Validation of an Italian Questionnaire of Adherence to the Ketogenic Dietary Therapies: iKetoCheck

Ketogenic dietary therapies (KDTs) are an effective and safe non-pharmacological treatment for drug-resistant epilepsy, but adherence can be challenging for both patients and caregivers. In Europe, there are no adequate tools to measure it other than monitoring ketosis. This study aimed to adapt and validate the Brazilian adherence questionnaire, Keto-check, into the Italian version: iKetoCheck. Using the Delphi technique, 12 judges validated the contents through agreement rates and the Content Validity Index (CVI). The iKetocheck was self-completed electronically by 61 drug-resistant epilepsy or GLUT1 deficiency patients within an interval of 15 days to measure its reproducibility. The test-retest reliability was evaluated using Pearson's correlation and relative significance test. Exploratory and confirmatory factorial analyses were made using Factor software version 12.03.02. The final tool, iKetoCheck, consists of 10 questions with 5-point Likert scale answers. It evaluates various aspects such as informing caregivers about the diet, organization of meals, measurement of ketosis, weighing food consumed, diet negligence, use of carbohydrate-free medications, attending follow-up visits, reading food labels, consulting an expert for dietary concerns, and cooking at home. The factorial analysis resulted in three factors: "attention," "organization," and "precision," with satisfactory results for indices in exploratory and confirmatory analyses. Although higher mean values of ketonemia measurement were observed in patients with a higher adherence score, these values were not statistically significant (p = 0.284). In conclusion, despite the small sample size, iKetoCheck is a valid tool for evaluating KDTs' adherence in Italian drug-resistant epilepsy or GLUT1 deficiency patients. It can provide valuable information to improve patient management and optimize the effectiveness of KDTs.

Ketonemia variability through menstrual cycle in patients undergoing classic ketogenic diet

Introduction

Ketogenic dietary therapies (KDT) are well-established, safe, non-pharmacologic treatments used for children and adults with drug-resistant epilepsy and other neurological disorders. Ketone bodies (KBs) levels are recognized as helpful to check compliance to the KDT and to attempt titration of the diet according to the individualized needs. KBs might undergo inter-individual and intra-individual variability and can be affected by several factors. Possible variations in glycemia and ketone bodies blood levels according to the menstrual cycle have not been systematically assessed yet, but this time window deserves special attention because of hormonal and metabolic related changes.

Methods

This study aims at searching for subtle changes in KBs blood level during menstrual cycle in female patients undergoing a stable ketogenic diet, by analyzing 3-months daily measurement of ketone bodies blood levels and glucose blood levels throughout the menstrual cycle.

Results

We report the preliminary results on six female patients affected by GLUT1DS or drug resistant epilepsy, undergoing a stable classic ketogenic diet. A significant increase in glucose blood levels during menstruation was found in the entire cohort. As far as the ketone bodies blood levels, an inversely proportional trend compared to glycemia was noted.

Conclusion

Exploring whether ketonemia variations might occur according to the menstrual cycle is relevant to determine the feasibility of transient preventive diet adjustments to assure a continuative treatment efficacy and to enhance dietary behavior support.

Clinical trial registration

clinicaltrials.gov, identifier NCT05234411.

A Review of Ketogenic Dietary Therapies for Epilepsy and Neurological Diseases: A Proposal to Implement an Adapted Model to Include Healthy Mediterranean Products

Based on the growing evidence of the therapeutic role of high-fat ketogenic dietary therapies (KDTs) for neurological diseases and on the protective effect of the Mediterranean diet (MD), it could be important to delineate a Mediterranean version of KDTs in order to maintain a high ketogenic ratio, and thus avoid side effects, especially in patients requiring long-term treatment. This narrative review aims to explore the existing literature on this topic and to elaborate recommendations for a Mediterranean version of the KDTs. It presents practical suggestions based on MD principles, which consist of key elements for the selection of foods (both from quantitative and qualitative prospective), and indications of the relative proportions and consumption frequency of the main food groups that constitute the Mediterranean version of the KDTs. We suggest the adoption of a Mediterranean version of ketogenic diets in order to benefit from the multiple protective effects of the MD. This translates to: (i) a preferential use of olive oil and vegetable fat sources in general; (ii) the limitation of foods rich in saturated fatty acids; (iii) the encouragement of high biological value protein sources; (iv) inserting fruit and vegetables at every meal possible, varying their choices according to seasonality.

