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Biomedical subjects

Pekka Kannus

Publications and source records attributed to Pekka Kannus.

At least 37 records · Page 2Linked to original sources
PubMed2005

Occurrence of violence and violence-related injuries among 12-18 year-old Finns.

AIMS: The aim of this study was to investigate the occurrence, nature, and severity of violence and violence-related injuries, and the occurrence of alcohol-related violence among Finnish adolescents. METHODS: A 12-page questionnaire was mailed to a nationwide representative sample of 12-, 14-, 16-, and 18-year-olds (n = 10,883). The response rate was 75%. RESULTS: Of the 8,135 respondents, 7.9% (646) reported violence occurrence and 1.7% violence-related injury during the past month. The male-female ratio for violence occurrence was 1.9 (95% CI 1.6-2.2) and for violence-related injury occurrence 0.8 (95% CI 0.6-1.2). Sixteen-year-old girls reported the highest injury rate (23/1,000). Most typically, the violent persons were individuals known by the victim before the incident. Girls were significantly (p < 0.001) more often (43%) in a fight with, or assailed by, a family member than boys (8%). Although boys' violent actions were related to leisure-time activities (64%), violence rarely took place during sports activities. Alcohol-related violence increased with age. Some 13% of 14-year-olds reported being under the influence of alcohol at the time of violence. The corresponding figures for 16- and 18-year-olds were 41% and 62%, respectively. Moreover, alcohol was closely associated with violence-related injuries. CONCLUSIONS: Violence is common among Finnish adolescents. While violence does not always lead to injury, related injuries are an important cause of adolescent morbidity. Alcohol seems to be strongly associated with adolescent violence and related injuries.

Adolescent↗
PubMed2005

Serum TRACP 5b is a useful marker for monitoring alendronate treatment: comparison with other markers of bone turnover.

UNLABELLED: We studied clinical performance of serum TRACP 5b and other bone turnover markers, including S-CTX, U-DPD, S-PINP, S-BALP, and S-OC, for monitoring alendronate treatment. TRACP 5b had higher clinical sensitivity, area under the ROC curve, and signal-to-noise ratio than the other markers. INTRODUCTION: The purpose of this study was to compare the clinical performance of serum TRACP 5b (S-TRACP5b) with that of other markers of bone turnover in the monitoring of alendronate treatment. MATERIALS AND METHODS: This double-blinded study included 148 healthy postmenopausal women that were randomly assigned into two groups: one receiving 5 mg alendronate daily (n=75) and the other receiving placebo (n=73) for 12 months. All individuals in both groups received calcium and vitamin D daily. The bone resorption markers S-TRACP5b, serum C-terminal cross-linked telopeptides of type I collagen (S-CTX), and total urinary deoxypyridinoline (U-DPD), and the serum markers of bone formation procollagen I N-terminal propeptide (S-PINP), bone-specific alkaline phosphatase (S-BALP), and total osteocalcin (S-OC) were assessed at baseline and at 3, 6, and 12 months after initiation of treatment. Lumbar spine BMD (LBMD) was measured at baseline and 12 months. RESULTS: Compared with the placebo group, LBMD increased, and all bone markers decreased significantly more in the alendronate group (p<0.001 for each parameter). The decrease of S-TRACP5b after first 3 months of alendronate treatment correlated significantly with the changes of all other markers except S-OC, the best correlation being with S-CTX (r=0.60, p<0.0001). The changes of LBMD at 12 months only correlated significantly with the changes of S-TRACP5b (r=-0.32, p=0.005) and S-CTX (r=-0.24, p=0.037) at 3 months. Based on clinical sensitivity, receiver operating characteristic (ROC) curves, and signal-to-noise ratio, S-TRACP5b, S-CTX, and S-PINP were the best markers for monitoring alendronate treatment. Clinical sensitivity, area under the ROC curve, and signal-to-noise ratio were higher for S-TRACP5b than for the other markers. CONCLUSION: These results show that S-TRACP5b, S-CTX, and S-PINP are useful markers for monitoring alendronate treatment.

Acid Phosphatase↗
PubMed2005

Fall-induced deaths among elderly people.

Falls and fall-induced injuries in older people are a major public health problem in modern societies with aging populations. Injury is the fifth leading cause of death in older adults, and most of these fatal injuries are related to falls. We have assessed the nationwide trends in fall-induced deaths of older people in Finland for more than 3 decades (1971-2002), and the results showed that the number of fall-induced deaths among elderly Finns is clearly increasing, especially among men.

