Time trends in severe head injuries among elderly Finns.
Explore the source record for details and available documents.
Accidental Falls↗
Biomedical subjects
P Kannus
Publications and source records attributed to P Kannus.
Epidemiology of adulthood injuries: a quickly changing injury profile in Finland.
Although developed societies have undergone many profound changes during recent decades, including urbanization, increased traffic and aging of the populations, epidemiologic information on secular trends in profiles of injuries is limited. We investigated such trends in Finland by selecting from the National Hospital Discharge Register all Finns aged 15 years or more who required hospital treatment because of an unintentional injury during 1971-1995. The injury incidences were expressed as the number of patients per 100,000 individuals per year. In Finnish men, road traffic accidents and falls, the two leading causes of injury, produced equal numbers of injuries in 1971 (4935 and 4957), but thereafter the role of the traffic accidents gradually decreased (3512 injuries with unadjusted and age-adjusted incidences of 177 and 183 in 1995) and that of falls clearly increased (13,218 injuries with unadjusted and age-adjusted incidences of 664 and 635 in 1995). Changes in the other injury categories of men were less drastic. In Finnish women, falling was the most common cause of injury in 1971 (5051 injuries), after which its role increased sharply, to 17,250 injuries in 1995 (unadjusted and age-adjusted incidences of 804 and 698, respectively). In 1971, road traffic produced 2369 injuries in women, after which this number somewhat decreased (2160 injuries with unadjusted and age-adjusted incidences of 101 and 101 in 1995). The role of all the other injury categories was small in Finnish women during 1971-1995. We conclude that a quick change in the overall profile of injuries occurred in Finland in 1971-1995, a change in which falls replaced road traffic accidents as the major cause of a serious injury. This epidemiologic change will give a new challenge for injury prevention in the new millennium.
Accidental Falls↗
A bioabsorbable plug in bone-tendon-bone reconstruction of the anterior cruciate ligament: Introduction of a novel fixation technique.
PURPOSE: Our aim was to compare the fixation strength of a novel plugging technique with that of the conventional interference technique in bone-patellar tendon-bone reconstruction of the anterior cruciate ligament. TYPE OF STUDY: Randomized experimental study. METHODS: Twenty matched pairs of porcine knees were randomly assigned to 2 groups. The bone block of the graft was secured in the femoral drill hole with either the new bioabsorbable poly-L-lactide/D-lactide (PLA 96/4) copolymer plug (plugging technique) (n = 20) or a conventional interference screw (interference technique) (n = 20). Ten pairs were subjected to a single cycle loading test at a rate of 50 mm/min while the remaining 10 pairs underwent a cyclic loading test to further assess the quality of the fixation. The cyclic loading test consisted of 1,500 loading cycles between 50 and 200 N at half-hertz frequency, after which the specimens were loaded to failure at a rate of 50 mm/min. RESULTS: In the single cycle loading test, the average ultimate failure load was 1,061 +/- 342 N in the plugging technique group and 971 +/- 260 N in the interference technique group (P =.57). Significant group differences were found neither in the yield loads nor in the stiffness of the fixations. In the cyclic loading, significant displacement difference was not observed between the 2 fixation techniques. There were neither significant group differences with regard to the ultimate failure load (plugging technique 994 +/- 376 N versus interference technique 1,001 +/- 343 N, P =.97) nor yield load of the fixations in the subsequent single cycle loading. CONCLUSIONS: The results of this study indicate that, in anterior cruciate ligament reconstruction, the new plugging technique is a reasonable alternative for fixation of the femoral site of a bone-patellar tendon-bone graft.
Absorbable Implants↗
Achilles tendon injuries.
