Reproducibility of an optical measurement system for the clinical evaluation of active knee rotation in weight-bearing, healthy subjects

INTRODUCTION

A knee is typically evaluated passively by a clinician during an office visit, without using dedicated measurement tools. When the knee is evaluated with the patient standing and actively participating in the movement, the results will differ than when the knee is passively moved through its range-of-motion by the surgeon. If a precise measurement system was available, it could provide additional information to the clinician during this evaluation.

HYPOTHESIS

The goal of this study was to verify the reproducibility of a fast, flexible optical measurement system to measure rotational knee laxity during weight-bearing.

MATERIAL AND METHODS

Two passive reflective targets were placed on the legs of 11 subjects to monitor femur and tibia displacements in three dimensions. Subjects performed internal and external rotation movements with the knee extended or flexed 30°. During each movement, seven variables were measured: internal rotation, external rotation and overall laxity in extension and 30° flexion, along with neutral rotation value in 30° flexion. Measurement accuracy was also assessed and the right and left knees were compared. Reproducibility was assessed over two measurements sessions.

RESULTS

The calculated intra-class correlation coefficient (ICC) for reproducibility was above 0.9 for five of the seven variables measured. The calculated ICC for the right/left comparison was above 0.75 for five of the seven variables measured.

DISCUSSION

These results confirmed that the proposed system provides reproducible measurements. Our right/left comparison results were consistent with the published literature. This system is fast, reproducible and flexible, which makes it suitable for assessing various weight-bearing movements during clinical evaluations.

LEVEL OF EVIDENCE

Level III, experimental study.

Knee rotational laxity and proprioceptive function 2 years after partial ACL reconstruction

PURPOSE

The aim of our study was to evaluate knee rotational laxity and proprioceptive function 2 years after partial anterior cruciate ligament (ACL) reconstruction. According to our hypothesis, partial ACL reconstruction could restore knee laxity and function to the intact level.

METHODS

We conducted a study in fifteen consecutive patients undergoing partial ACL reconstruction. Fifteen anteromedial bundle tears were identified intraoperatively. Partial ACL reconstructions were performed by the same senior surgeon using a single-incision technique. A bone-patellar tendon-bone graft was used in 13 cases and a double-stranded semitendinosus graft in 2 cases of chronic patellar tendonitis. The mean age at surgery was 29 years. The time between ACL tear and surgery averaged 7.8 months (range 2.5-29.5 months). We developed an original device designed to assess knee proprioception (passive and active) and measure weight-bearing rotational laxity in full extension and at 30°, 60° and 90° of knee flexion. All measurements were taken on both the reconstructed and healthy knee.

RESULTS

The mean follow-up of the study was 3.4 years (range 2.6-4.4). No statistically significant difference in rotational laxity, active or passive proprioception could be observed between the reconstructed and healthy knee. External rotation was significantly greater than internal rotation in full extension and at 30° of flexion in the reconstructed and the healthy knee (P < 0.05). For each knee, active proprioception was found to be significantly different (higher) than passive proprioception (P < 0.05).

CONCLUSION

Our study did not detect any difference in rotational laxity and proprioception between the reconstructed and the healthy knee. Therefore, partial ACL reconstruction appears to restore satisfactory knee laxity and function in case of partial ACL tear.

LEVEL OF EVIDENCE

IV.

Leukocyte telomere length is associated with complications of type 2 diabetes mellitus

OBJECTIVE

The key goal of diabetes management is to prevent complications. While the patho-physiological mechanisms responsible for diabetes complications have been extensively studied, at present it is impossible to predict which patient with diabetes could develop complications. In recent years, the role of leukocyte telomere length in the pathogenesis of cardiovascular disease and Type 2 diabetes has been investigated. However, studies aiming to investigate the role of telomeres in the development and progression of Type 2 diabetes, as well as diabetic complications, are still lacking. As a consequence, this study aimed to verify whether leukocyte telomere length is associated with the presence and the number of diabetic complications in a sample of patients with Type 2 diabetes.

METHODS

This is a cross-sectional study. Nine hundred and one subjects were enrolled, including 501 patients with Type 2 diabetes, of whom 284 had at least one complication and 217 were without complications, and 400 control subjects. Leukocyte telomere length was measured by quantitative real-time PCR.