Accidental Falls↗
PubMed2004

Femoral neck structure in adult female athletes subjected to different loading modalities.

UNLABELLED: Loading modality is a strong external determinant of structure and concomitant strength of the femoral neck. Particularly effective seem to be loadings, which arise from high impacts or impacts from atypical loading directions. INTRODUCTION: Physical loading plays an important role, not only in the process of bone modeling and remodeling, but also in shaping a mechanically appropriate bone structure. This study aimed at testing the hypothesis that the type of loading partly determines the femoral neck structure. MATERIALS AND METHODS: A total of 255 premenopausal female athletes representing volleyball, hurdling, squash-playing, soccer, speed skating, step aerobics, weight-lifting, orienteering, cross-country skiing, cycling, and swimming and their 30 nonathletic counterparts were measured with DXA. Besides the conventional areal BMD (aBMD) of the femoral neck, the hip structure analysis (HSA) was used to estimate the cross-sectional area (CSA), subperiosteal width (W), and section modulus (Z, an index of bone strength) at the narrowest section of the femoral neck. Also, training history, muscle strength, and calcium intake were assessed. The above-mentioned sports were classified according to the type of loading they apparently produce at the hip region; that is, high-impact loading (volleyball, hurdling), odd-impact loading (squash-playing, soccer, speed-skating, step aerobics), high-magnitude loading (weightlifting), low-impact loading (orienteering, cross-country skiing), and nonimpact loading (swimming, cycling). RESULTS: High-impact and odd-impact loading sports were associated with the highest age-, weight-, and height-adjusted aBMD (23% and 29% higher values compared to nonathletic referents), CSA (22% and 27%), and Z (22% and 26%). In contrast, repetitive, nonimpact loading sports were not associated with any clear benefit in any bone value compared with the referents. The W at the narrowest femoral neck section was similar in all groups. Body height and weight accounted virtually for one-half of the variation in Z, whereas the type of loading predicted 13% of the total variation of this variable-clearly more than the 2% attributable to isometric leg extension strength. Both high-impact and odd-impact loading modalities were associated with a large benefit in Z, corresponding to >1 SD in the reference group, whereas repetitive, low-impact loading showed a benefit that was only one-half of that. Surprisingly, high-magnitude loading (weightlifting) was not associated with a statistically significant increase in Z. CONCLUSION: We conclude that mechanical loading and its modality are strong external determinants of structure and concomitant strength of the femoral neck. Particularly effective seem to be loadings, which arise from high impacts or impacts from atypical loading directions.

Adult↗
PubMed2004

Effect of discontinuation of alendronate treatment and exercise on bone mass and physical fitness: 15-month follow-up of a randomized, controlled trial.

The purpose of this study was to evaluate the remaining effects of 12-month intervention of alendronate and exercise on selected risk factors of fragility fractures in 15-month follow-up after withdrawal of intervention among early postmenopausal women. The trial consisted four experimental groups: (1) 5 mg of alendronate daily + exercise (Al+Ex+), (2) 5 mg alendronate daily (Al+Ex-), (3) placebo + exercise (Al-Ex+), and (4) placebo (Al-Ex-). At the follow-up measurements, bone mass and physical fitness of 102 women (mean age 53.5 +/- 2.5 years) out of initial 150 subjects could be evaluated. Alendronate increased bone mass significantly [mean; 95% confidence interval (CI)] during the intervention at the lumbar spine (3.9%; 2.2% to 5.7%) and femoral neck (2.1%; 0.9% to 3.4%). After withdrawal of alendronate, bone loss resumed to the rate comparable to that evident in the placebo group. Despite the declining bone mass, the between-group mean difference (3.2%; 1.0% to 5.4%) remained at the lumbar spine. However, the benefits at the femoral neck had disappeared 15 months after the withdrawal of alendronate. The 12-month exercise training resulted in significant increases in muscle power, dynamic balance, and aerobic capacity with no benefits on bone mass. Fifteen months later, these performance variables had declined among both the exercisers and nonexercisers. Although the between-group differences were no longer statistically significant, muscle power, dynamic balance, and aerobic capacity of those who exercised still remained above the pretraining levels. In conclusion, 12-month treatment with alendronate prevented postmenopausal bone loss, and residual effect was seen 15 months after withdrawal of the drug at the lumbar spine. Similarly, exercise improved muscle power, agility, and aerobic capacity during the intervention, but the improvement was lost after the cessation of the exercise program. Based on these results, it was evident that to maintain the benefits of alendronate or exercise, therapy should be continued.

