Quantification of bone density of the proximal femur after hip resurfacing arthroplasty--comparison of different DXA acquisition modes

Total hip arthroplasty (THA) is a traditional operative procedure in the treatment of osteoarthritis. The hip resurfacing arthroplasty (HRA) provides an alternative to the THA for young active patients. HRA is a bone-preserving procedure eliminating the problem of proximal femoral stress shielding and osteolysis associated to THA. Unfortunately, there is no standardized methodology to monitor the quality of bone after HRA. In this study, areal bone mineral density (BMD) in the operated hip (10 regions of interests [ROIs] of 34 volunteered HRA patients) was measured using Lunar Prodigy dual-energy X-ray absorptiometry, and the agreement of a standard (dual femur) and an orthopedic (orthopedic hip) acquisition modes was compared. Furthermore, reproducibility of the patient-specific analysis procedures was tested. The analysis procedures were reproducible with both acquisition modes (1.18%-1.37%). The mean (± standard deviation) difference between the acquisition modes was 1.46 ± 0.93%. At ROIs, a strong linear relationship was found between the results from 2 acquisition modes (R(2)=0.801-0.966, p<0.01). In conclusion, both acquisition modes were reproducible, and it is suggested that the error induced by the different acquisition modes does not affect interpretation of BMD changes after HRA surgery.

Heart rate dynamics after combined endurance and strength training in older men

PURPOSE

Aging alters cardiac autonomic function, which may contribute to a higher risk of cardiac events. Spectral measures of HR variability (HRV) and fractal-like behavior of HR are considered as markers of a healthy heart. The present study examined the effects of combining endurance and strength training compared with endurance or strength training alone on HR dynamics and physical fitness in older previously untrained men aged 40-67 yr.

METHODS

Subjects were randomized into endurance training (E, n = 23), strength training (S, n = 25), combined endurance and strength training (ES, n = 29), or control group (C, n = 16). Short-term fractal scaling exponent (alpha1) and spectral HRV were analyzed from maximal aerobic cycling tests and during supine rest, and leg extension one repetition maximum strength was measured.

RESULTS

Aerobic capacity and maximal strength increased in the training groups performing endurance and/or strength training, respectively. Only ES showed a decrease after training in fractal HR behavior during exercise, and the difference was significant between groups (P = 0.019). During supine rest, alpha1 only decreased significantly (P = 0.039) in ES from 1.18 (SD = 0.20) to 1.11 (SD = 0.21). The decrease in alpha1 at rest from 1.21 (SD = 0.19) to 1.11 (SD = 0.22) also approached significance (P = 0.061) in E. Changes in spectral measures of HRV were minor during the study period and only occurred during exercise.

CONCLUSION

Fractal HR dynamics were improved more by combining strength training with endurance training in our older men compared with endurance training alone, although strength training alone produced no changes in fractal HR behavior. The synergistic effect in fractal HR behavior occurred regardless of changes in aerobic capacity.

Effects of combined strength and endurance training on treadmill load carrying walking performance in aging men

The present study examined the effects of twice weekly total body strength training (ST), endurance cycling (ET), and combined ST and ET (2+2 times a week) (SET) training on the load carrying walking test performance on the treadmill (TM) and changes in neuromuscular and endurance performance during a 21-week training period in aging men. Forty healthy men (54.8+/-8.0 years) were divided into 3 training groups (ET n=9, ST n=11, SET n=11) and a control group (C, n=9). Peak oxygen uptake (VO2peak), heart rate, and blood lactate concentration were measured before and after a 21-week training program using a graded TM and maximal incremental bicycle ergometer (BE) tests. Isometric forces, vertical jump, and electromyographic activity of leg extensor and/or forearm flexor (F) muscles were measured before and after training and the TM tests. Increases of 20-21% in strength and of 7-12% in cycling BE VO2peak occurred in the training groups, whereas the changes of C remained minor. VO2peak was associated, both before and after training, with TM exercise time in all groups (from r=0.65, p=0.030 to r=0.93, p<0.001). Only SET showed a significant training-induced increase (p=0.011) in exercise time of the TM walking with no significant increase in TM VO2peak. The present data suggest that in older men ET and SET induced specific increases in BE VO2peak and ST and SET in strength. However, only SET increased walking exercise time indicating improved load carrying walking performance because of large individual differences in the magnitude of the development of either strength or endurance capacities.

