Clinical and biological assessment of cemented titanium femoral stems: an 11-year experience

This study prospectively assessed the outcome of 134 cemented titanium stems and serum ion levels. The stems were polished (0.1 μm Ra) with circular cross section. At the end point, only one stem revision was performed for aseptic loosening, and two were planned due to subsidence greater than 5 mm. Non-progressive radiolucencies in zones 1 and 7 were observed in 16 hips at the cement-bone interface without osteolysis. Median serum titanium concentrations were below the detection limit (30 nmol/l) except in patients with failed stems. The overall stem survival rate was 97.7% at nine years, which is comparable to other series of cemented stems. The protective layer of titanium oxide coating the stem and a thick cement mantle may help resist aseptic loosening. In addition, satisfactory monitoring of the stem was reached using titanium serum level determination

Dependência de exercício físico: humor, qualidade de vida em atletas amadores e profissionais Physical exercise dependence: mood, quality of life in amateur and professional athletes

O objetivo do presente estudo foi verificar se existem diferenças nos escores de Dependência de Exercício (DE), escores de humor e qualidade de vida em atletas profissionais e amadores de modalidade esportivas coletivas e individuais. MÉTODOS: Participaram deste estudo 116 atletas praticantes de modalidades esportivas coletivas (n = 60, sendo 20 profissionais e 40 amadores) e individuais (n = 56, sendo 16 profissionais e 40 amadores) do gênero masculino. As médias (± desvio-padrão) da idade, estatura, massa corporal e índice de massa corpórea (IMC) foram: 22,13 ± 6,16 anos; 1,77 ± 0,10cm; 72,76 ± 10,04kg; e 23,10 ± 2,04kg/m², respectivamente. Os atletas responderam aos seguintes questionários: Escala de Dependência de Exercício (EDE), Inventário Beck de Depressão, Idate Traço e Estado de Ansiedade, Questionário POMS de perfil de humor, Questionário SF-36 de Qualidade de Vida, em um dia de folga dentro da periodização normal de treinamento, caracterizando o estudo como transversal. O trabalho foi aprovado pelo Comitê de Ética em Pesquisa da Unifesp (# 0616/06). RESULTADOS: Atletas amadores e profissionais apresentaram escores similares de DE, mas quando considerados os tipos de modalidade, os amadores praticantes de modalidades coletivas apresentam maiores escores, o que se inverte quando considerados atletas profissionais. Em relação aos resultados de humor, atletas profissionais apresentaram mais qualidade de vida e menores escores de humor. CONCLUSÃO: Atletas amadores e profissionais praticantes de modalidades esportivas coletivas e individuais respondem diferentemente à DE; o tipo de modalidade e seu envolvimento social e competitivo parecem ser o grande determinante. Além disso, pode-se concluir que atletas profissionais de modalidades coletivas apresentam melhor perfil de humor e qualidade de vida, tanto quando comparados com profissionais de modalidades individuais, quando com atletas amadores praticantes de modalidades coletivas ou individuais.<br>The purpose of this study was to verify if there are differences between exercise dependence (ED), mood and quality of life scores in professional and amateur athletes of individual and collective sport modalities. METHODS: 116 male athletes of collective sport modalities (n=60, 20 professionals and 40 amateurs) and individual sport modalities (n=56, 16 professionals and 40 amateurs) participated in this study. Age, height, weight, BMI mean (± standard-deviation) were: 22.13 ± 6.16 years; 1.77 ± 0.10 cm; 72.76 ± 10.04 kg and 23.10 ± 2.04 kg/m², respectively. The athletes answered the following questionnaires: Exercise Dependence scale (EDE), Beck Depression Inventory, Trait and State of Anxiety - IDATE, POMS - profile of mood states, SF-36 Questionnaire of Quality of Life. The study was approved by the Ethics in Research Committee of UNIFESP (#0616/06). RESULTS: Amateur and professional athletes presented similar scores of ED, but when the kind of modality was considered, the amateurs of collective modalities presented higher scores than professional athletes. CONCLUSION: Amateur and professional athletes of collective and individual sport modalities answered differently to ED, and the sports modality and competitive and social involvement could be determinant. Moreover, it is possible to conclude that professional athletes of collective sports present better profile of mood and quality of life when compared with professional athletes of individual sports when compared with amateur athletes from collective or individual sport modalities

