Sex-related differential item functioning of the Jenkins Sleep Scale: a cross-sectional study among 77 967 employees in the Finnish public sector

OBJECTIVES

To investigate if the Jenkins Sleep Scale (JSS) demonstrates sex-related differential item functioning (DIF).

DESIGN

Cross-sectional study.

SETTING

Survey data from the Finnish Public Sector study (2015-2017).

PARTICIPANTS

77 967 employees in the Finnish public sector, with a mean age of 51.9 (SD 13.1) years and 82% women.

OUTCOME MEASURES

Item response theory estimates: difficulty and discrimination parameters of the JSS and differences in these parameters between men and women.

RESULTS

The mean JSS total score was 6.4 (4.8) points. For all four items of the JSS, the difficulty parameter demonstrated a slight shift towards underestimation of the severity of sleep difficulties. The discrimination ability of all four items was moderate to high. For the JSS composite score, overall discrimination ability was moderate (0.98, 95% CI 0.97 to 0.99). Mild uniform DIF (p<0.001) was seen: two items showed better discrimination ability among men and two others among women.

CONCLUSIONS

The JSS showed overall good psychometric properties among this healthy population of employees in the Finnish public sector. The JSS was able to discriminate people with different severities of sleep disturbances. However, when using the JSS, the respondents might slightly underestimate the severity of these disturbances. While the JSS may produce slightly different results when answered by men and women, these sex-related differences are probably negligible when applied to clinical situations.

Towards Tailored Rehabilitation by Implementation of a Novel Musculoskeletal Finite Element Analysis Pipeline

Tissue-level mechanics (e.g., stress and strain) are important factors governing tissue remodeling and development of knee osteoarthritis (KOA), and hence, the success of physical rehabilitation. To date, no clinically feasible analysis toolbox has been introduced and used to inform clinical decision making with subject-specific in-depth joint mechanics of different activities. Herein, we utilized a rapid state-of-the-art electromyography-assisted musculoskeletal finite element analysis toolbox with fibril-reinforced poro(visco)elastic cartilages and menisci to investigate knee mechanics in different activities. Tissue mechanical responses, believed to govern collagen damage, cell death, and fixed charge density loss of proteoglycans, were characterized within 15 patients with KOA while various daily activities and rehabilitation exercises were performed. Results showed more inter-participant variation in joint mechanics during rehabilitation exercises compared to daily activities. Accordingly, the devised workflow may be used for designing subject-specific rehabilitation protocols. Further, results showed the potential to tailor rehabilitation exercises, or assess capacity for daily activity modifications, to optimally load knee tissue, especially when mechanically-induced cartilage degeneration and adaptation are of interest.

Associations of Metabolic Syndrome and Its Components with the Risk of Incident Knee Osteoarthritis Leading to Hospitalization: A 32-Year Follow-up Study

OBJECTIVES

To examine whether metabolic syndrome or its individual components predict the risk of incident knee osteoarthritis (OA) in a prospective cohort study during a 32-year follow-up period.

DESIGN

The cohort consisted of 6274 participants of the Mini-Finland Health Survey, who were free from knee OA and insulin-treated diabetes at baseline. Information on the baseline characteristics, including metabolic syndrome components, hypertension, elevated fasting glucose, elevated triglycerides, reduced high-density lipoprotein, and central obesity were collected during a health examination. We drew information on the incidence of clinical knee OA from the national Care Register for Health Care. Of the participants, 459 developed incident knee OA. In our full model, age, gender, body mass index, history of physical workload, smoking history, knee complaint, and previous injury of the knee were entered as potential confounding factors.

RESULTS

Having metabolic syndrome at baseline was not associated with an increased risk of incident knee OA. In the full model, the hazard ratio for incident knee OA for those with metabolic syndrome was 0.76 (95% confidence interval [0.56, 1.01]). The number of metabolic syndrome components or any individual component did not predict an increased risk of knee OA. Of the components, elevated plasma fasting glucose was associated with a reduced risk of incident knee OA (hazard ratio 0.71, 95% confidence interval [0.55, 0.91]).

CONCLUSIONS

Our findings do not support the hypothesis that metabolic syndrome or its components increase the risk of incident knee OA. In fact, elevated fasting glucose levels seemed to predict a reduced risk.

Internal consistency and factor structure of Jenkins Sleep Scale: cross-sectional cohort study among 80 000 adults

OBJECTIVES

To assess the internal consistency and construct validity of the Finnish translation of the Jenkins Sleep Scale (JSS) in a large healthy working-age population with diverse work characteristics.

DESIGN

Survey-based cross-sectional cohort study.

SETTING

Survey conducted by an institute of occupational health.

PARTICIPANTS

Employees of 10 towns and 6 hospital districts.

PRIMARY AND SECONDARY OUTCOME MEASURES

The internal consistency defined by a Cronbach's alpha. Exploratory and confirmatory factor analyses to evaluate the construct structure of the JSS.

RESULTS

Of 81 136 respondents, 14 890 (18%) were men and 66 246 (82%) were women. Their average age was 52.1 (13.2) years. Of the respondents, 41 823 (52%) were sleeping 7 or less hours per night. The mean JSS total score was 6.4 (4.8) points. The JSS demonstrated high internal consistency with an alpha of 0.80 (lower 95% confidence limit 0.80). Exploratory factor analysis supported a one-factor solution with eigenvalue of 1.94. Confirmatory factor analysis showed that all four items were positively correlated with a single common factor explaining 44%-61% of common factor's variance.

CONCLUSIONS

The Finnish translation of JSS was found to be a unidimensional scale with good internal consistency. As such, the scale may be recommended as a practicable questionnaire when studying sleep difficulties in a healthy working-age population.

Eight-year trajectories of changes in health-related quality of life in knee osteoarthritis: Data from the Osteoarthritis Initiative (OAI)

Background

Knee osteoarthritis (OA) worsens health-related quality of life (HRQoL) but the symptom pathway varies from person to person. We aimed to identify groups of people with knee OA or at its increased risk whose HRQoL changed similarly. Our secondary aim was to evaluate if patient-related characteristics, incidence of knee replacement (KR) and prevalence of pain medication use differed between the identified HRQoL trajectory groups.

Methods

Eight-year follow-up data of 3053 persons with mild knee OA or at increased risk were obtained from the public Osteoarthritis Initiative (OAI) database. Group-based trajectory modeling was used to identify patterns of experiencing a decrease of ≥10 points (Minimal Important Change, MIC) in the Quality of Life subscale of the Knee injury and Osteoarthritis Outcome Score compared to baseline. Multinomial logistic regression, Cox regression and generalized estimating equation models were used to study secondary aims.

Results

Four HRQoL trajectory groups were identified. Persons in the ‘no change’ group (62.9%) experienced no worsening in HRQoL. ‘Rapidly’ (9.5%) and ‘slowly’ worsening (17.1%) groups displayed an increasing probability of experiencing the MIC in HRQoL. The fourth group (10.4%) had ‘improving’ HRQoL. Female gender, higher body mass index, smoking, knee pain, and lower income at baseline were associated with belonging to the ‘rapidly worsening’ group. People in ‘rapidly’ (hazard ratio (HR) 6.2, 95% confidence interval (CI) 3.6–10.7) and ‘slowly’ worsening (HR 3.4, 95% CI 2.0–5.9) groups had an increased risk of requiring knee replacement. Pain medication was more rarely used in the ‘no change’ than in the other groups.

Conclusions

HRQoL worsening was associated with several risk factors; surgical and pharmacological interventions were more common in the poorer HRQoL trajectory groups indicating that HRQoL does reflect the need for OA treatment. These findings may have implications for targeting interventions to specific knee OA patient groups.

