Systematic Screening of Adverse Reactions to Metal Debris after Recap-M2A-Magnum Metal-on-Metal Total Hip Arthroplasty.

BACKGROUND AND AIMS: An adverse reaction to metal debris is a known complication after large diameter head metal-on-metal total hip arthroplasty. However, the failure rate varies depending on the implant design. Therefore, we investigated the prevalence of adverse reaction to metal debris, as well as the symptoms and risk factors after undergoing a ReCap-M2a-Magnum large diameter head metal-on-metal total hip arthroplasty. MATERIALS AND METHODS: Between 2005 and 2012, 1188 patients (1329 hips) underwent ReCap-M2a-Magnum total hip arthroplasty at our institution. Systematic screening for adverse reaction to metal debris was arranged using the Oxford Hip Score questionnaire, hip and pelvic radiographs, and assessments of the serum chromium and cobalt ion levels. Clinical evaluation and magnetic resonance imaging were performed for the symptomatic patients, as well as those with either chromium or cobalt ion levels ⩾5 µg/L. The prevalence of adverse reaction to metal debris after ReCap-M2a-Magnum total hip arthroplasty was assessed, and the risk factors for adverse reaction to metal debris were evaluated using logistic regression. The mean follow-up time was 5.2 (0.003-9.1) years. This study was an extension of a previous study conducted at our institution with 80 patients. RESULTS: In total, 33 patients (33 hips, 2.5% of all hips) required a revision operation due to adverse reaction to metal debris. Moreover, 157 hips exhibited definitive adverse reaction to metal debris, but a revision operation was not performed (157 of 1329 hips, 11.8% of all hips). Overall, 190 out of 1329 (14.3%) hips had definitive adverse reaction to metal debris. Pain, subluxation sensation, clicking, swelling, a small head size, and a fair/poor Oxford Hip Score were associated with definitive adverse reaction to metal debris. CONCLUSION: We found a high prevalence of adverse reaction to metal debris in the ReCap-M2a-Magnum total hip arthroplasty patients in this study; however, most of the patients did not require revision operations.

Hip resurfacing arthroplasty versus large-diameter head metal-on-metal total hip arthroplasty: comparison of three designs from the Finnish Arthroplasty Register.

BACKGROUND AND AIMS: Large headed metal-on-metal total hip arthroplasty may produce more metal ions than hip resurfacing arthroplasty. Increased metal-ion levels may be associated with higher revision rates due to adverse reaction to metal debris. The purpose of our study was to compare the survivorship of three hip resurfacing arthroplasty designs with their analogous cementless large-diameter head metal-on-metal total hip arthroplasties. MATERIAL AND METHODS: Based on data obtained from the Finnish Arthroplasty Register, the revision risks of three metal-on-metal hip resurfacing arthroplasty/total hip arthroplasty design couples performed during 2001-2011 were analyzed using the Cox regression model. RESULTS: In the Cox regression analysis for compared design pairs adjusted for age, gender, operated side, head size, diagnosis, and implant, there was no statistically significant difference in revision risk between ReCap hip resurfacing arthroplasty and Bimetric/ReCap total hip arthroplasty (risk ratio = 1.43, confidence interval = 0.95-2.14, p = 0.09) or between Birmingham hip resurfacing arthroplasty and Synergy/Birmingham hip resurfacing total hip arthroplasty (risk ratio = 1.35, confidence interval = 0.75-2.43, p = 0.31). However, the revision risk of Corail and Summit/articular surface replacement total hip arthroplasty (ASR HRA) was significantly increased compared to ASR HRA. (risk ratio = 0.73, confidence interval = 0.54-0.98, p = 0.04). CONCLUSION: We conclude that the short-term revision risk of large headed metal-on-metal total hip arthroplasties was not increased compared to analogous hip resurfacing arthroplasties in two out of three devices studied at a nationwide level. There may be implant-related factors having an effect on the success of single manufacturer devices. However, more information on the incidence of adverse soft-tissue reactions in these patient cohorts is needed.

Experience of structural onlay allografts for the treatment of bone deficiency in revision total hip arthroplasty.