Neuromuscular performance and body mass as indices of bone loading in premenopausal and postmenopausal women

The strong association between body mass and skeletal robusticity has been attributed to increasing skeletal loading with increasing mass. However, it is unclear whether body mass is merely a coarse substitute for bone loading rather than a true independent predictor of bone strength. As indices of neuromuscular performance, impulse and peak power were determined from vertical ground reaction force during a maximal counter movement jump test in 221 premenopausal and 82 postmenopausal women. Bone compressive (BSI(d) g(2)/cm(4)) and bending (SSImax(mid) mm(3)) strength indices were measured with peripheral quantitative computed tomography (pQCT) at the distal ((d)) and midshaft ((mid)) sites of the tibia. A two-step forced regression model for predicting bone strength indices was constructed. Age, height and body mass were entered first, followed by impulse as an indicator of skeletal loading. The basic model explained 14% (P<0.001) of the variance in BSI(d) in the premenopausal group and 16% (P=0.004) in the postmenopausal group, and 32% (P<0.001) and 25% (P<0.001) of the variance in SSImax(nud) respectively. Entering impulse into the model increased the explanatory power by 9% (P<0.001) and 7% (P<0.001) for BSI(d) and by 8% (P<0.001) and 12% (P<0.001) for SSImax(mid). Furthermore, impulse replaced body mass as an independent significant factor explaining the variance in bone strength. These results indicate that neuromuscular performance should be measured and preferred over body mass in models predicting skeletal robusticity.

Association of physical fitness with health-related quality of life in Finnish young men

Background

Currently, there is insufficient evidence available regarding the relationship between level of physical fitness and health-related quality of life (HRQoL) in younger adults. Therefore, the aim of the present study was to investigate the impact of measured cardiovascular and musculoskeletal physical fitness level on HRQoL in Finnish young men.

Methods

In a cross-sectional study, we collected data regarding the physical fitness index, including aerobic endurance and muscle fitness, leisure-time physical activity (LTPA), body composition, health, and HRQoL (RAND 36) for 727 men [mean (SD) age 25 (5) years]. Associations between HRQoL and the explanatory parameters were analyzed using the logistic regression analysis model.

Results

Of the 727 participants who took part in the study, 45% were in the poor category of the physical fitness, while 37% and 18% were in the satisfactory and good fitness categories, respectively. A higher frequency of LTPA was associated with higher fitness (p < 0.001). Better HRQoL in terms of general health, physical functioning, mental health, and vitality were associated with better physical fitness. When the HRQoL of the study participants were compared with that of the age- and gender-weighted Finnish general population, both the good and satisfactory fitness groups had higher HRQoL in all areas other than bodily pain. In a regression analysis, higher LTPA was associated with three dimensions of HRQoL, higher physical fitness with two, and lower number of morbidities with all dimensions, while the effect of age was contradictory.

Conclusions

Our study of Finnish young men indicates that higher physical fitness and leisure-time physical activity level promotes certain dimensions of HRQoL, while morbidities impair them all. The results highlight the importance of health related physical fitness while promoting HRQoL.