RESULTS

Patients with diabetes complications had significantly shorter leukocyte telomere length than both patients without diabetes complications and healthy control subjects. Moreover, among patients with diabetes complications, leukocyte telomere length became significantly and gradually shorter with the increasing number of diabetes complications. The magnitude of the effect of the decrease of the abundance of telomeric template vs. a single-copy gene length (T/S ratio) on complications is described by the estimated odds ratio OR=5.44 (95%CI 3.52-8.42).

CONCLUSIONS

The results of the study support the hypothesis that telomere attrition may be a marker associated with the presence and the number of diabetic complications.

Long-term home ventilation of children in Italy: a national survey

BACKGROUND

Improved technology, as well as professional and parental awareness, enable many ventilator-dependent children to live at home. However, the profile of this growing population, the quality and adequacy of home care, and patients' needs still require thorough assessment.

OBJECTIVES

To define the characteristics of Italian children receiving long-term home mechanical ventilation (HMV) in Italy.

METHODS

A detailed questionnaire was sent to 302 National Health Service hospitals potentially involved in the care of HVM in children (aged <17 years). Information was collected on patient characteristics, type of ventilation, and home respiratory care.

RESULTS

A total of 362 HMV children was identified. The prevalence was 4.2 per 100,000 (95% CI: 3.8-4.6), median age was 8 years (interquartile range 4-14), median age at starting mechanical ventilation was 4 years (1-11), and 56% were male. The most frequent diagnostic categories were neuromuscular disorders (49%), lung and upper respiratory tract diseases (18%), hypoxic (ischemic) encephalopathy (13%), and abnormal ventilation control (12%). Medical professionals with nurses (for 62% of children) and physiotherapists (20%) participated in the patients' discharge from hospital, though parents were the primary care giver, and in 47% of cases, the sole care giver. Invasive ventilation was used in 41% and was significantly related to young age, southern regional residence, longer time spent under mechanical ventilation, neuromuscular disorders, or hypoxic (ischemic) encephalopathy.

CONCLUSIONS

Care and technical assistance of long-term HMV children need assessment, planning, and resources. A wide variability in pattern of HMV was found throughout Italy. An Italian national ventilation program, as well as a national registry, could be useful in improving the care of these often critically ill children.

Is transverse acetabular ligament an anatomical landmark to reliably orient the cup in primary total hip arthroplasty?

INTRODUCTION

Accurate positioning of the acetabular cup in primary total hip arthroplasty is critical to decrease the rate of dislocation. Inaccurate orientation of the cup is the most common error during this procedure. Target acetabular orientation is still controversial. An original study found a dislocation rate of 0.6% when the cup was aligned with the transverse acetabular ligament (TAL).

HYPOTHESIS

TAL is a patient-specific anatomical landmark and a tool for cup orientation.

MATERIALS AND METHODS

Eight cadaveric pelves (14 hips included for study) were harvested in toto at our research laboratory. Anatomical versions of the TAL, labrum and horns were measured in relation to the anterior pelvic plane. A navigator sensor and an optoelectronic device (Motion Analysis™) were used.

RESULTS

Anatomical versions of the TAL, horns and labrum averaged 1.9° (range, -8° to +13.3°), 3° (range, -12.2° to 14°), and 26.3° (range, 17.4° to 41.8°), respectively.

DISCUSSION

To our knowledge, this is the first study to report the orientation of the periacetabular soft-tissues. TAL anteversion was outside the safe zone described by Lewinnek, while labrum anteversion was within this safe-zone. We discuss the reference used, Lewinnek's safe zone, and functional orientation of the implants. Lewinnek's safe-zone does not seem to be valid. The TAL seems to be a specific reference for each patient but its reliability must still be confirmed as an adequate reference for positioning the cup in total hip arthroplasty.

Localized Wegener's granulomatosis

BACKGROUND

Wegener's granulomatosis (WG) is a rare granulomatous necrotizing vasculitis of small and medium vessels which has predilection for upper airways, lungs and kidney. However, any other organ, including the skin and oral cavity, can be involved. Although mucocutaneous lesions are relatively common, they have only rarely been reported as localized manifestation of the disease.

OBJECTIVES

Our aim was to evaluate the type and sites of skin and mucosal lesions, clinical course and response to treatment, histologic features and laboratory findings in localized WG.

METHODS

The medical records of three patients (two women and one man) with localized WG followed up at our hospitals for a mean time of 10 years were studied.