Femoral Head Size and Wear of Highly Cross-linked Polyethylene at 5 to 8 Years

Wear of highly cross-linked polyethylene is reportedly independent of head size. To confirm that observation we asked in our population whether head size related to wear with one type of electron beam highly cross-linked polyethylene. Of 146 hips implanted, we evaluated complete clinical and radiographic data for 90 patients (102 hips or 70%). The minimum followup was 5 years (mean, 5.7 years; range, 5–8 years). The head size was selected intraoperatively based on the size of the acetabular component and presumed risk of dislocation. Polyethylene wear measurements were performed in one experienced laboratory using the method of Martell et al. There was no hip with pelvic or femoral osteolysis. The median linear wear rate was 0.028 mm/year (mean, 0.04 mm/year), and the median volumetric wear rate was 25.6 mm3/year (mean, 80.5 mm3/year). Median total volumetric wear was 41.0 mm3 (mean, 98.5 mm3). We found no association between femoral head size and the linear wear rate, but observed an association between larger (36- and 40-mm) head size and volumetric wear rate and total volumetric wear. Although the linear wear rate of polyethylene was not related to femoral head diameter, there was greater volumetric wear (156.6 mm3/year) with the 36- and 40-mm heads. Pending long-term studies of large head sizes, we advise caution in using larger femoral heads in young or active patients and in those with a low risk of dislocation

Wear of a highly cross-linked polyethylene liner: a preliminary RSA study

Wear induced peri-prosthetic osteolysis and aseptic loosening remain the major contributing factors to failure of total hip arthroplasty. To reduce wear particles from acetabular liners, the process of polyethylene cross-linking has been modified. In this study, we examine the wear of Marathon™ acetabular liners using Radiostereometric Analysis. Thirty patients were enrolled in a prospective cohort study. Femoral head penetration was calculated for 25 patients at 6 months, 1 and 2 years postoperatively. The mean proximal head penetration was 0.067 mm at 6 months, 0.113 mm at 1 year and 0.120 mm at 2 years. The mean three-dimensional femoral head penetration was 0.240 mm at 6 months, 0.230 mm at 1 year and 0.232 mm at 2 years. For both parameters, there was no measurable wear between 1 and 2 years, and the mean annual linear wear was less than 0.06 mm/year, which is less than the suggested osteolysis threshold for polyethylene. All patients demonstrated a dramatic improvement in clinical scores. These results were comparable with other studies that used alternative techniques with conventional radiography to evaluate wear for Marathon™. Long-term studies using the RSA method are recommended to further quantify the clinical performance of this polyethylene liner.David Campbell, Graham Mercer, Kjell-Gunnar Nilsson, Vanessa Wells, John R. Field and Stuart A. Callar

Periprosthetic strain magnitude-dependent upregulation of type I collagen synthesis in human osteoblasts through an ERK1/2 pathway

Human osteoblasts sense mechanical stimulation and synthesise type I collagen in periprosthetic osseointegration following total hip arthroplasty. However, the regulation of type I collagen synthesis by periprosthetic strain is unclear because the cellular-level strain magnitude remains unknown to date. Fortunately, the tissue-level strain in implanted femurs is measurable. According to the mechanism of strain amplification, the tissue-level strain was amplified 20 times to stretch human osteoblasts in this study. Elongation of 0.8–3.2% enhanced the mRNA level of type I collagen, whereas the release of procollagen type I C propeptide only increased at 2.4% and 3.2% elongation. Type I collagen expression increased with the activation of ERK1/2 phosphorylation in a strain-magnitude-dependent manner, whereas JNK and P38 were unaffected. The responses were completely inhibited by blocking the ERK1/2 pathway with U0126. The results indicate that type I collagen synthesis in human osteoblasts depends on the level of periprosthetic strain and ERK1/2 activation