Effects of combined endurance and strength training on muscle strength, power and hypertrophy in 40-67-year-old men

Both strength and endurance training have several positive effects on aging muscle and physical performance of middle-aged and older adults, but their combination may compromise optimal adaptation. This study examined the possible interference of combined strength and endurance training on neuromuscular performance and skeletal muscle hypertrophy in previously untrained 40-67-year-old men. Maximal strength and muscle activation in the upper and lower extremities, maximal concentric power, aerobic capacity and muscle fiber size and distribution in the vastus lateralis muscle were measured before and after a 21-week training period. Ninety-six men [mean age 56 (SD 7) years] completed high-intensity strength training (S) twice a week, endurance training (E) twice a week, combined training (SE) four times per week or served as controls (C). SE and S led to similar gains in one repetition maximum strength of the lower extremities [22 (9)% and 21 (8)%, P<0.001], whereas E and C showed minor changes. Cross-sectional area of type II muscle fibers only increased in S [26 (22)%, P=0.002], while SE showed an inconsistent, non-significant change [8 (35)%, P=0.73]. Combined training may interfere with muscle hypertrophy in aging men, despite similar gains in maximal strength between the strength and the combined training groups.

Serum basal hormone concentrations, nutrition and physical fitness during strength and/or endurance training in 39-64-year-old women

We examined effects of 21 weeks of strength and/or endurance training and nutrition on serum hormones and physical fitness in 39-64-year-old women. Subjects (n=79) were randomized into the endurance group (E), strength group (S), combined group (SE) and controls (C). Total body strength training and high-intensity bicycle training were used. Average energy and nutrient intake remained the same in all groups. Body fat (dual energy X-ray absorptiometry) decreased significantly in all training groups and body mass index in E, SE and C. Only SE increased total body lean mass (2.2%, p=0.001), between groups p=0.044. Maximal cycling power increased more in E (16%) and SE (17%) than in S (8%)(all p<0.001), between groups p<0.001. Knee extension strength increased only in S (7%, p=0.006) and SE (11%, p<0.001). The changes in serum hormones did not differ between the groups, except insulin-like growth factor-1 (p=0.028), characterized by an 8% (p=0.097) increase in SE and a 7% (p=0.074) decrease in C. In women combined training led to marked improvements in physical fitness and body composition. Energy and protein intake was sufficient to ensure training-induced adaptations in muscle mass and physical fitness in response to both endurance and strength training, even though the energy balance was slightly negative in the endurance-trained groups.

Health-related quality of life and physical activity in persons at high risk for type 2 diabetes

PURPOSE

The aim of this study was to compare the health-related quality of life (HRQOL) of persons at risk for type 2 diabetes to that of the Finnish general population. In addition, the associations between physical activity and HRQOL at-risk persons were studied.

METHODS

One hundred thirty-two at-risk persons were recruited from health care centres in Central Finland. Participants filled out questionnaires including demographic characteristics, HRQOL (SF-36), frequency of vigorous physical activity (< or =2 times a week, once a week, less than once a week) and comorbidities.

RESULTS

HRQOL of at-risk persons differed significantly from that of the Finnish population in four of the eight dimensions of SF-36. Compared with reference values of the general population, the values of at-risk persons were worse for general health and pain, but better for mental health and role limitation (emotional) dimensions. Among at-risk persons those physically more active had less depressiveness and lower body weight. HRQOL decreased linearly with decreasing physical activity in all dimensions.

CONCLUSIONS

People with elevated risk for type 2 DM have reduced HRQOL in general health and body pain dimensions, but mental health and emotional role dimensions were better compared with that of the population. Among at-risk persons, the benefits of physical activity on HRQOL were seen in all HRQOL dimensions. Regular exercise and body weight control may improve subjective health and reduce risk for type 2 DM and its consequences.

Improvements of muscle strength predicted benefits in HRQOL and postural balance in women with fibromyalgia: an 8-month randomized controlled trial

OBJECTIVE

To evaluate whether changes in muscle strength due to 32 weeks of supervised aquatic training predicted improvements on health-related quality of life (HRQOL).