BACKGROUND AND AIMS: Loss of femoral bone stock in elective revision total hip arthroplasty poses unique and substantial challenges. Structural onlay allografts may provide mechanical stability for the cementless revision prosthesis and increase bone stock. MATERIAL AND METHODS: At least one cortical onlay allograft was used in 40 elective total hip arthroplasty revisions (40 patients) to reconstruct femoral bone defects. The operations were performed between January 1999 and August 2010 in the Turku University Hospital, Finland. The mean follow-up time was 52 months (range: 12-125 months). RESULTS: The allografts were incorporated into the bone tissue in 37 of 40 (92.5%) patients. Cementless revision stems healed in 36 of 40 (90.0%) patients, but these patients were not exactly the same patients whose allografts were successfully incorporated. One or more surgical complications were experienced by 14 of 40 (35.0%) patients during follow-up. In all, 4 of 40 (10.0%) patients (all women) had hip infections during follow-up. Of the 7 patients with rheumatoid arthritis, 4 (57.1%) had at least one complication. CONCLUSIONS: The use of the cortical onlay allografts provides a feasible option for restoring the integrity of the proximal femur in revision total hip arthroplasty, but the complication rate is high, particularly in female patients with rheumatoid arthritis.

Survivorship of high tibial osteotomy in the treatment of osteoarthritis of the knee: Finnish registry-based study of 3195 knees.

Previous studies from single centres or single-surgeon series report good early and mid-term results for high tibial osteotomy (HTO) in the treatment of osteoarthritis of the knee. However, the survivorship of HTO at a national level is unknown. This registry-based study included 3195 high HTOs performed between 1987 and 2008. Kaplan-Meier analysis revealed an overall survivorship of 89% (95% confidence interval (CI) 88 to 90) at five years and 73% (95% CI 72 to 75) at ten years, when conversion to total knee replacement was taken as the endpoint. Females and patients aged > 50 years had worse survivorship than males or patients aged ≤ 50 years (hazard ratio (HR) 1.26 (95% CI 1.11 to 1.43) and HR 1.41 (95% CI 1.23 to 1.64), respectively). The survivorship of HTOs performed between 1998 to 2008 was worse than for those performed between 1987 and 1997.

Reduction of carbon tetrachloride-induced hepatotoxic effects by oral administration of betaine in male Han-Wistar rats: a morphometric histological study.

Eighty-five male Han-Wistar rats were arranged into three groups: CCl4-exposed rats, CCl4 + betaine-exposed rats, and control rats. To see the effect of betaine alone, five rats of the control and of the CCl4 + betaine groups were sacrificed after 7 days, before exposure to CCl4. After that, two of the groups (the CCl4 and CCl4 + betaine groups) were exposed to CCl4 (1 ml/kg per day subcutaneously [SC] for 4 consecutive days), and one of the groups (control group) was given olive oil (1 ml/kg per day SC for 4 consecutive days). At the start of the study (day 0), day 1, day 2, day 3, day 4, and 3 days after the last CCl4 and olive oil injections (day 7), samples of five rats per group were sacrificed, and the livers were taken for chemical analyses and histological examination. Oral betaine, after the acclimation period of a week, increased the number of mitochondria but not mitochondria size (day 0), compared with the case in control rats. Exposure to CCl4 resulted in centrilobular hepatic steatosis, and the administration of betaine significantly reduced this. Morphometric analyses also revealed that the addition of betaine increased the volume density of rough endoplasmic reticulum (RER) in the perinuclear areas of liver cell cytoplasm (day 7). Additionally, the administration of betaine prevented the reduction of Golgi complexes and mitochondrial figures in the cytoplasm observed after the exposures to CCl4. Also, the volume density of mitochondria was smallest in the CCl4-group, but the difference was not statistically significant. The results indicate that oral betaine either improves recovery or reduces the toxic effects of CCl4 on cell organelles in liver cells of male Han-Wistar rats.

Betaine reduces hepatic lipidosis induced by carbon tetrachloride in Sprague-Dawley rats.

Carbon tetrachloride-injected rats were given liquid diets with and without betaine for 7 d. Hepatic lipidosis was induced by 4 daily injections of carbon tetrachloride (CCl4). Animals were killed and their livers and blood taken for analysis of betaine, S-adenosylmethionine (SAM), betaine homocysteine methyltransferase (BHMT), triglyceride, alanine aminotransferase and aspartate aminotransferase. Liver samples were also processed and stained for histological examination. Supplemental betaine reduced triglyceride in the liver and centrilobular hepatic lipidosis induced by the CCl4 injections. In both the control and experimental groups receiving betaine, liver betaine, BHMT and SAM were significantly higher than in their respective groups not receiving betaine. This study provides evidence that betaine protects the liver against CCl4-induced lipidosis and may be a useful therapeutic and prophylactic agent in ameliorating the harmful effects of CCl4.