The Achilles tendon is the strongest tendon in the human body. Because most Achilles tendon injuries take place in sports and there has been an common upsurge in sporting activities, the number and incidence of the Achilles tendon overuse injuries and complete ruptures have increased in the industrialized countries during the last decades. The most common clinical diagnosis of Achilles overuse injuries is tendinopathy, which is characterized by a combination of pain and swelling in the Achilles tendon accompanied by impaired ability to perform strenuous activities. Most patients with Achilles tendon injury respond favorably to conservative treatment and only those who fail to respond to carefully followed nonoperative treatment should undergo surgery for repair. A complete rupture of the Achilles tendon usually occurs in sports that require jumping, running, and quick turns. Although histopathologic studies have shown that ruptured Achilles tendons include clear degenerative changes before the rupture, many of the Achilles tendon ruptures occur suddenly without any preceding signs or symptoms. Neither conservative nor operative treatment is a treatment of choice for the ruptured Achilles tendon. It is generally accepted that surgery should be performed on ruptured Achilles tendons in young, physically active patients and in those patients for whom the diagnosis or the treatment of the rupture has been delayed, whereas the results of conservative treatment are an acceptable outcome in older patients with sedentary lifestyles. Many important issues still remain unanswered concerning the cause, pathogenesis, diagnosis, and management of the Achilles tendon disorders. Only when these issues have been solved by well-controlled studies can tailored treatment protocols be created.
Achilles Tendon↗
Good maintenance of exercise-induced bone gain with decreased training of female tennis and squash players: a prospective 5-year follow-up study of young and old starters and controls.
This prospective 5-year follow-up study of 64 adult female racquet sports players and 27 controls assessed the changes in the playing-to-nonplaying arm bone mineral content (BMC) differences to answer three questions: (1) Are training-induced bone gains lost with decreased training? (2) Is the bone response to decreased training different if the playing career has been started before or at puberty rather than after it? (3) Are the possible bone changes related to the changes in training? The players were divided into two groups according to the starting age of their tennis or squash playing. The mean starting age was 10.5 years (SD, 2.2) among the players who had started training before or at menarche (young starters; n = 36) while 26.4 years (SD, 8.0) among those players who had begun training a minimum of 1 year after menarche (old starters; n = 28). At baseline of the 5-year follow-up, the mean age of the young starters was 21.6 years (SD, 7.6) and that of old starters was 39.4 years (SD, 10.5). During the follow-up, the young starters had reduced the average training frequency from 4.7 times a week (2.7) to 1.4 times a week (1.3) and the old starters from 4.0 times a week (1.4) to 2.0 times a week (1.4), respectively. The 5-year follow-up revealed that despite reduced training the exercise-induced bone gain was well maintained in both groups of players regardless of their clearly different starting age of activity and different amount of exercise-induced bone gain. The gain was still 1.3-2.2 times greater in favor of the young starters (at the follow-up, the dominant-to-nondominant arm BMC difference was 22% [8.4] in the humeral shaft of the young starters versus 10% [3.8] in the old starters, and 3.5% [2.4] in controls). In the players, changes in training were only weakly related to changes in the side-to-side BMC difference (r(s) = 0.05-0.34, all NS), and this was true even among the players who had stopped training completely a minimum 1 year before the follow-up. In conclusion, if controlled interventions will confirm our findings that an exercise-induced bone gain can be well maintained with decreased activity and that the maintenance of the bone gain is independent of the starting age of activity, exercise can be recommended for preventing osteoporosis and related fractures.
Adult↗
Exercise in the prevention of falls in older people: a systematic literature review examining the rationale and the evidence.
Falls are a major source of death and injury in elderly people. For example, they cause 90% of hip fractures and the current cost of hip fractures in the US is estimated to be about 10 billion dollars. Age-related changes in the physiological systems (somatosensory, vestibular and visual) which contribute to the maintenance of balance are well documented in older adults. These changes coupled with age-related changes in muscle and bone are likely to contribute to an increased risk of falls in this population. The integrated rehabilitation-based model of fall risk factors reveals multiple sites for interventions that may reverse fall risk factors. Regular exercise may be one way of preventing falls and fall-related fractures. The evidence for this contention comes from a variety of sources. On the basis of 9 randomised controlled studies conducted since 1996, exercise appears to be a useful tool in fall prevention in older adults, significantly reducing the incidence of falls compared with control groups. However, current limitations such as inconsistencies in the measurement of key dependent and independent variables do not, at present, permit a meta-analysis of intervention trials. Further investigation, using trials designed with the current limitations in mind, is necessary to establish the optimum exercise programme to maximise fall prevention in older adults.
Accidental Falls↗
Prevention of hip fracture in elderly people with use of a hip protector.
