimize fertility outcomes in severely affected CHH patients. This paper reviews historical and recent literature to summarize the current evidence on therapeutic approaches for CHH men seeking fertility.

Effect of biomagnetic therapy versus physiotherapy for treatment of knee osteoarthritis: a randomized controlled trial.

OBJECTIVE: To assess the effectiveness of pulsed signal therapy in the treatment of knee osteoarthritis (Kellgren II or III). METHODS: A randomized, double-blind controlled clinical trial. The first 95 patients sent to the clinic with knee osteo-arthritis were selected and randomized into treatment with pulsed signal therapy or conventional physiotherapy. Assessment included recording of usual demographic data, pertinent history, baseline medication and radiographs. Clinical evaluation was made at baseline, 6 weeks and 6 months after the end of treatment by the same blinded doctor. At each follow-up time, the patient was asked to complete a visual analogue pain scale and a Lequesne score. The doctor recorded the degree of pain on motion and the ability to move the affected knee. RESULTS: Both treatments resulted in significant improvements in pain and physical function. A statistical difference was observed only for activities of daily living, where the physiotherapy was more efficient (p<0.03). The cost of treatment with pulsed signal therapy was significantly higher, double the treatment cost of conventional physiotherapy. CONCLUSION: Like physiotherapy, pulsed signal therapy has improved the clinical state of treated patients but with no significant statistical difference. Pulsed signal therapy is, however, more expensive.