Classic ketogenic diet in parenteral nutrition in a GLUT1DS patient: Doing more with less in an acute surgical setting

Ketogenic Dietary Treatments (KDTs) are to date the gold-standard treatment for glucose transporter type 1 (GLUT1) deficiency syndrome. Administration of KDTs is generally per os; however, in some conditions including the acute gastro-enteric post-surgical setting, short-term parenteral (PN) administration might be needed. We report the case of a 14-year-old GLUT1DS patient, following classic KDT for many years, who underwent urgent laparoscopic appendectomy. PN-KDT was required, after 1 day of fasting. No ad hoc PN-KDTs products were available and the patient received infusions of OLIMEL N4 (Baxter). On the sixth day postoperatively enteral nutrition was progressively reintroduced. The outcome was optimal with rapid recovery and no exacerbation of neurological manifestations. Our patient is the first pediatric patient with GLUT1DS in chronic treatment with KDT efficiently treated with exclusive PN for five days. This case reports on real-word management and the ideal recommendations for PN-KDT in an acute surgical setting.

PARENTERAL NUTRITION IN A GLUT1DS PATIENT FOLLOWING CLASSIC KETOGENIC DIET: IDEAL VERSUS REAL-WORLD MANAGEMENT IN AN ACUTE SURGICAL SETTING

BACKGROUND

GLUT1 deficiency syndrome is a rare neurometabolic disorder, whose current gold standard treatment is represented by ketogenic dietary treatments (KDTs). KDTs are generally administered per os; however, in an immediate gastro-enteric post-surgical setting, short-term parenteral (PN) administration might be required.

CASE REPORT

a 14-year-old boy diagnosed with GLUT1DS and in chronic treatment for many years with KDTs underwent urgent laparoscopic appendectomy. Subsequently, after one day of fasting, PN-KDT was started as the boy was unable to tolerate enteral nutrition postoperatively. On the sixth day, enteral nutrition was progressively reintroduced. Since ad hoc PN-KDTs products were unavailable, the patient received infusion of OLIMEL N4 (Baxter). Outcome was characterized by prompt recovery and no exacerbation of neurological symptoms was observed.

CONCLUSION

we described the first pediatric patient with GLUT1DS in chronic treatment with KDT efficiently treated with exclusive PN for five days. We presented our real word management and the ideal recommendations for PN-KDT in acute surgical setting. This article is protected by copyright. All rights reserved.

Long-Term Effects of a Classic Ketogenic Diet on Ghrelin and Leptin Concentration: A 12-Month Prospective Study in a Cohort of Italian Children and Adults with GLUT1-Deficiency Syndrome and Drug Resistant Epilepsy

The classical ketogenic diet (cKD) is an isocaloric, high fat, very low-carbohydrate diet that induces ketosis, strongly influencing leptin and ghrelin regulation. However, not enough is known about the impact of a long-term cKD. This study evaluated the effects of a 12-month cKD on ghrelin and leptin concentrations in children, adolescents and adults affected by the GLUT1-Deficiency Syndrome or drug resistant epilepsy (DRE). We also investigated the relationship between the nutritional status, body composition and ghrelin and leptin variations. We carried out a longitudinal study on 30 patients: Twenty-five children and adolescents (15 females, 8 ± 4 years), and five adults (two females, 34 ± 16 years). After 12-monoths cKD, there were no significant changes in ghrelin and leptin, or in the nutritional status, body fat, glucose and lipid profiles. However, a slight height z-score reduction (from −0.603 ± 1.178 to −0.953 ± 1.354, p ≤ 0.001) and a drop in fasting insulin occurred. We found no correlations between ghrelin changes and nutritional status and body composition, whereas leptin changes correlated positively with variations in the weight z-score and body fat (ρ = 0.4534, p = 0.0341; ρ = 0.5901, p = 0.0135; respectively). These results suggest that a long-term cKD does not change ghrelin and leptin concentrations independently of age and neurological condition.

