Recovery pattern after decompression of central lumbar spinal stenosis: a prospective observational cohort study

BACKGROUND

Detailed preoperative information is associated with superior outcomes. We aimed to describe the recovery pattern after decompression of central lumbar spinal stenosis (CLSS).

METHODS

50 patients aged 51-85 years who underwent decompression without fusion due to CLSS were followed from before to after surgery (post-op day 1, 7, and 14). Back and leg pain were evaluated using the Numeric Rating Scale (NRS; 0 = no pain 0, 10 = worst pain) and quality of life using the EuroQol-5D index (0 = death, 1 = best), and EQ-5D-visual analogue scale (VAS; 0 = worst, 100 = best).

RESULTS

NRS leg pain was reduced from preoperative to first postoperative day by 5.2 (6.1, 4.3) (mean (95%CI)], and NRS back pain from postoperative day 1-7 by 0.6 (1.2, 0.03) and from day 7 to 14 by 0.7 (1.3, 0.2)]. In contrast, EQ-5D index increased from preoperative to first postoperative day by 0.09 (0.06, 0.13) and from day 1 to 7 by 0.05 (0.02,0.08), and EQ-5D VAS from preoperative to first postoperative day by 13.7 (9.1, 18.3) and from day 1 to 7 by 6.0 (2.0, 10.0). After two weeks, 51% of the patients had improved above the minimal clinically important difference (MCID) in back pain and 71% in leg pain.

CONCLUSIONS

Patients scheduled for decompression due to CLSS should be informed that improvement in leg pain and quality of life in general can be expected within one day of surgery, that quality of life improves a little further in the first postoperative week, and that back pain improves in the first 2 postoperative weeks. In most patients, decompression without fusion due to CLSS seems to achieve clinically relevant improvement within 2 weeks.

3D Finite Element Models Reconstructed From 2D Dual-Energy X-Ray Absorptiometry (DXA) Images Improve Hip Fracture Prediction Compared to Areal BMD in Osteoporotic Fractures in Men (MrOS) Sweden Cohort

Bone strength is an important contributor to fracture risk. Areal bone mineral density (aBMD) derived from dual-energy X-ray absorptiometry (DXA) is used as a surrogate for bone strength in fracture risk prediction tools. 3D finite element (FE) models predict bone strength better than aBMD, but their clinical use is limited by the need for 3D computed tomography and lack of automation. We have earlier developed a method to reconstruct the 3D hip anatomy from a 2D DXA image, followed by subject-specific FE-based prediction of proximal femoral strength. In the current study, we aim to evaluate the method's ability to predict incident hip fractures in a population-based cohort (Osteoporotic Fractures in Men [MrOS] Sweden). We defined two subcohorts: (i) hip fracture cases and controls cohort: 120 men with a hip fracture (<10 years from baseline) and two controls to each hip fracture case, matched by age, height, and body mass index; and (ii) fallers cohort: 86 men who had fallen the year before their hip DXA scan was acquired, 15 of which sustained a hip fracture during the following 10 years. For each participant, we reconstructed the 3D hip anatomy and predicted proximal femoral strength in 10 sideways fall configurations using FE analysis. The FE-predicted proximal femoral strength was a better predictor of incident hip fractures than aBMD for both hip fracture cases and controls (difference in area under the receiver operating characteristics curve, ΔAUROC = 0.06) and fallers (ΔAUROC = 0.22) cohorts. This is the first time that FE models outperformed aBMD in predicting incident hip fractures in a population-based prospectively followed cohort based on 3D FE models obtained from a 2D DXA scan. Our approach has potential to notably improve the accuracy of fracture risk predictions in a clinically feasible manner (only one single DXA image is needed) and without additional costs compared to the current clinical approach. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

In old men Scheuermann's disease is not associated with neck or back pain: a Swedish cohort study

BACKGROUND AND PURPOSE

Scheuermann's disease is characterized by kyphosis and frequently mild back pain. As the level of kyphosis may progress over time, also the level of pain may increase. We evaluated the prevalence of Scheuermann's disease, and their pain, in Swedish elderly men.

PATIENTS AND METHODS

 The Osteoporotic Fractures in Men (MrOS) Study Sweden (n = 3,014) is a population-based prospective observational study of community-living men aged 69-81 years. At baseline, participants answered a questionnaire including history of neck/back pain during the preceding year and characteristics of any pain (severity, sciatica, and neurological deficits). Lateral thoracic/lumbar spine radiographs were taken of 1,453 men. We included the 1,417 men with readable radiographs. Scheuermann's disease was defined as 3 or more consecutive vertebrae with > 5° wedging with no other explanation for the deformity.

RESULTS

 92 of the 1,417 men (6.5%, 95% confidence interval 5.3-7.9) had Scheuermann's disease. 31% of men with and 31% without Scheuermann's disease reported neck pain (P = 0.90) and 51% with and 55% without the disease reported back pain (P = 0.4). Among men with Scheuermann's disease and back pain, none reported severe pain, 57% moderate, and 43% mild, compared with 7%, 50%, and 44% in those without Scheuermann's disease (P = 0.2). In those with Scheuermann's disease 63% reported no sciatica, 15% sciatica without neurological deficits, and 22% sciatica with neurological deficits, compared with 56%, 16%, and 28% in those without the disease (P = 0.6).

CONCLUSION

The prevalence of Scheuermann's disease in elderly Swedish men is between 5.3% and 7.9%. The condition seems at this age not to be associated with neck or back pain.

Time Trends in Trajectories of Forearm Mineral Content and Bone Size during Childhood-Results from Cross-Sectional Measurements with the Same Apparatus Four Decades Apart

Evidence suggests that single photon absorptiometry (SPA)-measured forearm bone mineral density (BMD) is lower in contemporary children in Malmö than it was four decades ago, but the fracture incidence in the at-risk population (all Malmö children) has been stable during the same period. The aim of this study was to evaluate if improvements in skeletal structure over time may explain this observation. In 2017-2018 we measured distal forearm bone mineral content (BMC; mg/cm) and periosteal diameter (mm) in 238 boys and 204 girls aged 7-15 using SPA. Based on the SPA measurements, we calculated forearm BMD (mg/cm²), bone mineral apparent density (BMAD, mg/cm³), section modulus, and strength index (BMAD × section modulus). The results were compared with those derived from measurements of 55 boys and 61 girls of the same ages using the same scanner in 1979-1981. We used log-linear regression with age, sex, and cohort as predictors to investigate differences in trait trajectories (trait versus age slopes [mean percent difference in beta values (95% confidence interval)]). SPA-measured forearm BMC was lower at each age in 2017-2018 compared to 1979-1981 (a mean age and sex adjusted relative difference of 9.1%), the forearm BMC trajectory was similar in 2017-2018 to that in 1979-1981 (reference) [0.0%/year (-1.0%, 1.0%)], while the 2017-2018 forearm periosteal diameter trajectory was steeper [1.1%/year (0.3%, 2.0%)]. Since bone size influences both BMD (BMC divided by scanned area) and mechanical characteristics, the forearm BMD trajectory was flatter in 2017-2018 [-1.1%/year (-2.0%, -0.2%)] and the forearm section modulus trajectory steeper [3.9%/year (1.4%, 6.4%)]. Forearm strength index trajectory was similar [1.8%/year (-0.5%, 4.1%)]. The lower SPA-measured forearm BMD trajectory in contemporary children compared to four decades ago may be offset by changes in forearm bone structure, resulting in similar overall bone strength. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Recent sarcopenia definitions-prevalence, agreement and mortality associations among men: Findings from population-based cohorts

BACKGROUND

The 2019 European Working Group on Sarcopenia in Older People (EWGSOP2) and the Sarcopenia Definitions and Outcomes Consortium (SDOC) have recently proposed sarcopenia definitions. However, comparisons of the performance of these approaches in terms of thresholds employed, concordance in individuals and prediction of important health-related outcomes such as death are limited. We addressed this in a large multinational assembly of cohort studies that included information on lean mass, muscle strength, physical performance and health outcomes.

METHODS

White men from the Health Aging and Body Composition (Health ABC) Study, Osteoporotic Fractures in Men (MrOS) Study cohorts (Sweden, USA), the Hertfordshire Cohort Study (HCS) and the Sarcopenia and Physical impairment with advancing Age (SarcoPhAge) Study were analysed. Appendicular lean mass (ALM) was ascertained using DXA; muscle strength by grip dynamometry; and usual gait speed over courses of 2.4-6 m. Deaths were recorded and verified. Definitions of sarcopenia were as follows: EWGSOP2 (grip strength <27 kg and ALM index <7.0 kg/m2 ), SDOC (grip strength <35.5 kg and gait speed <0.8 m/s) and Modified SDOC (grip strength <35.5 kg and gait speed <1.0 m/s). Cohen's kappa statistic was used to assess agreement between original definitions (EWGSOP2 and SDOC). Presence versus absence of sarcopenia according to each definition in relation to mortality risk was examined using Cox regression with adjustment for age and weight; estimates were combined across cohorts using random-effects meta-analysis.

RESULTS

Mean (SD) age of participants (n = 9170) was 74.3 (4.9) years; 5929 participants died during a mean (SD) follow-up of 12.1 (5.5) years. The proportion with sarcopenia according to each definition was EWGSOP2 (1.1%), SDOC (1.7%) and Modified SDOC (5.3%). Agreement was weak between EWGSOP2 and SDOC (κ = 0.17). Pooled hazard ratios (95% CI) for mortality for presence versus absence of each definition were EWGSOP2 [1.76 (1.42, 2.18), I2 : 0.0%]; SDOC [2.75 (2.28, 3.31), I2 : 0.0%]; and Modified SDOC [1.93 (1.54, 2.41), I2 : 58.3%].

CONCLUSIONS

There was low prevalence and poor agreement among recent sarcopenia definitions in community-dwelling cohorts of older white men. All indices of sarcopenia were associated with mortality. The strong relationship between sarcopenia and mortality, regardless of the definition, illustrates that identification of appropriate management and lifecourse intervention strategies for this condition is of paramount importance.

Prevalence and morbidity of neck pain: a cross-sectional study of 3000 elderly men

BACKGROUND

The purpose of this study is to determine the prevalence and morbidity of neck pain with or without cervical rhizopathy, upper extremity motor deficit and/or thoracolumbar pain in elderly men.