Health-related quality of life in relation to symptomatic and radiographic definitions of knee osteoarthritis: data from Osteoarthritis Initiative (OAI) 4-year follow-up study

Background

The purpose was to quantify the decrement in health utility (referred as disutility) associated with knee osteoarthritis (OA) and different symptomatic and radiographic uni- and bilateral definitions of knee OA in a repeated measures design of persons with knee OA or at increased risk of developing knee OA.

Methods

Data were obtained from the Osteoarthritis Initiative database. SF-12 health-related quality of life was converted into SF-6D utilities, and were then handled as the health utility loss by subtracting 1.000 from the utility score, yielding a negative value (disutility). Symptomatic OA was defined by radiographic findings (Kellgren-Lawrence, K-L, grade ≥ 2) and frequent knee pain in the same knee. Radiographic OA was defined by five different definitions (K-L ≥ 2 unilaterally / bilaterally, or the highest / mean / combination of K-L grades of both knees). Repeated measures generalized estimating equation (GEE) models were used to investigate disutility in relation to these different definitions.

Results

Utility decreased with worsening of symptomatic or radiographic status of knee OA. The participants with bilateral and unilateral symptomatic knee OA had 0.03 (p < 0.001) and 0.02 (p < 0.001) points lower utility scores, respectively, compared with the reference group. The radiographic K-L grade 4 defined as the mean or the highest grade of both knees was related to a decrease of 0.04 (p < 0.001) and 0.03 (p < 0.001) points in utility scores, respectively, compared to the reference group.

Conclusions

Knee OA is associated with diminished health-related quality of life. Health utility can be quantified in relation to both symptomatic and radiographic uni- and bilateral definitions of knee OA, and these definitions are associated with differing disutilities. The performance of symptomatic definition was better, indicating that pain experience is an important factor in knee OA related quality of life.

Electronic supplementary material

The online version of this article (10.1186/s12955-018-0979-7) contains supplementary material, which is available to authorized users.

Magnetic resonance imaging (MRI)-defined cartilage degeneration and joint pain are associated with poor physical function in knee osteoarthritis - the Oulu Knee Osteoarthritis study

OBJECTIVE

The main aim was to investigate the associations between Magnetic Resonance Imaging (MRI)-defined structural pathologies of the knee and physical function.

DESIGN

A cohort study with frequency matching on age and sex with eighty symptomatic subjects with knee pain and suspicion or diagnosis of knee osteoarthritis (OA) and 57 asymptomatic subjects was conducted. The subjects underwent knee MRI, and the severity of structural changes was graded by MRI Osteoarthritis Knee Score (MOAKS) in separate knee locations. WOMAC function subscores were recorded and physical function tests (20-m and 5-min walk, stair ascending and descending, timed up & go and repeated sit-to-stand tests) performed. The association between MRI-defined structural pathologies and physical function tests and WOMAC function subscores were evaluated by linear regression analysis with adjustment for demographic factors, other MRI-features and pain with using effect size (ES) as a measure of the magnitude of an association.

RESULTS

Cartilage degeneration showed significant association with poor physical performance in TUG-, stair ascending and descending-, 20-m- and 5-min walk-tests (ESs in the subjects with cartilage degeneration anywhere between 0.134 [95%CI 0.037-0.238] and 0.224 [0.013-0.335]) and with increased WOMAC function subscore (ES in the subjects with cartilage degeneration anywhere 0.088 [0.012-0.103]). Also, lateral meniscus maceration and extrusion were associated with poor performance in stair ascending test (ESs 0.067 [0.008-0.163] and 0.077 [0.012-0.177]).

CONCLUSIONS

After adjustments cartilage degeneration was associated with both decreased self-reported physical function and poor performance in the physical function tests. Furthermore, subjects with lateral meniscus maceration and extrusions showed significantly worse performance in stair ascending tests.

Associations between MRI-defined structural pathology and generalized and localized knee pain - the Oulu Knee Osteoarthritis study

OBJECTIVE

To determine the associations between multi-feature structural pathology assessed using magnetic resonance imaging (MRI) and the presence of knee pain, and to determine the associations between the locations of structural changes and different knee pain patterns.

METHOD

Eighty symptomatic subjects with knee pain and suspicion or diagnosis of knee OA and 63 asymptomatic subjects underwent knee MRI. Severity of structural changes was graded by MRI Osteoarthritis Knee Score (MOAKS) in separate knee locations. The associations between cartilage damage, bone marrow lesions (BMLs), osteophytes, Hoffa's synovitis, effusion-synovitis, meniscal damage and structural pathologies in ligaments, tendons and bursas and both the presence of pain and the knee pain patterns were assessed.

RESULTS

The presence of Hoffa's synovitis (adjusted RR 1.6, 95% CI 1.2-1.3) and osteophytes in any region (2.07, 1.19-3.60) was significantly associated with the presence of pain. Any Hoffa's synovitis was associated with patellar pain (adjusted RR 4.70, 95% CI 1.19-3.60) and moderate-to-severe Hoffa's synovitis with diffuse pain (2.25, 1.13-4.50). Medial knee pain was associated with cartilage loss in the medial tibia (adjusted RR 2.66, 95% CI 1.22-5.80), osteophytes in the medial tibia (2.66, 1.17-6.07) and medial femur (2.55, 1.07-6.09), medial meniscal maceration (2.20, 1.01-4.79) and anterior meniscal extrusions (2.78, 1.14-6.75).

CONCLUSIONS

Hoffa's synovitis and osteophytes were strongly associated with the presence of knee pain. Medial pain was associated most often with medially located structural pathologies.

Effectiveness of a cognitive-behavioural group intervention for knee osteoarthritis pain: a randomized controlled trial

OBJECTIVE

To assess the effectiveness of a six week cognitive-behavioural group intervention in patients with knee osteoarthritis pain.

DESIGN

Single-blinded randomized controlled trial.

STUDY SETTING

Primary care providers in a medium-sized city in Finland.

PATIENTS

A total of 111 participants aged from 35 to 75 with clinical symptoms and radiographic grading (Kellgren-Lawrence 2-4) of knee osteoarthritis were included.

INTERVENTIONS

In the intervention group, 55 participants attended a cognitive-behavioural training programme for pain management with six weekly group sessions supervised by a psychologist and a physiotherapist. Concurrently, they and the 56 participants of the control group continued in ordinary GP care that was not altered by the study.

MAIN MEASURES

The primary outcome on three-month and 12-month follow-up was the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis index pain subscale. Secondary outcome measures included self-reports of pain and physical function, health-related quality of life, and a comprehensive set of psychological questionnaires.

RESULTS

Mixed model results showed no significant differences between the intervention and control group for any measures of pain or function. A significant difference between the groups was found in the Pain Self-Efficacy Questionnaire (Pr = 0.022) in favour of the control group, and in the RAND-36 emotional well-being subscale in favour of the intervention group (Pr = 0.038). Conventional group comparisons of mean follow-up values showed no significant differences in any of the outcome variables.

CONCLUSION

This trial could not confirm the hypothesized advantage of a cognitive-behavioural training programme over ordinary GP care in knee osteoarthritis pain patients.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN64794760.

Determinants of pain and functioning in hip osteoarthritis - a two-year prospective study

OBJECTIVE

To identify predictors of pain and disability in hip osteoarthritis.

DESIGN

A prospective analysis of determinants of pain and functioning in hip osteoarthritis.

STUDY SETTING

Rehabilitation clinic in a central hospital.

PATIENTS

A total of 118 men and women aged 55-80 years who had radiologically diagnosed hip osteoarthritis and associated clinical symptoms and participated in a randomized controlled trial.