METHODS

Thirty women with FM aged 50.8 +/- 8.7 years were randomly assigned to an experimental group (n = 15), performing 3 weekly sessions of 60 min of warm-water exercise; or to a control group (n = 15). HRQOL was evaluated using the Short Form 36 Health Survey (SF-36). Maximal unilateral isokinetic strength was measured at 60 degrees/s and 210 degrees/s in the knee extensors and flexors in concentric action and at 60 degrees/s in knee extensors eccentric action. Postural balance was evaluated using the one-leg stance, eyes closed.

RESULTS

After 32 weeks of water exercise therapy, statistically significant improvements occurred in concentric knee flexors and extensors strength at 60 degrees/s, in eccentric knee extensors and in postural balance. The treatment led to additional improvements in physical function, role physical problems, body pain, general health, vitality, role emotional problems and mental health dimensions of SF-36. Gains in the concentric knee flexors strength predicted improvements in role of physical problems, whereas those in concentric knee extensors did the same for mental health and role emotional problems. Gains in eccentric knee extensors strength predicted improvements in postural balance.

CONCLUSIONS

A long-lasting exercise therapy in warm water produced relevant gains in muscle strength at low velocities of movements, some of which predicted improvements in physical problems, emotional problems, mental health and balance.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number ISRCTN53367487, information available in http://www.controlled-trials.com/ISRCTN53367487.

Health related quality of life after lumbar disc surgery: A prospective study of 145 patients

PURPOSE

This study compared health related quality of life (HRQOL) among lumber disc surgery patients to general population, and assessed the relationships between HRQOL and other outcome measures 2 and 14 months after surgery.

METHODS

The 15D instrument was use to measure HRQOL in 145 lumber disk surgery patients. Subjective outcome was also assessed by the Oswestry index, Short Depression Inventory (SDI) and pain, and objective outcome by trunk muscle strength and mobility of the spine.

RESULTS

The mean (SD) 15D score among the patients 2 months after surgery was 0.880 (0.104) compared to 0.941 (0.076) among general population (p = 0.016). The 15D, Oswestry and SDI scores remained unchanged during the follow-up, while the improvements in the spine mobility and trunk muscle strength were significant. Back pain decreased by 68% and leg pain by 74% from preoperative level to 2 months check-up. Leg pain further decreased during the following 12 months, while back pain remained unchanged. HRQOL was associated with age, pain, Oswestry and SDI indices, but not with physical function.

CONCLUSION

HRQOL measured by 15D was lower in lumber disc surgery patients compared to general population. 15D was associated with the subjective outcome measures of pain, Oswestry and SDI indices, but not with the objective measures of physical function. Thus, a combination of "disease specific" and "generic" measures is recommended to be used to obtain more accurate information about the overall welfare of individual.

Reproducibility of imaging human knee cartilage by delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) at 1.5 Tesla

OBJECTIVE

The purpose of this study was to investigate the day-to-day reproducibility of the delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) measurement at different knee joint surfaces in healthy subjects at 1.5 Tesla (T).

METHODS

The dGEMRIC experiment was repeated for 10 asymptomatic volunteers three times with an average interval of 5 days between scans. The measurement was performed from a single sagittal slice through the center of the lateral femoral condyle and from the center of the patella in the axial plane. Cartilage was manually segmented into superficial, deep and full-thickness regions of interests (ROIs) at different topographical locations of the femur, tibia and patella. The reproducibility was evaluated separately for each ROI as well as for the entire bulk cartilage in the slice of each joint surface.

RESULTS

The reproducibility at various ROIs expressed by root-mean-square average coefficient of variation (CV(RMS)) ranged between 4.7-12.9%. Thirty out of thirty-three ROIs showed a CV(RMS) less than 10%. Intraclass correlation coefficient (ICC) ranged between 0.45 and 0.98. The CV(RMS) and ICC for bulk dGEMRIC were 4.2% and 0.95 for femur, 5.5% and 0.87 for tibia, and 4.8% and 0.97 for patella.