Alendronate↗
PubMed2004

Collagen fibres of the spontaneously ruptured human tendons display decreased thickness and crimp angle.

PURPOSE: To study collagen fibre thickness and crimp formation in healthy and ruptured human tendons. METHODS: The thickness, crimp angle and wavelength of the collagen fibres were analyzed by interference and polarization microscopy and the samples were studied by transmission and scanning electron microscopy in four different healthy human tendons (Achilles, Quadriceps, Biceps brachii and Extensor pollicis longus) and in 66 spontaneously ruptured tendons. RESULTS: In the normal (healthy) tendons, the diameter and crimp angle of the collagen fibres varied greatly between the four different tendons, the thickest fibres with the largest crimp angle being in the Achilles and Quadriceps tendons, whereas the Biceps brachii and Extensor pollicis longus, tendons that bear lighter strains but carry functions of high specificity, were found to have substantially smaller collagen fibres with lower crimp angle. Ruptured tendons had significantly smaller collagen fibre diameter than the normal tendons, the fibre diameter being -36% in comparison to their healthy counterparts in the Achilles tendons (P < 0.0001), -24% in the Quadriceps tendons (P < 0.0001), -37% in the Biceps brachii (P < 0.0001) and -14% in the Extensor pollicis longus (P = 0.10), respectively. Similarly, the crimp angle of the collagen fibres was also found to be lower in the ruptured tendons than in healthy, normal tendons. Further, the collagen fibres in the ruptured human tendons showed great variation in the crimp angle between the adjacent fibres and in the successive crimps of the same fibre. CONCLUSION: Our results show that spontaneously ruptured tendons display focal regions with decreased collagen fibre thickness, decreased crimp angle and disrupted crimp continuity, microscopic alterations that possibly result in reduced strength of the tendons being less resistant to tensile forces, and thus, place them at increased risk of ruptures.

Achilles Tendon↗
PubMed2004

Occurrence and risk factors of unintentional injuries among 12- to 18-year-old Finns--a survey of 8219 adolescents.

The aim of this study was to evaluate the incidence, nature, and risk factors of unintentional injuries among 12-, 14-, 16- and 18-year-old Finnish adolescents. Of the 8219 respondents (response rate 75%) 5.5% reported an injury that had required medical attention during the past month. The total number of injuries was 506 and the incidence of injuries 62 per 1000 person-months. Boys had a slightly higher injury occurrence rate than girls (OR: 1.33; 95% CI: 1.13-1.59). The most common injuries were sprains (27%), fractures (26%) and wounds (16%) of the upper and lower limbs. In multivariate logistic regression analysis the strongest risk factors of injury were: having experienced violence during past month (OR: 3.6; 95% CI: 2.8-4.6), daily leisure time exercise in sports club (OR: 3.3; 95% CI: 2.3-4.6), having several somatic health complaints weekly (OR: 2.2; 95% CI: 1.7-2.9) and having chronic disease (OR: 2.0; 95% CI: 1.5-2.6). In conclusion, injuries were an important cause of morbidity among our 12-18-year-old adolescents. Adolescents' school success and their parents' education, occupation and employment status were not associated with injuries. The finding that several health and health behaviour variables are important risk factors for injuries challenges the researchers and the society to identify and treat the risk factors that can be modified to reduce the number of adolescent injuries.

Accidents↗
PubMed2004

Anterior knee pain and thigh muscle strength after intramedullary nailing of tibial shaft fractures: a report of 40 consecutive cases.

