Relació de l’aspecte de la ferida quirúrgica en el postoperatori immediat d’una artroplàstia total de genoll amb l’evolució funcional posterior

Mitjançant un estudi observacional prospectiu, hem descrit i classificat la ferida quirúrgica en el postoperatori immediat de 159 pacients que se’ls hi va implantar una artroplàstia total de genoll, mitjançant una escala descriptiva fiable i reproduïble creada pels autors (estudi de validesa). Es va observar que l’aspecte de la ferida quirúrgica en el postoperatori immediat no tenia relació amb la funcionalitat de la pròtesis als 6 mesos de seguiment ni amb el dolor que patia el pacient en l’estància hospitalària. Si que vam observar correlació estadísticament significativa entre el pitjor aspecte de la ferida i l’aparició d’infeccions protèsiques profundes.

Cuantificación de las partículas de polietileno en líquido sinovial tras artroplastia total de rodilla, utilizando un polietileno convencional o uno altamente entrecruzado: estudio preliminar y protocolo de estudio

La formació de partícules de polietilè és la principal causa de osteòlisi i per tant de fracàs a l’artroplàstia total de genoll. El nostre objectiu és comparar, in vivo, el nombre de partícules que es formen amb un polietilè convencional amb un altament entrecreuat, esperant que el segon cas el nombre sigui més petit. Utilitzem una tècnica de aïllament de partícules en líquid sinovial ja descrita, que reproduïm a l’estudi preliminar. Presentem un protocol d’estudi prospectiu a doble cec, on s’estudiaran pacients amb artroplàstia de genoll d’un any d’evolució.

Traitement de la coxarthrose par des prothèses totales de hanche sur mesure [Treatment of coxarthrosis with fitted total hip prostheses replacement]

The treatment of hip osteoarthritis with total hip arthroplasty has continuously evolved since it was first introduced in the sixties. The problem of aseptic loosening of the cemented prostheses, mainly in young active patients, has stimulated two different types of research: on one side the improvement of cementing techniques and on the other side the development of cementless osteoinegrable implants. We discuss the problems of these cementless hip prostheses. Recently published anatomic and biomechanic studies have led to the development of personalized custom femoral stems for each patient. The conception technique and first clinical results are described.

Multi-segment foot kinematics after total ankle replacement and ankle arthrodesis during relatively long-distance gait.

This study aimed to investigate the influence of ankle osteoarthritis (AOA) treatments, i.e., ankle arthrodesis (AA) and total ankle replacement (TAR), on the kinematics of multi-segment foot and ankle complex during relatively long-distance gait. Forty-five subjects in four groups (AOA, AA, TAR, and control) were equipped with a wearable system consisting of inertial sensors installed on the tibia, calcaneus, and medial metatarsals. The subjects walked 50-m twice while the system measured the kinematic parameters of their multi-segment foot: the range of motion of joints between tibia, calcaneus, and medial metatarsals in three anatomical planes, and the peaks of angular velocity of these segments in the sagittal plane. These parameters were then compared among the four groups. It was observed that the range of motion and peak of angular velocities generally improved after TAR and were similar to the control subjects. However, unlike AOA and TAR, AA imposed impairments in the range of motion in the coronal plane for both the tibia-calcaneus and tibia-metatarsals joints. In general, the kinematic parameters showed significant correlation with established clinical scales (FFI and AOFAS), which shows their convergent validity. Based on the kinematic parameters of multi-segment foot during 50-m gait, this study showed significant improvements in foot mobility after TAR, but several significant impairments remained after AA.

Estudio de la alineación rotacional en la artroplastia total de rodilla mediante tomografía computarizada