MAIN MEASURES

The self-reported disease-specific pain and physical function were assessed using the pain and functioning subscales of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis index. The self-reported generic physical and mental functioning were assessed by using the Finnish-validated SF-36-item Health Survey RAND-36 subscales for function and physical and mental component summary scores. Outcome measures were recorded at 0, 3, 6, 12, 18 and 24 months.

RESULTS

Multivariate linear mixed model analyses revealed that lower disease-specific pain score and better functioning (WOMAC) were predicted by higher educational level (9.61 (3.15 to 16.07); 9.07 (2.05 to 16.09)), supervised exercise training (-10.13 (-17.87 to -2.39); -11.58 (-19.40 to -3.77)), habitual conditioning physical activity (-0.48 (-0.96 to -0.01); -0.39 (-0.84 to 0.05)), absence of comorbidities (-6.30 (-12.35 to -0.24); -7.87 (-14.45 to -1.30)) and absence of additional knee osteoarthritis (-7.62 (-13.87 to -1.36); -8.02 (-14.81 to -1.23)), respectively. The same factors, except for the comorbidities, also predicted general physical functioning score (RAND-36).

CONCLUSIONS

Higher education, absence of knee osteoarthritis and comorbidities, supervised exercise training and habitual conditioning physical activity predicted a lower presence of pain and better functional status in patients with hip osteoarthritis.

Minor influence of lifelong voluntary exercise on composition, structure, and incidence of osteoarthritis in tibial articular cartilage of mice compared with major effects caused by growth, maturation, and aging

We investigated the effects of lifelong voluntary exercise on articular cartilage of mice. At the age of 4 weeks C57BL mice (n = 152) were divided into two groups, with one group serving as a sedentary control whereas the other was allowed free access to a running wheel from the age of 1 month onward. Mice were euthanized at four different time points (1, 2, 6, and 18 months of age). Articular cartilage samples were gathered from the load-bearing area of the tibial medial plateaus, and osteoarthritis was graded. Additionally, the proteoglycan content distribution was assessed using digital densitometry, collagen fibril orientation, and parallelism with polarized light microscopy, and collagen content using Fourier transform infrared imaging spectroscopy. The incidence of osteoarthritis increased with aging, but exercise had no effect on this trend. Furthermore, the structure and composition revealed significant growth, maturation, and age-dependent properties. Exercise exerted a minor effect on collagen fibril orientation in the superficial zone. Fibril orientation at 2 months of age was more perpendicular to surface (p < 0.05) in controls compared with runners, whereas the situation was reversed at the age of 18 months (p < 0.05). The collagen content of the superficial zone was higher (p < 0.01) at the age of 18 months in controls compared with runners but the proteoglycan content did not display any exercise-dependent changes. In conclusion, growth, maturation, and aging exerted a clear effect on integrity, structure, and composition of medial tibial plateau articular cartilage in mice, whereas lifelong voluntary exercise had only a minor effect on collagen architecture and content.

Collagen and mineral deposition in rabbit cortical bone during maturation and growth: effects on tissue properties

We characterized the composition and mechanical properties of cortical bone during maturation and growth and in adult life in the rabbit. We hypothesized that the collagen network develops earlier than the mineralized matrix. Growth was monitored, and the rabbits were euthanized at birth (newborn), and at 1, 3, 6, 9, and 18 months of age. The collagen network was assessed biochemically (collagen content, enzymatic and non-enzymatic cross-links) in specimens from the mid-diaphysis of the tibia and femur and biomechanically (tensile testing) from decalcified whole tibia specimens. The mineralized matrix was analyzed using pQCT and 3-point bend tests from intact femur specimens. The collagen content and the Young's modulus of the collagen matrix increased significantly until the rabbits were 3 months old, and thereafter remained stable. The amount of HP and LP collagen cross-links increased continuously from newborn to 18 months of age, whereas PEN cross-links increased after 6 months of age. Bone mineral density and the Young's modulus of the mineralized bone increased until the rabbits were at least 6 months old. We concluded that substantial changes take place during the normal process of development in both the biochemical and biomechanical properties of rabbit cortical bone. In cortical bone, the collagen network reaches its mature composition and mechanical strength prior to the mineralized matrix.

Economic evaluation of multidisciplinary rehabilitation after primary total knee arthroplasty based on a randomized controlled trial

OBJECTIVE

To conduct an economic evaluation of a multidisciplinary, biopsychosocial outpatient rehabilitation program implemented 2-4 months after total knee arthroplasty (TKA), compared with conventional orthopedic care.

METHODS

After surgery, 86 patients were randomized to a multidisciplinary rehabilitation group (n = 44) or a conventional orthopedic care group (n = 42). Alongside the randomized controlled trial, we estimated the costs of rehabilitation, health care resource use, and community support. Information about resource use was collected by means of a questionnaire together with data from hospital records. The primary outcome (effectiveness) measure was change in self-reported functional capacity and the secondary measure was quality-adjusted life years (QALYs) gained during the 12-month followup. Cost-effectiveness was assessed from between-group differences in costs, change in functional capacity, and QALYs gained.

RESULTS

Both protocols of providing rehabilitation services turned out to be equally effective, but the conventional orthopedic care protocol was unequivocally cost saving: the saving was €1,830 per patient (95% confidence interval -548, 3,623) using the available direct cost data.

CONCLUSION

Multidisciplinary rehabilitation for unselected osteoarthritis patients in the subacute period of recovery after TKA is not a cost-effective use of health care resources. Similar rehabilitation protocols cannot be recommended for clinical pathways of TKA in the future.

A pragmatic randomized controlled study of the effectiveness and cost consequences of exercise therapy in hip osteoarthritis

OBJECTIVE

To evaluate the short- and long-term effectiveness of exercise training in relation to pain, function and direct costs to health care systems attributable to hip osteoarthritis.

DESIGN

Prospective, two-year randomized controlled trial.

SETTING

An outpatient primary health care setting.

SUBJECTS

One hundred and twenty men and women aged from 55 to 80, with radiologically diagnosed hip osteoarthritis with associated clinical symptoms.

INTERVENTIONS

The combined exercise and general practitioner (GP) care group received 12 supervised (once per week) exercise sessions at the baseline and four additional booster sessions one year later. Both groups received standard GP care.

MAIN MEASURES

The WOMAC Osteoarthritis Index, physical functioning score of RAND-36 (SF-36), the use and health care system costs of doctor visits and physiotherapy associated with hip osteoarthritis, number of total hip replacements, the use of analgesic and non-steroidal anti-inflammatory drugs (NSAIDs), performance-based outcome scores and body mass index (BMI).

RESULTS

There were no differences between the groups with respect to WOMAC hip pain, physical functioning score of RAND-36, performance-based outcome scores or BMI. The effect of the exercise intervention on WOMAC function was statistically significant at 6 months (mean = -7.5; 95% confidence interval (CI) -13.9 to -1.0; P = 0.02) and 18 months (mean = -7.9; 95% CI -15.3 to -0.4; P = 0.04). There were no statistically significant differences in the total health care system costs between the groups.

CONCLUSION

The mostly home-based exercise training programme provided in this study did not result in reduced hip pain over the two-year follow-up period.

Postural control and thigh muscle activity in men with knee osteoarthritis

The aim of this study was to examine the standing balance and the function of vastus medialis (VM) and biceps femoris (BF) muscles with surface electromyography (EMG). Fifty-four subjects with uni- or bilateral knee osteoarthritis (OA) (aged 50-69 years) and 53 age-matched randomly selected clinically and radiologically healthy men participated in this study. Postural control was assessed on a force platform with a bipedal stance with eyes open (EO) and closed (EC) and a monopedal stance with EO. The balance parameters, mean sway velocity, velocity along AP and ML axes, elliptical area, standard deviation of center of pressure, average radial displacement, mean frequency and frequency domain balance parameters and different power spectral density frequency bands were determined. Root mean square (RMS) for EMG amplitude, mean EMG frequency (f(EMG,mean)) and median EMG frequency (f(EMG,med)) of motor unit activity were calculated from the normalized EMG data. During bipedal stance with EC and EO, there were no significant differences in balance parameters between groups, but during bipedal stance with EO, the RMS in VM was about 56% higher (p<0.05) in subjects with knee OA than in the control subjects and the values of f(EMG,mean) and f(EMG,med) were about 48% higher (p<0.05) in control subjects than subjects with knee OA. It is concluded that subjects with knee OA do not have any standing balance deficit, but they do exhibit increased muscle activity in VM muscle compared to control subjects.