METHODS

We conducted a cross-sectional questionnaire study of 3,000 community-dwelling older men with a mean age of 75.4 ± 3.2 years (range 69-81) to determine if they had experienced neck pain with or without cervical rhizopathy/upper extremity motor deficit/thoracolumbar pain (yes/no) during the preceding 12 months, and if so, morbidity with the condition (no/minor/moderate/severe).

RESULTS

Among the participants, 865 (29%) reported they had experienced neck and 1,619 (54%) thoracolumbar pain. Among the men with neck pain, 59% had experienced only neck pain, 17% neck pain and cervical rhizopathy and 24% neck pain, rhizopathy and motor deficit. For men with only neck pain, the morbidity was severe in 13%, for men with neck pain and rhizopathy it was 24%, and for men with pain, rhizopathy and motor deficit it was 46% (p < 0.001). Among the men with neck pain, 23% had experienced only neck pain and no thoracolumbar pain; the remaining 77% had both neck and thoracolumbar pain. The morbidity was severe in 10% of the men with neck pain but no thoracolumbar pain and 30% in men with neck and thoracolumbar pain (p < 0.001).

CONCLUSION

Neck pain in elderly men is common but symptoms and morbidity vary. For men who only have neck pain, 1/8 rated their morbidity as severe, while almost half who also had cervical rhizopathy and motor deficit and almost 1/3 of those who also had thoracolumbar pain reported severe morbidity.

Greater pQCT Calf Muscle Density Is Associated with Lower Fracture Risk, Independent of FRAX, Falls and BMD: A Meta-Analysis in the Osteoporotic Fractures in Men (MrOS) Study

We investigated the predictive performance of peripheral quantitative computed tomography (pQCT) measures of both calf muscle density (an established surrogate for muscle adiposity, with higher values indicating lower muscle adiposity and higher muscle quality) and size (cross-sectional area [CSA]) for incident fracture. pQCT (Stratec XCT2000/3000) measurements at the tibia were undertaken in Osteoporotic Fractures in Men (MrOS) United States (US), Hong Kong (HK), and Swedish (SW) cohorts. Analyses were by cohort and synthesized by meta-analysis. The predictive value for incident fracture outcomes, illustrated here for hip fracture (HF), using an extension of Poisson regression adjusted for age and follow-up time, was expressed as hazard ratio (HR) per standard deviation (SD) increase in exposure (HR/SD). Further analyses adjusted for femoral neck (fn) bone mineral density (BMD) T-score, Fracture Risk Assessment Tool (FRAX) 10-year fracture probability (major osteoporotic fracture) and prior falls. We studied 991 (US), 1662 (HK), and 1521 (SW) men, mean ± SD age 77.0 ± 5.1, 73.9 ± 4.9, 80 ± 3.4 years, followed for a mean ± SD 7.8 ± 2.2, 8.1 ± 2.3, 5.3 ± 2.0 years, with 31, 47, and 78 incident HFs, respectively. Both greater muscle CSA and greater muscle density were associated with a lower risk of incident HF [HR/SD: 0.84; 95% confidence interval [CI], 0.72-1.0 and 0.78; 95% CI, 0.66-0.91, respectively]. The pattern of associations was not materially changed by adjustment for prior falls or FRAX probability. In contrast, after inclusion of fn BMD T-score, the association for muscle CSA was no longer apparent (1.04; 95% CI, 0.88-1.24), whereas that for muscle density was not materially changed (0.69; 95% CI, 0.59-0.82). Findings were similar for osteoporotic fractures. pQCT measures of greater calf muscle density and CSA were both associated with lower incidence of fractures in older men, but only muscle density remained an independent risk factor for fracture after accounting for fn BMD. These findings demonstrate a complex interplay between measures of bone, muscle size, and quality, in determining fracture risk. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

A study comparing outcomes between obese and nonobese patients with lumbar disc herniation undergoing surgery: a study of the Swedish National Quality Registry of 9979 patients

Background

This study aimed to evaluate whether an increasing grade of obesity is associated with inferior outcomes after lumbar disc herniation (LDH) surgery.

Methods

We retrieved data from the Swedish register for spine surgery regarding patients aged 20–64 who underwent LDH surgery from 2006–2016 and had preoperative and one-year postoperative data. A total of 4156 patients were normal weight, 4063 were overweight, 1384 had class I obesity, 317 had class II obesity and 59 had class III obesity (“morbid obesity”). Data included patient satisfaction, improvement in leg pain (assessed using the National Rating Scale; NRS; rating 0–10), disability (assessed using the Oswestry Disability Index; ODI; rating 0–100) and complications.

Results

At one year postsurgery, 80% of normal-weight patients, 77% of overweight patients and 74% of obese patients (class I-III evaluated together) were satisfied (p < 0.001) [75%, 71%, 75% in obesity classes I, II, and III, respectively (p = 0.43)]. On average, all groups improved by more than the minimal clinically important difference (MCID) in both NRS leg pain (> 3.5) and ODI (> 20). NRS leg pain improved by 4.8 in normal weight patients (95% CI 4.7–4.9), by 4.5 in overweight patients (4.5–4.6) and by 4.3 in obese patients (4.2–4.4) (p < 0.001) [4.4 (4.3–4.6), 3.8 (3.5–4.1) and 4.6 (3.9–5.3) in obesity classes I, II, and III, respectively (p < 0.001)]. The ODI improved by 30 in normal weight patients (30–31), by 29 in overweight patients (28–29) and by 26 in obese patients (25–27) (p < 0.001) [29 (28–29), 25 (22–27) and 27 (22–32) in obesity classes I, II, and III, respectively (p < 0.01)]. A total of 3.0% of normal-weight patients, 3.9% of overweight patients and 3.9% of obese patients suffered complications (p = 0.047) [3.8%, 4.4%, 3.5% in obesity classes I, II, and III, respectively (p = 0.90)].

Conclusions

LDH surgery is also generally associated with favourable outcomes and few complications in patients with morbid obesity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05884-8.

Physical Activity in Late Prepuberty and Early Puberty Is Associated With High Bone Formation and Low Bone Resorption

Background

Physical activity (PA) increases bone mass, especially in late prepuberty and early puberty, but it remains unclear if and how PA affects both bone formation and bone resorption.

Materials and Methods

We included 191 boys and 158 girls aged 7.7 ± 0.6 (mean ± SD) in a population-based PA intervention study. The intervention group (123 boys and 94 girls) received daily physical education (PE) in school (40 min/day; 200 min/week) from study start and during the nine compulsory school years in Sweden. The controls (68 boys and 64 girls) received the national standard of 1–2 classes PE/week (60 min/week). During the intervention, blood samples were collected at ages 9.9 ± 0.6 (n = 172; all in Tanner stages 1–2) and 14.8 ± 0.8 (n = 146; all in Tanner stages 3–5) and after termination of the intervention at age 18.8 ± 0.3 (n = 93; all in Tanner stage 5) and 23.5 ± 0.7 (n = 152). In serum, we analyzed bone formation markers [bone-specific alkaline phosphatase (bALP), osteocalcin (OC), and N-terminal propeptide of collagen type 1 (PINP)] and bone resorption markers [C-terminal telopeptide cross links (CTX) and tartrate-resistant acid phosphatase (TRAcP 5b)]. Linear regression was used to compare age and sex-adjusted mean differences between intervention children and controls in these markers.

Results

Two years after the intervention was initiated (at Tanner stages 1–2), we found higher serum levels of bALP and OC, and lower serum levels of TRAcP 5b in the intervention compared with the control group. The mean difference (95% CI) was for bALP: 13.7 (2.1, 25.3) μg/L, OC: 9.1 (0.1, 18.1) μg/L, and TRAcP 5b: −2.3 (−3.9, −0.7) U/L. At Tanner stages 3–5 and after the intervention was terminated, bone turnover markers were similar in the intervention and the control children.

Conclusion

Daily school PA in the late prepubertal and early pubertal periods is associated with higher bone formation and lower bone resorption than school PA 1–2 times/week. In late pubertal and postpubertal periods, bone formation and resorption were similar. Termination of the intervention is not associated with adverse bone turnover, indicating that PA-induced bone mass benefits gained during growth may remain in adulthood.

Physical Activity at Growth Induces Bone Mass Benefits Into Adulthood – A Fifteen‐Year Prospective Controlled Study

Daily school physical activity (PA) improves musculoskeletal traits. Whether or not benefits remain in adulthood is debated. We included in this study 131 children that took part in an intervention with 40 minutes of PA per school day (200 minutes per week) from age 6 to 9 years (grade one) to age 14 to 16 years (grade nine), whereas 78 children continued with national recommended school physical education of 60 minutes per week. Measurements were done with dual‐energy X‐ray absorptiometry (bone mineral content [BMC], bone mineral density [BMD], and bone area), and a computerized knee dynamometer (peak torque muscle strength) at study start, at the end of the intervention, and 7 years after the intervention. Group differences from study start and end of the intervention to 7 years thereafter were estimated by analyses of covariance (adjusted for sex and follow‐up time). Musculoskeletal gains from study start to 7 years after termination of the intervention were higher in the intervention group (total body less head BMC +182.5 g [95% confidence interval {CI}, 55.1–309.9] and BMD +0.03 g/cm² [95% CI, 0.003–0.05], femoral neck area + 0.2 cm² [95% CI, 0.1–0.4], and knee flexion peak torque muscle strength at 60 degrees per second +9.2 Nm [95% CI, 2.9–15.5]). There was no attenuation during the 7 years that followed termination of the intervention (all group comparisons p > 0.05). Benefits in musculoskeletal gains remain 7 years after termination of a daily school‐based PA program, without attenuation after termination of the program. Daily school PA may counteract low bone mass and inferior muscle strength in adulthood. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Downturn in Childhood Bone Mass: A Cross‐Sectional Study Over Four Decades

