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Biomedical subjects

Markku Järvinen

Publications and source records attributed to Markku Järvinen.

At least 19 recordsLinked to original sources
PubMed2007

Fragile external phenotype of modern human proximal femur in comparison with medieval bone.

UNLABELLED: Proximal femur macroanatomy of 118 medieval and 67 contemporary adults, 84 contemporary elderly, and 48 contemporary hip fracture cases was evaluated. Within approximately 1000 years, the femoral neck axis has become longer, and its cross-section has become proportionally smaller and more oval in shape. These changes in the present external phenotype alone account for approximately 50% higher fall-induced stress compared with the medieval situation. INTRODUCTION: Bones, as whole skeletal structures, adapt to mechanical stresses they customarily experience. Because the present, mechanized lifestyle apparently deprives our skeletons of vigorous, habitual physical exertion, we studied whether the proximal femur phenotype has evolved vulnerable to fragility fractures by time. MATERIALS AND METHODS: Proximal femur macroanatomy of 118 medieval and 67 contemporary adults, 84 contemporary elderly, and 48 contemporary hip fracture cases was evaluated. Using direct measurements of external bone dimensions and geometric properties, we estimated the fall-induced stress as an index of hip fragility. RESULTS: Within approximately 1000 years, the femoral axis length has become substantially longer (analysis of covariance, body height adjusted, p < 0.001), whereas the neck circumference has not increased. The macroanatomy was found similar between the contemporary adult and elderly groups. In hip fracture cases, however, the femoral axis length was further lengthened (p < 0.001), but the circumference was somewhat smaller (p = 0.001). Consequently, the estimated fall-induced stress can be approximately 1.5-fold today compared with the medieval times (p < 0.001), and the secular trend seemed to be worse in women (sex-time interaction, p = 0.001). CONCLUSIONS: The modern, relatively slender phenotype of the proximal femur alone seems to increase the fall-induced stress considerably, and when this phenotype coincides the osteoporotic, internally deteriorated femoral neck structure, fracture risk is imminent. This mechanically compromised external phenotype underscores the importance of timely strengthening of the skeleton and its regular maintenance throughout life.

Adaptation, Physiological↗
PubMed2006

A sideways fall and hip fracture.

A sideways fall onto the hip is known to be a clear risk factor for hip fracture of elderly people, but it has remained unclear how severe injury such a fall can be. This retrospective patient file survey of young adults aged 15 to 49 years suggested that a fall onto the hip is indeed a serious high-impact injury possessing energy to fracture the proximal femur even in young healthy men. This being the case, it is evident that sideways falls can be very dangerous and thus a natural target for fracture prevention.

Accidental Falls↗
PubMed2006

Nationwide decline in incidence of hip fracture.

UNLABELLED: This epidemiologic study determined the trend in the number and incidence (per 100,000 persons) of hip fracture among older adults in Finland, an EU country with a well-defined white population of 5.2 million, between 1970 and 2004. The results show that the alarming rise in the fracture incidence from early 1970s until late 1990s has been now followed by declining fracture rates. Reasons for this are largely unknown, but a cohort effect toward a healthier aging population and increased average body weight and improved functional ability among elderly Finns could partly explain the phenomenon. INTRODUCTION: Although osteoporotic fractures of older adults are said to be a major public health concern in modern societies with aging populations, fresh nationwide information on their secular trends is limited. MATERIALS AND METHODS: This epidemiologic study determined the current trend in the number and incidence (per 100,000 persons) of hip fracture among older adults in Finland, an EU country with a well-defined white population of 5.2 million, by taking into account all persons >or= 50 years of age who were admitted to our hospitals for primary treatment of such fracture in 1970-2004. RESULTS: The number of hip fractures among >or= 50-year-old Finns rose very constantly between 1970 (1857 fractures) and 1997 (7122 fractures), but since then, the rise has leveled off (7083 fractures in 2004). After this and because of a continuous rise in population at risk, the crude incidence of hip fracture (showing a clear rise in 1970-1997) decreased between 1997 and 2004, from 438 (per 100,000 persons) in 1997 to 374 in 2004. Concerning the age-adjusted fracture incidence, findings were similar. Until 1997, the age-adjusted incidence of hip fracture clearly increased in both women and men, but thereafter, this incidence declined in both sexes: in women, from 494 in 1997 to 412 in 2004, and in men, from 238 in 1997 to 223 in 2004. CONCLUSIONS: The rise in the incidence of hip fracture in Finland from the early 1970s until the late 1990s has been followed by declining fracture rates. Exact reasons for this are unknown, but a cohort effect toward a healthier aging population and increased average body weight and improved functional ability among elderly Finns cannot be ruled out.