Assessment of Dietary Under-Reporting in Italian College Team Sport Athletes

BACKGROUND

Nutrition is an important factor for sports performance and the assessment of dietary intakes in athletes can correct unhealthy eating habits. However, dietary assessment may be biased due to misreporting. The aim of our study was to investigate the occurrence of misreporting in a sample of collegiate team sport athletes.

METHODS

A total of 50 athletes participated. Each athlete filled in food records for seven days. Reported energy intake (EI) was considered in relation to the predicted basal metabolic rate (BMR) and expressed as the ratio EI/ BMR. All participants with EI/BMRestd ≤1.23 were classified as "low energy reporters" (LER), and those with an EI/BMRestd ratio >1.23 were classified as "adequate energy reporters" (AER).

RESULTS

According to cut-off values for under-reporting, 28 out of 50 athletes (56%) were classified as LER. The LER (16 M/12 F) had significantly higher BMI (23.17 ± 3.46 kg/m2 compared to 21.41 ± 1.91 kg/m2; p = 0.038) than the AER. The EI/kg fat free mass (FFM) was significantly lower in LER than the AER (33.34 ± 6.56 kcal/FFM compared to 48.51 ± 8.59 kcal/FFM, p < 0.0001). Nutrient intake was also significantly different between the two groups.

CONCLUSIONS

Our results suggest that under-reporting of energy intake by collegiate team sport athletes may occur frequently and needs to be taken into consideration in the interpretation of nutrient intake.

An mHealth Application for Educating and Monitoring Patients Treated with a Ketogenic Diet Regimen

Ketogenic Diet (KD) is a high-fat diet used to treat refractory epilepsy in patients, also including children. Because of the inherent differences with a balanced diet, patients starting KD face an abrupt switch of dietary habits. Moreover, KD is associated with several side effects that should be closely monitored. In this paper, we propose an mHealth application for training and empowering patients in managing KD. The application also acts as a bridge connecting patients with the health care staff for coaching and monitoring purposes.

The changing face of dietary therapy for epilepsy

Ketogenic diet is an established and effective non-pharmacologic treatment for drug-resistant epilepsy. Ketogenic diet represents the treatment of choice for GLUT-1 deficiency syndrome and pyruvate dehydrogenase complex deficiency. Infantile spasms, Dravet syndrome and myoclonic-astatic epilepsy are epilepsy syndromes for which ketogenic diet should be considered early in the therapeutic pathway. Recently, clinical indications for ketogenic diet have been increasing, as there is emerging evidence regarding safety and effectiveness. Specifically, ketogenic diet response has been investigated in refractory status epilepticus and encephalopathy with status epilepticus during sleep. New targets in neuropharmacology, such as mitochondrial permeability transition, are being studied and might lead to using it effectively in other neurological diseases. But, inefficient connectivity and impaired ketogenic diet proposal limit ideal availability of this therapeutic option. Ketogenic diet in Italy is not yet considered as standard of care, not even as a therapeutic option for many child neurologists and epileptologists.

CONCLUSIONS

The aim of this review is to revisit ketogenic diet effectiveness and safety in order to highlight its importance in drug-resistant epilepsy and other neurological disorders.

WHAT IS KNOWN

• Ketogenic diet efficacy is now described in large case series, with adequate diet compliance and side effects control. • Ketogenic diet is far from being attempted as a first line therapy. Its availability varies worldwide. What is New: • New pharmacological targets such as mitochondrial permeability transition and new epileptic syndromes and etiologies responding to the diet such as refractory status epilepticus are being pointed out. • Ketogenic diet can function at its best when used as a tailor-made therapy. Fine tuning is crucial.

