Kashin-Beck disease: from etiology to prevention or from prevention to etiology?

The aetiology of Kashin-Beck disease (KBD) remains elusive. Four factors have been convincingly associated with the disease: selenium deficiency, iodine deficiency, grain contamination with mycotoxin-producing fungi, and water pollution with organic material and fulvic acid. The most credible studies from a scientific standpoint, i.e. randomised placebo controlled trials and observational cohort studies have either not been conducted or did not provide unequivocal demonstration in favour of any of these hypotheses. Many studies such as case-control, cross-sectional, "before-after", and even more so, ecological studies have been conducted. They merely produced weak evidence and fail to support any single factor to the exclusion of the others. The most scientifically sound studies have included animal models, laboratory experiments and pathology studies; however, these have only provided indirect evidence. Although none of the competing theories prevails when they are compared using a predefined and standard set of causality criteria (temporality, strength of the association, biological gradient, experimental evidence, biological plausibility, coherence, specificity and analogy), none should be discounted. This is an indication that a comprehensive and unifying theory is most likely to be multifactorial. Because the ultimate goal of those who are compelled by the challenge of KBD is to prevent its occurrence, a perfect understanding of its mechanisms is not indispensable for action. Well-conducted randomised intervention should be the priority of researchers as well as public health professionals to demonstrate what works and what does not.

Dose-response of physical activity and low back pain, osteoarthritis, and osteoporosis

PURPOSE

The purpose of this study was to examine the evidence for causal relationships between physical activity (PA) and low back pain (LBP), osteoarthritis (OA), and osteoporosis (OP), and for dose-response relations involved.

METHODS

Computer database searches and personal retrieval systems were used to locate relevant literature.

RESULTS

PA can be effective in preventing LBP (Category A) but prolonged, heavy loading can lead to LBP (Category C). Specific exercises have not been found effective in treatment of acute LBP (Category A), but PA can be effective in chronic LBP (Category B), especially for diminishing the effects of deconditioning. No evidence indicates that PA directly prevents OA. Large amounts of intensive PA involving high impacts or torsional loadings or causing injuries increases risk of OA (Category C). Light or moderate PA does not increase the risk of OA (Category C). PA can be effective in the treatment and rehabilitation of OA (Category B). High-intensity loading is osteogenic and possibly useful in prevention of OP (Category A) at the loaded site, but low to moderate loading is not osteogenic (Category D). Static efforts and slow movements are ineffective or less effective than fast application of force (Category B). The types of PA to attain the effects mentioned above are known except in the case of prevention of LBP, but dose-response relationships are poorly known; at best, semiquantitatively on the basis of just a few studies.

CONCLUSION

Given the shown primary and/or secondary preventative effectiveness of PA regarding LBP, OA, and OP, research to elucidate the inadequately known dose-response relations should be given high priority.

Early, aggressive treatment can boost arthritis outcomes

Those with osteoarthritis or rheumatoid arthritis can consider several new care strategies. They come with the risk of rare, though serious, side effects.

Ethno-agricultural approach to the rural environment in the prevention of Kashin-Beck disease

Kashin-Beck disease occurs in several villages of Tibet; however, its local importance varies greatly. The ecoclimatological as well as the phytogeographical framework of the studied area are presented. An ecological approach based upon the ethno-ecosystem concept was carried out in the vicinity of each village. This study identifies 18 vegetation units on a structural basis; they were named for the dominant plants of each unit. Half of them belonged to the aquatic milieu. The different factors controlling their distribution were also identified. Particular attention will be paid to the links between man and the environment, particularly regarding alternative food intakes and water supply access.

Homeopathic remedies for the treatment of osteoarthritis: a systematic review

Osteoarthritis is a common rheumatic disease. Limitations of conventional medical management of this condition indicate a real need for safe and effective treatment of osteoarthritic patients. The authors review the clinical evidence for and against the effectiveness of homeopathic medicines in the treatment of patients with osteoarthritis. A systematic review of all randomised controlled clinical trials of homeopathic treatment of patients with this condition is presented. A comprehensive search yielded four trials which are discussed in detail. The authors conclude that the small number of randomised clinical trials conducted to date, although favouring homeopathic treatment, do not allow a firm conclusion as to the effectiveness of homeopathic remedies in the treatment of patients with osteoarthritis. The clinical evidence appears promising, however, and more research into this area seems warranted.