Aged↗
PubMed2005

Secular trends in rates of unintentional injury deaths among adult Finns.

This study assessed the current secular trends in unintentional injury deaths among persons 15 years of age or older in Finland. For this purpose, we obtained from the Finnish Official Cause-of-Death Statistics (OCDS) the data for persons aged 15 years or older whose deaths occurred in 1971--2003 due to an unintentional injury. Among Finnish men, the most drastic change occurred in road traffic crashes. The age-standardised death rate (per 100,000 person-years) of men's road traffic crashes was 47 in 1971 but only 11 in 2003. In contrast, the rate of fall-induced deaths among Finnish men gradually rose, from 18 in 1971 to 24 in 2003, by which time falls became the leading category of men's unintentional injury death. Also alcohol poisonings seemed to bypass road traffic crashes as the cause of men's injury death. Among Finnish women, the age-standardised rate of fall-induced deaths decreased till 1975, after which the curve was rather flat. The death rate (per 100,000 person-years) of women's falls was 30 in 1971 and 18 in 2003. During the entire period of 1971--2003, traffic caused fewer deaths in women than men, but the declining trend in women's death rates was also clear, from 17 in 1971 to 5 in 2003. Other unintentional causes accounted for few deaths in women during 1971--2003, although it was of interest that the rate of women's deaths due to alcohol poisoning rose from 1 in 1971 to 4 in 2003. In conclusion, during 1971--2003 falls replaced road traffic crashes as the leading cause of unintentional injury death in adult Finns. The rise in men's fall-induced deaths occurred even with a rate that cannot be explained merely by demographic changes, and therefore, systematic fall prevention measures are needed to control the development. The rising incidence of women's deaths due to alcohol poisoning needs close follow-up.

Accidental Falls↗
PubMed2005

Muscle injuries: biology and treatment.

Muscle injuries are one of the most common traumas occurring in sports. Despite their clinical importance, few clinical studies exist on the treatment of these traumas. Thus, the current treatment principles of muscle injuries have either been derived from experimental studies or been tested only empirically. Although nonoperative treatment results in good functional outcomes in the majority of athletes with muscle injuries, the consequences of failed treatment can be very dramatic, possibly postponing an athlete's return to sports for weeks or even months. Moreover, the recognition of some basic principles of skeletal muscle regeneration and healing processes can considerably help in both avoiding the imminent dangers and accelerating the return to competition. Accordingly, in this review, the authors have summarized the prevailing understanding on the biology of muscle regeneration. Furthermore, they have reviewed the existing data on the different treatment modalities (such as medication, therapeutic ultrasound, physical therapy) thought to influence the healing of injured skeletal muscle. In the end, they extend these findings to clinical practice in an attempt to propose an evidence-based approach for the diagnosis and optimal treatment of skeletal muscle injuries.

Athletic Injuries↗
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

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

The bone gain induced by exercise in puberty is not preserved through a virtually life-long deconditioning: a randomized controlled experimental study in male rats.