Short-term effects of ketogenic diet on anthropometric parameters, body fat distribution, and inflammatory cytokine production in GLUT1 deficiency syndrome

OBJECTIVE

The aim of this study was to evaluate the effects of a 12-wk ketogenic diet (KD) on inflammatory status, adipose tissue activity biomarkers, and abdominal visceral (VAT) and subcutaneous fat (SAT) in children affected by glucose transporter 1 deficiency syndrome GLUT1 DS.

METHODS

We carried out a short-term longitudinal study on 10 children (mean age: 8.4 y, range 3.3-12 y, 5 girls, 5 boys) to determine fasting serum proinflammatory cytokines (high sensitivity C-reactive protein, tumor necrosis factor-α interleukin-6), adipocyte-derived chemokines (leptin and adiponectin), lipid profile, homeostatic model assessment-insulin resistance (HOMA-IR), quantitative insulin sensitivity index (QUICKI), anthropometric measurements, and VAT and SAT (by ultrasonography).

RESULTS

Children showed no significant changes in inflammatory and adipose tissue activity biomarkers, blood glucose, lipid profile, anthropometric measurements, VAT, and SAT. Fasting insulin decreased (6 ± 3.2 μU/mL versus 3 ± 2 μU/mL; P = 0.001), and both HOMA-IR and QUICKI indexes were significantly modified (1.2 ± 0.6 versus 0.6 ± 0.4; P = 0.002; 0.38 ± 0.03 versus 0.44 ± 0.05; P = 0.002, respectively).

CONCLUSIONS

Only HOMA-IR and QUICKI indexes changed after 12 wk on a KD, suggesting that over a short period of time KD does not affect inflammatory cytokines production and abdominal fat distribution despite being a high-fat diet. Long-term studies are needed to provide answers concerning adaptive metabolic changes during KD.

Cognitive-behavioral treatment reduces attrition in treatment-resistant obese women: results from a 6-month nested case-control study

OBJECTIVE

The aim of this nested case-control study was to compare the effectiveness of cognitive-behavioral treatment (CBT) for treatment-resistant obese (body mass index [BMI] ≥ 30 kg/m²) women compared with standard dietary treatment. The main outcome measures were attrition and weight loss success.

METHODS

We designed a 6-month case-control study, nested within a cohort of adult (age ≥ 18 years) treatment-resistant (history of at least two previous diet attempts) obese women. Cases were 20 women who were offered CBT sessions. Controls (n=39) were randomly selected from the source population and matched to cases in terms of baseline age, BMI, and number of previous diet attempts.

RESULTS

Compared with controls, cases were significantly more likely to complete the 6-month program in both age-adjusted (odds ratio [OR]=2.94, 95% confidence interval [CI]=1.05-8.97) and multivariate-adjusted (OR=2.77, 95% CI=1.02-8.34) analyses. In contrast, cases were not more likely to achieve weight loss success in age-adjusted (OR=1.32, 95% CI=0.86-1.67) and multivariate-adjusted (OR=1.21, 95% CI=0.91-1.44) analyses.

CONCLUSIONS

Compared with a standard dietary treatment, CBT was significantly more effective in reducing attrition in treatment-resistant obese women, without differences in terms of weight loss success.

Is drop-out from obesity treatment a predictable and preventable event?

Background

Attrition is an important but understudied issue that plays a vital role in the successful treatment of obesity. To date, most studies focusing on attrition rates and/or its predictors have been based on pretreatment data routinely collected for other purposes. Our study specifically aims at identifying the predictors of drop-out focusing on empirically or theoretically-based factors.

Methods

We conducted a retrospective observational study in an academic outpatient clinical nutrition service in Pavia, Italy. We examined a total of 98 adult obese patients (36 males, 62 females) who underwent a 6-month dietary behavioral weight-loss treatment at our Center. Pre-treatment and treatment-related variables were collected or calculated from clinical charts in order to discriminate those subjects who completed treatment from those who abandoned it before its completion. Multivariable regression analysis was used to identify the independent predictors of drop-out.