L'alineació rotacional a l'astroplàstia total de genoll es refereix a la posició dels implants en el pla axial. Un mínim desplaçament afectarà la distribució de la càrrega y variarà l'estabilitat, l'alineació i la cinemàtica de l'articulació. Tot i que hi ha un consens pel que fa als efectes adversos d'una alineació rotacional incorrecta, encara no està clar quines són les referències anatòmiques que cal utilitzar. Les mesures de l'alineació rotacional requereixen un estudi d'alta qualitat. La TC és la modalitat d'imatge d'elecció per a l'estudi postoperatori de l'artroplàstia total de genoll. L'objectiu d'aquest treball es avaluar la capacitat diagnòstica de la TC per a l'estudi de l'alineació rotacional postoperatòria en l'artroplàstia total de genoll i presentar les variacions en el protocol de TC que minimitzen l'artefacte metàl•lic. Aquest estudi avalua la reproductibilitat de l'angle condili posterior, format per l'eix epicondili quirúrgic i la línia bicondilia posterior, mesurant la correlació entre dos observadors. El coeficient de correlació de Pearson mostra una forta correlació positiva (R=0.84) entre els dos observadors. La mitja d'error de les mesures adquirides és de -0.14º amb una desviació estàndar de 2.06º (-0.14 ± 2.06), per la qual cosa la modificació dels paràmetres tècnics de la TC per a la minimització dels artefactes metàl•lics és eficaç per l'avaluació rotacional. No obstant, l'alta magnitud de l'error indica que el radiòleg ha de ser prudent en el diagnòstic de mínimes variacions angulars que impliquin canvis en l'actitud mèdica i terapèutica.

Assessment of total energy expenditure in free-living patients with cystic fibrosis.

The increase in resting energy expenditure (REE) reported in patients with cystic fibrosis (CF) does not necessarily imply an increase in total energy expenditure (TEE). In this study REE was assessed with open-circuit indirect calorimetry, and free-living 24-hour TEE with the heart rate method. Thirteen patients with CF, aged 8 to 24 years, with adequate nutritional status and moderately decreased pulmonary function, were studied. They were compared with 13 healthy control subjects matched for gender, age, height, and nutritional status. Resting energy expenditure was higher in patients with CF (1512 +/- 88 kcal/day) than in control subjects (1339 +/- 76 kcal/day; p less than 0.01), whereas free-living 24-hour TEE (2345 +/- 127 kcal/day and 2358 +/- 256 kcal/day, respectively) and net mechanical work efficiency of walking on a treadmill (20.4 +/- 0.7% and 19.8 +/- 0.6%, respectively) were similar. Respiratory quotient was higher in patients with CF than in control subjects at rest (0.834 +/- 0.009 vs 0.797 +/- 0.008; p less than 0.05), and tended to remain so during physical exercise, indicating a higher contribution of carbohydrate oxidation to energy expenditure. We conclude that in free living conditions, patients with CF can compensate for their increase in REE by a reduction in spontaneous physical activities or other yet undefined mechanisms.

Diagnostic accuracy of free and total metanephrines in plasma and fractionated metanephrines in urine of patients with pheochromocytoma.

BACKGROUND: Plasma free and urinary metanephrines are recognized biomarkers for the assessment of pheochromocytoma. Plasma total metanephrines with a long half-life may represent another useful biomarker. OBJECTIVE: The aim of this study is to evaluate the diagnostic performances of plasma total metanephrines alone or combined with free metanephrines and fractionated 24-h urinary metanephrines. METHODS: A retrospective, case-control diagnostic test study was conducted between 1999 and 2007 in two university hospitals in Switzerland and two institutions in France. The patients included 46 cases with histologically proven pheochromocytoma, and 181 controls suspected of tumor with negative investigations and 3-year follow-up. None had renal dysfunction. Sensitivity and specificity were compared after expressing each measurement result as a ratio over its upper reference limit, adding the ratios of normetanephrine and metanephrine, and defining cut-off values of 1 or 2 for this sum. RESULTS: Applying a cut-off value of 1, plasma free and total metanephrines and urinary fractionated metanephrines had similar sensitivities of 96% (95% confidence interval, 86-99%), 95% (85-99%), and 95% (84-99%) along with similar specificities of 89% (83-94%), 91% (84-95%), and 86% (80-91%). A cut-off of 2 for the sum of ratios over reference limit improves the specificity, and it can be used for a confirmation test based on another biomarker taken among the three biomarkers. CONCLUSION: All three metanephrine-based tests perform equivalently for diagnosing pheochromocytoma in the absence of renal insufficiency, and can be conveniently associated two by two for confirming/excluding tumor.