Multidisciplinary rehabilitation after primary total knee arthroplasty: a randomized controlled study of its effects on functional capacity and quality of life

OBJECTIVE

To examine whether a multidisciplinary rehabilitation programme can improve functional recovery and quality of life and reduce the use of rehabilitation services compared with conventional care one year after total knee arthroplasty.

DESIGN

Prospective, randomized, non-blinded, controlled trial.

SETTING

An outpatient centre-based setting.

SUBJECTS

Eighty-six patients who were scheduled for primary total knee arthroplasty due to osteoarthritis of the knee.

INTERVENTIONS

A ten-day multidisciplinary rehabilitation programme, which was focused on enhancing functional capacity, was organized 2-4 months after surgery. In both groups, a standard amount of physiotherapy was included in conventional care.

MAIN MEASURES

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the 15D, 15-m walk test, stair test, isometric strength measurement of the knee. Use of rehabilitation services was asked about with a questionnaire. Outcomes were assessed preoperatively and at 2-, 6- and 12-month follow-ups.

RESULTS

In both groups, functional capacity and quality of life improved significantly. The mean absolute change in the WOMAC function score was -32.4 mm (SD 26.4) in the rehabilitation group and -32.8 mm (SD 20.1) in the control group (P-time*group = 0.40). No difference was found between groups in any outcome measure or in the use of rehabilitation services during the study period.

CONCLUSIONS

This study indicates that for knee osteoarthritis patients treated with primary total knee arthroplasty, a 10-day multidisciplinary outpatient rehabilitation programme 2-4 months after surgery does not yield faster attainment of functional recovery or improvement in quality of life than can be achieved with conventional care.

[Myofascial pain syndrome--fascial muscle pain]

Symptoms of myofascial pain syndrome, i.e. fascial muscle pain may occur in several areas of the body, particularly in the neck-shoulder region. The muscle pain symptom in the neck-shoulder region is commonly termed tension neck pain or nonspecific neck pain, but myofascial pain syndrome can also be distinguished into its own diagnosis. This review deals with the clinical picture of myofascial pain syndrome along with pathophysiological hypotheses and treatment options.

Physical exercise improves properties of bone and its collagen network in growing and maturing mice

This study characterized bone structure, composition, and mechanical properties in growing male mice. The development of the collagen network during maturation was monitored, and the effect of voluntary physical exercise was investigated. We hypothesized that increased bone loading from exercise would increase the amount and improve the properties of the collagen network during growth and maturation. Half of the mice (total n = 168) had access to running wheels, while half were kept sedentary. Weight and running activity were recorded, and groups of mice were killed at 1, 2, 4, and 6 months of age. The collagen network was assessed by biochemical evaluation of collagen content and cross-links and by tensile testing of decalcified bone. Mineralized femur was analyzed with pQCT and three-point-bending and femoral neck-strength tests. After 6 months, the exercising mice had 10% lower body weight than the sedentary group. There was no difference in the amount of collagen or collagen cross-links, while tensile testing had higher breaking force and stiffness of the collagen network in runners after 4 months but not after 6 months. The bone mineral density and cross-sectional area were higher in the running group after 6 months. Runners also showed higher breaking force and stiffness of the diaphysis and the femoral neck at 2 and 6 months. The significant modulation of mechanical properties of the collagen network without any change in collagen content indicates that physical exercise improves properties of the collagen network in maturing bone. The improvement after exercise of the properties of mineralized bone appears to be more pronounced and long-lasting compared to the early improved properties of the collagen network.

Long-term voluntary exercise of male mice induces more beneficial effects on cancellous and cortical bone than on the collagenous matrix

The effects of lifelong physical exercise on the composition, structure and mechanical properties of bone are not well understood. Earlier, we found that voluntary physical exercise improved various properties of bone in maturing male mice up to 6 months of age. In this study, we extended the previous study to 18 months. Half of the mice (total N=144) had access to running wheels while half were kept sedentary. The collagen network was assessed biochemically and by tensile testing of decalcified bone. The mineralized femur was analyzed with pQCT and three-point-bending of the diaphysis and neck-strength-test. The proximal tibia was analyzed with microCT. The bone collagen revealed inferior tensional properties with aging and the mineralized femur demonstrated decreased stiffness with age. In the running mice, tensile properties and the BMD were reduced at 18 months of age compared to the sedentary mice. In contrast, the stiffness of both the diaphysis and femoral neck was higher, and trabecular architecture and structure were improved in the running mice. In summary, the results suggest that lifelong exercise training of male mice results in more beneficial effects on intact mineralized bone in both the diaphysis and epiphysis than on bone collagenous matrix.

Agreement between clinical and radiological methods of diagnosing knee osteoarthritis

OBJECTIVE

To determine the agreement between clinical diagnosis and different radiological grading scales of knee osteoarthritis (OA) in an epidemiological study.

METHODS

Health 2000 Survey is an extensive population study focusing on major health problems in a representative sample of 8028 Finns over 30 years of age. In the survey, physicians diagnosed knee OA on the basis of physical status, symptoms, and medical history. A total of 130 participants (mean age 60 years, 68% female) were re-examined 1 year later (Kuopio OA 2000 Study) to determine the agreement between clinical and radiological diagnosis as well as between three different radiological grading scales (Kellgren and Lawrence, Ahlbäck, and Piperno). Weight-bearing knee radiographs were taken and graded by a radiologist in Kuopio University Hospital. The history of knee symptoms was obtained using the Western Ontario MacMaster (WOMAC) and Lequesne questionnaires.

RESULTS

Knee OA was diagnosed clinically in 17.7% and radiologically in 24.6-30% of participants. The strength of agreement was moderate (kappa values 0.34-0.54) between the clinical and the radiological diagnosis and substantial (0.62-0.78) between the different radiological scales. Those subjects identified by any diagnostic method as having OA in either knee reported significantly more symptoms and disability than the other subjects.

CONCLUSION

The agreement between the clinical diagnosis performed in a large population study and radiological grading scales was only moderate. By contrast, the agreement between different radiological scales was substantial.

Disability in end-stage knee osteoarthritis

OBJECTIVE

To examine the attributes of disability in end-stage knee osteoarthritis (OA) by analyzing the relationships between self-reported disability and objectively measured physical function after controlling pain, personal characteristic factors, and pathophysiological factors.

METHODS

The present study adopted a cross-sectional design. The subjects (n=88, aged 60-80 years) were scheduled for primary unilateral total knee arthroplasty (TKA) due to knee OA. Self-reported disability and pain were measured with the Western Ontario and McMaster Universities OA Index (WOMAC) and the RAND 36-item Health Survey 1.0 (RAND-36). Physical performance tests included a 15-m walk test and stair performance. Knee isometric muscle strength was measured. A clinical examination included analyses of comorbidity, body mass index (BMI), and a detailed knee examination: The flexion range of motion (ROM) was measured; the presence of varus/valgus malalignments and antero-posterior laxity was assessed. Radiographs were analyzed with the Kellgren-Lawrence grading scale.