Results

The drop-out rates were 21% at 1 month and 57% at 6 months. Compared with completers, noncompleters were significantly younger in terms of age at first dieting attempt (24.0 ± 10.7 vs. 31.3 ± 11.2 years, P = 0.005), had lower diastolic blood pressure (87.8 ± 9.7 vs. 92.7 ± 11.4 mmHg, P = 0.022), had a lower baseline body fat percentage (38.5 ± 6.4 vs. 41.2 ± 4.4% weight, P = 0.015), and had a lower percentage of early weight loss (-1.8 ± 1.8% vs. -3.1 ± 2.1%, P = 0.035). Moreover, noncompleters significantly differed from completers with regard to type of referral (34.1% vs. 53.3% sent by a physician, P = 0.036) and SCL-90 anger-hostility subscale (0.83 ± 0.72 vs. 0.53 ± 0.51, P = 0.022). A multivariable logistic regression analysis including pre-treatment variables showed that body fat percentage (P = 0.030) and SCL-90 anger-hostility subscale (P = 0.021) were independently associated with attrition. In a multivariable model considering both pre-treatment and treatment-related factors, attrition was found to be independently related to the age at first dieting attempt (P = 0.016) and the achievement of early weight loss (P = 0.029).

Conclusions

Our data confirm that psychopathological tracts, early dieting attempts, and a poor initial treatment response are key independent predictors of drop-out from obesity treatment.

Long-term effects of a ketogenic diet on body composition and bone mineralization in GLUT-1 deficiency syndrome: a case series

OBJECTIVE

The only known treatment of glucose transporter 1 deficiency syndrome (GLUT-1 DS) is a ketogenic diet (KD), which provides the brain with an alternative fuel. Studies in children with intractable epilepsy have shown that a prolonged KD can induce a progressive loss of bone mineral content associated with poor bone health status, probably as a consequence of a chronic acidic environment. The aim of this study is to determine the long-term effects of a KD on body composition and bone mineral status of patients with GLUT-1 DS, is currently unknown.

METHODS

In this case series, we report the changes in body composition and bone mineral status observed in three adult patients with GLUT-1 DS who have been treated with a KD for more than 5 y.

RESULTS

A long-term KD did not produce appreciable changes in weight and body composition of adults with GLUT-1 DS. Moreover, we found no evidence of potential adverse effects of a KD on bone health. In summary, this case series contributes to a small but growing body of literature that investigated the potential long-term effects of a KD on bone health.

CONCLUSIONS

Our data suggest that maintaining a KD for more than 5 y does not pose any major negative effects on body composition, bone mineral content, and bone mineral density in adults with GLUT-1 DS, a finding that is at variance with previous reports focusing on children with intractable epilepsy. Further studies with larger sizes are needed to confirm and expand our findings.

Clinical and psychological features of normal-weight women with subthreshold anorexia nervosa: a pilot case-control observational study

OBJECTIVE

Weight preoccupations have been frequently reported in normal-weight subjects. Subthreshold anorexia nervosa (s-AN, all DSM IV TR criteria except amenorrhea or underweight) is a form of eating disorder not otherwise specified that has received scarce scientific attention. Under a case-control design we compared the general characteristics, body composition, and psychopathological features of normal-weight patients with s-AN with those of BMI- and sex-matched controls.

DESIGN

Participants in this pilot study included 9 normal-weight women who met the DSM IV TR criteria for s-AN and 18 BMI-matched normal-weight controls. The general characteristics of the study participants were collected by questionnaire. Body composition was measured by bioelectrical impedance. Behavioral and psychological measures included the standardized symptom checklist (SCL-90-R) and the eating disorder inventory (EDI-2).