To investigate the controversial issue whether exercise-induced positive effects on bone can be maintained after cessation of exercise, 100 5-week-old male Sprague-Dawley rats were used to assess the effects of long-term exercise (EX, treadmill running) and subsequent deconditioning (DC, free cage activity) on the femoral neck and femoral midshaft. At entry, the rats were randomly assigned into eight groups: four control groups (C14, C28, C42, and C56), and four exercise groups (EX, EX + DC14, EX + DC28, and EX + DC42). Rats in the exercise groups were first subjected to a 14-week period of progressively intensifying running, after which the rats of group EX were killed and the remaining exercise groups (EX + DC14, EX + DC28, and EX + DC42) were allowed to move freely in their cages for a subsequent deconditioning period of 14, 28, or 42 weeks, whereas control rats were kept free in their cages for the entire study period (0-56 weeks) and killed with their respective exercise group. At each time point, a comprehensive analysis of the femoral neck and midshaft characteristics (peripheral quantitative computed tomography analysis and fracture load [Fmax]) was performed. In comparison with their age-matched controls, 14 weeks of treadmill training resulted in significant (p < 0.05) increases in all measured femoral neck parameters of the growing male rats (i.e., +25% in total cross-sectional area [tCSA], +28% in total bone mineral content [tBMC], +11% in total bone mineral density [tBMD], and +30% in Fmax). On the contrary, no exercise-induced positive effects were seen in femoral midshaft. The exercise-induced benefits in the femoral neck were partially maintained during the deconditioning period of 14 weeks, the tCSA being + 17%, tBMC + 18% (both p < 0.05), and the Fmax + 11% (p = 0.066) higher in the exercised group than control group. However, after 42 weeks of deconditioning, these benefits were eventually lost. In conclusion, exercise through the period of the fastest skeletal growth results in significant improvements in size, mineral mass, and strength of the femoral neck of male rats. However, these exercise-induced bone benefits are eventually lost if exercise is completely ceased, and thus, continued training is probably needed to maintain the positive effects of youth exercise into adulthood. Further studies should focus on assessing the minimal level of activity needed to maintain the exercise-induced bone gains.

Animals↗
PubMed2003

Effect of 8-month vertical whole body vibration on bone, muscle performance, and body balance: a randomized controlled study.

Recent animal studies have given evidence that vibration loading may be an efficient and safe way to improve mass and mechanical competence of bone, thus providing great potential for preventing and treating osteoporosis. Randomized controlled trials on the safety and efficacy of the vibration on human skeleton are, however, lacking. This randomized controlled intervention trial was designed to assess the effects of an 8-month whole body vibration intervention on bone, muscular performance, and body balance in young and healthy adults. Fifty-six volunteers (21 men and 35 women; age, 19-38 years) were randomly assigned to the vibration group or control group. The vibration intervention consisted of an 8-month whole body vibration (4 min/day, 3-5 times per week). During the 4-minute vibration program, the platform oscillated in an ascending order from 25 to 45 Hz, corresponding to estimated maximum vertical accelerations from 2 g to 8 g. Mass, structure, and estimated strength of bone at the distal tibia and tibial shaft were assessed by peripheral quantitative computed tomography (pQCT) at baseline and at 8 months. Bone mineral content was measured at the lumbar spine, femoral neck, trochanter, calcaneus, and distal radius using DXA at baseline and after the 8-month intervention. Serum markers of bone turnover were determined at baseline and 3, 6, and 8 months. Five performance tests (vertical jump, isometric extension strength of the lower extremities, grip strength, shuttle run, and postural sway) were performed at baseline and after the 8-month intervention. The 8-month vibration intervention succeeded well and was safe to perform but had no effect on mass, structure, or estimated strength of bone at any skeletal site. Serum markers of bone turnover did not change during the vibration intervention. However, at 8 months, a 7.8% net benefit in the vertical jump height was observed in the vibration group (95% CI, 2.8-13.1%; p = 0.003). On the other performance and balance tests, the vibration intervention had no effect. In conclusion, the studied whole body vibration program had no effect on bones of young, healthy adults, but instead, increased vertical jump height. Future human studies are needed before clinical recommendations for vibration exercise.

Adult↗
PubMed2003

Femoral neck response to exercise and subsequent deconditioning in young and adult rats.