CONCLUSIONS

The dGEMRIC technique showed good day-to-day reproducibility, on the average 8% for small deep or superficial segments, 7% for full-thickness ROIs and 5% for bulk ROIs covering all visible cartilage in a single joint surface. We conclude that dGEMRIC imaging at field strength 1.5 T can be used as a reliable instrument for the assessment of articular cartilage when staff has been carefully trained.

Self-report functioning according to the ICF model in elderly patients with rheumatoid arthritis and in population controls using the multidimensional health assessment questionnaire

OBJECTIVE

To assess disability and functioning of elderly patients with rheumatoid arthritis (RA) and population controls by linking the items included in the self-report Multidimensional Health Assessment Questionnaire (MDHAQ) with components of the WHO International Classification of Functioning, Disability and Health (ICF) instrument.

METHODS

In total, 1439 patients with RA (mean age 66 yrs, men 29%) and 957 population controls (65 yrs, men 27%) completed a mailed questionnaire. Functioning was recorded by the Finnish version of MDHAQ. Data included comorbidity, subjective health, education level, employment, exercise habits, self-report joint pain/tenderness, and, for patients, the disease duration.

RESULTS

Patients had lower levels of functioning compared to controls in all ICF domains, with the exception that male patients functioned comparably to male controls in the "general tasks and demands" domain. In patients, disease activity, education, exercise frequency, and comorbidities were expectedly associated with lower functioning in the body structure and function component, while male sex and subjectively perceived health were associated with more favorable functioning. In the activity and participation components, disease activity, exercise frequency, and comorbidities were associated with impaired functioning, while better health on self-report was associated with better functioning.

CONCLUSION

There is an extra burden of disability in elderly patients with RA compared to the reference population. With a large patient and control population sample, our study shows that use of the self-report MDHAQ identifies all 3 main components of the ICF framework, thus covering a wide spectrum of functioning. Elderly patients with RA, in comparison to population controls, encounter more difficulties in daily activities and their social life.

Positive treatment response improves the health-related quality of life of patients with early rheumatoid arthritis

OBJECTIVE

To examine treatment induced changes in health-related quality of life (HR-QoL) in patients with early rheumatoid arthritis (RA).

METHODS

Changes in HR-QoL were assessed by the Nottingham Health Profile (NHP) instrument in 62 consecutive working age patients with recent onset RA with duration of symptoms of less than two years and naive with regard to disease-modifying antirheumatic drugs (DMARDs) and glucocorticoids. Treatment-response was assessed by the criteria of the European League against Rheumatism (EULAR; 28-joint score; DAS28) at 6 months.

RESULTS

NHP mean scores for pain (p=0.029) and emotional reaction (p=0.035) at baseline were related to EULAR response at 6 months, i.e. non-responders had the poorest baseline HR-QoL scores. When the patients were grouped according to EULAR response at 6 months there was a statistically significant mean linear change to better HR-QoL in NHP energy (p=0.0023), pain (p<0.001) and mobility (p=0.0085) from baseline to 6 months from the lowest to highest treatment-response level.

CONCLUSION

Our results show that good treatment-response as measured by the EULAR response criteria translates into improved HR-QoL dimensions for energy, pain and mobility.

Body composition and fitness during strength and/or endurance training in older men

PURPOSE

This study examined adaptations in body composition and physical fitness during a 21-wk strength and/or endurance training period in 40- to 65-yr-old men. We also compared the usefulness of different methods for the analysis of body composition to detect training-induced adaptations.

METHODS

Fifty-three men were randomized into the endurance training (E: N = 14), strength training (S: N = 13), combined strength and endurance training (SE: N = 15), or control (C: N = 11) groups. S and E trained 2 and SE 2 x 2 times a week for strength and endurance.