BACKGROUND: Hip fractures are common in frail elderly adults worldwide. We investigated the effect of an anatomically designed external hip protector on the risk of these age-related fractures. METHODS: We randomly assigned 1801 ambulatory but frail elderly adults (1409 women and 392 men; mean age, 82 years), in a 1:2 ratio, either to a group that wore a hip protector or to a control group. Fractures of the hip and all other fractures were recorded until the end of the first full month after 62 hip fractures had occurred in the control group. The risk of fracture in the two groups was compared, and in the hip-protector group the risk of fracture was also analyzed according to whether the protector had been in use at the time of a fall. RESULTS: During follow-up, 13 subjects in the hip-protector group had a hip fracture, as compared with 67 subjects in the control group. The respective rates of hip fracture were 21.3 and 46.0 per 1000 person-years (relative hazard in the hip-protector group, 0.4; 95 percent confidence interval, 0.2 to 0.8; P=0.008). The risk of pelvic fracture was slightly but not significantly lower in the hip-protector group than in the control group (2 subjects and 12 subjects, respectively, had pelvic fracture) (relative hazard, 0.4; 95 percent confidence interval, 0.1 to 1.8; P > or = 0.05). The risk of other fractures was similar in the two groups. In the hip-protector group, four subjects had a hip fracture (among 1034 falls) while wearing the protector, and nine subjects had a hip fracture (among 370 falls) while not wearing the protector (relative hazard, 0.2; 95 percent confidence interval, 0.05 to 0.5; P=0.002). CONCLUSIONS: The risk of hip fracture can be reduced in frail elderly adults by the use of an anatomically designed external hip protector.
Aged↗
A controlled trial of the health benefits of regular walking on a golf course.
PURPOSE: To study the effects of regular walking during a golf game on various health and fitness indicators in middle-aged men. METHODS: Study subjects were 55 healthy male golfers aged 48 to 64 years who had been sedentary during the 7 months before the study, and 55 age-matched, similarly sedentary controls. During the 20-week study, those in the intervention group were encouraged to play golf two to three times a week; the controls were not. Measurements of body composition, cardiorespiratory performance, motor and musculoskeletal fitness, blood pressure, and serum lipid, glucose, and insulin levels were obtained at baseline and after the 20-week study. RESULTS: Walking during a golf game was a practical and safe form of physical activity with high adherence. It significantly increased aerobic performance and trunk muscle endurance, with a net difference (pretraining to posttraining change between the golfers and controls) of 36 seconds (95% confidence interval [CI]: 19 to 53 seconds, P < 0.001) for treadmill walking time and 13 seconds (95% CI: 2 to 24 seconds, P = 0.02) for static back extension. In addition, regular walking favorably affected body composition, including reductions in weight of 1.4 kg (95% CI: 0.6 to 2.1 kg, P < 0.001), in waist circumference of 2.2 cm (95% CI: 1.0 to 3.3 cm, P < 0.001), and in abdominal skin fold thickness of 2.2 cm (95% CI: 0.9 to 3.4 cm, P = 0.001). Golfers also had significantly greater increases in serum high-density lipoprotein (HDL) cholesterol levels and in the ratio of HDL cholesterol to total cholesterol. CONCLUSIONS: Regular walking had many positive effects on the health and fitness of sedentary middle-aged men. Walking during a golf game is characterized by high adherence and low risk of injury and is therefore a good form of health-enhancing physical activity.
Aged↗
Continuously increasing number and incidence of fall-induced, fracture-associated, spinal cord injuries in elderly persons.
BACKGROUND: Although osteoporosis, falls, and fractures among older adults are said to be a continuously increasing public health problem, reliable epidemiological information on their secular trends is very limited. OBJECTIVE: To determine the current trend in the number and incidence of fall-induced, fracture-associated, spinal cord injuries in a typical white population (Finland, a country with about 5 million inhabitants). METHODS: All Finns aged 50 years or older who were admitted to hospitals from January 1, 1970, through December 31, 1995, for primary treatment of an acute fall-induced, fracture-associated, spinal cord injury were selected from the National Hospital Discharge Register. Similar patients aged 20 through 39 years served as a reference group. In each year of the study, the number and the age-specific and age-adjusted incidences of injuries were expressed as the number of patients per 100,000 persons. RESULTS: The total number of fall-induced, fracture-associated, spinal cord injuries of Finnish older adults increased considerably during the study period, from 60 in 1970 to 419 in 1995 (an average increase of 24% annually). The corresponding injury incidence was 5 in 1970 and 27 in 1995. The age-adjusted incidence of these injuries also increased from 1970 to 1995: in women, from 5 to 29, and in men, from 7 to 17 (relative increases were 480% and 143%, respectively). In the reference group, no trend changes by time were observed. CONCLUSIONS: In Finnish persons aged 50 years or older, the number of fall-induced, fracture-associated, spinal cord injuries shows a rise with a rate that cannot be explained merely by demographic changes. The finding shows an increasing influence of osteoporosis and falls on health and well-being of our older adults, and therefore, vigorous preventive measures are needed to control this development.