RESULTS

In the linear regression model the WOMAC pain score, antero-posterior laxity of the knee, age, and BMI accounted for 54.8% of the variance in the WOMAC function score. In the bivariate analyses the WOMAC function score had a positive correlation with the 15-m walk (r(s)=0.32, p=0.003), stairs up (r(s)=0.40, p=0.001), and stairs down (r(s)=0.38, p=0.001) tests, and a negative correlation with RPT extension (r(s)=-0.45, p < 0.001) and RPT flexion (r(s)=-0.39, p=0.001) of the affected side and RPT flexion (r(s)=-0.39, p <0.001) of the contralateral side. The results of the physical performance tests also correlated with the RAND-36 Physical function (PF) score. Comorbid diseases and pain deteriorated the results of the physical performance tests and self-reported disability. Female gender deteriorated the results of the physical performance tests and the RAND-36 PF, but not the WOMAC function score. Malalignments, restriction in the flexion ROM of the knee, and the radiologic severity of knee OA did not affect self-reported disability.

CONCLUSION

Pain, BMI, and antero-posterior laxity of the knee joint were major attributes of self-reported disability. The negative effect of comorbid diseases and female gender on health-related quality of life was significant. The results of objectively measured physical performance tests correlated with self-reported disability.

Myofascial syndrome and pain: A neurophysiological approach

It has been debated whether muscle spindles have a role in myofascial pain or not. We present a number of arguments for the former hypothesis. It was hypothesized that firing of intrafusal muscle fibres, i.e. fusimotor activity can be observed as "end plate spikes" (EPSs) in electromyography (EMG). The EPSs may be found in local active spots of muscle, often associated with miniature end plate potentials (MEPPs). Insertion of EMG needle electrodes into an active spot is painful, indicating nociception in the muscle spindle. Myofascial syndrome patients have taut bands with active trigger points (TrPs) in painful muscles. End plate activity (EPSs and MEPPs) is a significantly more common finding in TrPs of myofascial pain than in control points of the muscle, indicating the presence of muscle spindles. However, some control sites may show EPSs of normal muscle spindles. Increased amount of inflammatory metabolites have been observed in active TrPs. Muscle spindle is a capsulated gel-filled container, where inflammatory and contraction metabolites may be heavily concentrated during sustained fusimotor activation. Thus the intrafusal chemosensitive pain mediating III- and IV-afferents are sensitized and activated. Intrafusal inflammation causes further reflex activation of the fusimotor and skeletofusimotor systems via sensitized III- and IV-afferents. The taut band itself may be a contracture (rigor) of local skeletofusimotor (beta) units caused by sustained reflex drive by the given muscle spindles. In EMG this may be seen as complex repetitive discharges. We conclude that TrPs of myofascial pain are related to painful muscle spindles in taut bands.

Loading and gait symmetry during level and stair walking in asymptomatic subjects with knee osteoarthritis: importance of quadriceps femoris in reducing impact force during heel strike?

Repetitive impulsive forces during walking are claimed to result in joint osteoarthritis (OA). The aim of this study was to investigate impact loading and gait symmetry during level and stair walking in asymptomatic elderly subjects with knee OA. It was hypothesised that pre-activity of the quadriceps femoris muscle (QF) would be an important factor reducing impulsive loading when walking on level ground. Subjects [21 female, six men, 66.2 (7.6) years] were studied. The subjects had no knee pain or diminished functional capacity, but showed radiographically light or moderate bilateral knee OA changes. Ground reaction forces (GRFs), plantar pressure distribution, muscle activation pattern [vastus medialis (VM), vastus lateralis, biceps femoris and gastrocnemius medialis] and asymmetry during level walking and stair walking were evaluated. Almost 20% of subjects had a distinct heel-strike transient at maximal speed with lower pre-activity of VM (P<0.05). The most forceful maximum vertical GRF in the braking phase occurred in stair descent [1.52 (0.21) BW]. This was 32.5% (P<0.001) higher than seen when walking on the level at normal speed. The loading rate of stair descent [10.87 (2.96) BW/s] was significantly stronger (P<0.05) than in level walking at normal speed [8.55 (1.93) BW/s]. There was no asymmetry in kinematic or kinetic variables in level walking. However, asymmetry increased during stair walking. The control of quadriceps femoris prior to heel-strike is possibly an important factor that reduces impulsive loading during walking in asymptomatic OA subjects. Stair walking is a demanding motor task and the musculoskeletal system is loaded more during stair descent than level walking at normal speed.

Low metacarpal index predicts hip fracture: a prospective population study of 3,561 subjects with 15 years of follow-up

BACKGROUND

Metacarpal index (MCI), measured from hand radiographs as the ratio between combined cortical thickness and bone diameter, has been suggested for assessment of bone mass and risk of osteoporotic fracture. We studied MCI for its ability to predict hip fractures.

METHODS

Hand radiographs were taken and MCI determined in 3,561 subjects from a representative population sample of 8,000 Finns who were 30 years of age or over in 1978-80. Record linkage to the National Hospital Discharge Register identified 117 subjects who had been hospitalized for primary treatment of hip fracture by the end of 1994.

RESULTS

High age, low body mass index, tall stature and smoking at baseline showed, independently of each other, significant associations with low MCI. Low MCI was a strong predictor of hip fracture. When adjusted for all potential confounding factors, the relative risk of hip fracture per decrement of MCI by one standard deviation (0.1) was 1.5 (95% CI 1.2-1.8).

INTERPRETATION

Low MCI is associated with known risk factors of osteoporosis and predicts hip fracture. Since hand radiographs are easily available at low cost, measurements of MCI can be used as an alternative approach to find osteoporotic individuals with a high risk of hip fracture.

Postural control in male patients with hip osteoarthritis

Earlier studies have demonstrated that postural control is worse in patients with knee osteoarthritis (OA) than in control subjects, whereas little information is available about the postural control in patients with hip OA. The aim of this study was to investigate the standing balance in different test conditions in men with hip OA and to compare the results with those of age- and sex-matched healthy controls. Twenty-seven volunteers 47-64-year-old men with hip OA and 30 randomly selected, healthy age-matched men were tested using the sensory organisation test (SOT). The center point of force velocity (CPFV (cm/s)) was also determined during one- and two-footed standing. There was no difference between the patients and controls in the SOT test, in the strategy analysis or during one-footed standing. There were no significant differences in CPFV values between the better and worse hip side. Fatiguing exercise had no effect on two-footed CPFV with eyes open, but when the eyes were closed both two and one-footed CPFV values were significantly increased (p<0.01-0.05) in both groups. No differences were found in fatiguing exercise between control and OA subjects with eyes open or closed or in one-footed trials. In OA patient's subjective pain was related to increasing CPFV (p<0.05). In conclusion, the hip OA had no effect on static balance in men.

The Effect of Small Doses of Botulinum Toxin A on Neck-Shoulder Myofascial Pain Syndrome: A Double-Blind, Randomized, and Controlled Crossover Trial

OBJECTIVES

Myofascial pain syndrome is a common cause of muscular pain in the shoulder-neck region. Injections of large amounts of botulinum toxin A have been found to be beneficial for the alleviation of myofascial pain, but large doses of this toxin may cause paresis of the muscle and other adverse events. The aim of this work was to determine the effect of small doses (5 U) of botulinum toxin A (BTA) injected directly into the painful trigger points of the muscles, using a double-blind crossover technique.

METHODS

On the basis of the empirical criteria proposed for diagnosis of myofascial pain syndrome, 31 patients suffering from myofascial pain in the neck-shoulder region were studied. The patients received either botulinum toxin A or physiological saline injections on 2 occasions 4 weeks apart. The total dose varied from 15 to 35 U of botulinum toxin A [28+/- 6 U (mean+/- SD)]. The follow-up measurements were carried out at 4 weeks after each treatment. Neck pain and result of treatment were assessed with questionnaires. The pressure pain threshold was determined using a dolorimeter.

