Is there evidence for accelerated polyethylene wear in uncemented compared to cemented acetabular components? A systematic review of the literature

Joint arthroplasty registries show an increased rate of aseptic loosening in uncemented acetabular components as compared to cemented acetabular components. Since loosening is associated with particulate wear debris, we postulated that uncemented acetabular components demonstrate a higher polyethylene wear rate than cemented acetabular components in total hip arthroplasty. We performed a systematic review of the peer-reviewed literature, comparing the wear rate in uncemented and cemented acetabular components in total hip arthroplasty. Studies were identified using MEDLINE (PubMed), EMBASE and the Cochrane Central Register of Controlled Trials. Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The search resulted in 425 papers. After excluding duplicates and selection based on title and abstracts, nine studies were found eligible for further analysis: two randomised controlled trials, and seven observational studies. One randomised controlled trial found a higher polyethylene wear rate in uncemented acetabular components, while the other found no differences. Three out of seven observational studies showed a higher polyethylene wear in uncemented acetabular component fixation; the other four studies did not show any differences in wear rates. The available evidence suggests that a higher annual wear rate may be encountered in uncemented acetabular components as compared to cemented components

Rapid visuomotor corrective responses during transport of hand-held objects incorporate novel object dynamics

Numerous studies have shown that people are adept at learning novel object dynamics, linking applied force and motion, when performing reaching movements with hand-held objects. Here we investigated whether the control of rapid corrective arm responses, elicited in response to visual perturbations, has access to such newly acquired knowledge of object dynamics. Participants first learned to make reaching movements while grasping an object subjected to complex load forces that depended on the distance and angle of the hand from the start position. During a subsequent test phase, we examined grip and load force coordination during corrective arm movements elicited (within ~150 ms) in response to viewed sudden lateral shifts (1.5 cm) in target or object position. We hypothesized that, if knowledge of object dynamics is incorporated in the control of the corrective responses, grip force changes would anticipate the unusual load force changes associated with the corrective arm movements so as to support grasp stability. Indeed, we found that the participants generated grip force adjustments tightly coupled, both spatially and temporally, to the load force changes associated with the arm movement corrections. We submit that recently learned novel object dynamics are effectively integrated into sensorimotor control policies that support rapid visually driven arm corrective actions during transport of hand held objects

Prevalence of obstructive sleep apnea in patients with mucopolysaccharidosis types I, II, and VI in a reference center

Mucopolysaccharidosis (MPS) encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans in organs and tissues. Respiratory disorders occur in all MPS types. in these patients, the prevalence of obstructive sleep apnea syndrome (OSAS), which may confer additional morbidity, remains overlooked, and the results of the few existing studies are controversial. the present study aimed to characterize the prevalence of OSAS in patients with MPS types I, II, and VI in a reference center.Forty-five patients with MPS (I, n = 17; II, n = 16; and VI; n = 12) in the Centro de Referncia em Erros Inatos do Metabolismo, who underwent full-night polysomnography, were enrolled in a retrospective study. Demographic data and clinical history were collected from medical records of the first medical consultation.The prevalence of OSAS in patients with MPS was 69.8 %. MPS type I patients seemed to be more susceptible to OSA-induced hypoxemia, as indicated by reduced mean SpO(2) levels during both NREM and rapid eye movement sleep as well as during SpO(2) nadir.Patients with MPS displayed a high prevalence of OSAS, often with moderate to high severity. Together, our results reinforce the need for OSAS screening in all patients with MPS.Instituto de Genetica e Erros Inatos do Metabolismo (IGEIM)BiomarinShireAssociacao Fundo de Incentivo a Pesquisa (AFIP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)IGEIMInst Sono, BR-04020060 São Paulo, BrazilUniversidade Federal de São Paulo, Ctr Erros Inatos Metab CREIM, BR-04020041 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, São Paulo, BrazilUniversidade Federal de São Paulo, Ctr Erros Inatos Metab CREIM, BR-04020041 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Psicobiol, São Paulo, BrazilWeb of Scienc