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Biomedical subjects

Vane Antolic

Publications and source records attributed to Vane Antolic.

8 recordsLinked to original sources
PubMed2006

Biological impact of polyacetal particles on loosening of isoelastic stems.

The aim of our study was to identify biological factors responsible for premature loosening of polyacetal hip stems. The results of histological analyses of the tissue around 11 total hip prostheses with loosened polyacetal femoral stems were compared to those obtained in a group of 11 total hip prostheses with loosened metal (CoCr) femoral components. A higher number of polymer wear particles surrounded by giant cells, more bone chips, and a more extensive necrosis were found around loosened polyacetal stems. Histomorphological characteristics of polyacetal wear particles containing BaSO(4) granules in the tissue around loosened polyacetal stems were described. Radiological evaluation of the wear of polyethylene cups suggested that elastic modulus of the stem had no influence on the wear of polyethylene cups. This study indicates that polyacetal wear particles have a great biological potential accelerating the process of loosening.

Acetals↗
PubMed2005

The Bernese periacetabular osteotomy: clinical, radiographic and mechanical 7-15-year follow-up of 26 hips.

BACKGROUND: The Bernese periacetabular osteotomy is used in dysplastic hips to increase the load-bearing area of the hip and to prevent osteoarthritis. The aim of our work was to determine the contact hip stress before and after the osteotomy and to compare the relief of stress with the long-term radiographic and clinical outcome. PATIENTS AND METHODS: We followed 26 dysplastic hips (26 patients) for 7-15 years after the index operation. Clinical evaluation was based on the WOMAC score, osteoarthrosis was evaluated with the Tönnis classification, the angles of lateral (CE) and anterior (VCA) femoral coverage were measured, and biomechanical parameters were studied. RESULTS: Periacetabular osteotomy increased the mean CE from 15 degrees to 37 degrees , and the mean VCA from 22 degrees to 38 degrees . The mean normalized peak contact stress was reduced from 5.2 to 3.0 kPa/N. Four hips required total hip arthroplasty after an average of 4.5 years, 8 hips showed considerable arthrosis progression, and 14 hips had no or mild arthrosis at follow-up. Preoperative WOMAC score, preoperative Tönnis grade and postoperative normalized peak contact stress were the most important predictors of outcome. INTERPRETATION: The Bernese periacetabular osteotomy improves the mechanical status of the hip. Long-term success depends on the grade of arthrosis preoperatively and on the magnitude of operative correction of the contact hip stress.

Acetabulum↗
PubMed2002

The influence of the biomechanical parameters of the hip on the outcome of treatment of hips subject to avascular necrosis of the femoral head.

We were interested in whether or not the biomechanical status of the hip influences the course of avascular necrosis of the femoral head. To investigate this, we used a computer aided system based on a three dimensional mathematical model for determining the stress distribution in the hip joint from standard anteroposterior rentgenographs (X-ray images) of both hips and pelvis. Based on the results of our study, we suggest that the biomechanical parameters of the hip play an important role in the outcome of treatment of hips affected by avascular necrosis of the femoral head.

Biomechanical Phenomena↗
PubMed2002

Sphericity of the femoral head on anterior-posterior radiographs of dysplastic hips.

We analyzed the sphericity of the femoral head of dysplastic hips. Using standard anterior-posterior radiographs of the hips, we assessed the femoral head's deviation from a spherical shape using a computer algorithm and via Severin grading. The method presented could serve as a useful tool to quantify differences in sphericity in cases where it is difficult to grade the hip radiologically.

Bone Diseases, Developmental↗
PubMed2002

How should dysplastic human hips be evaluated?

Dysplasia of the human hip is characterised by insufficient anterolateral covering of femoral head by the acetabulum. In our study, we evaluated dysplastic human hip joints using biomechanical parameters (the peak contact stress in the weight-bearing area of the hip - pmax) and X-ray image parameters (the centre-edge angle - thetaCE, the transverse acetabular inclination angle - thetaUS, the acetabular index of the weight-bearing zone - thetaAC, the ACM angle - thetaACM, and the hip value - HV). The purpose of this study is to make use of X-ray and biomechanical parameters to evaluate hips diagnosed with "hip dysplasia", and to establish whether or not there is a correlation between the two. Our results show a statistically significant correlation between pmax and thetaCE, thetaUS and thetaAC. The correlation between pmax and thetaACM and HV is not statistically significant.

Biomechanical Phenomena↗
PubMed2002

Hip biomechanics in orthopaedic clinical practice.

Radiographic and clinical studies, coupled with biomechanical assessment of the hip, are important tools for predicting the development of osteoarthitis of the hip. In order to better understand the treatment of hip dysplasia, it is necessary to determine the contact stress in the hip joint. In this study, a three-dimensional mathematical model was used to determine hip joint contact stress. Because of the discrepancy in the results of analyses of different radiographic indicators of hip dysplasia, the calculation of hip joint contact stress is proposed for a more accurate assessment of the severity of hip dysplasia.

Cartilage, Articular↗
PubMed2002

Biomechanical analysis of Chiari osteotomy.

The decrease in contact hip joint stress after Chiari osteotomy is studied using a mathematical model. In the model, additional coverage of the femoral head by the ala ossis ilei segment is taken into account. It is shown that this additional coverage significantly decreases stress, mostly by the indirect effect caused by the shift of the stress pole.

Computer Simulation↗