RESULTS

Neck pain values decreased from 4.3+/- 2.4 to 3.3+/- 2.0 after saline injections and from 4.1+/- 2.1 to 3.3+/- 2.2 after botulinum toxin A. The pressure pain threshold values increased from 5.2+/-1.6 to 5.9+/-1.5 and from 5.7+/-1.6 to 5.9+/-1.6 after injections with saline and botulinum toxin A, respectively. No statistically significant changes in the neck pain and pressure pain threshold values occurred between the botulinum toxin A and saline groups. After the first injections, the subjective result of treatment was significantly (P=0.008) in favor of botulinum toxin A, and after the second injections, the subjective result was better for saline, but the difference was not statistically significant (P=0.098). There was no significant difference in the prevalence of side effects between saline and botulinum toxin A.

CONCLUSIONS

Our study shows that there was no difference between the effect of small doses of botulinum toxin A and those of physiological saline in the treatment of myofascial pain syndrome.

Wireless on-line electromyography in recording neck muscle function: A pilot study

AIM

The surface electromyography (SEMG) records muscle activity without causing pain and therefore it can be used in the on-line kinetic evaluation of rehabilitation methods. The cables are a problem in the clinical work. The aim of this pilot study was to introduce a wireless on-line SEMG method in the measurements of neck muscle activity and preliminarily evaluate its usability in dynamic exercises in a healthy and a neck pain subject.

METHOD

The bilateral wireless on-line SEMG measurements were performed at the level C4-C5 of the cervical spine. The subjects (one healthy 32-year-old female and one neck pain patient, 35-year-old female) were performing slow cervical flexions with eyes open. The angle of the flexion was measured with inclinometer.

RESULTS

In healthy subjects, the SEMG curve demonstrated clear flexion-relaxation rhythm whereas in the patient the rhythm was blurred. The SEMG signal quality was, however, good in both cases.

CONCLUSION

Wireless on-line SEMG method seems promising in daily clinical work for the measurements of neck muscle activity.

Association of radiological hand osteoarthritis with bone mineral mass: a population study

OBJECTIVES

A number of previous studies have reported an inverse relationship between osteoarthritis and osteoporosis. However, the association has remained controversial because osteoarthritis in hand joints seems to associate differently from osteoarthritis in weight-bearing joints with bone mineral mass. We studied osteoarthritis in distal interphalangeal (DIP) joints and osteoarthritis in the base of the thumb (CMC-1) for their cross-sectional associations with metacarpal cortical bone mineral mass, and for their prediction of calcaneal broadband ultrasound attenuation.

METHODS

A population sample of 8000 Finns aged 30 yr and over was invited to a comprehensive health examination in 1978-1980; 90% complied. Hand radiographs were taken from 3568 participants to diagnose osteoarthritis in various hand joints, and to determine two indicators of cortical bone mineral mass, the combined cortical thickness (CCT) and the metacarpal index (MCI). Calcaneal broadband ultrasound attenuation was measured 20 yr later in 340 of these participants with the Sahara sonometer.

RESULTS

In the cross-sectional setting, osteoarthritis in the DIP joints and osteoarthritis in the base of the thumb (CMC-1) were significantly associated with low CCT and low MCI. These associations were proportional to the radiological severity of osteoarthritis. In the follow-up setting, symmetrical DIP osteoarthritis adjusted for age, sex, body mass index, smoking, education, workload and MCI significantly predicted low values of broadband ultrasound attenuation.

CONCLUSIONS

Our results indicate a direct relation of both radiological DIP osteoarthritis and CMC-1 osteoarthritis with low cortical bone mineral mass, in proportion to the severity of osteoarthritis. The presence of symmetrical DIP osteoarthritis, a possible indicator of generalized osteoarthritis, suggests an increased risk of osteoporosis over time.

Increased bone mineral content but not bone mineral density in the hip in surgically treated knee and hip osteoarthritis

OBJECTIVE

The inverse relationship between the occurrence of osteoarthritis (OA) and osteoporosis is controversial. Some investigators have found higher bone mineral density (BMD) in the hips, lumbar spine, and other skeletal sites of patients with OA; others have not. We investigated the relationship between BMD and OA.

METHODS

We compared the BMD, bone mineral content (BMC), and projected area of the femoral neck (FN) and trochanter (TR) of 99 women with a validated diagnosis of primary OA from the Kuopio Osteoporosis Risk Factor and Prevention Study (OSTPRE) cohort, with 2012 controls. The measurements were made twice in women aged 47-59 years in 1989-91, and then repeated in 1994-98.

RESULTS

After correction for age, body mass index (BMI), menopausal status, and hormone replacement therapy use before inclusion, we found no significant difference in femoral BMD of the OA patients compared with controls at baseline and at 5-year followup (FN +2.7%, +4.6%, respectively; nonsignificant). However, the BMC was significantly higher in all regions of interest in OA patients at baseline [FN +8.3% (p = 0.004); TR +13.3% (p = 0.017)]. The projected area of FN was also significantly higher at baseline and followup in OA patients (FN +3.7%, +3.9%, respectively; p < 0.001). The projected area of the bones increased in all subjects over the followup period. The BMD decrease rate was higher in OA patients for all regions of interest during followup.

CONCLUSION

Hip BMD of women treated surgically for hip or knee OA was not different from that of healthy controls when measured twice with a 5-year interval. However, at 5-year followup, OA can be accompanied by an increase in bone size or changes in shape, and faster loss of BMD.

Physical therapy and rehabilitation programs in the management of hip osteoarthritis

Nonpharmacological treatment programmes are as important as drug treatment in hip osteoarthritis (OA). Drugs (analgesic and nonsteroidal anti-inflammatory drugs) should not be used as sole treatments in hip OA. Patient education and weight reduction are the primary therapeutic approaches. Different types of exercises are beneficial for patients with hip OA. Occupational therapy plays a central role in the management of hip OA patients with functional limitations. More and better-designed trials are needed to evaluate the efficacy of nonpharmacological treatment programmes used in hip OA.

Feasibility of the use of a novel soft tissue stiffness meter

Simple but objective measurement of soft tissue consistency would be advantageous in the assessment of many neurological, lymphostatic and venous disorders. The aim of the present study was to evaluate the feasibility of using a novel hand-held computerized soft tissue stiffness meter (STSM). The STSM describes the soft tissue stiffness (STS) in the form of the instantaneous force (N) by which the tissue resists the constant deformation produced by a cylindrical intender. Firstly, the STSM was used to test elastomer samples with known mechanical properties. In the in vivo assessment, 12 healthy, nondisabled adults (age range, 24-57 years) and 16 subjects with chronic myofascial neck pain syndrome (age range, 27-55 years) were studied. To study the reproducibility (coefficient of variation (CV(%))) of the method, the measurement sites were either marked with a marker pen (marked points) or localized anatomically (unmarked points). Measurements were made from the dorsal forearm (Arm), trapezius (Tra), levator scapulae (Lev), infraspinatus (Inf) and deltoideus (Del) muscle areas. STS in the forearm was studied during different types of short-term relative isometric loading of the muscle as well as during venous occlusion. STS values of the myofascial trigger points in the Lev muscles were evaluated bilaterally. A linear, positive relationship was found between the indenter force (N) and the dynamic compressive modulus (MPa) of elastomer stiffness (r(2) = 0.90, n = 9). Intra- and interrater CVs of marked and unmarked sites varied between 4.31% and 12.06%. STS increased linearly along the relative muscle load (r(2) = 0.96) and nonlinearly during the venous occlusion (r(2) = 0.97). Statistically significant regional variation of STS was found between the different measurement sites (p < 0.05). In conclusion, STSM can evaluate tissue stiffness quantitatively and yield reproducible data.