Accidental Falls↗
Physical activity and osteoporotic hip fracture risk in men.
BACKGROUND: Physical activity has been related to reduced risk of osteoporotic hip fractures, but the evidence among men is weak. OBJECTIVE: To determine the association between baseline leisure physical activity and future risk of osteoporotic hip fracture in men. METHODS: At baseline in 1975 our prospective study cohort included 3,262 men who were 44 years or older and did not have chronic disease restricting their ability to exercise. At baseline, physical activity was assessed by a questionnaire. Hip fractures were followed for 21 years, or from the age of 50 years for subjects who were initially younger than 50 years. RESULTS: The hazard ratio of osteoporotic hip fracture, adjusted for other possible predictors (height, body mass index, baseline diseases, smoking, use of alcohol, work-related physical activity, and occupational group), in men participating in vigorous physical activity compared with men not participating was 0.38 (95% confidence interval, 0.16-0.91) (P = .03). CONCLUSION: These results provide further evidence that there is an inverse association between baseline physical activity and future hip fracture risk among men.
Accidental Falls↗
Disc degeneration and bone density in monozygotic twins discordant for insulin-dependent diabetes mellitus.
The effects of insulin-dependent diabetes mellitus on bone density and connective tissue degeneration have theoretical interest and practical relevance. Several experimental studies in animals have demonstrated the harmful effects of insulin deficiency on connective tissues. However, clinical studies in humans have produced somewhat contradictory results, most likely due to difficulties controlling for general degeneration and factors associated with diabetes. In nine pairs of monozygotic twins discordant for insulin-dependent diabetes mellitus, we compared femoral and lumbar bone mineral density (assessed by dual-energy x-ray absorptiometry) and spinal degeneration (assessed by magnetic resonance imaging). The bone densities were, on average, 0.1-0.3% lower (p = 0.87-0.96) in diabetic patients. However, after controlling for smoking, we found that the bone density in the femoral neck was 2.5% (0.025 g/cm2) lower in diabetic individuals than in their twins (p = 0.09). The five magnetic resonance imaging parameters used to evaluate disc degeneration did not differ between diabetic patients and their twins. In conclusion, our results provide no evidence that insulin-dependent diabetes mellitus has any major effect on bone density or disc degeneration.
Absorptiometry, Photon↗
High-impact exercise and bones of growing girls: a 9-month controlled trial.
The maximum amount of bone a person can obtain during the first two decades of life is an important determinant of bone mass in later life, and an increase in peak bone mass has been associated with decreased risk for osteoporotic fractures. It is known that growth of bone and thus development of peak bone mass are strongly controlled by genetic factors, but information on the role of environmental factors, such as exercise and nutrition, (e.g., exercise) on growing bone is limited. We tested a hypothesis that in growing girls the benefit of mechanical loading on bone mineral mass and bone strength is better before rather than after the menarche. Sixty-four girls (25 premenarcheal, 39 postmenarcheal) carried out a supervised 9-month step-aerobic program (two sessions per week), each session complemented with additional jumps. Sixty-two girls (33 premenarcheal, 29 postmenarcheal) served as controls. Bone mineral content (BMC) at the lumbar spine and proximal femur was measured by dual-energy X-ray absorptiometry (DXA). In addition, the cortical density (CoD, mg/cm3) and cortical cross-sectional area (CoA, mm2) and the density-weighted polar section modulus (BSI, mm3) of the tibial midshaft were determined by peripheral quantitative tomography (pQCT). In the premenarcheal girls, BMC increased statistically significantly more in the trainees than controls at the lumbar spine (p = 0.012) (8.6% vs 5.3%) and femoral neck (p = 0.014) (9.3% vs 5.3%). In the tibial midshaft, the intergroup differences (CoD, CoA and BSI) were not significant. The postmenarcheal girls showed no significant post-training intergroup differences in any of the bone parameters (BMC increased in the lumbar spine 6.0% vs 4.9%; femoral neck 3.4% vs 3.2%; and trochanter 2.6% vs 3.5%). Although a large proportion of bone mineral increase in the growing girls of this study was attributable to growth itself, this 9-month exercise intervention showed that a clear and large additional bone gain could be obtained in exercising premenarcheal girls, but not in exercising postmenarcheal girls. In other words, exercise seemed more beneficial for additional bone mineral acquisition before menarche (i.e., during the growth spurt) rather than after it.