RESULTS

All patients presented with facial plaques infiltrating the nasal and palatal mucosae and cartilages and, in one case, perforating the palatal bone. Anti-neutrophil cytoplasmic antibodies, which are the marker for multisystem WG, were negative. The disease, refractory to various immunosuppressants, responded well, albeit incompletely, to prednisone plus cyclophosphamide.

LIMITATIONS

The limited number of patients is counterbalanced by the rarity of the disease.

CONCLUSIONS

Our cases may represent a rare distinctive subset of WG limited to the facial region and upper airway mucosa but showing a locally aggressive behaviour leading to cartilage and bony destruction.

Risk profiles in type 2 diabetes (metabolic syndrome): integration of IL-10 polymorphisms and laboratory parameters to identify vascular damages related complications

Recently it has been reported that low serum IL-10 levels are associated with an increased susceptibility for metabolic syndrome and type 2 diabetes mellitus (T2DM). We investigated whether the -1087G/A (rs1800896), -824C/T (rs1800871), -597C/A (rs1800872) IL-10 polymorphisms were associated with type 2 diabetes in a study on a cohort of Italian Caucasians comprising 490 type 2 diabetic and 349 control subjects. Stratifying the data according to IL-10 genotypes, trends for the progressive increase of glucose and neutrophil levels were observed in -1087GG vs. -1087GA vs. -1087AA positive diabetic patients (-1087GG<-1087GA<-1087AA). In addition, evaluating the laboratory parameters according to the -597/-824/-1087 derived haplotypes a significant increase of neutrophils was found in diabetic vs. non-diabetic -597A/ -824T/-1087A positive subjects (Student t test = 3.707, p<0.01). In an attempt to integrate clinical laboratory and immunogenetic data to determine whether these factors taken together define sufficient risk sets for type 2 diabetes we performed the grade-of-membership analysis (GoM). GoM allowed to identify a population of subjects negative for IL-10 -824T allele, 74.4% of which were diabetic patients characterised by vascular damages (Chronic kidney failure and/or Myocardial Infarction), reduction of haematocrit, increase of blood urea nitrogen, creatinin and monocyte levels. These data seem to suggest that -597A/-824T/-1087A negative subjects are more prone to the major type 2 diabetic vascular damages and allow to hypothesise that the contemporary evaluation of some simple hematochemical parameters and IL-10 SNPs may allow identifying diabetic patients with the worse prognostic profile, needing both better complication prevention planning and therapeutic strategies.

Choking injuries and food products containing inedibles: a survey on mothers' perception in the United Kingdom

Although recent investigations showed no specific hazard resulting from Food Products Containing Inedibles as compared to the wider category of toys, in view of recent findings and subsequent study of the European Registry of Foreign Bodies Injuries, a potential threat has been identified in a lack of parental supervision in the event of injury. Indeed, according to the report of the European Registry of Foreign Bodies Injuries, almost 80% of the injuries occur under parental supervision, which is obviously inadequate. The aim of this short contribution is to present the results of a Computer Assisted Personal Interviewing survey in the UK focused on the knowledge that mothers, fathers and other adults have on the issue of choking. A total of 1946 interviews have been conducted in the UK, in January 2001, all of which directed to subjects over 15 years of age. Data are presented as percentages and absolute numbers. The statistical significance of group differences has been evaluated with the chi-square test with continuity correction. All analyses have been performed using the R system. Those replying to the interview comprised 804 males and 1102 females. Of these, 10% had a child between 0 and 36 months, 9% between 3 and 4 years, 16% between 5-10 years and 13% between 11-15 years. Of those responding, 7% had bought Kinder Surprise within the last two weeks before the interview, 14% within the last three months, and the remaining 53% before, while 26% had never bought Kinder Surprise. These findings would appear to offer a confirmation that mothers tend to balance potential risks with the benefits of exposing the child to a stimulating activity. This mechanism of a controlled exposure to risk, has already been identified as one of the important mechanisms in the psychological development of the child.