Total energy expenditure and patterns of activity in 8-10-year-old obese and nonobese children.

Total energy expenditure (TEE) and patterns of activity were measured by means of a heart rate (HR)-monitoring method in a group of 8-10-year-old children including 13 obese children (weight, 46 +/- 10 kg; fat mass: 32 +/- 9%) and 16 nonobese children (weight, 31 +/- 5 kg; fat mass, 18 +/- 5%). Time for sleeping was not statistically different in the two groups of children (596 +/- 33 vs. 582 +/- 43 min; p = NS). Obese children spent more time doing sedentary activities (400 +/- 129 vs. 295 +/- 127 min; p < 0.05) and less time in nonsedentary activities (449 +/- 126 vs. 563 +/- 135 min; p < 0.05) than nonobese children. Time spent in moderate or vigorous activity-i.e., time spent at a HR between 50% of the maximal O2 uptake (peak VO2) and 70% peak VO2 (moderate) and at a HR > or = 70% peak VO2 (vigorous)-was not statistically different in obese and nonobese children (88 +/- 69 vs. 52 +/- 35 min and 20 +/- 21 vs. 16 +/- 13 min, respectively; p = NS). TEE was significantly higher in the obese group than in the nonobese group (9.46 +/- 1.40 vs. 7.51 +/- 1.67 MJ/day; p < 0.01). The energy expenditure for physical activity (plus thermogenesis) was significantly higher in the obese children (3.98 +/- 1.30 vs. 2.94 +/- 1.39 MJ/day; p < 0.05). The proportion of TEE daily devoted to physical activity (plus thermogenesis) was not significantly different in the two groups, as shown by the ratio between TEE and the postabsorptive metabolic rate (PMR): 1.72 +/- 0.25 obese vs 1.61 +/- 0.28 non-obese. In conclusion, in free-living conditions obese children have a higher TEE than do nonobese children, despite the greater time devoted to sedentary activities. The higher energy cost to perform weight-bearing activities as well as the higher absolute PMR of obese children help explain this apparent paradox.

Ambulatory gait analysis results after total knee arthroplasty : arguments for mobile or fixed bearing?

Background: Mobile-bearing knee replacements have some theoretical advantages over fixed-bearing devices. However, very few randomized controlled clinical trials have been published to date, and studies showed little clinical and subjective advantages for the mobile-bearing using traditional systems of scoring. The choice of the ideal outcome measure to assess total joint replacement remains a complex issue. However, gait analysis provides objective and quantifying evidences of treatment evaluation. Significant methodological advances are currently made in gait analysis laboratories and ambulatory gait devices are now available. The goal of this study was to provide gait parameters as a new objective method to assess total knee arthroplasty outcome between patients with fixed- and mobile-bearing, using an ambulatory device with minimal sensor configuration. Methods: This randomized controlled double-blind study included to date 31 patients: the gait signatures of 12 patients with mobile-bearing were compared to the gait signatures of 19 patients with fixed-bearing pre-operatively and post-operatively at 6 weeks, 3 months and 6 months. Each participant was asked to perform two walking trials of 30m long at his/her preferred speed and to complete a EQ-5D questionnaire, a WOMAC and Knee Society Score (KSS). Lower limbs rotations were measured by four miniature angular rate sensors mounted respectively, on each shank and thigh. Results: Better relative differences between pre-operative and post-operative 3 months and 6 months KSS (122% vs 34% at 3 months, 138% vs 36% at 6 months) and KSS function (154% vs 8% at 3 months, 183% vs 42% at 6 months) scores were observed for the fixed-bearing compared to the mobile-bearing. The same better improvements for fixed-bearing were also found with the range of knee angles (Affected side: 31% vs -5% at 3 months, 47% vs 5% at 6 months), (Unaffected side: 16% vs 5% at 3 months, 15% vs 6% at 6 months) and peak swing speeds of shank (Affected side: 18% vs -2% at 3 months, 30% vs 4% at 6 months), (Unaffected side: 8% vs -3% at 3 months, 7% vs 4% at 6 months). Conclusions: A new method for a portable system for gait analysis has been developed with very encouraging results regarding the objective outcome of total knee arthroplasty using mobile- and fixed-bearings.