RESULTS

There were no differences in age, education, employment status, marital status, and history of previous slimming treatment in the two study groups. In addition, anthropometric measures and body composition of s-AN patients and BMI-matched normal weight controls were not significantly different. In the s-AN subgroup, we found a significant relationship between waist circumference and the SCL-90-R obsessivity-compulsivity scale (n=9, r=-0.69, p<0.05). After multiple regression analysis, the SCL-90-R obsessivity-compulsivity scale (beta = 0.61, t=2.7, p=0.017) was the only independent predictor of the presence s-AN in our study cohort.

CONCLUSIONS

These pilot results suggest that psychopathological criteria (particularly related to the obsessivity-compulsivity dimension) may be more useful than anthropometric measures for screening of s-AN in normal-weight women.

Effects of the ketogenic diet on nutritional status, resting energy expenditure, and substrate oxidation in patients with medically refractory epilepsy: a 6-month prospective observational study

BACKGROUND & AIMS

This 6-month prospective, single-arm observational study was designed to assess the effects of the KD on the nutritional status, resting energy expenditure (REE), and substrate oxidation in patients with drug-resistant epilepsy.

METHODS

Eighteen patients with medically refractory epilepsy underwent assessment of body composition, REE, and substrate oxidation rates before and after 6 months of KD.

RESULTS

Compared with baseline, there were no statistically significant differences at 6 months in terms of height, weight, BMI z-scores, and REE. However, the respiratory quotient decreased significantly (from 0.80 ± 0.06 to 0.72 ± 0.05, p < 0.001) whereas fat oxidation was significantly increased (from 50.9 ± 25.2 mg/min to 97.5 ± 25.7 mg/min, p < 0.001). Interestingly, we found that the increase in fat oxidation was the main independent predictor of the reduction in seizure frequency (beta = -0.97, t = -6.3, p < 0.05).

CONCLUSIONS

Administering a KD for 6 months in patients with medically refractory epilepsy increases fat oxidation and decreases the respiratory quotient, without appreciable changes in REE.

To treat or not to treat: comparison of different criteria used to determine whether weight loss is to be recommended

Background

Excess body fat is a major risk factor for disease primarily due to its endocrine activity. In recent years several criteria have been introduced to evaluate this factor. Nevertheless, treatment need is currently assessed only on the basis of an individual's Body Mass Index (BMI), calculated as body weight (in kg) divided by height in m². The aim of our study was to determine whether application of the BMI, compared to adiposity-based criteria, results in underestimation of the number of subjects needing lifestyle intervention.

Methods

We compared treatment need based on BMI classification with four adiposity-based criteria: percentage body fat (%BF), considered both alone and in relation to metabolic syndrome risk (MS), waist circumference (WC), as an index of abdominal fat, and Body Fat Mass Index (BFMI, calculated as fat mass in kg divided by height in m²) in 63 volunteers (23 men and 40 women, aged 20 – 65 years).

Results

According to the classification based on BMI, 6.3% of subjects were underweight, 52.4% were normal weight, 30.2% were overweight, and 11.1% were obese. Agreement between the BMI categories and the other classification criteria categories varied; the most notable discrepancy emerged in the underweight and overweight categories. BMI compared to almost all of the other adiposity-based criteria, identified a lower percentage of subjects for whom treatment would be recommended. In particular, the proportion of subjects for whom clinicians would strongly recommend weight loss on the basis of their BMI (11.1%) was significantly lower than those identified according to WC (25.4%, p = 0.004), %BF (28.6%, p = 0.003), and MS (33.9%, p = 0.002).

Conclusion

The use of the BMI alone, as opposed to an assessment based on body composition, to identify individuals needing lifestyle intervention may lead to unfortunate misclassifications. Population-specific data on the relationships between body composition, morbidity, and mortality are needed to improve the diagnosis and treatment of at-risk individuals.

Evaluation of nutritional status in children with refractory epilepsy

Background

children affected by refractory epilepsy could be at risk of malnutrition because of feeding difficulties (anorexia, chewing, swallowing difficulties or vomiting) and chronic use of anticonvulsants, which may affect food intake and energy metabolism. Moreover, their energy requirement may be changed as their disabilities would impede normal daily activities. The aim of the present study was to evaluate nutritional status, energy metabolism and food intake in children with refractory epilepsy.