UNLABELLED: Aged bones have been considered to have reduced capacity to respond to changes in incident loading. By subjecting young and adult rats to increased loading and subsequent deconditioning, we observed quantitatively similar adaptive responses of bone in these two groups, but young skeletons adapted primarily through geometric changes and adult bones through increased volumetric density. Loss of the exercise-induced bone benefits did not depend on age. INTRODUCTION: Aging has been shown to decrease the sensitivity of the mechanosensory cells of bones to loading-induced stimuli, presumably resulting in not only reduced capacity but also different adaptive mechanism of the aged skeleton to altered loading, as well as poorer capacity to preserve exercise-induced bone benefits. MATERIALS AND METHODS: Fifty young (5-week-old) and 50 adult (33-week-old) male rats were randomized into control and exercise (+deconditioning) groups. After a 14-week progressively intensified running program, one-half of the exercised rats (both young and adult) were killed, and the remaining rats underwent subsequent 14-week period of deconditioning (free cage activity). A comprehensive analysis of the femoral neck was performed using peripheral quantitative computed tomography and mechanical testing. RESULTS: In comparison with the controls, both young and adult exercised rats had significant increases in almost all measured parameters: +25% (p < 0.001) and +10% (not significant [NS]) in the cross-sectional area; +28% (p < 0.001) and +18% (p < 0.001) in bone mineral content; +11% (p < 0.05) and +23% (p < 0.001) in bone mineral density; and +30% (p < 0.01) and +28% (p < 0.01) in the breaking load, respectively. The skeletal responses were not statistically different between the young and adult rats. After the 14-week period of deconditioning, the corresponding exercised-to-controls differences were +17% (p < 0.05) and +10% (NS), +18% (p < 0.05) and +13% (p < 0.05), +2% (NS) and +2% (NS), and +11% (NS) and +6% (NS), respectively. Again, the response differences were not significant between the age groups. CONCLUSION: Quantitatively, the capacity of the young and adult skeleton to adapt to increased loading was similar, but the adaptive mechanisms appeared different: growing bones seemed to primarily display geometric changes (increase in bone size), whereas the adult skeleton responded mainly through an increase in density. Despite this apparent difference in the adaptive mechanism, aging did not modulate the ability of the skeleton to preserve the exercise-induced bone gain, because the bone loss was similar in the young and adult rats after cessation of training.

Aging↗
PubMed2003

Use of a cast compared with a functional ankle brace after operative treatment of an ankle fracture. A prospective, randomized study.

BACKGROUND: Controversy continues with regard to the optimal postoperative care after open reduction and internal fixation of an ankle fracture. The hypothesis of this study was that postoperative treatment of an ankle fracture with a brace that allows active and passive range-of-motion exercises would improve the functional recovery of patients compared with that after conventional treatment with a cast. Thus, the purpose of this prospective, randomized study was to compare the long-term subjective, objective, and functional outcome after conventional treatment with a cast and that after use of functional bracing in the first six weeks following internal fixation of an ankle fracture. METHODS: One hundred patients with an unstable and/or displaced Weber type-A or B ankle fracture were treated operatively and then were randomly allocated to two groups: immobilization in a below-the-knee cast (fifty patients) or early mobilization in a functional ankle brace (fifty patients) for the first six postoperative weeks. The follow-up examinations, which consisted of subjective and objective (clinical, radiographic, and functional) evaluations, were performed at two, six, twelve, and fifty-two weeks and at two years postoperatively. RESULTS: There were no perioperative complications in either study group, but eight patients who were managed with a cast and thirty-three patients who were managed with a brace had postoperative complications, which were mainly related to wound-healing. Two patients in the group treated with a cast had deep-vein thrombosis. All fractures healed well in both groups. The difference between the two groups with respect to the complication rate was significant (p = 0.0005). No significant differences between the study groups were observed in the final subjective or objective (clinical) evaluation. At the two-year follow-up examination, the average score (and standard deviation) according to the ankle-rating scale of Kaikkonen et al. was 85 +/- 9 points for the group treated with a cast and 83 +/- 10 points for the group treated with a brace, and the average ankle score according to the system of Olerud and Molander was 87 +/- 8 points and 87 +/- 9 points, respectively. CONCLUSIONS: The long-term functional outcome after postoperative treatment of an ankle fracture with a cast and that after use of a functional brace are similar. Although early mobilization with use of a functional ankle brace may have some theoretical beneficial effects, the risk of postoperative wound complications associated with this treatment approach is considerably increased compared with that after conventional cast treatment. Thus, the postoperative protocol of treatment with a functional brace requires refinement before it can be generally advocated for use after operative treatment of an ankle fracture.

Adult↗
PubMed2002

Expression of alpha7beta1 integrin splicing variants during skeletal muscle regeneration.