Kinematics of a cementless mobile bearing posterior cruciate ligament-retaining total knee arthroplasty

Mobile bearing (MB) total knee arthroplasty (TKA) was developed to provide low contact stress and unconstrained joint motion. We studied a consecutive series of 41 knees with mobile-bearing, posterior cruciate-retaining (CR) TKAs to determine if kinematics resembled normal knees or if kinematics changed over time. Patients were studied at 3 and 21 months average follow-up with weight-bearing radiographs at full extension, 30 degrees flexion and maximum flexion. Shape-matching techniques were used to measure TKA kinematics. Implant hyperextension, maximum flexion and total ROM increased with follow-up. Tibial rotation and condylar translations did not change with time. The medial condyle did not translate from extension to 30 degrees, but translated 5 mm anteriorly from 30 degrees to maximum flexion. Lateral condylar translation was 3 mm posterior from extension to 30 degrees, with no translation from 30 degrees to maximum flexion. Tibiofemoral kinematics in CR-MB-TKAs were stable over time, but did not replicate motions observed in healthy knees. The mobile tibial insert showed rotation and translation at both follow-up examinations, but the patterns of translation were not predictable.

Mobile-bearing insert translational and rotational kinematics in a PCL-retaining total knee arthroplasty

INTRODUCTION

Total knee prostheses with a mobile-bearing insert were developed to provide nonconstrained joint range of motion while reducing friction forces. The purpose of this study was, based on weightbearing X-rays, to evaluate the mobility of the polyethylene tibial insert in relation to the femoral and tibial components. We studied the results of a cementless total knee arthroplasty (TKA) retaining the posterior cruciate ligament (PCL), with a mobile-bearing platform in rotation and anteroposterior translation (Innex Anterior-Posterior Glide, Zimmer) with a mean 23-month follow-up duration after surgery.

HYPOTHESIS

Both anterior-posterior tibiofemoral translation and intraprosthetic axial rotation occur between the mobile polyethylene insert and the tibial endplate.

MATERIAL AND METHOD

In a series of 51 primary TKA, the three-dimensional (3D) kinematics of the femoral, tibial, and mobile insert components were determined using a computerized matching system between the prosthetic 3D models and the radiographic images of the implants on three lateral follow-up weightbearing knee X-rays: films were taken in full extension, at 45 degrees flexion, and at maximum flexion.

RESULTS

There was a statistically significant increase in the internal rotation of the mobile tray with flexion, (up to a mean -3+/-3 degrees between the femoral box and the mobile tray [p<0.0001] and up to a mean -5+/-7 degrees between the tibial tray and the mobile tray [p<0.0001]). The mobile tray did not translate in relation to the tibial endplate from extension to 45 degrees flexion (0+/-2 mm [range: -5 to 6 mm]). However, from 45 degrees to maximum flexion, a statistically significant mean 1+/-2 mm (range: -2 to 9 mm) of anterior translation (p<0.0001) was found.

DISCUSSION

The extent of insert mobility varies from one study to another. Some have reported relatively limited mobility stemming from a superior surface that is not highly congruent, (thus allowing anterior-posterior and mediolateral translation through gliding of the femur in contact with the insert). Other studies have reported mobile-bearing tray mobility in relation to the tibial endplate and minimal rotation at the femoral component level. In this series of PCL retaining TKA with a mobile-bearing platform, the mobile-bearing platform showed a progressive increase in internal rotation during flexion. Most of this rotational mobility occurred between the mobile platform and the tibial endplate, confirming our hypothesis. However, with flexion, the femoral component increased its mobility relatively to the platform. During flexion, an anterior-posterior translation occurred between the femoral implant and the tibial insert, and between the tibial insert and the tibial endplate, but the direction of the mobile tibial insert translation remained unpredictable with this nonconstrained implant design used.

LEVEL OF EVIDENCE

Level IV. Prospective non-controlled therapeutic study.

Comparative study of knee anterior cruciate ligament reconstruction with or without fluoroscopic assistance: a prospective study of 73 cases

INTRODUCTION

Correct placement of both tibial and femoral tunnels is one of the main factors for a favorable clinical outcome after anterior cruciate ligament (ACL) reconstruction. We used an original system of computer assisted surgery (CAS). The system, based on fluoroscopic guidance combined with special graphical software of image analyzing, showed to the surgeon, before drilling, the recommended placement of tibial and femoral tunnel centers. We compared the first anatomical and clinical results of this procedure to the usual one single incision technique.

MATERIALS AND METHODS

We conducted a prospective study on 73 patients; 37 patients were operated on with CAS and 36 without CAS, by the same senior surgeon. The mean age was 27 years for both groups. Every patient was reviewed at an average of 2.2 years (range 1-4.5) by an independent observer, using IKDC scoring system, KT-1000, and passive stress radiographs.