Absorptiometry, Photon↗
The injury mechanisms of osteoporotic upper extremity fractures among older adults: a controlled study of 287 consecutive patients and their 108 controls.
The risk factors for falls in older adults are well known but knowledge on the direct injury mechanisms that result in various osteoporotic fractures has been very sparse. The purpose of this study was therefore to clarify the injury mechanisms of osteoporotic upper extremity fractures of older adults and to compare these mechanisms with those of the control fallers, and in this way to obtain reliable insight into the etiology and pathogenesis of upper extremity fractures and thus to enable fracture prevention. One hundred and twelve patients with a fresh fracture of the proximal humerus, 65 patients with an elbow fracture, 110 patients with a wrist fracture and 108 controls (no fracture, or a fracture other than the case fracture) were interviewed and examined between September 1995 and December 1997. The inclusion criteria of the subjects were that the patient was 50 years of age or older at the time of the accident, and that the fracture/injury had occurred as a result of low-energy trauma (typically a fall from standing height or less) within a week before the interview and examination. In 97% of patients with a proximal humerus or elbow fracture, and in all patients (100%) with a wrist fracture, the fracture was a result of a fall. In the control group this figure was 93%. In a polychotomous logistic regression analysis the intergroup differences in the fall directions (adjusted by gender, age and functional capacity) were statistically highly significant (chi 2 = 43.6, d.f. = 15, p < 0.001). Most of the patients with a proximal humerus fracture or elbow fracture reported that they had fallen 'obliquely forward' (43% and 38%) or 'to the side' (29% and 26%), whereas in the wrist fracture group the main fall direction was also 'obliquely forward' (34%) but the other fall directions (i.e., 'forward', 'to the side', 'obliquely backward' and 'backward') were quite equally represented (13-19%). The odds ratio (OR) for an obliquely forward fall resulting in a proximal humerus fracture was 3.5 [95% confidence interval (CI) 1.4-9.2), as compared with the fall directions of the controls and the 'obliquely backward' fall direction. In a logistic regression analysis the patients with a wrist fracture managed to break their fall (e.g., with an outstretched arm) more frequently than the patients in the other groups (OR 3.9; 95% CI 2.0-7.3). The patients with a proximal humerus fracture, in turn, managed to break their fall less frequently than the controls (OR 0.33; 95% CI 0.14-0.80). The same was true of the patients with an elbow fracture, although the difference was not significant (OR 0.49%; 95% CI 0.19-1.3). As objective evidence for a direct fall-induced impact on the fracture site, 68% of patients with a proximal humerus fracture revealed a fresh subcutaneous hematoma on the shoulder/upper arm, while such a hematoma was rare in the controls (2%) (p < 0.001). Correspondingly, 62% of patients with an elbow fracture showed a similar hematoma on the elbow area, while this was seen in none of the controls (p < 0.001). In patients with a wrist fracture a hand/wrist hematoma was seen in 58% of the victims, as compared with 18% of the controls (p < 0.001). The study shows that the most typical osteoporotic upper extremity fractures of older adults have their specific injury mechanisms. A great majority of these fractures occur as a result of a fall and a subsequent direct impact of the fractured site. Effective fracture prevention could be achieved by minimizing the obvious risk factors of falling and reducing the fall-induced impact force with injury site protection.
Accidental Falls↗
Epidemiology of osteoporotic pelvic fractures in elderly people in Finland: sharp increase in 1970-1997 and alarming projections for the new millennium.