Dietary betaine promotes generation of hepatic S-adenosylmethionine and protects the liver from ethanol-induced fatty infiltration.

Previous studies have shown that ethanol feeding to rats alters methionine metabolism by decreasing the activity of methionine synthetase. This is the enzyme that converts homocysteine in the presence of vitamin B12 and N5-methyltetrahydrofolate to methionine. The action of the ethanol results in an increase in the hepatic level of the substrate N5-methyltetrahydrofolate but as an adaptive mechanism, betaine homocysteine methyltransferase, is induced in order to maintain hepatic S-adenosylmethionine at normal levels. Continued ethanol feeding, beyond 2 months, however, produces depressed levels of hepatic S-adenosylmethionine. Because betaine homocysteine methyltransferase is induced in the livers of ethanol-fed rats, this study was conducted to determine what effect the feeding of betaine, a substrate of betaine homocysteine methyltransferase, has on methionine metabolism in control and ethanol-fed animals. Control and ethanol-fed rats were given both betaine-lacking and betaine-containing liquid diets for 4 weeks, and parameters of methionine metabolism were measured. These measurements demonstrated that betaine administration doubled the hepatic levels of S-adenosylmethionine in control animals and increased by 4-fold the levels of hepatic S-adenosylmethionine in the ethanol-fed rats. The ethanol-induced infiltration of triglycerides in the liver was also reduced by the feeding of betaine to the ethanol-fed animals. These results indicate that betaine administration has the capacity to elevate hepatic S-adenosylmethionine and to prevent the ethanol-induced fatty liver.

Gentled and non-handled rats in a stressful open-field situation; differences in performance.

Open-field behaviour of individually gentled and non-handled adult Wistar rats in a stressful test situation (loud noise with bright light) was studied. The behaviour on the whole of the two groups differed significantly. While the gentled rats showed mainly signs of stress and explorativity, signs of fear beside stress and, on later trials, explorativity were typical of the non-handled animals. On later trials the behaviour of the non-handled rats neared to that of the gentled ones. In the behaviour of the gentled rats there was but little change as a function of trials. We suggest that individual gentling, beside minimizing fear of human contact, also increases the stability of the rat's reactions.

A preliminary study on the use of betaine as a cryoprotective agent in deep freezing of stallion semen.

In a preliminary experiment, betaine was added in concentrations ranging from 0 to 3.0 percent to stallion semen diluted with 4% glycerol extender. Motility of frozen-thawed semen was better in the extenders with high betaine concentration than in those of low concentration or the control. In a subsequent experiment, betaine was added to extended semen from five stallions to make a 2.5% betaine concentration. Two different cooling rates were used. The effect of betaine on spermatozoal motility was positive at both cooling rates studied. Motility of frozen-thawed 2.5% betaine semen samples was significantly (p less than 0.001) higher than that of the control samples.

Behavioural and glial cell effects of inhalation exposure to styrene vapour with special reference to interactions of simultaneous peroral ethanol intake.

Male Wistar rats were exposed to 300 p.p.m. of styrene vapour with simultaneous ethanol ingestion for 4 to 17 weeks. The effects on behaviour were analyzed after 4, 9 and 13 weeks of the experiment. The most manifest behavioural effects were found in rats exposed to the combination, and the changes included increased preening time at the 4th week and increased ambulation and rearing at the end of the exposure. The ethanol ingestion affected also the accumulation of the solvent burden by delaying the peak solvent concentration in the perirenal fat to the 8th week of exposure. The fat solvent concentration did not differ from each other in the two groups at the end of the experiment, and they were similar as compared the concentration found in phenobarbital-pretreated rats exposed for reference. The styrene exposure had almost no effects on cerebral glial cells whereas ethanol induced unexpectedly increased protein destruction in them throughout the experiment. Co-exposure to ethanol and styrene decreased the magnitude of protein destruction in the glial cells. Withdrawal of the rats after an 8-week exposure showed that the styrene effects were largely abolished in two weeks of exposure-free period as analyzed by the determination of brain RNA and acid proteinase activity. Brain RNA was lower than control after two weeks of ethanol deprivation. The present data indicate that marked metabolic interactions between ethanol and styrene take place in agreement with experience on other similar solvent combinations.