RESULTS

Time between ACL rupture and reconstruction averaged 30 months for both groups. CAS needed 9.3 min extra surgery time. Clinical evaluation was graded from A to C as per the IKDC scoring system: 67.6% A, 29.7% B, 2.7% C with CAS; and 60% A, 37.1% B, 2.9% C without CAS. IKDC subjective knee evaluation score averaged 89.7 with CAS and 89.5 without CAS. Pre operative KT-1000 maxi manual differential laxity averaged 7. At revision time, all the patients after CAS had a differential laxity less than 2 and 97.7% without CAS. Stress X-rays differential laxity averaged 2.4 mm with CAS and 3 mm without CAS. The area of dispersion of the tunnels' center was smaller on the femoral side using the CAS method. There was no statistically significant difference between both groups using IKDC score, KT-1000 and passive stress radiographs.

CONCLUSIONS

The CAS method provided a more accurate and reproducible tunnels placement without clinical significant effect.

+647 A/C and +1245 MT1A polymorphisms in the susceptibility of diabetes mellitus and cardiovascular complications

Diabetes mellitus is a chronic disease characterized by an overproduction of reactive oxygen species, which perturbs zinc metabolism and promotes the onset of cardiovascular disease (CVD) in diabetic patients. Metallothioneins (MT) are cysteine-rich metal-binding proteins which, by means of their antioxidant and zinc-buffering properties, might prevent the development of diabetic cardiovascular complications. A recent investigation shows that a polymorphism (+647 A/C) in the human MT-1A gene, affects the intracellular zinc ion release (iZnR) from the proteins and is associated with longevity in Italian population. The aim of the present study is to assess the involvement of +647 A/C and +1245 A/G MT1A polymorphisms with the susceptibility to type 2 diabetes (DM2) and cardiovascular complications. The study included 694 old individuals: 242 old healthy controls, 217 DM2 patients without clinical evidence of CVD (DNC) and 235 diabetic patients with diagnosis of CVD (DCVD). +647 A/C MT1A polymorphism, but not the second SNP, was associated with DM2. C allele carriers were more prevalent in DNC and DCVD patients than in control group (OR=1.37, p=0.034; OR=1.54, p=0.002, respectively). C+ carriers was associated with higher glycemia and glycosylated hemoglobin in DCVD patients, but not in DNC or control subjects. No differences in plasma zinc, but a modulation of MT levels and iZnR in PBMCs were observed in DCVD cohort when related to +647 A/C MT1A polymorphism. In summary, this work provides novel evidence on the association of the +647 A/C MT1A polymorphism with DM2. Moreover, C+ carriers in DCVD patients presented a worse glycemic control, a reduced iZnR and a higher MT levels, suggesting a possible role of MT in diabetic cardiovascular complications.

C-reactive protein is directly related to plasminogen activator inhibitor type 1 (PAI-1) levels in diabetic subjects with the 4G allele at position -675 of the PAI-1 gene

BACKGROUND AND AIMS

C-reactive protein (CRP) has been identified as a possible factor able to promote atherosclerosis. "In vitro" studies have demonstrated that CRP induces plasminogen activator inhibitor type 1 (PAI-1) expression, suggesting a hypofibrinolytic role for CRP. As CRP and PAI-1 levels increase in type 2 diabetic subjects, we decided to study the relationship between CRP and PAI-1, and the role of the 4G/5G polymorphism of the PAI-1 gene on this relationship in a diabetic population without complications.

METHODS AND RESULTS

Two hundred and ninety-five type 2 diabetic patients (age 60.9+/-10.5 years) and 290 healthy controls (age 59.2+/-11.5 years) were enrolled. A significant correlation between PAI-1 and CRP in diabetic subjects was found (r=0.45, p<0.001), whereas no relationship was evident in the control subjects between these inflammatory markers. Multiple regression analysis highlighted that CRP is the only one significant variable of PAI-1 antigen in diabetic subjects (partial r=0.31, p<0.01). Stratifying by genotype, a positive correlation between PAI-1 and CRP in 4G/4G (partial r=0.64 p<0.001) and 4G/5G (partial r=0.47, p<0.001) subjects was found, whereas no correlation in 5G/5G was present. Multiple regression analysis confirmed the presence of this correlation in 4G/4G (partial r=0.45, p<0.001) and in 4G/5G (partial r=0.34, p=0.007) diabetic patients.