Integrin alpha7beta1 is a laminin receptor, both subunits of which have alternatively spliced, developmentally regulated variants. In skeletal muscle beta1 has two major splice variants of the intracellular domain (beta1A and beta1D). alpha7X1 and alpha7X2 represent variants of the alpha7 ectodomain, whereas alpha7A and alpha7B are variants of the intracellular domain. Previously we showed that during early regeneration after transection injury of muscle alpha7 integrin mediates dynamic adhesion of myofibers along their lateral aspects to the extracellular matrix. Stable attachment of myofibers to the extracellular matrix occurs during the third week after injury, when new myotendinous junctions develop at the ends of the regenerating myofibers. Now we have analyzed the relative expression of beta1A/beta1D and alpha7A/alpha7B and alpha7X1/alpha7X2 isoforms during regeneration for 2 to 56 days after transection of rat soleus muscle using reverse transcriptase-polymerase chain reaction and immunohistochemistry. During early regeneration beta1A was the predominant isoform in both the muscle and scar tissue. Expression of muscle-specific beta1D was detected in regenerating myofibers from day 4 onwards, ie, when myogenic mitotic activity began to decrease, and it became more abundant with the progression of regeneration. alpha7B isoform predominated on day 2. Thereafter, the relative expression of alpha7A transcripts increased until day 7 with the concomitant appearance of alpha7A immunoreactivity on regenerating myofibers. Finally, alpha7B again became the predominant variant in highly regenerated myofibers. Similarly as in the controls, alpha7X1 and alpha7X2 isoforms were both expressed throughout the regeneration with a peak in alpha7X1 expression on day 4 coinciding with the dynamic adhesion stage. The results suggest that during regeneration of skeletal muscle the splicing of beta1 and alpha7 integrin subunits is regulated according to functional requirements. alpha7A and alpha7X1 appear to have a specific role during the dynamic phase of adhesion, whereas alpha7B, alpha7X2, and beta1D predominate during stable adhesion.

Animals↗
PubMed2002

Treatment of tendon disorders. Is there a role for corticosteroid injection?

Tendon injuries and other tendon disorders are a source of major concern in competitive and recreational athletes and in many working conditions requiring repetitive movements. The exact etiology, pathophysiology, and healing mechanisms of the various tendon complaints are, however, only partly known and even origin of pain in the chronic tendon disorders is unknown. Thus, the treatment strategies recommended for tendon complaints vary considerably and the given treatment is frequently based on empirical evidence only. Corticosteroid injections are one of the most commonly used treatments for chronic tendon disorders. Despite their popularity, the biologic basis of their effect and the systematic evidence for their benefits are largely lacking. In addition to suppressing inflammation, the effects of local corticosteroid injections could be mediated through their effect on the connective tissue and adhesions between the tendon and the surrounding peritendinous tissues by inhibiting the production of collagen, other extracellular matrix molecules, and granulation tissue in these sites. Also, if the pain in tendinopathy is a result of stimulation of nociceptors by chemicals released by the damaged, degenerated tendon, corticosteroids might mediate their effect thorough alterations in the release of these noxious chemicals, the behavior of these receptors, or both. Achilles tendinopathy, rotator-cuff tendinopathy, tennis elbow, and trigger finger are among the most frequent tendon problems. There is good evidence, however, strongly supporting the use of local corticosteroid injections in the trigger finger only. This can be to the result of either a true lack of the effect or just a lack of good trials in the other complaints. Intimidation with adverse effects of peritendinous corticosteroid injections is based on case reports only rather than convincing data from controlled clinical studies. In light of the animal studies, corticosteroid injection into tendon substance should be avoided, although the true incidence of side effects after local corticosteroid injection(s) for tendon disorders is unknown. Also, the relevance of the steroid used, the tissue affected, the extent of the tendon problem, the duration of the symptoms, the phase of healing at the time of injections, and the postinjection events remain undetermined. Although a complete tendon rupture with loading after steroid injection has been reported, no reliable proof exists of the deleterious effects of peritendinous injections; conclusions in literature are based mainly on uncontrolled case reports that fail under scientific scrutiny, whereas scientifically rigorous studies have not been performed. An acute tendon disorder often responds favorably to early intervention with conservative treatment modalities. Local corticosteroid injections gives good short-term results in prolonged or subacute cases that do not respond to the conventional conservative treatments. Although corticosteroid injections are one of the most commonly used treatment modalities for chronic tendon disorders, there is an obvious lack of good trials defining the indications for and efficacy of such injections, and subsequently, many of the recommendations for the use of local corticosteroid injections do not rely on sound scientific basis. Thus, there is an obvious need for high-quality basic science studies and controlled clinical trials in examining the effects corticosteroids on various tendon disorders.

Adrenal Cortex Hormones↗