RESULTS

Percentage of fat (fat%) decreased (5-8%) similarly in all training groups. Fat% measured by DXA at baseline and its change correlated with those recorded by bioimpedance (r = 0.90 and 0.66), skinfolds (r = 0.80 and 0.78), and waistline (r = 0.84 and 0.74). Lean mass in legs (DXA) increased only in S (2.0 +/- 1.5%, P < 0.001), but the thickness of vastus lateralis and intermedius measured by ultrasound increased (7-11%) in all training groups, and that of triceps brachii increased in S (22%) and SE (20%). Maximal concentric force increased significantly in S, SE, and E (by 22, 23, and 7%), and maximal oxygen uptake increased in both E (11%) and SE (11%).

CONCLUSIONS

Waist circumference and skinfold thickness seem to reasonably assess changes in percent body fat during training. However, only DXA was capable to separate small differences between the groups in training-induced changes in lean body mass. Combined strength and endurance training is of greater value than either alone in optimizing body composition or improving physical fitness in older men.

Changes in pain and physical function during waiting time and 3 months after knee joint arthroplasty

OBJECTIVE

To determine changes in physical and social function during a prolonged preoperative waiting period and at 3 months after total knee arthroplasty.

SUBJECTS

Forty-three patients were evaluated on the day that surgery was decided, the day before surgery, and 3 months afterwards.

METHODS

Knee pain and function were assessed using a visual analogue scale and a functional assessment system. Isometric knee flexion extension strength and mobility were measured.

RESULTS

Knee pain and muscle strength remained unchanged during the mean waiting time of 10 (standard deviation 8) months. On the affected side, knee extension strength was 19% weaker than on the contralateral side and did not change pre-operatively. Post-operatively, knee pain decreased by 50%. Knee extension strength decreased by 26% and flexion strength by 12% compared with the initial assessments. Knee extension strength of the operated side was 42% lower than on the non-operated side. Knee flexion mobility was decreased by 8%, while the initially detected knee extension deficit of 10 degrees (SD 7) remained unchanged. The functional assessment system did not detect any changes in function.

CONCLUSION

Waiting time did not affect knee pain or isometric knee extension/flexion strength. Three months post-operatively, knee pain had decreased significantly, but the strength of the operated knee was significantly lower than the pre-operative level.

Poor physical fitness and performance as predictors of mortality in normal populations and patients with rheumatic and other diseases

Poor physical function and low muscle strength are significant predictors of mortality in rheumatoid arthritis, other chronic diseases, ageing individuals, and the general population. Poor physical function predicts earlier mortality in diseased and normal populations at levels of significance similar to or greater than most known biomedical predictors such as laboratory tests. This chapter summarizes data concerning the prediction of premature mortality by poor physical fitness and musculoskeletal function, according to performance and self-report measures. The data support recommendations for regular exercise in all individuals whether or not they have a disease, to promote health and longevity.

Effects of strength and endurance training on metabolic risk factors in healthy 40-65-year-old men

This study compared 21 weeks of combined high-intensity strength and endurance training with endurance or strength training only on metabolic risk factors in 40-65-year-old men. The healthy men (n=63) were randomized into endurance (E), strength (S), combined strength and endurance training (SE) and control (C) groups. S and E trained two times a week and SE 2+2 times a week. Systolic (SBP) and diastolic blood pressure decreased significantly both in E (-6+/-8 and -4+/-6 mmHg) and in S (-9+/-8 and -5+/-7 mmHg), but not in SE or C (P=0.003 for the difference in the changes of SBP between the groups). The changes in serum glucose and insulin during an oral glucose tolerance test did not differ between the groups. Only E decreased serum fasting insulin levels (-17+/-27%, P=0.013). Minor changes were observed in blood lipids and lipoproteins in all groups. Both endurance and strength training can modestly improve metabolic health even in relatively lean older men with normal glucose tolerance. Combined strength and endurance training did not produce complementary benefits on metabolic risk factors. Combined training is effective in improving body composition and cardiorespiratory and muscular fitness, however, which is likely to decrease the risk of future metabolic and cardiovascular disease.