CONCLUSIONS

These findings demonstrate that CRP plays an important role in the complex mechanism regulating PAI-1 antigen in 4G diabetic carriers.

Effect of etanercept on insulin sensitivity in nine patients with psoriasis

Metabolic syndrome is associated to chronic low grade inflammation, characterized by increased levels of inflammatory cytokines, such as Tumor Necrosis Factor-alpha (TNF-alpha) and Interleukin-6 (IL-6). In particular, TNF-alpha causes a decrease in the insulin-stimulated kinases related to the early phases of the insulin cascade, thereby leading to insulin resistance. Etanercept is a human fusion protein used in the treatment of psoriasis and inflammatory arthritis. It blocks inflammatory response by interfering in the binding of TNF-alpha to its receptors. The aim of this case report study is to verify the effect of Etanercept on insulin sensitivity, lipid profile and inflammatory status in psoriatic patients. Nine psoriatic patients with stable, active, plaque type psoriasis were enrolled and treated with Etanercept for 24 weeks. We found an improvement in the metabolic assessment with a significant reduction of insulin plasma levels. In particular, this treatment allows to maintain their euglycemic state with lower insulin plasma levels, as confirmed by the improved Homeostasis Model Assessment (HOMA) index. We conclude that Etanercept, probably acting on inflammation, improves insulin sensitivity in psoriatic subjects.

An open population screening study for HFE gene major mutations proves the low prevalence of C282Y mutation in Central Italy

BACKGROUND

The C282Y mutation in the HFE gene is responsible for most cases of hereditary haemochromatosis.

AIM

To investigate the allele frequency of HFE mutations and the associations between mutations and cases of iron overload or liver diseases in an open population of Central Italy.

METHODS

A total of 502 individuals over 8 years of age, comprising 203 males and 299 females, who were residents in Arsita (a small town in Central Italy), were assayed for: C282Y, H63D and S65C mutations of the HFE gene by TaqMan probes; body mass index, serum ferritin, transferrin saturation, transaminases, GGT, glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, HBV and HCV serum markers. Information was obtained on alcohol intake. Liver ultrasound was performed in 334 (67%) subjects.

RESULTS

The allele frequencies for C282Y, H63D and S65C were 2%, 15%, and 0.01%, respectively. C282Y/wt was found in 19 subjects (4%), H63D/wt in 127 (25%), H63D/H63D in 11 (2%) and S65C/wt in one (2.0 per thousand). No homozygosity for C282Y or compound mutation (C282Y/H63D) was found in the study population, but 27 subjects (5%) had TfSat >45% (including 10 subjects with high serum ferritin). Overall, 49 subjects (9.8%) were HCV-RNA-positive. Logistic regression analysis indicated that male gender (P = 0.000) and hepatic steatosis (P = 0.017) were independent variables correlating to a high serum ferritin.

CONCLUSION

C282Y HFE mutation is less frequent in Central Italy than in Northern Italy.

Effects of radiograph projection parameter uncertainty on TKA kinematics from model-image registration

Model-image registration techniques have been used extensively for the measurement of joint kinematics in vivo. These techniques typically utilize an explicit measurement of X-ray projection parameters (principal distance, principal point), which is easily done for prospective studies. However, there is vast opportunity to derive useful information from previously collected clinical radiographic films where the projection parameters are unknown. The purpose of this study was to determine variation in measured knee arthroplasty kinematics when the X-ray projection parameters were unknown, but bounded. Based on the clinical radiographic protocol, a nominal principal point was chosen and eight additional points +/-2 and +/-5 cm in the horizontal and vertical directions were defined. Tibiofemoral kinematics were determined for all nine projection parameter sets for a series of 10 lateral radiographs. In addition, the principal distance was varied +/-15 cm and tibiofemoral kinematics were determined for these two projection sets. Measured joint kinematics varied less than 0.6 degrees and 0.4 mm for +/-2 cm variations in principal point location, and 0.7 degrees and 0.6 mm for +/-5 cm variations in principal point location. Measured joint kinematics varied less than 0.6 degrees and 0.7 mm for +/-15 cm variations in principal distance. Variation in X-ray principal point and principal distance over clinically bounded ranges has a small effect on knee arthroplasty kinematics computed from model-image registration with high-quality clinical radiographs.