Effects of vocationally oriented medical rehabilitation for aircraft maintenance personnel--a preliminary study of long-term effects with 5-year follow-up

Changes in the physical capacity, musculoskeletal symptoms, and perceived work ability of Finnish Air Force maintenance personnel were studied after vocationally oriented medical rehabilitation (VOMR). Twenty persons with chronic musculoskeletal symptoms in their back or neck took part in VOMR courses. The measurements were carried out at the beginning of the rehabilitation course and after two follow-up periods (0.5 and 5 years). The subjects worked most of the time in a bent position and often with their backs twisted and their arms above their shoulders. The severity of low-back pain and the number of days of sick leave decreased significantly (p < 0.05-0.01) during the 5-years follow-up. Also the exercise breaks at work increased (p < 0.01). After half a year of medical rehabilitation the measured range of the cervical spine and the dynamic and endurance strength of the upper and lower extremities was greater (p < 0.05-0.001) than at the beginning of the rehabilitation. There were no statistically significant differences in the use of physical therapy, experienced work strain, physical exercise or maximal oxygen consumption during the follow-up. This is a preliminary follow-up study lasting 5 years showed some significant changes in physical capacity, musculoskeletal symptoms and work ability. However, controlled studies are needed to evaluate these preliminary findings of this kind of rehabilitation model.

Osteoarthritis in the carpometacarpal joint of the thumb. Prevalence and associations with disability and mortality

BACKGROUND

This study was designed to investigate the prevalence of osteoarthritis in the carpometacarpal joint of the thumb in adults thirty years of age or older in Finland.

METHODS

Between 1978 and 1980, a representative population sample of 8000 Finns thirty years of age or older were invited to have a comprehensive health examination; 90% accepted. Hand radiographs were made of 3595 subjects. Since the examination, the subjects have been followed systematically to assess work disability and mortality by reviewing registers covering the whole population.

RESULTS

The age-adjusted prevalence of thumb carpometacarpal osteoarthritis of Kellgren grade 2, 3, or 4 was 7% for men and 15% for women. After adjustment for age, sex, and other alleged risk factors, body mass index was found to be directly proportional to the prevalence of thumb carpometacarpal osteoarthritis in both sexes. The adjusted odds ratio was 1.29 (95% confidence interval, 1.15 to 1.43) per 5-kg/m(2) increment in body mass index. No significant association was found between the physical workload history and thumb carpometacarpal osteoarthritis. Restricted mobility of the thumb and local tenderness and swelling were frequently found in conjunction with radiographic evidence of thumb carpometacarpal osteoarthritis. Advanced (grade-3 or 4) thumb carpometacarpal osteoarthritis predicted the total mortality rate in men (adjusted relative risk, 1.32; 95% confidence interval, 1.03 to 1.69). Radiographic signs of thumb carpometacarpal osteoarthritis did not predict work disability.

CONCLUSIONS

and

CLINICAL RELEVANCE

Obesity is a strong determinant of thumb carpometacarpal osteoarthritis in both sexes. The effect of thumb carpometacarpal osteoarthritis on disability and mortality in the general population is modest. Because of the rarity of ensuing disability, carpometacarpal osteoarthritis of the thumb is likely to be underdiagnosed in clinical practice.

Estimation of femoral head bone density using magnetic resonance imaging: comparison between men with and without hip osteoarthritis

Bone changes are thought to be one important etiological element in the pathogenesis of hip osteoarthritis (OA). The magnetic resonance imaging (MRI)-derived T2* relaxation time has been shown to provide information about bone mineral status of the femoral neck. The aim of this study was to test the hypothesis that the MRI-derived T2* relaxation time of the proximal femur in hip OA differs from that seen in healthy subjects. Based on the American College of Rheumatology criteria regarding classification of the OA of the hip, 27 men (aged 47-64 yr) with unilateral or bilateral hip OA and 30 age-matched randomly selected healthy men were studied. Bone mineral density (BMD), bone mineral content (BMC), and bone width of the femoral neck were measured with dual-energy X-ray absorptiometry (DXA). Subsequently, T2* measurements were performed with a 1.5-T scanner (Siemens Magnetom 63SP; Erlangen, Germany). A single 10-mm-thick coronal slice was generated on the femur, with a repetition time of 60 ms and nine echo times (4-20 ms) to derive T2* values. T2* measurements were performed from the different region of interests (ROIs) from the femoral neck and head. T2* relaxation times showed significant negative correlations with BMC, BMD (r = -0.401 to -0.794; p < 0.05-0.001). T2* relaxation time values revealed no significant differences between the groups in the femoral neck and in the head of the femur, whereas it was 12% lower (p < 0.01) in OA subjects than in controls in acetabulum. There were no significant differences in the T2* relaxation time values between the radiographic OA subgroups. Our findings suggest that hip OA is not associated with an increase of BMD in the femoral neck or in the head of the femur.

Osteoarthritis of finger joints in Finns aged 30 or over: prevalence, determinants, and association with mortality

BACKGROUND

Prevalence and risk factors of osteoarthritis (OA) in finger joints have been amply explored in previous studies. However, no study has focused on finger joint OA as a predictor of mortality.

OBJECTIVE

To investigate finger joint OA for its associations with alleged risk factors and with life expectancy in an extensive health survey.

METHODS

From 1978 to 1980 a representative population sample of 8000 Finns aged 30 years or over was invited to participate in a comprehensive health examination; 90% accepted. Hand radiographs were taken from 3595 subjects. By the end of 1994, 897 of these had died.

RESULTS

The prevalence of OA of Kellgren's grade 2 to 4 in any finger joint and in at least two symmetrical pairs of distal interphalangeal joints (DIPs) was 44.8% and 16.0%, respectively. Age and body mass index were significant determinants for OA both in any finger joint and in symmetrical DIP OA. The history of physical workload in women showed a positive association with OA in any finger joint. Smoking in men seemed to protect against symmetrical DIP OA. As adjusted for the determinants above, symmetrical DIP OA predicted mortality in women (relative risk (RR), 1.23; 95% confidence interval (95% CI) 1.01 to 1.51), but not in men (RR 0.89; 95% CI 0.68 to 1.16). In men, however, OA in any finger joint significantly predicted cardiovascular deaths (RR 1.42; 95% CI 1.05 to 1.92).

CONCLUSION

OA in any finger joint and symmetrical DIP OA have different risk factor profiles and predict mortality in different patterns between men and women.

Hip muscle strength and muscle cross sectional area in men with and without hip osteoarthritis

OBJECTIVE

To study the hip muscle strength and cross sectional area (CSA) in men with hip osteoarthritis (OA) compared to age and sex matched healthy controls.

METHODS

Based on the American College of Rheumatology criteria regarding classification of hip OA, 27 men (aged 47-64 yrs) with unilateral or bilateral hip OA and 30 age matched randomly selected healthy male controls were studied. The maximal isometric hip abductor, adductor, flexor, and extensor strength (Nm) at 0 degree of hip flexion in the supine position was determined with a dynamometer. The isokinetic hip flexion and extension strength (peak torque, Nm) was determined using angular velocities of 60 degrees /s and 120 degrees /s. The subjective severity of hip pain was rated by visual analog scale prior to the muscle strength test. CSA of the pelvic and thigh muscles was measured from magnetic resonance images.