Sport, exercise and health. Toward the next century

In most countries throughout the world, except those affected by the HIV-Aids epidemic, populations are increasing in size, rapidly getting older, and becoming more sedentary. This combination, along with the adoption of unhealthy habits such as cigarette smoking and consumption of an animal-based rather than a plant-based diet, will result in chronic degenerative diseases becoming the most common cause of disability and premature death throughout the world during the first twenty-five years of this new millennium. As more and more populations acquire the technology that reduces the need to exercise for transportation, occupation or maintaining a household, lack of activity quickly becomes a major risk for coronary heart disease, stroke, hypertension and noninsulin dependent diabetes mellitus. This lack of activity appears to contribute to other disorders such as osteoporosis and selected site-specific cancers. In older persons, inactivity can become a major reason for loss of physical independence and a reduction in their quality of life. Public health approaches will be needed to reverse this trend of increasing "hypokinetic" diseases as the computer/communication revolution becomes worldwide. These public health programs will need to be supported by government and corporate changes in policies that provide time, facilities and incentives for maintaining an appropriately active life-style. The goal should be for all adults to perform at least 30 minutes of moderate to vigorous intensity exercise on most days.

Modification of articular cartilage and subchondral bone pathology in an ovine meniscectomy model of osteoarthritis by avocado and soya unsaponifiables (ASU)

OBJECTIVE

To examine the effect of an oral preparation of avocado and soya unsaponifiables (ASU) on the development of joint pathology in an ovine model of osteoarthritis (OA), using computer-assisted histomorphometric methods.

DESIGN

OA was induced in ovine knee joints by bilateral lateral meniscectomy (N=32). ASU (900 mg/weekday) was given orally to half the group (MenX+ASU), the remainder receiving placebo (MenX). Sixteen animals were used as non-operated controls (NOC). At 3 and 6 months post-meniscectomy, histological sections from the medial and lateral femoral condyles (MFC, LFC), tibial plateaux (MTP, LTP) and trochlear groove (TG) were prepared from all joints. Sections were scored using traditional histopathological scales, and computerized image analysis, measuring total cartilage area, uncalcified cartilage (UCC) and subchondral bone plate (SCP) thickness, and intensity of articular cartilage toluidine blue staining (mean greyscale intensity, black=255) as an index of proteoglycan (PG) content.

RESULTS

Computerized image analysis showed significant histological differences not detectable by traditional scoring methods. ASU-treated animals at 6 months showed reduced loss of toluidine blue stain in the MTP (P=0.015) and LTP (P=0.001), and significantly greater staining in the TG than either placebo or NOC groups (P=0.011). UCC thickness increased after meniscectomy, but tended to be highest in ASU-treated animals, significantly so in the middle zone of the LFC (MenX+ASU: 1.03+/-0.21mm vs MenX: 0.79+/-0.14 mm, P=0.018; NOC: 0.77+/-0.17 mm). Lateral compartment SCP thickness increased post-meniscectomy but was increased significantly less in the inner zone of the LTP in ASU-treated sheep (MenX+ASU: 1.37+/-0. 23 mm vs MenX: 1.68+/-0.28 mm, P=0.033; NOC=1.22+/-0.33 mm).

CONCLUSIONS

In this model ASU treatment following meniscectomy appeared to confer a subtle but statistically significant protective effect on articular cartilage. Although the drug failed to prevent focal cartilage lesions, characteristic of this model, histomorphometric analysis demonstrated greater PG content and UCC thickness in adjacent joint regions of ASU-treated animals. In addition, a statistically significant reduction of subchondral bone sclerosis was noted in the LTP region of the drug-treated group. An anabolic effect on chondrocytes, resulting in the stimulation of matrix production in regions distant to the insult, was also suggested by the data. These findings support other studies which have proposed that ASU may exhibit disease-modifying anti-OA activity.

[Aging and physical activity]

Advancing age is accompanied by changes in the cardiovascular system with a rapid reduction of, among other things, cardiac output, respiratory capacity, and maximum oxygen absorption capacity. Changes in articular cartilage, muscles, and intervertebral ligaments are the cause for many degenerative diseases of old age and considerably restrict physical performance capacity in later years. Nevertheless, there is increasing evidence that a high level of activity during old age and thus an influence on the aging process can be achieved by constant training begun as early as young adulthood. This type of training must concentrate on improving muscle strength, general flexibility, and endurance. Thus, it is our task to perceive physical activity as a medical prescription for the aging population.

Epidemiological perspective on prophylactic pinning in patients with unilateral slipped capital femoral epiphysis

The purpose of this review was to determine whether the literature supports in situ prophylactic pinning of the hip contralateral to a hip with a slipped capital femoral epiphysis (SCFE). Three hundred twenty-five articles on SCFE between 1931 and 1998 were reviewed. Two hundred six studies were used to establish normative data. Patients with a unilateral SCFE were 2,335 times more likely to develop a SCFE in the contralateral hip when compared to children in the general population experiencing an initial SCFE. Because a majority of these sequential SCFEs were detected and treated early, we concluded that close follow-up and not prophylactic pinning was most supported by the literature.