OBJECTIVES: Chronic anterior knee pain is a common complication following intramedullary nailing of a tibial shaft fracture. The source of pain is often not known nor is the reason for a simultaneous decrease in thigh muscle strength. Anterior knee pain has also been reported following an anterior cruciate ligament rupture. No previous investigation has assessed whether weakness of the thigh muscles is associated with anterior knee pain following intramedullary nailing of tibial shaft fractures. DESIGN: Prospective study. SETTING: University Hospital of Tampere, University of Tampere. PATIENTS: Fifty consecutive patients with a nailed tibial shaft fracture were initially included in the study. Ten patients did not have isokinetic strength testing for various reasons and were eliminated from the study. MAIN OUTCOME MEASUREMENTS: Isokinetic muscle strength measurements were done in 40 patients at an average 3.2 +/- 0.4 (SD) years after nail insertion (1.7 +/- 0.3 years after the nail extraction). RESULTS: Twelve (30%) patients were painless and 28 (70%) patients had anterior knee pain at follow-up. With reference to the hamstrings muscles, the mean peak torque deficit of the injured limb (as compared with the uninjured limb) was 2 +/- 11% in the painless group and 11 +/- 17% in the pain group at a speed of 60 degrees /s (P = 0.09, [95% CI for the group difference = -18% to 0%]). At a speed of 180 degrees /s, the corresponding deficits were -3 +/- 13% and 10 +/- 21% (P = 0.03, [95% CI for the group difference = -4% to -2%]). With reference to the quadriceps muscles, the mean peak torque deficit of the injured limb was 14 +/- 15% in the painless group and 15 +/- 15% in the pain group at speed of 60 degrees /s (P = 0.71, [95% CI for the group difference = -11% to 10%]). At a speed of 180 degrees /s, the corresponding deficits were 9 +/- 11% and 14 +/- 17% (P = 0.46, [95% CI for the group difference = -14% to 5%]). CONCLUSION: Based on this prospective study, we conclude that anterior knee pain after intramedullary nailing of a tibial shaft fracture, although of multifactorial origin, may be related to deficiency in the flexion strength of the thigh muscles.

Adult↗
PubMed2004

Interference screw fixation of soft tissue grafts in anterior cruciate ligament reconstruction: part 1: effect of tunnel compaction by serial dilators versus extraction drilling on the initial fixation strength.

BACKGROUND: Compaction of the bone-tunnel walls by serial dilation is believed to enhance the interference screw fixation strength of the soft tissue grafts in anterior cruciate ligament (ACL) reconstruction. HYPOTHESIS: Serial dilation enhances the fixation strength of soft tissue grafts in ACL reconstruction over extraction drilling. STUDY DESIGN: Randomized experimental study. METHODS: Initial fixation strength of the doubled anterior tibialis tendon grafts (fixed with a bioabsorbable interference screw) was assessed in 21 pairs of human cadaver tibiae with either serially dilated or extraction-drilled bone tunnels. The specimens were subjected to a cyclic-loading test, and those surviving were then tested using the single-cycle load-to-failure test. RESULTS: During the cyclic-loading test, there were 3 fixation failures in the serially dilated and 6 failures in the extraction-drilled specimens but no significant stiffness or displacement differences between the groups. In the subsequent load-to-failure test, the average yield loads were 473 +/- 110 N and 480 +/- 115 N for the 2 groups respectively (P =.97) and no difference with regard to stiffness or mode of failure. CONCLUSIONS: Serial dilation does not increase the strength of interference fixation of soft tissue grafts in ACL reconstruction over extraction drilling. CLINICAL RELEVANCE: The results of this experiment do not support the use of serial dilators in ACL reconstruction.

Adolescent↗
PubMed2004

Interference screw fixation of soft tissue grafts in anterior cruciate ligament reconstruction: part 2: effect of preconditioning on graft tension during and after screw insertion.

BACKGROUND: Preconditioning of tendon grafts is believed to eliminate natural viscoelasticity of the tendons and prevent knee laxity after anterior cruciate ligament (ACL) reconstruction. HYPOTHESIS: Preconditioned ACL grafts maintain their initially set tension. STUDY DESIGN: Randomized experimental study. METHODS: Forty-two human anterior tibialis (AT) tendon grafts were subjected to either no preconditioning (group 1), cyclic preconditioning (group 2), or isometric preconditioning (group 3). The residual graft tension was then recorded immediately after the application of an initial graft tension of 80 N and fixation into tibia with an interference screw, as well as 10 minutes later. In another experiment, the residual graft tension was recorded 1, 10, and 60 minutes after 10 AT and quadrupled hamstring tendon (HT) grafts alone (no fixation) had been subjected to isometric preconditioning (80 N). RESULTS: Immediately after screw insertion, the residual (AT) graft tensions were 79 +/- 19 N, 100 +/- 17 N, and 102 +/- 15 N in groups 1 through 3, respectively. Ten minutes later, the corresponding values were 49 +/- 16 N, 60 +/- 11 N, and 64 +/- 12 N. For the AT and HT grafts alone, the residual graft tensions were 67 +/- 2 N and 67 +/- 2 N, 45 +/- 2 N and 46 +/- 4 N, and 29 +/- 3 N and 34 +/- 5 N at 1, 10, and 60 minutes, respectively. CONCLUSIONS: A steady decrease (-60% within 60 minutes after initial tensioning) occurs in the initially set tension of the soft tissue ACL grafts. CLINICAL RELEVANCE: Clinically applicable preconditioning protocols cannot eliminate the intrinsic viscoelasticity from ACL soft tissue grafts, and thus, the reasonableness of preconditioning per se is questioned in ACL reconstruction.

