[When HbA1c is unreliable : a case report of hereditary spherocytosis]. / Cas clinique. Quand le dosage de l'HbA1c n'est pas fiable : à propos d'un cas de sphérocytose héréditaire.

Glycated haemoglobin (HbA1c) is a biological parameter used in the management of diabetic patients. Independent of the daytime glycaemic variations, but complementary to the measurement of blood glucose or subcutaneous glucose concentrations, it allows both the clinician and the patient to have an appreciation of the glycaemic balance of the last weeks. In this way, anti-diabetic treatment can be adjusted if necessary to achieve the desired goal and hopefully delay or prevent diabetes-related micro- and macroangiopathic complications. Some conditions can alter the glycation of haemoglobin. In this case, the HbA1c level becomes difficult to interpret. Hereditary spherocytosis may be revealed by a dissociation between low HbA1c level and high blood glucose levels. A family history, Coombs-negative haemolytic anaemia, or a finding of spherocytes in the blood smear is suggestive of hereditary spherocytosis. Fructosamine testing may be an alternative. This article will present a patient with hereditary spherocytosis in whom the HbA1c level was not interpretable when compared to the elevated blood glucose measurements.

: L'hémoglobine glyquée (HbA1c) est une valeur biologique utilisée dans le suivi des patients diabétiques. Indépendante de la variation glycémique nycthémérale, mais complémentaire à la mesure de la glycémie ou de la concentration sous-cutanée de glucose, elle permet tant au clinicien qu'au patient d'avoir une appréciation de l'équilibre glycémique des dernières semaines. De cette manière, le traitement anti-diabétique peut être éventuellement adapté pour atteindre l'objectif escompté et espérer retarder, voire prévenir, les complications micro- et macroangiopathiques liées au diabète. Certaines affections peuvent altérer la glycation de l'hémoglobine. Dans ce cas, le taux d'HbA1C devient difficile à interpréter. La sphérocytose héréditaire peut se révéler par un tableau de dissociation entre un taux bas d'HbA1C et des valeurs élevées de glycémie. Des antécédents familiaux, une anémie hémolytique à Coombs négatif, ou une observation de sphérocytes dans le frottis sanguin sont en faveur d'un diagnostic de sphérocytose héréditaire. Le dosage de la fructosamine peut être une alternative. Le présent article abordera le cas d'un patient atteint d'une sphérocytose héréditaire chez qui le taux d'HbA1c n'était pas interprétable en regard des contrôles glycémiques.

Pre-operative flexion contracture determines the functional outcome of haemophilic arthropathy treated with total knee arthroplasty.

End-stage haemophiliac arthropathy can be successfully treated with total knee arthroplasty. However, the functional results may not be as good as anticipated and certain pre-op knee characteristics may alter the functional results. The purpose of this study was to evaluate the functional outcome of TKA in haemophilic patients with specific attention to final range of motion and residual flexion contracture of the joint. Twenty-one consecutive patients were retrospectively reviewed. The average age was 34 years with an average follow-up of 5.7 years. Functional status was evaluated with Hospital for Special Surgery Knee Score. Receiving Operating Characteristics analysis was used to determine the threshold of pre-operative flexion contracture degree to avoid residual knee contracture. The range of motion was increased in 16 joints and unchanged in three joints and decreased in the remaining two. Preoperative average range of motion was 37.6°, improved to 57.1° post-operatively. The average knee score increased from 27.85 (15-30) points pre-operatively to 79.42 (12-94) points at the last follow-up. The degree of pre-operative flexion contracture was found to be a good predictor for residual flexion contracture. (Specificity: 85.7%, sensitivity: 100%, cut-off: 27.5°). Total knee replacement improves the quality of life in patients with advanced haemophilic arthropathy. Statistical analysis revealed that pre-op flexion contracture of 27.5° is an important threshold. Patients should be operated before that stage to gain maximum benefit with minimal gait abnormalities.

Mortality after hip fracture in diabetic patients.