Osteoarthritis: new insights. Part 1: the disease and its risk factors

Osteoarthritis is the most common form of arthritis, affecting millions of people in the United States. It is a complex disease whose etiology bridges biomechanics and biochemistry. Evidence is growing for the role of systemic factors (such as genetics, dietary intake, estrogen use, and bone density) and of local biomechanical factors (such as muscle weakness, obesity, and joint laxity). These risk factors are particularly important in weight-bearing joints, and modifying them may present opportunities for prevention of osteoarthritis-related pain and disability. Major advances in management to reduce pain and disability are yielding a panoply of available treatments ranging from nutriceuticals to chondrocyte transplantation, new oral anti-inflammatory medications, and health education. This article is part 1 of a two-part summary of a National Institutes of Health conference. The conference brought together experts on osteoarthritis from diverse backgrounds and provided a multidisciplinary and comprehensive summary of recent advances in the prevention of osteoarthritis onset, progression, and disability. Part 1 focuses on a new understanding of what osteoarthritis is and on risk factors that predispose to disease occurrence. It concludes with a discussion of the impact of osteoarthritis on disability.

Strength training in the elderly: effects on risk factors for age-related diseases

Strength training (ST) is considered a promising intervention for reversing the loss of muscle function and the deterioration of muscle structure that is associated with advanced age. This reversal is thought to result in improvements in functional abilities and health status in the elderly by increasing muscle mass, strength and power and by increasing bone mineral density (BMD). In the past couple of decades, many studies have examined the effects of ST on risk factors for age-related diseases or disabilities. Collectively, these studies indicate that ST in the elderly: (i) is an effective intervention against sarcopenia because it produces substantial increases in the strength, mass, power and quality of skeletal muscle; (ii) can increase endurance performance; (iii) normalises blood pressure in those with high normal values; (iv) reduces insulin resistance; (v) decreases both total and intra-abdominal fat; (vi) increases resting metabolic rate in older men; (vii) prevents the loss of BMD with age; (viii) reduces risk factors for falls; and (ix) may reduce pain and improve function in those with osteoarthritis in the knee region. However, contrary to popular belief, ST does not increase maximal oxygen uptake beyond normal variations, improve lipoprotein or lipid profiles, or improve flexibility in the elderly.

Endoscopic reconstruction of the anterior cruciate ligament with an ipsilateral patellar tendon autograft. A prospective longitudinal five-year study

A total of 90 patients with an isolated rupture of the anterior cruciate ligament (ACL) had a reconstruction using the ipsilateral patellar tendon secured with round-headed cannulated interference screws. Annual review for five years showed three failures of the graft (two traumatic and one atraumatic); none occurred after two years. Ten patients sustained a rupture of the contralateral ACL. At five years, 69% of those with surviving grafts continued to participate in moderate to strenuous activity. Using the International Knee Documentation Committee assessment, 90% reported their knee as being normal or nearly normal and had a median Lysholm knee score of 96 (64 to 100). Most patients (98%) had a pivot shift of grade 0 with the remaining 2% being grade 1; 90% of the group had a Lachman test of grade 0. The incidence of subsequent meniscectomy was similar in the reconstructed joint to that in the contralateral knee. Radiological examination was normal in 63 of 65 patients. Our study supports the view that reconstruction of the ACL is a reliable technique allowing full rehabilitation of the previously injured knee. In the presence of normal menisci there is a low incidence of osteoarthritic change despite continued participation in sporting activity.

The long-term effects of hyaluronan during development of osteoarthritis following partial meniscectomy in a rabbit model

OBJECTIVE

The long-term effect of hyaluronan (HA) on meniscus remodeling and articular cartilage preservation was assessed during the development of osteoarthritis following partial meniscectomy in a rabbit model.

DESIGN

Approximately 60% of the region of each medial meniscus of 20 rabbit knees was excised bilaterally. The left knee joint was treated with five weekly intraarticular injections of 0.3 ml of HA, beginning 1 week after surgery. The right control knee was injected with PBS on the same schedule. Six months after surgery, animals were killed and the medial menisci and tibial articular cartilage were evaluated morphologically, histologically and biochemically.