Screen time and physical inactivity have increased among children. As physical activity is a determinant of bone mass, there is a concern that children today have lower bone mass than earlier. If this is true, fractures may become more common in the future. In 2017–2018, we used single‐photon absorptiometry (SPA) to measure distal forearm bone mineral density (BMD; mg/cm²) in a normative cohort of 238 boys and 204 girls aged 7 to 15 years. We compared these results to BMD in a normative cohort collected in 1979–1981 (55 boys and 61 girls aged 7 to 15 years) measured by the same scanner. To investigate difference between the two cohorts, we used multiple linear regression with age, sex, and cohort as predictors. Predicted bone density at age 16 years was estimated through the slope values. The bone density‐age slope was flatter in the cohort measured in 2017–2018 than in the cohort measured 1979–1981 (−5.6 mg/cm²/yr [95% confidence interval −9.6 to −1.5]). Predicted bone density was at age 16 years in 2017–2018 in boys was 10% lower (−0.9 SD) and in girls 11% lower (−1.1 SD) than in their counterparts measured in 1979–1981. We found indications that children nowadays develop lower bone mass than four decades ago, giving concern that they may have a higher risk of osteoporosis and fragility fractures as they grow old. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Musculoskeletal Benefits from a Physical Activity Program in Primary School are Retained 4 Years after the Program is Terminated

Daily school physical activity (PA) improves musculoskeletal traits. This study evaluates whether the benefits remain 4 years after the intervention. We followed 45 boys and 36 girls who had had 40 min PA/school day during the nine compulsory school years and 21 boys and 22 girls who had had 60 min PA/school week (reference), with measurements at baseline and 4 years after the program terminated. Bone mineral content (BMC; g) and bone mineral density (BMD; g/cm²) were measured by dual-energy X-ray absorptiometry and knee flexion peak torque relative to total body weight (PT_flexTBW) at a speed of 180 degrees/second with a computerized dynamometer. Group differences are presented as mean differences (adjusted for sex and duration of follow-up period) with 95% confidence intervals. The total gain bone mass [mean difference in spine BMC +32.0 g (14.6, 49.4) and in arms BMD of +0.06 g/cm² (0.02, 0.09)] and gain in muscle strength [mean difference in PT_flex180TBW +12.1 (2.0, 22.2)] were greater in the intervention than in the control group. There are still 4 years after the intervention indications of benefits in both bone mass and muscle strength gain. Daily school PA may counteract low bone mass and inferior muscle strength in adult life. ClinicalTrials.gov.NCT000633828 retrospectively registered 2008-11-03.

Sarcopenia Definitions as Predictors of Fracture Risk Independent of FRAX® , Falls, and BMD in the Osteoporotic Fractures in Men (MrOS) Study: A Meta-Analysis

Dual-energy X-ray absorptiometry (DXA)-derived appendicular lean mass/height2 (ALM/ht2 ) is the most commonly used estimate of muscle mass in the assessment of sarcopenia, but its predictive value for fracture is substantially attenuated by femoral neck (fn) bone mineral density (BMD). We investigated predictive value of 11 sarcopenia definitions for incident fracture, independent of fnBMD, fracture risk assessment tool (FRAX® ) probability, and prior falls, using an extension of Poisson regression in US, Sweden, and Hong Kong Osteoporois Fractures in Men Study (MrOS) cohorts. Definitions tested were those of Baumgartner and Delmonico (ALM/ht2 only), Morley, the International Working Group on Sarcopenia, European Working Group on Sarcopenia in Older People (EWGSOP1 and 2), Asian Working Group on Sarcopenia, Foundation for the National Institutes of Health (FNIH) 1 and 2 (using ALM/body mass index [BMI], incorporating muscle strength and/or physical performance measures plus ALM/ht2 ), and Sarcopenia Definitions and Outcomes Consortium (gait speed and grip strength). Associations were adjusted for age and time since baseline and reported as hazard ratio (HR) for first incident fracture, here major osteoporotic fracture (MOF; clinical vertebral, hip, distal forearm, proximal humerus). Further analyses adjusted additionally for FRAX-MOF probability (n = 7531; calculated ± fnBMD), prior falls (y/n), or fnBMD T-score. Results were synthesized by meta-analysis. In 5660 men in USA, 2764 Sweden and 1987 Hong Kong (mean ages 73.5, 75.4, and 72.4 years, respectively), sarcopenia prevalence ranged from 0.5% to 35%. Sarcopenia status, by all definitions except those of FNIH, was associated with incident MOF (HR = 1.39 to 2.07). Associations were robust to adjustment for prior falls or FRAX probability (without fnBMD); adjustment for fnBMD T-score attenuated associations. EWGSOP2 severe sarcopenia (incorporating chair stand time, gait speed, and grip strength plus ALM) was most predictive, albeit at low prevalence, and appeared only modestly influenced by inclusion of fnBMD. In conclusion, the predictive value for fracture of sarcopenia definitions based on ALM is reduced by adjustment for fnBMD but strengthened by additional inclusion of physical performance measures. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Association between circulating furin levels, obesity and pro-inflammatory markers in children

AIM

To, in children, investigate the associations between serum furin, obesity, overweight, body fat and circulating markers reflecting adipose tissue or systemic inflammation.

METHODS

We analysed furin, leptin, adipocyte fatty acid-binding protein, triglycerides, interleukin (IL)-6, IL-8 and C-reactive protein in serum from 166 children in the Pediatric Osteoporosis Prevention (POP) study collected at mean age (SD) 9.9 (0.6) years. Children were classified as low-to-normal weight, overweight or obese. Total body fat mass (kg), trunk fat mass (kg) and total body lean mass (kg) were measured by dual-energy X-ray absorptiometry. Body fat percentage (%) was calculated.

RESULTS

We found that circulating furin levels were higher in children with obesity and overweight compared with children with low-to-normal weight (p < 0.001 and p = 0.006, respectively). Also, there were positive correlations between circulating furin, total body fat mass, trunk fat mass, body fat percentage, triglycerides, adipokines and pro-inflammatory markers.

CONCLUSION

This study indicates associations between furin, adiposity and a pro-inflammatory milieu in children. We suggest that future studies investigate the role of furin in fat tissue inflammation and associated increased risk of cardiometabolic diseases in children. Studies should also investigate whether higher furin levels could be a link between obesity and severe coronavirus disease 2019 in children.

Time trends in pediatric hand fracture incidence in Malmö, Sweden, 1950-2016

Background

The hand is the second most fractured region in children. It is therefore important to update fracture epidemiology to be able to identify time trends for adequate health care planning. This study reports pediatric hand fracture incidence 2014–2016 and, using published data, also long-term time trends in 1950–2016.

Patients and methods

The Swedish city of Malmö, with 328,494 inhabitants in 2016, has only one hospital. We used the hospital radiological archive, medical charts, and diagnosis registry to identify hand fractures in city residents < 16 years in 2014–2016. These data were compared to those from three published studies that evaluated periods in 1950–2006. Differences between two periods were calculated as both unadjusted and age- and sex-adjusted incident rate ratios (IRR) with 95% confidence intervals (95% CI). We used joinpoint regression to estimate time trends during the entire period and present annual percent changes (APC) with 95% CI.

Results

In 2014–2016 phalangeal fractures accounted for 71% of all hand fractures, metacarpal fractures for 24%, and carpal fractures for 5%. We identified 615 hand fractures (419 in boys and 196 in girls) during 181,617 person-years in 2014–2016, resulting in an unadjusted pediatric hand fracture incidence of 339/100,000 person-years (boys 452/100,000 person-years and girls 220/100,000 person-years). The age-adjusted incidence 2014–2016 was similar to 2005–2006, the most recently evaluated period (IRR in boys 0.9; 95% CI 0.8 to 1.01, and in girls 1.0; 95% CI 0.8 to 1.2). Looking at the entire period 1950–2016, we found that age-adjusted incidence increased in 1950–1979, in boys by APC + 3.8%; 95% CI 3.0 to 4.5 and in girls by + 3.9%; 95% CI 2.8 to 5.0, but decreased in 1979–2016, in boys by − 0.7%; 95% CI − 1.4 to − 0.003, and girls by − 1.3%; 95% CI − 2.4 to − 0.1.

Conclusions

Phalangeal fractures accounted for about three quarters of all hand fractures. The age-adjusted hand fracture incidence increased in both sexes in 1950–1979 and decreased in 1979–2016.

Level of evidence

III

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02380-y.

Childhood Distal Forearm Fracture Incidence in Malmö, Sweden 1950 to 2016

Background  Distal forearm fracture is the most common pediatric fracture. As studies have indicated time trends in fracture incidence, we wanted to update the epidemiology and estimate time trends between 1950 and 2016 in Malmö, Sweden. Methods  The city of Malmö, Sweden, had 318,107 inhabitants (58,585 of the population was aged <16 years) in 2014 and one hospital. We, therefore, used the hospital diagnosis registry and hospital medical records to identify and classify distal forearm fractures 2014 to 2016 in children aged 0 to 15 years. For long-term trend calculations, we also included published data from 1950 to 2006 (resulting in 17 evaluated years) and used joinpoint regression to estimate annual percent changes (APC). To describe differences in incidence between two periods, we calculated incident rate ratios (IRR) with 95% confidence intervals (95% CI) to describe uncertainty. Results  Childhood distal forearm fracture incidence in 2014 to 2016 was 546/100,000 person-years (660 in boys and 427 in girls). The age-adjusted incidence in 2014 to 2016 and in 2005 to 2006 was similar (boys IRR 1.0, 95% CI: 0.9-1.2 and girls IRR 1.1, 95% CI: 0.9-1.3). Time-trend analyses from 1950 to 2016 revealed increasing age-adjusted incidence in both boys (APC +0.9%, 95% CI: 0.7-1.2) and girls (APC +0.6%, 95% CI: 0.3-0.9). Conclusion  Distal forearm fracture incidence was similar in 2014 to 2016 and in 2005 to 2006. Age-adjusted incidence had increased in both sexes from 1950 to 2016. Level of Evidence  This is a Level III b study.