Methods

17 children with refractory epilepsy (13 boys and 4 girls; mean age 9 ± 3,2 years; Body Mass Index 15,7 ± 3,6) underwent an anthropometric assessment, body composition evaluation by dual-energy X-ray absorptiometry, detailed dietetic survey and measurement of resting energy expenditure by indirect calorimetry. Weight-for-age, height-for-age (stunting) and weight-for-height (wasting) were estimated compared to those of a reference population of the same age.

Results

40% of children were malnourished and 24% were wasted. The nutritional status was worse in the more disabled children. Dietary intake resulted unbalanced (18%, 39%, 43% of total daily energy intake derived respectively from protein, lipid and carbohydrate). Adequacy index [nutrient daily intake/recommended allowance (RDA) × 100] was < 60% for calcium iron and zinc.

Conclusion

many children with refractory epilepsy would benefit from individual nutritional assessment and management as part of their overall care.

[Drug-resistant epilepsy treated with ketogenic diet]

A 4-year old girl affected by intractable seizures was treated with ketogenic diet. The diet was calculated to provide appropriate protein intake for growth (1.4 g/kg body weight) and adequate calories (1600 kcal) derived from 4 parts fat and 1 part protein + carbohydrates. The child remained on the diet for 8 months and had a decrease in seizure frequency of 90%. No serious side effects were reported and it was possible to discontinue or decrease antiepileptic drugs. Our results confirm the efficacy of ketogenic diet in the treatment of epilepsy. Since it is known that 20 to 30% of all patients with epilepsy do not have their seizures completely controlled with established antiepileptic drugs, it would be useful to increase the application of this dietetic treatment in selected patients in Italy as it already happens in other countries.

How reliable is bio-electrical impedance analysis for individual patients?

We performed bio-electrical impedance analysis (BIA) on 38 healthy adults with an initial body mass index (+/- s.d.) of 30 kg/m2 (+/- 5) before and after a low calorie diet. Five weeks later a mean weight loss of 4.2 +/- 2.3 kg was observed. According to BIA, fat-free mass (FFM) decreased in 28 subjects and increased in ten. In four cases the reduction was greater than the weight loss. At the end of the ten week diet regimen all 27 subjects followed up demonstrated a further weight reduction. According to BIA, FFM decreased in 22 subjects, increased in four and did not change in one case. In one case the reduction was greater than the weight loss. Although mean FFM values assessed by skinfolds and BIA were not significantly different before and after the weight loss period, no correlations were found among the individual changes in FFM evaluated by the two methods. Our results suggest that single frequency (50 KHz) impedance must be used with care in clinical conditions.

Complications in surface replacement arthroplasty of the hip: experience with the Paltrinieri-Trentani prosthesis

A method of surface replacement arthroplasty of the hip joint is described for use in selected patients, often in the younger age group. One hundred and forty patients were reviewed after a mean interval of four years. Seventy-two per cent were graded 5 or 6 on the Charnley scale, the remainder had symptoms due to femoral neck fracture or loosening of the prosthetic components. In the main the bad results were attributed to incorrect patient selection or technical imperfections with the operative technique. The advantages of the operation are no alteration in the relationship of the femoral head, neck and acetabulum and minimal interference with the surrounding muscle and soft tissues. The amount of implanted material is reduced and no entry is made into the femoral medullary canal, which facilitates any further revision surgery that may be necessary.

The Paltrinieri-Trentani hip joint resurface arthroplasty

The Paltrinieri-Trentani type of resurfacing the hip has been under clinical investigation for over 6 years. The prostheses consist of a metal cap, which is fitted to the head of the femur (no amputation of the neck and the head being required) and an acetabular cup made of high density polyethylene. Matched cups and caps are available in different sizes. The biomechanical preconditions upon which this hip resurfacing is based must be understood to successfully perform the operation. The series of patients reported here were aged between 32 and 70 years. The results after 6 years are 76% successful, and typical cases rate between 5 and 6 on the Charnley Scale; 12% rated between 3 and 4; 12% were failures owing either the fracture of the neck of the femur or to loosening of the femoral prosthesis. Further analysis of the cases demonstrated that: prostheses applied with the correct surgical technique gave satisfactory results; failures were attributable to errors of technique and indication.