RESULTS

The reliability of intraclass correlation coefficients for repeated measures of muscle strength varied from 0.70 to 0.94 in controls and from 0.84 to 0.98 in subjects with OA. Hip isometric adductor and abductor strength was 25% and 31% lower (p < 0.001) in OA subjects than in controls, respectively. The hip isometric and isokinetic flexion strength was 18-22% lower (p < 0.01) in OA subjects than in controls, but extension strength did not differ between groups. In OA subjects, the hip flexion and extension isometric and isokinetic strength values were 13-22% lower (p < 0.05) on the more deteriorated side compared to the better side. CSA of the pelvic and thigh muscles did not differ between the groups. However, in OA subjects, the CSA of the pelvic and thigh muscles was 6-13% less (p < 0.05 to < 0.001) on the more severely affected hip compared to the better hip.

CONCLUSION

Men with hip OA have significantly lower abduction, adduction, and flexion muscle strength than controls. The decrease of muscle size and hip pain may contribute to the decrease of muscle strength in hip OA. Other possible underlying causes of the muscle weakness need to be studied.

Use of health-care services, work absenteeism, leisure-time physical activity, musculoskeletal symptoms and physical performance after vocationally oriented medical rehabilitation-description of the courses and a one-and-a-half-year follow-up study with farmers, loggers, police officers and hairdressers

The aim of this study was to evaluate the effectiveness of vocationally oriented medical rehabilitation (VOMR) carried out in institutions with regard to the use of health-care services, work absenteeism, leisure-time physical activity, musculoskeletal symptoms and physical performance during 112 years of follow-up. The prospective cohort study consisted of 265 patients from four different occupational groups (loggers, hairdressers, police officers and female farmers) who took part in VOMR courses in three inhouse phases, financed by the Finnish Social Insurance Institution, and who had chronic musculoskeletal symptoms in their back and neck. The subjective physical and mental strain of work, subjective neck-shoulder and low-back pain, use of health-care services and leisure-time physical activity were assessed with a questionnaires. The muscle strength of the upper and lower extremities and trunk was determined and maximal VO2 was measured using the direct maximal bicycle ergometer test. The subjective physical and mental strain of work, subjective neck-shoulder and low-back pain and physical performance showed positive significant development and improvement. The changes in the use of health-care services and work absenteeism were minor or insignificant. The general finding was that the results from the second phase of the VOMR courses did not differ from those of the third phase. VOMR courses had a beneficial effect on physical performance and subjective pain caused by neck and back musculoskeletal diseases of farmers, loggers, police officers and hairdressers within 112 years of follow-up, but VOMR courses did not decreased the use of health-care services.

Activation of paraspinal and abdominal muscles during manually assisted and nonassisted therapeutic exercise

OBJECTIVE

To assess the activities of the paraspinal and abdominal muscles during manually assisted therapeutic exercises (MATEs) and nonassisted therapeutic exercises (NATEs) that are used in the initial phases of the progressive exercise programs designed for the treatment of low back pain.

DESIGN

Thirteen healthy subjects volunteered in the study. Surface electromyography (EMG) was recorded. The recorded EMG signal was averaged and normalized to the maximal EMG amplitude obtained during the maximal voluntary contraction (%EMGmax).

RESULTS

In general, the %EMGmax values were higher during NATEs than during MATEs. Sitting seemed to activate lumbar L5 level paraspinal muscles to the same extent as MATEs.

CONCLUSION

MATEs require only minimal trunk muscle activities, and thus, they may not be sufficiently intense to improve the trunk muscle performance. NATEs require high trunk muscle activities that are adequate for improving the trunk muscle performance, but they may cause high compressive loading of the lumbar spine, and if unchecked, this can aggravate low back pain.

Increased bone mineral content and bone size in the femoral neck of men with hip osteoarthritis

OBJECTIVES

Even though clinical findings support the idea that hip osteoarthritis (OA) is associated with increased bone mineral density (BMD), the subject remains controversial. This study was therefore initiated to investigate the relation between the severity of hip OA and femoral and calcaneal BMD.

METHODS

On the basis of the American College of Rheumatology criteria on classification of OA of the hip, 27 men (aged 47-64 years) with unilateral or bilateral hip OA and 30 age matched randomly selected healthy men were studied. Plain radiographs were graded using Li's scale from 0 (no OA) to 4 (severe OA). According to the side of the highest radiographic score from the patients with clinical hip OA, 29.6% had grade 1, 29.6% grade 2, and 40.8% grade 3 OA. Bone mineral content (BMC), areal BMD (BMD(areal)), and bone dimensions (area and width) were measured by dual x ray absorptiometry at the proximal femur. BMD(areal) of the calcaneus was measured from the central area of the bone. Volumetric measurements from magnetic resonance images of the femoral neck were used to create a BMD measure that was corrected for the femoral neck volume (BMD(mri)).

RESULTS

There were no differences in weight, or body mass index between the study groups. There were no significant BMD(areal) differences in any of the subregions of the proximal femur (femoral neck and trochanter) or calcaneus between the OA and control groups. Neither did the BMD(mri) of the femoral neck differ between the groups. However, the BMC of the femoral neck was 18% higher (p<0.01) in patients with OA than in controls. Similarly femoral neck bone width and volume were 9% and 18% respectively higher (p<0.001) in patients with OA.

CONCLUSIONS

The results suggest that men with hip OA have larger femoral neck size and consequently higher BMC than healthy controls matched for age and sex. There is no significant difference in femoral neck BMD (BMD(areal) or BMD(mri)) between the groups. Furthermore, increased BMD(areal) was not found in the peripheral skeleton. These findings suggest that hip OA is not associated with an increase in BMD(areal) in the femoral neck. However, the increase in BMC and bone size in patients with hip OA may play a part in the pathogenesis of the disease.

Comparison of DXA and MRI methods for interpreting femoral neck bone mineral density

The aim of the study was to improve the practical implementation of the dual X-ray absorptiometry (DXA) by converting the areal bone mineral density BMD (BMD(areal)) to volumetric BMD using magnetic resonance (MR) imaging (MRI) because a failure to control for the femoral neck size can lead to erroneous interpretation of BMD values. We also evaluated the feasibility of MR T2* relaxation time in assessing bone mineral status of the femoral neck. Twenty-eight randomly selected 47- to 64-yr-old healthy men were studied. The men had neither unilateral nor bilateral hip osteoarthritis according to radiographs. Bone width, mineral content (BMC), BMD(areal), and apparent volumetric BMD (BMD(vol)) of the right femoral neck were measured with DXA. The BMD(vol) was calculated by approximating the femoral neck to be cylindrical with a circular cross-section (Vol(dxa)). Volumetric measurements from MR (Vol(mri)) images of the femoral neck were also used to create a BMD measure that was corrected for the femoral neck volume (BMD(mri)). T2* measurements were performed with a 1.5-T scanner (Siemens Magnetom 63SP, Erlangen, Germany). A single 10-mm-thick coronal slice was generated on the femur with a repetition time of 60 ms, and nine echo times (4-20 ms) were used to derive T2* values. Vol(mri) correlated positively (r = 0.828, p < 0.001) with Vol(dxa). However, the Vol(mri) of the femoral neck was 18% lower than the Vol(dxa). Similarly, the BMD(mri) was related to the BMD(vol) (r = 0.737, p < 0.001). Because of the difference in the volumetric measures, the BMD(mri) of the femoral neck was 21% higher than the BMD(vol) (p < 0.001). T2* relaxation time showed a significant negative correlation with BMC, BMD(areal), BMD(vol), and BMD(mri) (r = -0.423 to -0.757, p < 0.05-0.001). In conclusion, these results are evidence that DXA-derived volume approximations by the cylinder with circular cross-section geometry may lead to lower DXA-derived BMD(vol) values, as compared to true MRI-derived volumetric bone mineral density. Thus, the BMD(vol) may not be an accurate method to calculate the true volumetric BMD in the femoral neck. Our results also suggest that the MRI-derived T2* method may be used to approximate the BMD in the proximal femur.