Back pain is also improved by lumbar disc herniation surgery

Background and purpose - Indication for lumbar disc herniation (LDH) surgery is usually to relieve sciatica. We evaluated whether back pain also decreases after LDH surgery.Patients and methods - In the Swedish register for spinal surgery (SweSpine) we identified 14,097 patients aged 20-64 years, with pre- and postoperative data, who in 2000-2016 had LDH surgery. We calculated 1-year improvement on numeric rating scale (rating 0-10) in back pain (N_back) and leg pain (N_leg) and by negative binomial regression relative risk (RR) for gaining improvement exceeding minimum clinically important difference (MCID).Results - N_leg was preoperatively (mean [SD]) 6.7 (2.5) and N_back was 4.7 (2.9) (p < 0.001). Surgery reduced N_leg by mean 4.5 (95% CI 4.5-4.6) and N_back by 2.2 (CI 2.1-2.2). Mean reduction in N_leg) was 67% and in N_back 47% (p < 0.001). Among patients with preoperative pain ≥ MCID (that is, patients with significant baseline pain and with a theoretical possibility to improve above MCID), the proportion who reached improvement ≥ MCID was 79% in N_leg and 60% in N_back. RR for gaining improvement ≥ MCID in smokers compared with non-smokers was for N_leg 0.9 (CI 0.8-0.9) and -N_back 0.9 (CI 0.8-0.9), and in patients with preoperative duration of back pain 0-3 months compared with > 24 months for N_leg 1.3 (CI 1.2-1.5) and for N_back 1.4 (CI 1.2-1.5).Interpretation - LDH surgery improves leg pain more than back pain; nevertheless, 60% of the patients with significant back pain improved ≥ MCID. Smoking and long duration of pain is associated with inferior recovery in both N_leg and N_back.

Time trends in pediatric fractures in a Swedish city from 1950 to 2016

Background and purpose - As previous studies indicate time trends in pediatric fracture incidence, we followed the incidence in a Swedish city between 1950 and 2016.Patients and methods - Malmö city, Sweden had 322,574 inhabitants in 2015. We used diagnosis registry, charts, and radiographs of the only city hospital to classify fractures in individuals < 16 years in 2014-2016, and compared these with data from 1950-2006. We used joinpoint regression to analyze time trends and present results as mean annual percentage changes (APC). Differences between periods are described as incident rate ratios (IRR). To describe uncertainty, 95% confidence intervals (CI) are used.Results - During 2014-2016 the pediatric fracture incidence was 1,786 per 10⁵ person-years (boys 2,135 and girls 1,423). From 1950 onwards age-adjusted fracture incidence increased until 1979 in both boys (APC +1.5%, CI 1.2-1.8) and girls (APC +1.6%, CI 0.8-2.5). The incidence remained stable from 1979 to 2016 (APC in boys 0.0%, CI -0.3 to 0.3 and in girls -0.2%, CI -1.1 to 0.7). Age-adjusted incidence 2014-2016 was higher than 2005-2006 in girls (IRR 1.1, CI 1.03-1.3), but not in boys (IRR 1.0, CI 0.9-1.1).Interpretation - Fracture incidence was in girls higher in 2014-2016 than in 2005-2006. However, only with more than 2 measuring points are meaningful trend analyses possible. When we analyzed the period 1950-2016 with 17 measuring points and joinpoint regression, we found that fracture incidence increased in both sexes until 1979 but has thereafter been stable.

Daily School Physical Activity Improves Academic Performance

Physical activity (PA) may improve brain development, cognition, concentration and academic performance. In this prospective controlled intervention study, we increased the level of PA in 338 children aged 6–8 years at study start, from the Swedish standard of 60 min per week to 200 min per week (40 min daily). The intervention continued in all nine compulsory school years until the students graduated between 2007–2012. All other 689,881 Swedish children who graduated the same years were included as a control group. We registered at graduation eligibility rate for upper secondary school and the final grade score (from 0 to 320 grade points). We also registered the same end points in the 295 students in the index school and in all other 471,926 Swedish students who graduated in 2003–2006, that is, those who graduated before the intervention study started. Before the intervention, academic performance was similar among children in the index school as for all other Swedish boys and girls. With the intervention, the eligibility rate increased for boys in the index school by 7.3 percentage points and the mean grade scores by 13.3 points. This should be compared with a decrease of 0.8 percentage points in eligibility rate and an increase by 2.7 points in grade score in other Swedish boys. No changes were seen for intervention girls, neither in eligibility rates or grade scores. By introducing daily school-based PA in compulsory school, more boys would probably reach the eligibility rate for higher education.

Exercise and Peak Bone Mass

PURPOSE OF REVIEW

The main goal of this narrative review is to assess whether physical activity (PA) influences peak bone mass and fracture risk.

RECENT FINDINGS

Several randomized controlled trials (RCT) show that short-term PA intervention programs in childhood improve the accrual of bone mineral. There are now also long-term controlled PA intervention studies demonstrating that both boys and girls with daily school PA through puberty gain higher bone mineral content (BMC) and bone mineral density (BMD) and greater bone size than boys and girls with school PA 1-2 times/week. These benefits seem to be followed by a gradual reduction in expected fracture rates, so that in children with daily school PA, the incidence rate ratio (IRR) after 8 years is less than half that expected by age. Daily school PA from before to after puberty is associated with beneficial gains in bone traits and gradually lower relative fracture risk.

Daily School Physical Activity from Before to After Puberty Improves Bone Mass and a Musculoskeletal Composite Risk Score for Fracture

This 7.5-year prospective controlled exercise intervention study assessed if daily school physical activity (PA), from before to after puberty, improved musculoskeletal traits. There were 63 boys and 34 girls in the intervention group (40 min PA/day), and 26 boys and 17 girls in the control group (60 min PA/week). We measured musculoskeletal traits at the start and end of the study. The overall musculoskeletal effect of PA was also estimated by a composite score (mean Z-score of the lumbar spine bone mineral content (BMC), bone area (BA), total body lean mass (TBLM), calcaneal ultrasound (speed of sound (SOS)), and muscle strength (knee flexion peak torque)). We used analyses of covariance (ANCOVA) for group comparisons. Compared to the gender-matched control group, intervention boys reached higher gains in BMC, BA, muscle strength, as well as in the composite score, and intervention girls higher gains in BMC, BA, SOS, as well as in the composite score (all p < 0.05, respectively). Our small sample study indicates that a daily school-based PA intervention program from Tanner stage 1 to 5 in both sexes is associated with greater bone mineral accrual, greater gain in bone size, and a greater gain in a musculoskeletal composite score for fractures.

Better implant survival with modern ankle prosthetic designs: 1,226 total ankle prostheses followed for up to 20 years in the Swedish Ankle Registry

Background and purpose - We have previously reported on the prosthetic survival of total ankle replacements (TAR) in Sweden performed between 1993 and 2010. Few other reports have been published on 5- and 10-year survival rates. Furthermore, there is a lack of long-term outcome data on modern prosthetic designs. Therefore, we compared early and current prosthetic designs after a mean 7-year follow-up.Patients and methods - On December 31, 2016, 1,230 primary TARs had been reported to the Swedish Ankle Registry. We analyzed prosthetic survival, using exchange or permanent extraction of components as endpoint for 1,226 protheses with mean follow-up of 7 years (0-24). Differences between current (Hintegra, Mobility, CCI, Rebalance, and TM Ankle) and early prosthetic designs (STAR, BP, and AES) were examined by log rank test.Results - 267/1,226 prostheses (22%) had been revised by December 31, 2016. We found an overall prosthetic survival rate at 5 years of 0.85 (95% CI 0.83-0.87), at 10 years 0.74 (CI 0.70-0.77), at 15 years 0.63 (CI 0.58-0.67), and at 20 years 0.58 (CI 0.52-0.65). For early prosthetic designs the 5- and 10-year survival rates were 0.81 (CI 0.78-0.84) and 0.69 (CI 0.64-0.73) respectively, while the corresponding rates for current designs were 0.88 (CI 0.85-0.91) and 0.84 (CI 0.79-0.88). Current prosthetic designs had better survival (log rank test p < 0.001).Interpretation - Our results point to a positive time trend of prosthetic survival in Sweden; use of current prosthetic designs was associated with better prosthetic survival. Improved designs and instrumentation, more experienced surgeons, and improved patient selection may all have contributed to the better outcome.

Predictors of satisfaction after lumbar disc herniation surgery in elderly

Background

The aim of this study was to evaluate satisfaction and factors associated with satisfaction in elderly undergoing lumbar disc herniation surgery.

Methods

In the national Swedish register for spinal surgery (SweSpine) we identified 2095 patients aged > 65 years (WHO definition of elderly) whom during 2000–2016 had undergone LDH surgery and had pre- and one-year postoperative data (age, gender, preoperative duration and degree of back- and leg pain, quality of life (SF-36) and one-year satisfaction (dissatisfied, uncertain, satisfied). We utilized a logistic regression model to examine preoperative factors that were independently associated with low and high satisfaction and after LDH surgery.

Results

One year after surgery, 71% of the patients were satisfied, 18% uncertain and 11% dissatisfied. Patients who were satisfied were in comparison to others, younger, had shorter preoperative duration of leg pain, higher SF-36 mental component summary and more leg than back pain (all p < 0.01). Patients who were dissatisfied were compared to others older, had longer preoperative duration of leg pain and lower SF-36 scores (all p < 0.01). 81% of patients with leg pain up to 3 months were satisfied in comparison with 57% of patients with leg pain > 2 years (p < 0.001).

Conclusion

Only one out of ten elderly, is dissatisfied with the outcome of LDH surgery. Age, preoperative duration of leg pain, preoperative SF 36 score, and for satisfaction also dominance of back over leg pain, are in elderly factors associated to good and poor subjective outcome after LDH surgery.

Socioecological and biological associations of lower levels of physical activity in 8-year-old children: a 2-year prospective study

Objectives

Evaluate if socioecological and biological factors, at the age of 8 years, are associated with lower level of physical activity (PA) 2 years later.

Method

In a study cohort of 199 children aged 7.8±0.6 years, we used questionnaires and physical measurements to evaluate biological (eg, sex), social (eg, parental PA) and environmental (eg, school settings) factors. Objective PA was measured 2 years later with accelerometers. General PA (GPA) was defined as mean counts per minute (cpm) and moderate to vigorous PA (MVPA) as min/day >3500 cpm. We used analysis of covariance to evaluate if socioecological factors at age 8 are associated with level of PA 2 years later.