[A ceramic total hip endoprosthesis for implantation without bone cement. Preliminary report (author's transl)]

A new total hip endoprosthesis for implantation without bone cement is reported. This prosthesis consists of a ceramic socket and a titanium femoral component which is covered with a ceramic layer (Al2O3). The proximal end of the femoral component is shaped to a conus on which a ceramic ball for articulation with the socket is placed. Beside the construction principles the implantation technique and first clinical experiences are described.

Evaluation of hip arthroprostheses by means of body environment simulators

Laboratory tests carried out by means of body environment simulators have proved to be very important for the evaluation of endoprostheses potentially useful for implantation. The present paper examines the problems connected with the design of such a simulator. The results obtained with an initial, very primitive simulator concerning the outlines of the phenomena of wear, corrosion, and friction and some wear properties of commercially available hip endoprostheses are presented. From these results, the motivation that led to the design of a more advanced simulator is presented. This latter simulator is also described.

Epiphyseal chondroblastoma (a study of 39 cases)

A fully documented series of thirty nine cases of epiphyseal chondroblastoma is described. This is a remarkable series because of the rarity of this tumour. There is a slight predilection for the male sex. The age most affected is ten to twenty years. The tumour progresses slowly and joint involvement and pain are slight. The commonest site is the proximal epiphysis of the humerus, followed by the epiphyses of the knee. The classical appearances are of a clearly defined area of osteolysis, central or eccentric, with foci of calcification, in the epiphyseal or apophyseal regions, and often transgressing the epiphyseal cartilage. We have never observed involvement of the opposite bone in the affected joint. In four of our thirty nine cases the neoplasm invaded the point and/or soft tissues. The differential diagnosis, especially in localisations at the knee, is with giant cell tumour. The tumour is slow growing and the prognosis is always good. We have never seen malignant transformations or so-called "benign" pulmonary metastases. The few recurrences in this series (five out of thirty nine) were all cured by a second operation. Curettage and grafting is the operation of choice.

Scaglietti's method for conservative treatment of simple bone cysts with local injections of methylprednisolone acetate

The results of 30 consecutive cases of simple bone cysts treated conservatively by intracystic injections of methylprednisolone acetate (MPA) according to the method of Scaglietti are reported. The injections were given under general or local anaesthesia in doses of 80-200 mgs repeated every 2 months up to a total of 2 or 3 injections, rarely more. The minimum period required for achieving a result is 6 months; but there is a continuation of radiographic improvement for 1 to 2 years. There is complete radiographic cure in about half the cases; in the others there is a substantial improvement which makes surgery unnecessary. We have used this method systematically for 3 years, and out of 42 cases only one required operation because of a displaced subtrochanteric fracture. There was a partial recurrence in one case after apparent radiographic cure. The patients' age does not seem to affect the result but we gained the impression that the effect of MPA is quicker and more reliable in younger patients. Although we do not understand the mechanism of cure in this method it has undoubted advantages over surgery.

Thermodifferential analysis of ceramic implants

Ceramic pelletes (in Al2O3 92% and in calcium aluminate) implanted into the muscles of rabbits for varying periods of time, and samples of similar material, not implanted but mixed with organic substances, have been analyzed by means of thermal differential analysis (TDA). Which hydrated calcium aluminates are formed from implants after contract with the tissue fluid, has been established. It has also been ascertained that the ceramic implants absorb organic substances from the tissue fluid, which, from a first evaluation, seem to be composed of simple molecules. The results of this initial inquiry have provided positive indications of the utility of TDA to assist in elucidating the phenomena that occur between implant and tissue.