The purpose of our epidemiologic study was to determine the current trend in the number and incidence of osteoporotic pelvic fractures in Finland, a country with a Caucasian population of 5 million. Thus, all Finns 60 years of age or older who were admitted to hospitals in 1970-1997 for primary treatment of a first osteoporotic pelvic fracture were selected from The National Hospital Discharge Register. In each year of the study, the number and the age-specific and age-adjusted incidences of fractures were expressed as the number of. patients per 100,000 individuals. The total number of osteoporotic pelvic fractures increased considerably in Finland during the study period, from 128 in 1970 to 913 in 1997, an average increase of 23% a year. The corresponding fracture incidence (per 100,000 persons 60 years of age or older) was 20 in 1970 and 92 in 1997. The mean age of the patients also increased, from 74 years (1970) to 80 years (1997). Despite this, the age-adjusted incidence of osteoporotic pelvic fractures also showed a steady increase from 1970 to 1997: in women, from 31 to 103, and in men, from 13 to 38 (relative increases were 232% and 192%, respectively). If this trend continues, the current number of osteoporotic pelvic fractures in this country (about 900 fractures per year) may treble by the year 2030 (about 2,700 fractures per year). We conclude that the number of osteoporotic pelvic fractures in elderly Finns is increasing at a rate that cannot be explained simply by demographic changes and therefore effective preventive measures should be urgently initiated to control the increasing burden of these age-related fractures.
Age Distribution↗
Does childhood and adolescence provide a unique opportunity for exercise to strengthen the skeleton?
Osteoporosis is a major, and increasing, public health problem. In this review we examine the evidence that childhood physical activity is an important determinant of bone mineral in adult years, and as such, may help to prevent osteoporosis. Animal studies provide incontrovertible evidence that growing bone has a greater capacity to add new bone to the skeleton than does adult bone. Observational studies in children undertaking routine physical activity and cross-sectional athlete studies in young sportspeople both reveal that activity is positively associated with bone mineral density (BMD). Longitudinal studies in pre- and peripubertal gymnasts reveal BMD gains far in excess of those that can be achieved in adulthood. However, such studies permit only limited conclusions as they contain the potential for selection bias and can be confounded by other determinants of bone mineral (e.g. dietary and lifestyle factors). Thus, research comparing inter-individual playing-to-nonplaying arm differences in bone mineral (e.g., in racquet sports) have proven to be extremely useful. These studies suggest that the BMD differences are clearly greater when bone is subjected to mechanical loading prior to the end of puberty and longitudinal growth of the body (in women, before menarche) rather than after it. Tanner stage II and III appears to be the maturational stage when the association between exercise and BMD becomes manifest in most adolescents. Do conclusions drawn from athlete studies apply to the general population? Randomised intervention studies of physical activity and bone mineral accrual in normal children confirm that childhood activity is strongly associated with bone mineral accrual. Furthermore, some retired athlete studies and a detraining study suggest that adolescent bone gain may, at least partly, persist despite reduced adult physical activity. Mechanisms that may underlie the association between childhood physical activity and bone mineral accrual are outlined. Thus, it appears that physical activity during the most active period of maturity (with respect to longitudinal growth of the body) plays a vital role in optimising peak bone mass and that benefits may extend into adulthood.
Adult↗
Exercise-induced bone gain is due to enlargement in bone size without a change in volumetric bone density: a peripheral quantitative computed tomography study of the upper arms of male tennis players.