RESULTS

Meniscal regeneration was observed as newly synthesized translucent tissue, and image analysis revealed that the amount of this tissue was significantly greater in the HA-treated menisci than in the vehicle-treated menisci. Safranin-O staining and image analysis revealed the increased presence of glycosaminoglycans in the HA-treated menisci relative to vehicle-treated menisci while vascularity and biochemical parameters (hydration, total GAGs and reducible collagen crosslinks) were statistically similar in HA- and vehicle-treated menisci. Gross morphologic grading with India ink revealed a trend for less deterioration of tibial articular cartilage in the HA group (P=0.09) while Mankin's score of the HA-treated tibial articular cartilage was marginally lower than that of the vehicle group (P=0.06). Biochemical assessments showed a trend for higher total GAGs concentration in the HA-treated articular cartilage when compared to the vehicle treatment group (P=0.06).

CONCLUSION

The present study has demonstrated that following partial meniscectomy, treatment with hyaluronan can enhance meniscal regeneration and may inhibit articular cartilage degeneration as long as six months post surgery.

Living with hurting and difficulty doing: older women with osteoarthritis

Osteoarthritis (OA) is the most common rheumatologic health problem of older adults. Developing a greater understanding of what it is like to live with this chronic, progressive, and frequently unsuccessfully treated condition is necessary to improve evidence-based nursing care to support independent living. Eighteen women aged 65 to 92 years participated in narrative descriptive research based on naturalistic-framework and qualitative-analysis methods. Data were the transcribed narratives of the participants, field notes of observations and impressions, theoretical memos, coded units of the narratives, and categories noted. Deconstructions and reconstructions of the narratives led to the meaning of "Being With OA," with intermediate categories, "Living With Hurting" and "Living With Difficulty Doing." Recommendations included nursing interventions based on individual problems and strengths and further studies of older adults with chronic health problems.

Effect of public symphysiodesis on pelvic development in the skeletally immature greyhound

OBJECTIVE

To evaluate the effect of pubic symphysiodesis (PS) on pelvic development in skeletally immature dogs.

STUDY DESIGN

Prospective randomized clinical trial.

ANIMALS

Eight 4 month-old, sexually intact female Greyhounds.

METHODS

Initial PS was performed at 4 months of age using a powered stapling device. Because of failure of the initial surgery, a second PS was performed 1 month later by resecting the pubic symphysis with a rongeur followed by placement of handmade bone staples in four dogs. Sham PS was performed in four control dogs at 4 months of age. Pubic growth rate and pelvic development were evaluated using standard plane radiography and computed tomography. Specific measurements included acetabular ventroversion, Norberg angle, lateral center-edge angle, and pelvic inlet dimensions. Hip distraction indices were determined as well.

RESULTS

PS at 4 months of age using a stapling device failed. Pubic symphysiodesis using hand made staples was successful at 5 months of age and did not result in any clinically significant intraoperative or postoperative complications. Pubic symphysiodesis markedly decreased pubic symphysis growth in the treatment group. Hip distraction indices and pelvic inlet circumference, area, and width significantly decreased in treated dogs compared to those in the control group. Acetabular ventroversion was significantly increased in treated dogs compared to those in the control group.

CONCLUSIONS

PS decreases pelvic canal size, increases acetabular ventroversion, and does not appear to have any clinically significant complications.

CLINICAL RELEVANCE

PS performed in skeletally immature dogs with hip dysplasia may provide an effect similar to a triple pelvic osteotomy and warrants further investigation.

The role of exercise in the prevention and treatment of osteoporosis and osteoarthritis

Osteoporosis and osteoarthritis are two distinctly different rheumatic conditions that target elderly, primarily female, populations. This article examines the scientific evidence supporting the use of exercise as a specific therapeutic modality, the general physiologic and psychological benefits of exercise, and the exercise programs currently recommended to combat these prevalent musculoskeletal disorders. Exercise is a valuable adjunct to treatment programs aimed at alleviating the risks and symptoms of osteoporosis and osteoarthritis. In addition to its potential impact on the disease processes themselves, exercise improves general health and well being, enhances quality of life, and preserves physical independence.

Hormone replacement therapy and patterns of osteoarthritis: baseline data from the Ulm Osteoarthritis Study

OBJECTIVES

It has been suggested that hormone replacement therapy (HRT) may protect against osteoarthritis (OA). The aim of this paper was to assess the association between HRT and radiographically defined patterns of OA.

METHODS

475 consecutive women aged 50 years or older (mean age 66.1) who underwent hip or knee joint replacement because of advanced OA in four hospitals in south west Germany were enrolled in a cross sectional study. Participants underwent a standardised interview including detailed history of medication use and a physical examination. Furthermore, radiographs of the joint being replaced and of the contralateral joint as well as of both hands were obtained. Patients were categorised as having bilateral or unilateral OA according to the presence or absence of radiographic OA in the contralateral joint. If radiographic OA of different hand and finger joint groups was present, participants were categorised as having generalised OA (GOA). Logistic regression was used to estimate odds ratios and their 95% confidence intervals for the association between HRT and bilateral or GOA while adjusting for potential confounders.