Results

Daily GPA was 690.5±216.6 cpm and the children spent 40.9±18.3 min on MVPA. Female sex is associated with -131.1 (-183.4, -78.7) cpm GPA, each 10 cm shorter body height with -48.7 (-94.8, -26.5), each unit higher body mass index (BMI) with -26.0 (-37.5, -14.5) and allocation to 60 min school PA/week with -73.8 (-131.5, -16.2) compared with allocation to 200 min school PA/week. Female sex is associated with -10.3 (-14.8, -5.7) min of MVPA and each unit higher BMI with -1.9 (-2.9, -0.9) min.

Conclusion

Female sex, shorter body height and higher BMI are at age 8 years associated with lower level of PA 2 years later. It appears possible to increase PA by daily school PA.

Trial registration number

NCT00633828.

Pediatric Distal Forearm Fracture Epidemiology in Malmö, Sweden-Time Trends During Six Decades

Background  The distal forearm fracture is the most common fracture in children. To allocate health care resources and evaluate if prevention strategies have been successful, it is essential to monitor changes in the epidemiology of common fractures. Methods  Our hospital serves a city in which year 2006 included 276,244 inhabitants (49,664 <17 years of age). Through the hospital archives, we identified fractures sustained by individuals younger than 16 years during 2005 and 2006 and compared these with previous collected and published data from the same area and hospital for the period 1950 to 1994. We used official population data to estimate period-specific fracture rates and age and gender standardized time trends. We report rates as number of fractures per 100,000 person-years and changes between periods as rate ratios (RR) with 95% confidence intervals (CIs). Results  We identified 521 distal forearm fractures, corresponding to a crude fracture incidence of 564/100,000 person-years (boys 719; girls 401). Age-adjusted fracture incidence was 70% higher in boys than in girls (RR 1.7; 95% CI 1.3-2.3). The age- and gender-adjusted hand fracture incidence was 40% higher in 2005-2006 than in 1950/1955 (RR 1.4; 95% CI 1.2 to 1.8) but no higher than 1993-1994 (RR 1.1; 95% CI 0.9-1.3). Fracture etiology of 2005 to 2006 included sports injuries in 41% and traffic accidents in 11% of the cases, while sports injuries explained 37% and traffic accidents 18% in 1950 to 1955. Conclusion  In 2005 to 2006, we found higher rates in boys and higher overall rates compared with the 1950s but no significant differences compared with the rates in 1993 to 1994. Future studies should include patient-specific data to unravel causal factors. Level of evidence  This is a Level III b study.

Does peak bone mass correlate with peak bone strength? Cross-sectional normative dual energy X-ray absorptiometry data in 1052 men aged 18-28 years

Background

Areal bone mineral density (aBMD) estimated by dual-energy X-ray absorptiometry (DXA) is used to estimate peak bone mass, define osteoporosis and predict fracture. However, as aBMD is calculated as bone mineral content (BMC) divided by the scanned area, aBMD displays an inverse relationship with bone size. In a skeleton that is increasing in size, this is a problem, as bone size is an independent factor that determines bone strength. It could therefore be questioned whether peak aBMD is the period with greatest bone strength, a period that in the hip then would occur in ages 16–19. The aim of this study was to evaluate whether there are changes in bone size in men after age 18 that may influence peak bone strength. Another aim was to provide updated normative DXA data.

Methods

We scanned left femoral neck by DXA in a cross-sectional study with a population-based selection of 1052 men aged 18–28, and then registered bone mineral content (BMC, gram), aBMD (gram/cm²) and bone area (cm²) in each one-year age group. We performed analyses of variance (ANOVA) to evaluate whether there were differences in these traits between the age groups. We then used Pearson’s correlation analyses to test for trends with ageing after peak bone mass was reached.

Results

We found the highest absolute femoral neck aBMD at age 19, with statistically significant differences between the one-year age groups in BMC, aBMD, and bone area (all p < 0.05). From peak bone mass onwards (n = 962), there are negative correlations between age and BMC (r = − 0.07; p < 0.05) and age and aBMD (r = − 0.12; p < 0.001), and positive correlation between age and bone area (r = 0.06; p < 0.05).

Conclusion

As femoral neck bone size in young adult men becomes larger after peak bone mass, it could be questioned whether DXA estimated peak aBMD correlates with peak bone strength. We infer that aBMD must be interpreted with care in individuals with a growing skeleton, since skeletal strength may then increase, in spite of decreasing aBMD. This should be taken into account when performing DXA measurements in these ages.

Hand fracture epidemiology and etiology in children-time trends in Malmö, Sweden, during six decades

BACKGROUND

The aim of this study was to describe hand fracture epidemiology/etiology in city children and describe time trend during six decades.

PATIENTS AND METHODS

A single hospital serves the entire city population of 271,271 (year 2005). Through the hospital medical and radiological archives, we collected epidemiology and etiology data concerning pediatric (age < 16 years) hand fractures in city residents, treated during 2005-2006. We compared these data to previously collected data in in the same city during 12 evaluated periods from 1950/1955 to 1993-1994. We present period-specific crude and age- and gender-adjusted fracture incidence rates and group differences as incidence rate ratios (RR) with 95% confidence intervals (95% CI).

RESULTS

In 2005-2006, we identified 414 hand fractures (303 in boys and 111 in girls), 247 phalangeal fractures (60% of all hand fractures), 140 metacarpal/carpal fractures (except the scaphoid bone) (34%), and 27 scaphoid fractures (6%). The crude hand fracture rate in children was 448/100,000 person years (639/100,000 in boys and 247/100,000 in girls), with a 2.5 times higher age-adjusted incidence in boys than in girls. Compared to 1950/1955, the age and gender-adjusted hand fracture incidence was twice as high in 2005-2006 and more than twice as high in 1976-1979. Compared to 1976-1979, we found no significant difference in the age and gender-adjusted hand fracture incidence in 2005-2006. In 2005-2006, sports injuries explained 42%, fights 20%, and traffic accidents 13% of the hand fractures. In 1950/1955, sports injuries explained 27% of fractures, fights 10%, and traffic accidents 21%.

CONCLUSIONS

The incidence of hand fractures in children was more than twice as high in the end of the 1970s compared to the 1950s, where after no significant change could be found. Also, fracture etiology has changed. New studies are needed, to adequately allocate health care resources and identify new fracture prone activities suitable for preventive measures.

LEVEL OF EVIDENCE

III.

The fracture predictive ability of a musculoskeletal composite score in old men - data from the MrOs Sweden study

Background

Detection of high-risk individuals for fractures are needed. This study assessed whether level of physical activity (PA) and a musculoskeletal composite score could be used as fracture predictive tools, and if the score could predict fractures better than areal bone mineral density (aBMD).

Methods

MrOs Sweden is a prospective population-based observational study that at baseline included 3014 men aged 69–81 years. We assessed femoral neck bone mineral content (BMC), bone area, aBMD and total body lean mass by dual energy X-ray absorptiometry, calcaneal speed of sound by quantitative ultrasound and hand grip strength by a handheld dynamometer. PA was assessed by the Physical Activity Scale for the Elderly (PASE) questionnaire. We followed the participants until the date of first fracture, death or relocation (median 9.6 years). A musculoskeletal composite score was calculated as mean Z-score of the five measured traits. A Cox proportional hazards model was used to analyze the association between the musculoskeletal traits, the composite score and incident fractures (yes/no) during the follow-up period. Data are presented as hazard ratios (HR) with 95% confidence intervals (95% CI) for fracture for a + 1 standard deviation (SD) change (+ 1 Z-score) in the various musculoskeletal traits as well as the composite score. We used a linear regression model to estimate the association between level of PA, measured as PASE-score and the different musculoskeletal traits as well as the composite score.

Results

A + 1 SD higher composite score was associated with an incident fracture HR of 0.61 (0.54, 0.69), however not being superior to aBMD in fracture prediction. A + 1 SD higher PASE-score was associated with both a higher composite score and lower fracture incidence (HR 0.83 (0.76, 0.90)).

Conclusions

The composite score was similar to femoral neck aBMD in predicting fractures, and also low PA predicted fractures. This highlights the need of randomized controlled trials to evaluate if PA could be used as a fracture preventive strategy.

Measures of Physical Performance and Muscle Strength as Predictors of Fracture Risk Independent of FRAX, Falls, and aBMD: A Meta-Analysis of the Osteoporotic Fractures in Men (MrOS) Study

Measures of muscle mass, strength, and function predict risk of incident fractures, but it is not known whether this risk information is additive to that from FRAX (fracture risk assessment tool) probability. In the Osteoporotic Fractures in Men (MrOS) Study cohorts (Sweden, Hong Kong, United States), we investigated whether measures of physical performance/appendicular lean mass (ALM) by DXA predicted incident fractures in older men, independently of FRAX probability. Baseline information included falls history, clinical risk factors for falls and fractures, femoral neck aBMD, and calculated FRAX probabilities. An extension of Poisson regression was used to investigate the relationship between time for five chair stands, walking speed over a 6 m distance, grip strength, ALM adjusted for body size (ALM/height2 ), FRAX probability (major osteoporotic fracture [MOF]) with or without femoral neck aBMD, available in a subset of n = 7531), and incident MOF (hip, clinical vertebral, wrist, or proximal humerus). Associations were adjusted for age and time since baseline, and are reported as hazard ratios (HRs) for first incident fracture per SD increment in predictor using meta-analysis. 5660 men in the United States (mean age 73.5 years), 2764 men in Sweden (75.4 years), and 1987 men in Hong Kong (72.4 years) were studied. Mean follow-up time was 8.7 to 10.9 years. Greater time for five chair stands was associated with greater risk of MOF (HR 1.26; 95% CI, 1.19 to 1.34), whereas greater walking speed (HR 0.85; 95% CI, 0.79 to 0.90), grip strength (HR 0.77; 95% CI, 0.72 to 0.82), and ALM/height2 (HR 0.85; 95% CI, 0.80 to 0.90) were associated with lower risk of incident MOF. Associations remained largely similar after adjustment for FRAX, but associations between ALM/height2 and MOF were weakened (HR 0.92; 95% CI, 0.85 to 0.99). Inclusion of femoral neck aBMD markedly attenuated the association between ALM/height2 and MOF (HR 1.02; 95% CI, 0.96 to 1.10). Measures of physical performance predicted incident fractures independently of FRAX probability. Whilst the predictive value of ALM/height2 was substantially reduced by inclusion of aBMD requires further study, these findings support the consideration of physical performance in fracture risk assessment. © 2018 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Age- and Gender-Specific Normative Values for the Self-Reported Foot and Ankle Score (SEFAS)

BACKGROUND

The Self-Reported Foot and Ankle Score (SEFAS) is a foot- and ankle-specific patient-reported outcome measurement (PROM) score that has been validated with good results for a variety of foot and ankle disorders. SEFAS is sensitive detecting improvement or deterioration after surgery. However, normative values, required to put a specific patient's summary score into perspective, are lacking.