AIM: Type 2 diabetic patients have an increased incidence of hip fracture. In this study, we aimed to evaluate the mortality rate after hip fracture and determine the predictors of mortality in diabetic patients. METHODS: 356 patients who sustained a hip fracture between January 1997 and June 2008 were retrospectively reviewed for the study. Of the eligible 230 patients, 69 had type 2 diabetes. Each of these patients' medical and nursing notes were reviewed to ascertain additional information, including patient demographic factors, prior co-morbidities, fracture type, length of post-fracture stay and post-operative complications, the presence and duration of diabetes, glucose levels, HbA1c levels, albumin and hemoglobin levels. RESULTS: 148 women (64.3%) and 82 men (35.7%) were included in the study. The mean age of the study group was 76.1 ± 10.4 years. The mean age for diabetics was 76.1 ± 12.0 years and was 75.1 ± 9.4 years for non-diabetics ( P=0.343). Diabetic patients with hip fracture had a higher risk of mortality than the non-diabetic patients. One year survival probabilities of diabetic and non-diabetic patients were respectively 68.0% and 87.3% (p=0.033). In diabetic patients with a hip fracture, predictors of mortality were advanced age, the presence of postoperative complications and elevated HbA1c levels. CONCLUSIONS: Diabetic patients have an increased risk of mortality after hip fracture. The medical care in the post-operative period, including glycemic control and postoperative complications, should be optimized in diabetic patients suffering from hip fracture in order to decrease mortality in these patients.

Graphene at the edge: stability and dynamics.

Although the physics of materials at surfaces and edges has been extensively studied, the movement of individual atoms at an isolated edge has not been directly observed in real time. With a transmission electron aberration-corrected microscope capable of simultaneous atomic spatial resolution and 1-second temporal resolution, we produced movies of the dynamics of carbon atoms at the edge of a hole in a suspended, single atomic layer of graphene. The rearrangement of bonds and beam-induced ejection of carbon atoms are recorded as the hole grows. We investigated the mechanism of edge reconstruction and demonstrated the stability of the "zigzag" edge configuration. This study of an ideal low-dimensional interface, a hole in graphene, exhibits the complex behavior of atoms at a boundary.

Position of the acetabular component determines the fate of femoral head autografts in total hip replacement for acetabular dysplasia.

We have reviewed 54 patients who had undergone 61 total hip replacements using bulk femoral autografts to augment a congenitally dysplastic acetabulum. There were 52 women and two men with a mean age of 42.4 years (29 to 76) at the time of the index operation. A variety of different prostheses was used: 28 (45.9%) were cemented and 33 (54.1%) uncemented. The graft technique remained unchanged throughout the series. Follow-up was at a mean of 8.3 years (3 to 20). The Hospital for Special Surgery hip score improved from a mean of 10.7 (4 to 18) pre-operatively to a mean of 35 (28 to 38) at follow-up. The position of the acetabular component was anatomical in 37 hips (60.7%), displaced less than 1 cm in 20 (32.7%) and displaced more than 1 cm in four (6.6%). Its cover was between 50% and 75% in 34 hips (55.7%) and less than 50% in 25 (41%). In two cases (3.3%), it was more than 75%. There was no graft resorption in 36 hips (59%), mild resorption in 21 (34%) and severe resorption in four (6%). Six hips (9.8%) were revised for aseptic loosening. The overall rate of loosening and revision was 14.8%. Overall survival at 8.3 years was 93.4%. The only significant factor which predicted failure was the implantation of the acetabular component more than 1 cm from the anatomical centre of rotation of the hip.

Total hip replacement in high riding developmental dysplasia of the hip: cementless total hip arthroplasty with femoral shortening using a subtrochanteric resection.

Total hip arthroplasty in younger patients with high riding dislocations is a challenging procedure. Although many procedures have been proposed, our preferred technique for this is to insert a small sized cementless acetabular component in the native acetabulum, a small sized cementless femoral component and perform a subtrochanteric oblique cylindrical resection of 4 centimeters. The femur is fixed with a plate using unicortical screw fixation. This technique is preferred to avoid stretching the neurovascular structures. This procedure was performed on 91 hips of 83 patients with a mean age of 45 years, between 1990 and 2005. After 8 years we observed a 10% failure with a good clinical outcome. The Merle d'Aubigne Hip Scores were improved from 10.65 preoperatively to 34.95 postoperatively. Despite a high complication and failure rate the patients were pleased with the final outcome. We continue to recommend this procedure in this unique patient population.