[Radioprotection optimization measures in hospital workers]

In this contribution, a revision of ionizing radiations exposed workers' dosimetric data in four hospital structures is showed, and, consequently, recommended optimization measures are identified.

Noninvasive ratio indexes to evaluate fibrosis staging in chronic hepatitis C: role of platelet count/spleen diameter ratio index

OBJECTIVES

Noninvasive evaluation of fibrosis is an on-going effort in the management of chronic hepatitis C. This study was planned to noninvasively evaluate fibrosis staging.

DESIGN

We evaluated the biochemical, functional [aminopyrine breath test (ABT)] and ultrasonographic variables of 75 chronic hepatitis C patients.

RESULTS

Clinical [body mass index (BMI)], biochemical [aspartate aminotransferase (AST), alanine aminotransferase (ALT) and platelets (PLT)] and ratio indexes, together with the ABT, showed a higher relationship with fibrosis: initial (score<or=2) versus evident (score>2) fibrosis: BMI (24+/-2 vs. 26+/-2, P=0.0007), AST (56+/-36 vs. 88+/-65, P=0.0159), ALT (92+/-54 vs. 139+/-108, P=0.0290), PLT (220+/-64 vs. 173+/-61, P=0.0007), PLT/spleen diameter ratio (PLT/SPD) (2133+/-786 vs. 1540+/-681, P=0.0003), AST/platelet count ratio index (APRI) (0.80+/-0.87 vs. 1.51+/-1.47, P=0.0010), ABT%d/h30 min (10.8+/-4.5 vs. 7.6+/-3.8, P=0.0007), ABT%d/cum120 min (8.9+/-3.3 vs. 6.5+/-3.1, P=0.0007). Considering the differences between fibrosis score 2 and 3 patients, BMI, ABT and PLT/SPD ratio proved to be statistically significant. Multivariate stepwise analysis (with and without BMI) identified two models for distinguishing between initial and evident fibrosis: Model 1: -0.569+(BMIx0.107)+(APRIx0.169)-(PLT/SPDx0.304), and Model 2: 2.376+( APRIx0.152)-(ABTd/h30x0.043)-(PLT/SPDx0.249). These models showed concordance in identifying or ruling out evident fibrosis in 76% and 78.7% of the patients respectively. The PLT/SPD ratio also showed 78.7% concordance with the histological score.

CONCLUSION

These results suggest that noninvasive evaluation of fibrosis in chronic hepatitis C may be considered an effective tool thanks to the use of an inexpensive, reproducible ratio index.

Interleukin-6-174 G > C polymorphism affects the association between IL-6 plasma levels and insulin resistance in type 2 diabetic patients

Interleukin-6 (IL-6), a powerful inflammatory mediator, plays a pivotal role in the pathogenesis of insulin resistance and type 2 diabetes. Recently, the IL-6 promoter polymorphism, at position -174 (G > C), has been associated to insulin sensitivity although contrasting data have been reported. The aim of this study was to evaluate the effect of the IL-6-174 G > C polymorphism on insulin resistance. In 238 type 2 diabetic patients without diabetic complications and in 255 control subjects, age and gender-matched, we evaluated the IL-6 -174 G > C genotype, the IL-6 plasma levels and the insulin resistance by the homeostasis model assessment (HOMA). The levels of IL-6 and HOMA were not genotype-dependent and were higher in diabetic patients (p < 0.01). Control subjects, both C+ (CG + CC genotypes) and C- (GG genotype) carriers, showed IL-6 plasma levels significantly related to BMI, fasting insulin and HOMA. The same relationships were found in C+ diabetic carriers. Differently, diabetic C- carriers did not show any relationship between IL-6 levels and all the evaluated variables. Interestingly, all the correlations were dependent on BMI. These findings highlight that IL-6-174 G > C polymorphism affects insulin resistance in type 2 diabetes, where C+ carriers have an insulin resistance "IL-6-sensitive", while C- carriers do not. The identification of two categories of diabetic patients may, therefore, lead to different therapeutic strategies in the management of insulin resistance.

A study of 4- and 7-day triple therapy with rabeprazole, high-dose levofloxacin and tinidazole rescue treatment for Helicobacter pylori eradication

BACKGROUND

Helicobacter pylori treatment failure is becoming an emergent problem in clinical practice. Shorter treatment duration should improve compliance to therapy and keep an acceptable H. pylori eradication rate.