METHODS

In this report, we included 396 population-based men and 383 women (43% of the invited individuals), age 20-89 years, who had completed the SEFAS questionnaire and questions regarding anthropometrics and health. We used Mann-Whitney U test to test gender differences and Spearman correlation coefficients to determine any association between SEFAS score and age. We present gender-specific median SEFAS scores with range and 5th to 95th percentiles and mean with standard deviation.

RESULTS

The SEFAS normative values were median 48 in men (range 11-48), 5th to 95th percentiles 31 to 48 and mean 45 ± 6, and in women, median 47 (range 6-48), 5th to 95th percentiles 23 to 48 and mean 43 ± 8 (gender comparison P < .001). SEFAS normative values correlated inversely with age (r = -0.12, P < .001).

CONCLUSION

In the general population, older age was associated with lower SEFAS value, and men had higher values than women. The population-based normative SEFAS values provided in this study can facilitate quantification of disability related to foot and ankle with and without surgery in the foot and ankle.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Re-arthrodesis after primary ankle fusion: 134/1,716 cases from the Swedish Ankle Registry

Background and purpose - Arthrodesis is the most common treatment of severe ankle arthritis. Large studies on the occurrence of re-arthrodesis are few, especially with information in terms of risk. We used the National Swedish Ankle Registry to assess incidence and risk factors for re-arthrodesis. Patients and methods - In the Registry, we examined the occurrence of re-arthrodesis in 1,716 patients with a primary ankle arthrodesis. We also analyzed associations between the re-arthrodesis risk and sex, diagnosis, and surgical method. Results - The risk of first re-arthrodesis at 2.5 years was 7.4% and the rate at 9 years 7.8%. The risk following arthroscopic surgery with fixation by screws was 15%, which is statistically significantly higher than the 8% following the gold standard technique with open screw fixation, the 5% following fixation by intramedullary nailing, and the 3% following fixation by plate and screws. Patients with either idiopathic osteoarthritis or posttraumatic arthritis had a higher risk of re-arthrodesis than patients with rheumatoid arthritis. We could not find that the risk of re-arthrodesis was associated with sex. Interpretation - In Sweden, the re-arthrodesis risk varied by primary technique and was especially high after arthroscopic surgery. Reasons are unknown but poor surgical technique and/or surgeon inexperience may contribute, as may patient selection.

Serum DHEA and Its Sulfate Are Associated With Incident Fall Risk in Older Men: The MrOS Sweden Study

The adrenal-derived hormones dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) are the most abundant circulating hormones and their levels decline substantially with age. Many of the actions of DHEAS are considered to be mediated through metabolism into androgens and estrogens in peripheral target tissues. The predictive value of serum DHEA and DHEAS for the likelihood of falling is unknown. The aim of this study was, therefore, to assess the associations between baseline DHEA and DHEAS levels and incident fall risk in a large cohort of older men. Serum DHEA and DHEAS levels were analyzed with mass spectrometry in the population-based Osteoporotic Fractures in Men study in Sweden (n = 2516, age 69 to 81 years). Falls were ascertained every 4 months by mailed questionnaires. Associations between steroid hormones and falls were estimated by generalized estimating equations. During a mean follow-up of 2.7 years, 968 (38.5%) participants experienced a fall. High serum levels of both DHEA (odds ratio [OR] per SD increase 0.85; 95% CI, 0.78 to 0.92) and DHEAS (OR 0.88, 95% CI, 0.81 to 0.95) were associated with a lower incident fall risk in models adjusted for age, BMI, and prevalent falls. Further adjustment for serum sex steroids or age-related comorbidities only marginally attenuated the associations between DHEA or DHEAS and the likelihood of falling. Moreover, the point estimates for DHEA and DHEAS were only slightly reduced after adjustment for lean mass and/or grip strength. Also, the addition of the narrow walk test did not substantially alter the associations between serum DHEA or DHEAS and fall risk. Finally, the association with incident fall risk remained significant for DHEA but not for DHEAS after simultaneous adjustment for lean mass, grip strength, and the narrow walk test. This suggests that the associations between DHEA and DHEAS and falls are only partially mediated via muscle mass, muscle strength, and/or balance. In conclusion, older men with high DHEA or DHEAS levels have a lesser likelihood of a fall. © 2018 American Society for Bone and Mineral Research.

Extended physical education in children aged 6-15 years was associated with improved academic achievement in boys

AIM

Physical activity (PA) has been associated with enhanced cognition, brain development and concentration. This study evaluated whether increased physical education (PE) improved academic achievement.

METHODS

We recruited 304 children (55% boys) from a Swedish school in Skane County in 1998-2002 when they were six to seven years of age and followed them through all nine mandatory school years. Their PE level was increased from 60 to 200 minutes per week, and their results were compared with 73 885 control children (51% boys) in the county who graduated in the same years and did the standard 60 minutes of PE per week. Their academic achievements were measured as their final grade scores and the proportion of students eligible for upper secondary school.

RESULTS

The eligibility for further education increased in the intervention boys by 6.8 percentage points and the mean grade score by 12.1 points, while in the control group as a whole, the eligibility rate decreased by 0.7 percentage points and the mean grade score increased by 1.7 points. No changes in eligibility rates or mean grade scores were seen in the intervention girls.

CONCLUSION

Increasing weekly PE over nine years was associated with improved academic achievement in boys.

Long-term effects of daily physical education throughout compulsory school on duration of physical activity in young adulthood: an 11-year prospective controlled study

Objectives

We examined whether daily physical activity (PA) during compulsory school encourages children to be more physically active during the intervention and 4 years after termination of the programme.

Methods

This prospective controlled intervention study followed the same 124 children (81 children in an intervention group and 43 controls) aged 7.7±0.6 (mean±SD) during a 7-year PA intervention and 4 years after the intervention when the children were 18.7±0.3 years old. The intervention included daily school physical education (PE) (200 min/week), whereas the controls continued with the Swedish standard of 60 min/week. Using a questionnaire, we gathered data about total PA, leisure time PA and sedentary activities (SA). Group comparisons are adjusted for age and gender, and data are provided as means with 95% CIs.

Results

At baseline, we found similar duration of PA and SA between groups. After a mean of 7 years with intervention, the intervention group was more physically active than the controls (+4.5 (2.9 to 6.0) hours/week), whereas SA was similar (+0.6 (−2.5 to 3.9) hours/week). Four years beyond the intervention, the intervention group was still more physically active than the controls (2.7 (0.8 to 4.7) hours/week), and SA was still similar (−3.9 (−9.7 to 1.7) hours/week).

Conclusions

Intervention with daily school PE throughout compulsory school is associated with higher duration of PA not only during the intervention but also 4 years after termination of the programme.

A comparative study found that a seven-year school-based exercise programme increased physical activity levels in both sexes

AIM

This study assessed whether a Swedish school-based exercise intervention programme could increase total physical activity.

METHODS

We followed up 228 children who started school in 1998-2000 seven years later, when they had reached a mean age of 14.8. The 152 children (59% boys) at the intervention school did 200 minutes of physical education per week during that period, and the 76 children (50% boys) in the three control schools did the standard 60 minutes. Questionnaires assessed the durations of total and leisure-time physical activity and screen-time activity at baseline and after five and seven years.

RESULTS

Physical activity and screen-time activity were similar between the two groups before the study started. The intervention group then achieved higher durations of total physical activity than the controls (p < 0.001) and these levels remained in the sex-specific evaluations. There were no differences between the groups in the durations of leisure-time activity (p 0.08-0.77) or screen-time activity (p 0.31-0.91).

CONCLUSION

A school-based exercise intervention programme increased the total duration of physical activity in both sexes without any compensatory increase in screen-time activity. The findings contradict the activity-stat theory, which stated that the duration of physical activity in children is constant.

Falls Predict Fractures Independently of FRAX Probability: A Meta-Analysis of the Osteoporotic Fractures in Men (MrOS) Study

Although prior falls are a well-established predictor of future fracture, there is currently limited evidence regarding the specific value of falls history in fracture risk assessment relative to that of other clinical risk factors and bone mineral density (BMD) measurement. We therefore investigated, across the three Osteoporotic Fractures in Men (MrOS) Study cohorts, whether past falls predicted future fracture independently of FRAX and whether these associations varied with age and follow-up time. Elderly men were recruited from MrOS Sweden, Hong Kong, and USA. Baseline data included falls history (over the preceding 12 months), clinical risk factors, BMD at femoral neck, and calculated FRAX probabilities. An extension of Poisson regression was used to investigate the associations between falls, FRAX probability, and incident fracture, adjusting for age, time since baseline, and cohort in base models; further models were used to investigate interactions with age and follow-up time. Random-effects meta-analysis was used to synthesize the individual country associations. Information on falls and FRAX probability was available for 4365 men in USA (mean age 73.5 years; mean follow-up 10.8 years), 1823 men in Sweden (mean age 75.4 years; mean follow-up 8.7 years), and 1669 men in Hong Kong (mean age 72.4 years; mean follow-up 9.8 years). Rates of past falls were similar at 20%, 16%, and 15%, respectively. Across all cohorts, past falls predicted incident fracture at any site (hazard ratio [HR] = 1.69; 95% confidence interval [CI] 1.49, 1.90), major osteoporotic fracture (MOF) (HR = 1.56; 95% CI 1.33, 1.83), and hip fracture (HR = 1.61; 95% CI 1.27, 2.05). Relationships between past falls and incident fracture remained robust after adjustment for FRAX probability: adjusted HR (95% CI) any fracture: 1.63 (1.45, 1.83); MOF: 1.51 (1.32, 1.73); and hip: 1.54 (1.21, 1.95). In conclusion, past falls predicted incident fracture independently of FRAX probability, confirming the potential value of falls history in fracture risk assessment. © 2017 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Low physical activity is related to clustering of risk factors for fracture-a 2-year prospective study in children

The study investigates the effect of physical activity (PA) on a composite score for fracture risk in pre-pubertal children. Low PA in children is related to the composite score for fracture risk and the pre-pubertal years seem to be a period when PA positively affects the score.