Adolescent↗
PubMed2003

Mechanical loading regulates the expression of tenascin-C in the myotendinous junction and tendon but does not induce de novo synthesis in the skeletal muscle.

Tenascin-C is a hexabrachion-shaped matricellular protein with a very restricted expression in normal musculoskeletal tissues, but it is expressed abundantly during regenerative processes of these tissues and embryogenesis. To examine the importance of mechanical stress for the regulation of tenascin-C expression in the muscle-tendon unit, the effects of various states of mechanical loading (inactivity by cast-immobilization and three-varying intensities of subsequent re-activity by treadmill running) on the expression of tenascin-C were studied using immunohistochemistry and mRNA in situ hybridization at the different locations of the muscle-tendon unit of the rat gastrocnemius muscle, the Achilles tendon complex. This muscle-tendon unit was selected as the study site, because the contracting activity of the gastrocnemius-soleus muscle complex, and thus the mechanical loading-induced stimulation, is easy to block by cast immobilization. Tenascin-C was expressed abundantly in the normal myotendinous and myofascial junctions, as well as around the cells and the collagen fibers of the Achilles tendon. Tenascin-C expression was not found in the normal skeletal muscle, although it was found in blood vessels within the muscle tissue. Following the removal of the mechanical loading-induced stimulation on the muscle-tendon unit by cast immobilization for 3 weeks, the immonoreactivity of tenascin-C substantially decreased or was completely absent in the regions expressing tenascin-C normally. Restitution of the mechanical loading by removing the cast and allowing free cage activity for 8 weeks resulted in an increase in tenascin-C expression, but it could not restore the expression of tenascin-C to the normal level (in healthy contralateral leg). In response to the application of a more strenuous mechanical loading stimulus after the removal of the cast (after 8 weeks of low- and high-intensity treadmill running), the expression of tenascin-C was markedly increased and reached the level seen in the healthy contralateral limb. Tenascin-C was abundantly expressed in myotendinous and myofascial junctions and in the Achilles tendon, but even the most strenuous mechanical loading (high-intensity treadmill running) could not induce the expression of tenascin-C in the skeletal muscle. This was in spite of the marked immobilization-induced atrophy of the previously immobilized skeletal muscle, which had been subjected to intensive stress during remobilization. mRNA in situ hybridization analysis confirmed the immunohistochemical results for the expression of tenascin-C in the study groups. In summary, this study shows that mechanical loading regulates the expression of tenascin-C in an apparently dose-dependent fashion at sites of the muscle-tendon unit normally expressing tenascin-C but can not induce de novo synthesis of tenascin-C in the skeletal muscle without accompanying injury to the tissue. Our results suggest that tenascin-C provides elasticity in mesenchymal tissues subjected to heavy tensile loading.

Animals↗
PubMed2003

Does hysterectomy with ovarian conservation affect bone metabolism and density?

We evaluated whether hysterectomy with ovarian conservation (HYX) has an effect on bone metabolism and density in 176 healthy Caucasian postmenopausal women aged 48-59 years. Bone properties of the hip, spine, radius, tibia, and calcaneus were measured using different bone assessment modalities. In addition, bone turnover was assessed using serum bone-specific alkaline phosphatase (BAP), osteocalcin (OC), and tartrate-resistant acid phosphatase (TRAP) 5b as biomarkers. Our results showed that women having HYX had a significantly lower level of OC ( P = 0.017) and a marginally lower level of TRAP 5b ( P = 0.051) and higher bone mineral density (BMD) of the femoral neck ( P = 0.037) and lumbar spine ( P= 0.001) than women with no history of HYX. In addition, the cortical BMD and bone strength index (I(polar)) of the tibia also showed higher values at different sections in women having HYX than women with no history of HYX ( P = 0.055 to P< 0.005). These results suggest that the uterus may have a role in regulating bone metabolism that has not been detected previously.

Bone Density↗