AIMS

To evaluate the efficacy of two rabeprazole, high-dose levofloxacin and tinidazole-based regimens as 'rescue' treatment for H. pylori eradication in an open-label, randomized, pilot study carried out in a clinical practice setting.

METHODS

Eighty-five consecutive patients who have previously failed at least one H. pylori eradication attempt were randomized to receive rabeprazole (20 mg, b.d.), levofloxacin (500 mg, b.d.) and tinidazole (500 mg, b.d.) either for 4 (4-day RLT, n = 42) or 7 days (7-day RLT, n = 43). Cure of H. pylori infection was assessed by means of 13C-urea breath test.

RESULTS

The 7-day RLT achieved 84% (95% CI: 69-93%) and 86% (95% CI: 72-95%) eradication rates in intention-to-treat and per-protocol analyses respectively. The shorter treatment obtained an 83% (95% CI: 69-93%) eradication rate in both intention-to-treat and per-protocol analysis. Both regimens were well tolerated, although patients who received the 4-day RLT reported fewer side-effects.

CONCLUSIONS

In patients who have previously failed at least one H. pylori eradication attempt, both 4- and 7-day rabeprazole, high-dose levofloxacin, tinidazole-based regimens are effective in curing the infection in more than 80% of patients.

Application of the platelet count/spleen diameter ratio to rule out the presence of oesophageal varices in patients with cirrhosis: a validation study based on follow-up

BACKGROUND

Screening for oesophageal varices represents an important part of the diagnostic work-up of cirrhotic patients. We have previously shown that the platelet count/spleen diameter ratio is a parameter that can rule out the presence of oesophageal varices safely and in a cost-effective fashion.

AIM

To evaluate the prognostic and diagnostic accuracy of the platelet count/spleen diameter ratio for ruling out the presence of oesophageal varices in the follow-up of a cohort of cirrhotic patients without oesophageal varices at inclusion.

METHODS

After initial endoscopy, the 106 cirrhotic patients without oesophageal varices who participated in our previous study were followed-up with annual or biannual surveillance endoscopy. Patients were censored at the time of diagnosis of oesophageal varices or at their last visit, and at that time platelet count and spleen diameter were recorded. Sixty-eight patients made up the study cohort after excluding patients who were lost to follow-up or died before undergoing control endoscopy.

RESULTS

During the follow-up, 27 patients (40%) developed oesophageal varices. Patients with higher baseline platelet count/spleen diameter ratios (p<0.0001) as well as a ratio above 909 were less likely to develop oesophageal varices (p<0.0005). At follow-up, a platelet count/spleen diameter ratio < or = 909 had 100% negative predictive value and 84% efficiency in identifying the presence of oesophageal varices.

CONCLUSIONS

The use of the platelet count/spleen diameter ratio proved to be an effective means for ruling out the presence of oesophageal varices even in the longitudinal follow-up of patients.

5-ASA and colorectal cancer chemoprevention in inflammatory bowel disease: can we afford to wait for 'best evidence'?

Patients with inflammatory bowel disease have a higher risk of developing colorectal cancer. The main risk factors for colorectal cancer are not suitable targets for therapeutic intervention, and primary chemoprevention is an intriguing therapeutic option. The analogies between acetyl-salicylic acid and 5-amino-salicylic acid, and the results obtained by using acetyl-salicylic acid as a chemopreventive agent in patients with sporadic colorectal cancer have prompted the study of potential chemopreventive effects of 5-amino-salicylic acid in inflammatory bowel disease. The results of both epidemiological and experimental studies have shown that long-term 5-amino-salicylic acid treatments appear to have a chemopreventive effect. The evidence for this effect is provided by retrospective and case-control studies whose results, however, do not reach the highest grades for evidence-based recommendations. Nevertheless, these results are supported by a series of experimental studies demonstrating the multiplicity of actions of 5-amino-salicylic acid. Although data regarding the chemopreventive effect of 5-amino-salicylic acid may not be rigorous enough to meet the criteria for the highest evidence-based medicine recommendations, we feel that the argument to wait until we have Grade A evidence is not necessarily rational in this case, because discontinuation of 5-amino-salicylic acid treatment to perform a randomised controlled trial would be unethical secondary to their proven efficacy for maintenance treatment.