In vitro stability of cemented and cementless femoral stems with compaction.

Rigidity of initial fixation is a key factor contributing to the longevity of cemented and cementless femoral components in total hip arthroplasty. The objective of this study was to measure the initial stability of primary cemented and cementless femoral components under load when 15 pairs of cadaveric femurs were prepared by outward compaction of femoral cancellous bone in situ or by conventional extraction broaching. Three-dimensional micromotion was measured at proximal and distal locations on the femoral components using a device with spherical targets and linear variable differential transformers. External loads simulating the stance phases of level walking and stair ascent were applied to the femoral components by a materials test machine. Bone preparation method significantly affected each of the translation and rotation components of micromotion with cemented and cementless fixation. Micromotion with broaching was consistently greater than with compaction. Compared with compaction, the magnitude of the micromotion translation vector for broaching was an average of 3.9 (standard deviation, 3.1) times greater with cemented fixation, and an average of 2.3 (standard deviation, 1.4) times greater with cementless fixation. The results of this study showed the effectiveness of compaction of femoral cancellous bone in improving the initial stability of cemented and cementless femoral components in primary total hip arthroplasty.     

Lipid peroxidation,glutathione, vitamin E,and antioxidant enzymes in synovial fluid from patients with osteoarthritis

Aim: To compare levels of lipid peroxidation and antioxidants in synovial fluid from primary knee osteoarthritis (OA) patients with severe cartilage damage undergoing total knee replacement with those in the synovial fluid from injured knee joint patients with intact cartilage undergoing knee arthroscopy. Methods: Thirty‐two OA patients and 10 injured knee joint patients were recruited. Lipid peroxidation (thiobarbituric acid reactive substances [TBARs]), iron and glutathione (GSH) were measured using a colorimetric method. Vitamin E was measured with high‐performance liquid chromatography (HPLC). Activities of antioxidant enzymes (glutathione peroxidase [GPx], superoxide dismutase [SOD]) were analyzed with the use of a kinetic method. Results: TBARs, iron and GSH levels in synovial fluid were not significantly different between OA patients and injured knee joint patients. Antioxidant enzymes such as GPx and SOD activities also indicated no significant difference. Only vitamin E level was significantly lower in the synovial fluid of OA patients than in that of the injured knee joint patients. Conclusions: Oxidative stress may have a role in pathogenesis of knee osteoarthritis. Vitamin E supplementation may have a role in the management of patients.     

Compacted cancellous bone has a spring-back effect

A new surgical technique, compaction, has been shown to improve implant fixation. It has been speculated that the enhanced implant fixation with compaction could be due to a spring-back effect of compacted bone. However, such an effect has yet to be shown. Therefore we investigated in a canine model whether implant cavities prepared with compaction had spring back. Before killing the animals, we used one of two surgical techniques to make implant cavities of identical dimensions in both lateral femoral condyles of 7 dogs. One side had the implant cavity prepared with compaction, the other side with drilling. The cavities were left empty in vivo for 10 minutes before the dogs were killed. Postoperative micro-CT scanning showed that the diameters of the compacted cavities were significantly smaller than those of the drilled cavities, although they had had identical dimensions initially. Thus we found a spring-back effect of compacted bone, which may be important for increasing implant fixation by reducing initial gaps between the implant and bone.     

Novel method of measuring patellar height ratio using a distal femoral reference point

Purpose  

Patellar height is an important factor in patellar tracking and alters the force of the patellofemoral joint reaction. Several methods for measuring patellar height ratio have been described, with no single method recognised as a gold standard. This study developed a new measurement method using a distal femoral reference, where the normal values of measurement are unaffected by varying angles of knee flexion.     

Comparison of Overall Survival between Transarterial Chemoembolization and Best Supportive Care in Intermediate- Stage Hepatocellular Carcinoma

Objective: The Thailand management guideline allows the use of transarterial chemoembolization (TACE) for the treatment of intermediate-stage hepatocellular carcinoma (HCC) in patients with decompensated cirrhosis, whereas other guidelines do not. The aim of this study was to compare the overall survival between TACE and the best supportive care (BSC) in HCC patients with Child–Pugh score 5–8 cirrhosis and in subgroups with compensated cirrhosis (Child–Pugh score 5–6) and early decompensated cirrhosis (Child–Pugh score 7–8). Methods: This retrospective study comprised 118 patients with intermediate-stage HCC. The overall survival was compared between TACE and BSC using the Kaplan–Meier method. Results: The median overall survival time for all patients was 21.4 months in the TACE group and 8.2 months in the BSC group (P <0.001). In the subgroup analyses, the overall survival times for TACE and BSC were 26 months and 9 months, respectively, for compensated cirrhosis (P <0.001), and 14.5 months and 6.9 months, respectively, for early decompensated cirrhosis (P <0.001). In the Cox proportional-hazards model, TACE was an independent prognostic factor for prolonged overall survival in all patients [hazard ratio (HR) 0.29; 95% confidence interval (CI), 0.17–0.49; P <0.001], patients with compensated cirrhosis (HR, 0.31; 95% CI, 0.16–0.62; P <0.001), and patients with early decompensated cirrhosis (HR, 0.16; 95% CI, 0.061–0.44; P <0.001). Conclusion: TACE improves the overall survival in patients with intermediate-stage HCC and compensated or early decompensated cirrhosis.     