INTRODUCTION

This study evaluates if PA in children is related to clustering of risk factors for fracture. Research questions are the following: (i) What is the effect of physical activity (PA) on single traits and a composite score for fracture risk? (ii) Could this score be used to identify the level of PA needed to reach beneficial effects?

METHODS

This prospective population-based study included 269 children, aged 7-9 years at baseline while 246 attended the 2-year follow-up. We estimated duration of PA by questionnaires and measured traits that independently predict fractures. We then calculated gender specific Z-scores for each variable. The mean Z-score of all traits was used as a composite score for fracture risk. We tested correlation between duration of PA, each trait, and the composite score and group differences between children in different quartiles of PA.

RESULTS

At baseline, we found no correlation between duration of PA and any of the traits or the composite score. At follow-up, we found a correlation between PA and the composite score. Physical activity had an effect on composite score, and children in the lowest quartiles of PA had unbeneficial composite score compared to children in the other quartiles.

CONCLUSION

Low PA in children is related to clustering of risk factors for fracture, and the pre-pubertal years seem to be a period when PA positively affects the composite score.

Good outcome scores and high satisfaction rate after primary total ankle replacement

Background and purpose - Total ankle replacement (TAR) is gaining popularity for treatment of end-stage ankle arthritis. Large patient-centered outcome studies are, however, few. Here, we report data from the Swedish Ankle Registry. Patients and methods - We examined outcomes after primary TAR in patients from the Swedish Ankle Registry using PROMs (Patient Reported Outcome Measures; generic: EQ-5D and SF-36, region specific: SEFAS (Self-Reported Foot and Ankle Score), and a question on satisfaction). We included 241 patients registered with primary TAR between 2008 and 2016 and who completed PROMs preoperatively and postoperatively up to 24 months. We evaluated changes in PROMs following surgery and estimated effects of age, diagnosis, prosthetic design, and preoperative functional score on the outcomes. Results - All absolute scores improved from preoperative to 24 months after surgery (p ≤ 0.001). 71% of the patients were satisfied or very satisfied at the latest follow-up and 12% dissatisfied or very dissatisfied. Postoperative SEFAS correlated with age (r = 0.2, p = 0.01) and preoperative SEFAS (r = 0.3, p < 0.001), as did patient satisfaction (r = -0.2; p ≤ 0.03). Postoperative SEFAS and EQ-5D were similar between different diagnoses or prosthetic designs. Preoperative SF-36 was associated with diagnosis (p ≤ 0.03), postoperative SF-36 with age (r = 0.2, p = 0.01) and diagnosis (p < 0.03). Interpretation - We found statistically and clinically significant improvements in patient-reported outcomes following TAR surgery. The postoperative region-specific SEFAS was positively associated with older age. Prosthetic design seemed not to influence patient-reported outcome, whereas diagnosis partly did. Studies with longer follow-up are necessary to establish the long-term outcome of TAR and to elucidate whether short- and mid-term outcomes may predict implant failure.

Fall-related mortality in southern Sweden: a multiple cause of death analysis, 1998-2014

OBJECTIVES

To investigate temporal trend in fall mortality among adults (aged ≥20 years) in southern Sweden using multiple cause of death data.

METHODS

We examined all death certificates (DCs, n=2 01 488) in adults recorded in the Skåne region during 1998-2014. We identified all fall deaths using International Statistical Classification of Diseases (ICD)-10 codes (W00-W19) and calculated the mortality rates by age and sex. Temporal trends were evaluated using joinpoint regression and associated causes were identified by age-adjusted and sex-adjusted observed/expected ratios.

RESULTS

Falls were mentioned on 1.0% and selected as underlying cause in 0.7% of all DCs, with the highest frequency among those aged ≥70 years. The majority (75.6%) of fall deaths were coded as unspecified fall (ICD-10 code: W19) followed by falling on or from stairs/steps (7.7%, ICD-10 code: W10) and other falls on the same level (6.3%, ICD-10 code: W18). The mean age at fall deaths increased from 77.5 years in 1998-2002 to 82.9 years in 2010-2014 while for other deaths it increased from 78.5 to 79.8 years over the same period. The overall mean age-standardised rate of fall mortality was 8.3 and 4.0 per 1 00 000 person-years in men and women, respectively, and increased by 1.7% per year in men and 0.8% per year in women during 1998-2014. Head injury and diseases of the circulatory system were recorded as contributing cause on 48.7% of fall deaths.

CONCLUSIONS

There is an increasing trend of deaths due to falls in southern Sweden. Further investigations are required to explain this observation particularly among elderly men.

Low Serum DHEAS Predicts Increased Fracture Risk in Older Men: The MrOS Sweden Study

The adrenal-derived hormones dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) are the most abundant circulating hormones and their levels decline substantially with age. DHEAS is considered an inactive precursor, which is converted into androgens and estrogens via local metabolism in peripheral target tissues. The predictive value of serum DHEAS for fracture risk is unknown. The aim of this study was, therefore, to assess the associations between baseline DHEAS levels and incident fractures in a large cohort of older men. Serum DHEAS levels were analyzed with mass spectrometry in the population-based Osteoporotic Fractures in Men study in Sweden (n = 2568, aged 69 to 81 years). Incident X-ray validated fractures (all, n = 594; non-vertebral major osteoporotic, n = 255; hip, n = 175; clinical vertebral, n = 206) were ascertained during a median follow-up of 10.6 years. DHEAS levels were inversely associated with the risk of any fracture (hazard ratio [HR] per SD decrease = 1.14, 95% confidence interval [CI] 1.05-1.24), non-vertebral major osteoporotic fractures (HR = 1.31, 95% CI 1.16-1.48), and hip fractures (HR = 1.18, 95% CI 1.02-1.37) but not clinical vertebral fractures (HR = 1.09, 95% CI 0.95-1.26) in Cox regression models adjusted for age, body mass index (BMI) and prevalent fractures. Further adjustment for traditional risk factors for fracture, bone mineral density (BMD), and/or physical performance variables as well as serum sex steroid levels only slightly attenuated the associations between serum DHEAS and fracture risk. Similarly, the point estimates were only marginally reduced after adjustment for FRAX estimates with BMD. The inverse association between serum DHEAS and all fractures or major osteoporotic fractures was nonlinear, with a substantial increase in fracture risk (all fractures 22%, major osteoporotic fractures 33%) for those participants with serum DHEAS levels below the median (0.60 μg/mL). In conclusion, low serum DHEAS levels are a risk marker of mainly non-vertebral fractures in older men, of whom those with DHEAS levels below 0.60 μg/mL are at highest risk. © The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Time trends in pediatric fracture incidence in Sweden during the period 1950-2006

Background and purpose - Pediatric fracture incidence may not be stable. We describe recent pediatric fracture epidemiology and etiology and compare this to earlier data. Patients and methods - The city of Malmö (population 271,271 in 2005) in Sweden is served by 1 hospital. Using the hospital diagnosis registry, medical charts, and the radiographic archive, we identified fractures in individuals <16 years that had occurred during 2005 and 2006. We also retrieved previously collected fracture data from between 1950 and 1994, from the hospital's pediatric fracture database. We used official population data to estimate period-specific fracture incidence (the number of fractures per 10⁵ person-years) and also age- and sex-adjusted incidence. Differences are reported as rate ratios (RRs) with 95% confidence intervals. Results - The pediatric fracture incidence during the period 2005-2006 was 1,832 per 10⁵ person-years (2,359 in boys and 1,276 in girls), with an age-adjusted boy-to-girl ratio of 1.8 (1.6-2.1). Compared to the period 1993-1994, age-adjusted rates were unchanged (RR =0.9, 95% CI: 0.8-1.03) in 2005-2006, with lower rates in girls (RR =0.8, 95% CI: 0.7-0.99) but not in boys (RR =1.0, 95% CI: 0.9-1.1). We also found that the previously reported decrease in unadjusted incidence in Malmö from 1976-1979 to 1993-1994 was based on changes in demography, as the age-adjusted incidences were similar in the 2 periods (RR =1.0, 95% CI: 0.9-1.1). Interpretation - In Malmö, pediatric fracture incidence decreased from 1993-1994 to 2005-2006 in girls but not in boys. Changes in demography, and also other factors, influence the recent time trends.

Low Testosterone, but Not Estradiol, Is Associated With Incident Falls in Older Men: The International MrOS Study

Fracture risk is determined by bone strength and the risk of falls. The relationship between serum sex steroids and bone strength parameters in men is well known, whereas the predictive value of sex steroids for falls is less studied. The aim of this study was to assess the associations between serum testosterone (T) and estradiol (E2) and the likelihood of falls. Older men (aged ≥65 years) from the United States (n = 1919), Sweden (n = 2495), and Hong Kong (n = 1469) participating in the Osteoporotic Fractures in Men Study had baseline T and E2 analyzed by mass spectrometry. Bioavailable (Bio) levels were calculated using mass action equations. Incident falls were ascertained every 4 months during a mean follow-up of 5.7 years. Associations between sex steroids and falls were estimated by generalized estimating equations. Fall rate was highest in the US and lowest in Hong Kong (US 0.50, Sweden 0.31, Hong Kong 0.12 fall reports/person/year). In the combined cohort of 5883 men, total T (odds ratio [OR] per SD increase = 0.88, 95% confidence interval [CI] 0.86-0.91) and BioT (OR = 0.86, 95% CI 0.83-0.88) were associated with incident falls in models adjusted for age and prevalent falls. These associations were only slightly attenuated after simultaneous adjustment for physical performance variables (total T: OR = 0.94, 95% CI 0.91-0.96; BioT: OR = 0.91, 95% CI 0.89-0.94). E2, BioE2, and sex hormone-binding globulin (SHBG) were not significantly associated with falls. Analyses in the individual cohorts showed that both total T and BioT were associated with falls in MrOS US and Sweden. No association was found in MrOS Hong Kong, and this may be attributable to environmental factors rather than ethnic differences because total T and BioT predicted falls in MrOS US Asians. In conclusion, low total T and BioT levels, but not E2 or SHBG, are associated with increased falls in older men. © 2017 American Society for Bone and Mineral Research.