Bilateral bone characteristics of the humerus (proximal, shaft, and distal sites) and radius (shaft and distal sites) in 12 former Finnish national-level male tennis players (mean age 30 years) and their 12 age-, height-, and weight-matched controls were measured with peripheral quantitative computed tomography (pQCT). The pQCT variables analyzed were bone mineral content (BMC), total cross-sectional area of bone (Tot.Ar), cross-sectional area of the marrow cavity (M.Cav.Ar), cortical bone (Co.Ar) and trabecular bone (Tr.Ar), volumetric density of cortical (Co.Dn) and trabecular (Tr. Dn) bone, cortical wall thickness (Co.Wi.Th), bone strength index (BSI), and principal moments of inertia (I(min) and I(max)). In the players, significant side-to-side differences, in favor of the dominant (playing) arm, were found in BMC (ranging 14%-27%), Tot.Ar (16%-21%), Co.Ar (12%-32%), BSI (23%-37%), I(min) (33%-61%), and I(max) (27%-67%) at all measured bone sites, and in Co.Wi.Th. (5%-25%) at the humeral and radial shafts, and distal humerus. The side-to-side M.Cav.Ar difference was significant at the proximal humerus (19%) and radial shaft (29%). Concerning the players' Co.Dn and Tr.Dn, the only significant side-to-side difference was found in the Co.Dn of the distal humerus, with the playing arm showing a slightly smaller Co.Dn than the nonplaying arm (-2%). In controls, significant dominant-to-nondominant side differences were also found, but with the majority of the differences being rather small, and significantly lower than those of the players. In conclusion, despite the large side-to-side differences in BMC, the volumetric bone density (Co.Dn, Tr.Dn) was almost identical in the dominant and nondominant arms of the players and controls. Thus, the players' high playing-arm BMC was due to increases in the Tot.Ar, M.Cav.Ar, Co.Ar, and CW.Th. In other words, the playing arm's extra bone mineral, and thus increased bone strength, was mainly due to increased bone size and not due to a change in volumetric bone density. These upper arm results may not be generalized to the entire skeleton, but the finding may give new insight into conventional dual-energy X-ray absorptiometry (DXA)-based bone density measurements when interpreting the effects of exercise on bone.
Adult↗
Anterior knee pain 7 years after an anterior cruciate ligament reconstruction with a bone-patellar tendon-bone autograft.
In order to evaluate the occurrence and predicting factors of anterior knee pain in patients after an anterior cruciate ligament reconstruction with a bone-patellar tendon-bone autograft, a functional, clinical and radiographic evaluation was performed on 91 patients on average 7 years after the surgery. Also, the isokinetic muscle torque was measured. At 7 years, anterior knee pain, as classified by the International Knee Documentation Committee (IKDC), was absent in 40 patients, mild in 47 patients, and moderate in 4 patients. None was classified as suffering from severe anterior knee pain. In the logistic regression analysis of predicting factors (forward-stepping), knee extension torque deficit of the operated limb was the only factor that showed significant association with anterior knee pain. The other objective measurements of the knee (flexion torque deficit, range of motion, stability evaluation, and radiographic evaluation of the knee) were not associated with anterior knee pain. Subjectively and not surprisingly, the patients without anterior knee pain were more often satisfied with the overall outcome than the patients with anterior knee pain. Also, the Lysholm and Marshall knee scores and the final outcome in the IKDC rating scale were significantly better in patients without than with anterior knee pain.
Adult↗
Structure of the tendon connective tissue.
Tendons consist of collagen (mostly type I collagen) and elastin embedded in a proteoglycan-water matrix with collagen accounting for 65-80% and elastin approximately 1-2% of the dry mass of the tendon. These elements are produced by tenoblasts and tenocytes, which are the elongated fibroblasts and fibrocytes that lie between the collagen fibers, and are organized in a complex hierarchical scheme to form the tendon proper. Soluble tropocollagen molecules form cross-links to create insoluble collagen molecules which then aggregate progressively into microfibrils and then into electronmicroscopically clearly visible units, the collagen fibrils. A bunch of collagen fibrils forms a collagen fiber, which is the basic unit of a tendon. A fine sheath of connective tissue called endotenon invests each collagen fiber and binds fibers together. A bunch of collagen fibers forms a primary fiber bundle, and a group of primary fiber bundles forms a secondary fiber bundle. A group of secondary fiber bundles, in turn, forms a tertiary bundle, and the tertiary bundles make up the tendon. The entire tendon is surrounded by a fine connective tissue sheath called epitenon. The three-dimensional ultrastructure of tendon fibers and fiber bundles is complex. Within one collagen fiber, the fibrils are oriented not only longitudinally but also transversely and horizontally. The longitudinal fibers do not run only parallel but also cross each other, forming spirals. Some of the individual fibrils and fibril groups form spiral-type plaits. The basic function of the tendon is to transmit the force created by the muscle to the bone, and, in this way, make joint movement possible. The complex macro- and microstructure of tendons and tendon fibers make this possible. During various phases of movements, the tendons are exposed not only to longitudinal but also to transversal and rotational forces. In addition, they must be prepared to withstand direct contusions and pressures. The above-described three-dimensional internal structure of the fibers forms a buffer medium against forces of various directions, thus preventing damage and disconnection of the fibers.
Collagen↗