Gemcitabine plus cisplatin (GC): a salvage regimen for advanced breast cancer patients who have failed anthracycline and/or taxane therapy

BACKGROUND: In clinical studies of both heavily and minimally pretreated patients with advanced breast cancer, the combination of Gemcitabine plus cisplatin (GC), given in a variety of schedules and doses, has demonstrated moderate safety and efficacy in both heavily and minimally pretreated advanced breast cancer with response rate from 29-63% (median 46%). METHODS: We evaluated the activity and toxicity of another GC regimen (gemcitabine 1,000 mg/m(2) days 1, 8 plus cisplatin 75 mg/m(2) day 1 every 3 weeks) in 30 breast cancer patients who failed chemotherapy with anthracycline and/or taxanes as adjuvant or neoadjuvant, or primary therapy. RESULTS: We obtained overall response in 15 of 29 evaluable patients (52%), with responses occurring in all subgroups of disease (unresectable locally advanced, locoregional recurrence, and distant metastasis). Toxicity was primarily hematologic, with grade 3/4 neutropenia and thrombocytopenia in 37% and 17% of patients, respectively. The only grade 3/4 non-hematologic toxicity was grade 3 nausea/vomiting in 12% of patients. CONCLUSION: Our data suggest that gemcitabine plus cisplatin appears to be effective and has an acceptable toxicity profile in anthracycline and/or taxane pretreated patients with advanced breast cancer.     

Significant enhancement of dielectric permittivity and percolation behaviour of La2−xSrxNiO4/poly(vinylidene fluoride) composites with different Sr doping concentrations

The percolation behaviour and dielectric properties of La_2−xSr_xNiO₄ (LSNO)/poly(vinylidene fluoride) (PVDF) composites with different Sr doping concentrations were investigated. The semiconducting LSNO filler particles with x = 0.2 (LSNO-1) and x = 0.4 (LSNO-2) were prepared using a chemical combustion method. The microstructures, thermal properties, and phase compositions of the polymer composites and filler particles were systematically investigated. The conductivity of the LSNO fillers increased with the Sr content and had an important impact on the dielectric properties of the LSNO/PVDF composites. The percolation threshold of the LSNO-2/PVDF composite was lower than that of the LSNO-1/PVDF composite. An ultra-high dielectric permittivity (ε′) of 3384.7 (at 1 kHz and room temperature), which was approximately 340 times higher than that of pure PVDF, was obtained for the LSNO-2/PVDF composite with a filler volume fraction of 25 vol%. The enhanced dielectric properties were attributed to interfacial polarisation at the semiconductor–insulator interface, a micro-capacitor model, and the intrinsically remarkable dielectric properties of the LSNO ceramic.

The percolation behaviour and dielectric properties of La_2−xSr_xNiO₄ (LSNO)/poly(vinylidene fluoride) (PVDF) composites with different Sr doping concentrations were investigated.     

Chronic treatment with prebiotics,probiotics and synbiotics attenuated cardiac dysfunction by improving cardiac mitochondrial dysfunction in male obese insulin-resistant rats

European Journal of Nutrition - In metabolic syndrome, the composition of gut microbiota has been disrupted, and is associated with left ventricular (LV) dysfunction. Several types of prebiotics,...     

Reasons for revision of failed hemiarthroplasty: Are there any differences between unipolar and bipolar?

Background

Hemiarthroplasty (HA) is an effective procedure for treatment of femoral neck fracture. However, it is debatable whether unipolar or bipolar HA is the most suitable implant.

Objective

The purpose of this study was to compare the causes of failure and longevity in both types of HA.

Materials and methods

We retrospectively reviewed 133 cases that underwent revision surgery of HA between 2002 and 2012. The causes of revision surgery were identified and stratified into early (≤?5 years) failure and late (>?5 years) failure. Survival analyses were performed for each implant type.

Results

The common causes for revision were aseptic loosening (49.6%), infection (22.6%) and acetabular erosion (15.0%). Unipolar and bipolar HA were not different in causes for revision, but the unipolar group had a statistically significantly higher number of acetabular erosion events compared with the bipolar group (p?=?0.002). In the early period, 24 unipolar HA (52.9%) and 28 bipolar HA (34.1%) failed. There were no statistically significant differences in the numbers of revised HA in each period between the two groups (p?=?0.138). The median survival times in the unipolar and bipolar groups were 84.0?±?24.5 and 120.0?±?5.5 months, respectively. However, the survival times of both implants were not statistically significantly different.

Conclusions

Aseptic loosening was the most common reason for revision surgery after hemiarthroplasty surgery in early and late failures. Unipolar and bipolar hemiarthroplasty were not different in terms of causes of failure and survivorship except bipolar hemiarthroplasty had many fewer acetabular erosion events.

     

Cementless acetabular revision for aseptic failure of cemented hip arthroplasty

This study is a 5- to 11-year retrospective followup of 40 hips in 33 patients with cementless acetabular revision for aseptic failure of a cemented total hip arthroplasty. A porous coated, Harris-Galante acetabular component was used in all revisions. Thirty-eight of the 40 hips received acetabular bone grafting at revision. The mean Harris Hip Score improved from 51 points just before the index cementless revision to 87 points at the most recent followup. Twenty-nine of 40 (73%) hips were classified as having a good or excellent result. Radiolucencies were observed in seven of the 40 (18%) hips at the most recent followup, but none of these radiolucencies were complete or progressive. Five of the 40 (13%) hips were rated as failures and required repeat revision. Two (5%) of these failures were caused by aseptic loosening, with both hips having severe acetabular bone damage at the time of the index revision. This failure rate for aseptic loosening was less than that reported for cemented acetabular revision, thereby confirming the efficacy of cementless acetabular components in revision hip surgery in the intermediate term.