How does a physical activity programme in elementary school affect fracture risk? A prospective controlled intervention study in Malmo, Sweden

OBJECTIVES

Recent evidence from the 7-year follow-up of the Pediatric Osteoporosis Prevention (POP) study indicates an inverse correlation between years of participation in a physical activity (PA) intervention and fracture risk in children. However, we could not see a statistically significant reduction in fracture risk, which urged for an extension of the intervention.

SETTING

The study was conducted in 4 neighbouring elementary schools, where 1 school functioned as intervention school.

PARTICIPANTS

We included all children who began first grade in these 4 schools between 1998 and 2012. This resulted in 1339 children in the intervention group and 2195 children in the control group, all aged 6-8 years at the state of the study.

INTERVENTION

We launched an 8-year intervention programme with 40 min of moderate PA per school day, while the controls continued with the Swedish national standard of 60 min of PA per week.

PRIMARY OUTCOME MEASURE

We used the regional radiographic archive to register objectively verified fractures and we estimated annual fracture incidences and incidence rate ratios (IRRs).

RESULTS

During the first year after initiation of the intervention, the fracture IRR was 1.65 (1.05 to 2.08) (mean 95% CI). For each year of the study, the fracture incidence rate in the control group compared with the intervention group increased by 15.7% (5.6% to 26.8%) (mean 95% CI). After 8 years, the IRR of fractures was 52% lower in the intervention group than in the control group (IRR 0.48 (0.25 to 0.91) (mean 95% CI))].

CONCLUSIONS

Introduction of the school-based intervention programme is associated with a higher fracture risk in the intervention group during the first year followed by a gradual reduction, so that during the eighth year, the fracture risk was lower in the intervention group.

TRIAL REGISTRATION NUMBER

NCT00633828.

Risk factors for low back pain and sciatica in elderly men-the MrOS Sweden study

Introduction

The aim of this study was to identify whether factors beyond anatomical abnormalities are associated with low back pain (LBP) and LBP with sciatica (SCI) in older men.

Material and Methods

Mister Osteoporosis Sweden includes 3,014 men aged 69–81 years. They answered questionnaires on lifestyle and whether they had experienced LBP and SCI during the preceding 12 months. About 3,007 men answered the back pain (BP) questions, 258 reported BP without specified region. We identified 1,388 with no BP, 1,361 with any LBP (regardless of SCI), 1,074 of those with LBP also indicated if they had experienced LBP (n = 615), LBP+SCI (n = 459).

Results

About 49% of those with LBP and 54% of those with LBP+SCI rated their health as poor/very poor (P < 0.001). Men with any LBP to a greater extent than those without BP had poor self-estimated health, depressive symptoms, dizziness, fall tendency, serious comorbidity (diabetes, stroke, coronary heart disease, pulmonary disease and/or cancer) (all P < 0.001), foreign background, were smokers (all P < 0.01), had low physical activity and used walking aids (all P < 0.05). Men with LBP+SCI to a greater extent than those with LBP had lower education, lower self-estimated health, comorbidity, dizziness and used walking aids (all P < 0.001).

Conclusions

In older men with LBP and SCI, anatomical abnormalities such as vertebral fractures, metastases, central or lateral spinal stenosis or degenerative conditions may only in part explain prevalent symptoms and disability. Social and lifestyle factors must also be evaluated since they are associated not only with unspecific LBP but also with LBP with SCI.

Recent hip fracture trends in Sweden and Denmark with age-period-cohort effects

This study used nationwide hip fracture data from Denmark and Sweden during 1987-2010 to examine effects of (birth) cohort and period. We found that time trends, cohort, and period effects were different in the two countries. Results also indicated that hip fracture rates may increase in the not so far future.

INTRODUCTION

The reasons for the downturn in hip fracture rates remain largely unclear but circumstances earlier in life seem important.

METHODS

We ascertained hip fractures in the populations ≥50 years in Denmark and Sweden in national discharge registers. Country- and sex-specific age-period-cohort (APC) effects during 1987-2010 were evaluated by log-likelihood estimates in Poisson regression models presented as incidence rate ratios (IRR).

RESULTS

There were 399,596 hip fractures in SE and 248,773 in DK. Age-standardized hip fracture rate was stable in SE men but decreased in SE women and in DK. Combined period + cohort effects were generally stronger in SE than DK and in women than men. IRR per period ranged from 1.05 to 1.30 in SE and 0.95 to 1.21 in DK. IRR per birth cohort ranged from 1.07 to 3.13 in SE and 0.77 to 1.67 in DK. Relative period effects decreased with successive period in SE and described a convex curve in DK. Relative cohort effects increased with successive birth cohort in both countries but with lower risks for DK women and men and SE women born around the 1930s (age 75-86 years today and responsible for most hip fractures) partly explaining the recent downturn. Men and women born thereafter however seem to have a higher hip fracture risk, and we expect a reversal of the present decline in rates, with increasing hip fracture rates in both Denmark and Sweden during the upcoming decade.

CONCLUSIONS

Time trends, cohort, and period effects were different in SE and DK. This may reflect differences in general health as evident in known differences in life expectancy, healthcare organization, and prevention such as use of anti-osteoporosis drugs. Analyses indicate that hip fracture rates may increase in the not so far future.

Effects of an 8-year childhood physical activity intervention on musculoskeletal gains and fracture risk

BACKGROUND

Physical activity (PA) in childhood is associated with musculoskeletal benefits while the effect on fracture risk is yet to be determined. The aim of this study was to evaluate whether extension of a PA intervention leads to improvement in musculoskeletal traits with an accompanied reduced fracture risk. We hypothesized that the PA program would have beneficial effects in both sexes, but more so in girls since they tend to be less physically active than boys during this time frame.

METHODS

In one elementary school we increased physical education (PE) from 60 to 200min per school week and followed 65 girls and 93 boys from a mean age of 7years until a mean age of 15years. Thirty-nine girls and 37 boys in three other schools continued with 60min of PE per week during the same years and served as controls. We measured bone mineral content (BMC), areal bone mineral density (aBMD), and bone area annually with dual energy X-ray absorptiometry, and leg muscle strength with a computerized dynamometer. In 3534 children within the same PE program (1339 in the intervention and 2195 in the control group) we registered incident fractures during the 8-year study period and estimated annual sex-specific fracture incidence rate ratios (IRRs).

RESULTS

Girls in the intervention group annually gained more total body less head aBMD, spine aBMD (p<0.01), femoral neck BMC (p<0.05), lumbar vertebrae size (p<0.05), and knee flexion strength (p<0.05) than girls in the control cohort. In boys we found no group differences. There was an inverse correlation between number of years with extra PE and the annual IRR of sustaining fractures in both girls (r=-0.90 (95% CI -0.98 to -0.51); p<0.001) and boys (r=-0.74 (95% CI -0.94 to -0.02); p<0.05).

CONCLUSION

In this 8-year pediatric school-based moderate exercise intervention program there is an inverse correlation in both sexes between annual IRR and each additional year of extra PA. A sub-cohort of girls in the intervention group had greater gains in bone mass, bone size, and muscle strength, which could possibly explain the inverse correlation between years within the PA program and fracture risk, while in boys the reason for the inverse correlation remains unknown. It should be noted that differences in unreported factors such as skeletal maturity status, diet, and spare time PA could confound our inferences. That is, true causality cannot be stated.

Influence of a School-based Physical Activity Intervention on Cortical Bone Mass Distribution: A 7-year Intervention Study

Cortical bone mass and density varies across a bones length and cross section, and may be influenced by physical activity. This study evaluated the long-term effects of a pediatric school-based physical activity intervention on tibial cortical bone mass distribution. A total of 170 children (72 girls and 98 boys) from one school were provided with 200 min of physical education per week. Three other schools (44 girls and 47 boys) continued with the standard 60 min per week. Tibial total and cortical area, cortical density, polar stress-strain index (SSI), and the mass and density distribution around the center of mass (polar distribution, mg) and through the bones cortex (radial distribution subdivided into endo-, mid-, and pericortical volumetric BMD: mg/cm³) at three sites (14, 38, and 66 %) were assessed using peripheral quantitative computed tomography after 7 years. Girls in the intervention group had 2.5 % greater cortical thickness and 6.9 % greater SSI at the 66 % tibia, which was accompanied by significantly greater pericortical volumetric BMD compared to controls (all P < 0.05). Region-specific differences in cortical mass were also detected in the anterior, medial, and lateral sectors at the 38 and 66 % tibial sites. There were no group differences at the 14 % tibia site in girls, and no group differences in any of the bone parameters in boys. Additional school-based physical education over seven years was associated with greater tibial structure, strength, and region-specific adaptations in cortical bone mass and density distribution in girls, but not in boys.

A seven-year physical activity intervention for children increased gains in bone mass and muscle strength

AIM

This study evaluated the musculoskeletal effects of increased physical activity on children, starting at six to nine years of age.

METHODS

In one school we increased the physical education of 72 girls and 100 boys to 200 minutes per week over seven years. In three other schools, 45 girls and 47 boys continued to receive 60 minutes per week. We measured areal bone mineral density (aBMD) with dual energy X-ray absorptiometry and muscle strength with computerised dynamometer at baseline and after seven years and tibial cortical thickness with peripheral quantitative computed tomography after seven years.

RESULTS

Girls in the intervention group gained 0.04 g/cm(2) (0.01-0.08) more total spine aBMD (p < 0.05) and 6.2Nm (1.6, 10.7) more knee flexion strength (p < 0.01) than control group girls and had a 0.1 mm (0.0, 0.3) higher tibial cortical thickness at follow-up (p < 0.05). Boys in the intervention group gained 7.3Nm (0.4, 14.2) more knee extension strength (p < 0.05) and 7.4Nm (2.3, 12.4) more knee flexion strength (p < 0.01) than the control group boys, but their aBMD was no higher than the control group.

CONCLUSION

A seven-year, population-based moderately intense exercise intervention enhanced gains in spine bone mass in girls and knee muscle strength in both genders.