RESULTS

Fifty five women (11.6%) were using HRT. The median duration of use was 5.4 years. The prevalence of bilateral and GOA was similar among users of ORT (86.3% and 27.5%, respectively) and among non-users of HRT (88.7% and 35.7%, respectively). After adjustment for potential confounding factors, the odds ratios (95% confidence intervals) of bilateral OA and GOA among HRT users compared with non-users was 1.21 (0.48, 3.03) and 1. 21 (0.53, 2.74), respectively.

CONCLUSION

Despite limited generalisability because of the selective study sample, these data do not support the hypothesis that HRT acts as a systemic protective factor against OA.

Hormone replacement therapy and incident arthritis

OBJECTIVES

This article provides estimates of the incidence of arthritis between 1994/95 and 1996/97 among women aged 38 or older. It also examines the association between hormone replacement therapy (HRT) and a new diagnosis of arthritis by 1996/97.

DATA SOURCE

The data are from the household component of the National Population Health Survey, conducted by Statistics Canada. Results are based on a sample of 2,673 female respondents who reported that they did not have arthritis in 1994/95. This sample, when weighted, represents 4.3 million women.

ANALYTICAL TECHNIQUES

Two-year incidence of arthritis was estimated using weighted bivariate frequencies. Associations of arthritis with HRT use and numerous covariates were examined using multivariate logistic regression.

MAIN RESULTS

In the two years between 1994/95 and 1996/97, about 8% of women (338,600) aged 38 or older were newly diagnosed with arthritis. The odds of incident arthritis for current HRT users who had used hormones for five years or longer were twice as high as for non-users. These results persisted even after controlling for potential confounders including age, number of medical visits, and body mass index.

Consequences of long-term hormone replacement therapy

The use of oestrogens in the longer term is an area of considerable current scientific and clinical debate. The extra-reproductive range of oestrogen actions is broad, with these steroid hormones and their receptors (ERs) being intimately involved in the normal function of, inter alia, the adult female skeleton, the cardiovascular system and the brain. Desirable as the restoration of normal circulating oestrogen may be after menopause, HRT use is compromised by the engagement of the reproductive sites of breast and uterus. This may cause concern to patient and physician alike due to the consequent imposition of cyclical bleeding and risk of breast malignancy. In the individual patient, therefore, a balance of risk against benefit has to be struck so that the patient may be precisely advised of the type and duration of oestrogen replacement which may be indicated in her own case. The advent of selective oestrogen receptor modulation with its ability to delete adverse effects in breast and endometrium, is a substantial pharmacological and clinical advance.

Effects of sodium hyaluronate on experimental osteoarthritis in rabbit knee joints

The aim of this study was to examine the effects of intraarticular administration of hyaluronan (HA) on cartilage degradation. Using a partial menisectomy model of osteoarthritis (OA) in the rabbit knee, the authors investigated the catabolic and anabolic changes induced by intraarticular injection of HA. To analyze anabolic changes, the authors assessed cell proliferation by measuring [3H] thymidine uptake, and proteoglycan biosynthesis by noting [35S] sulfate incorporation. For catabolic changes, messenger ribonucleic acid (mRNA) expression of interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) in cartilage and synovium were detected with reverse transcriptase polymerase chain reaction (RT-PCR). Of significance for blocking the development of early OA in chondrocytes was the finding that total proteoglycan synthesis in the HA treatment group was significantly higher than in the controls. At the mRNA level in cartilage and synovium, HA inhibited MMP-3 and TIMP-1 production in the same way in the HA treatment group, while not affecting MMP-1 production. Thus it can be concluded that HA affects cartilage catabolism and anabolism to prevent the progress of OA.

Partial patellectomy induces a decrease in the proteoglycan content in the remaining patellar articular cartilage. An experimental study in rabbits

We studied the alterations and distribution of the proteoglycan (PG) content of the remaining patellar articular cartilage after unilateral partial patellectomy in 13 rabbits. Sagittal sections of the patella were prepared and stained with Safranin O for quantification of changes in the PG content of the patellar articular cartilage using a commercially available imaging analysis system. Our findings suggest that partial patellectomy results in a decreased PG content in the remaining patellar articular cartilage. In addition, the postoperative development of metaplasia in the scar tissue next to the healing interface may represent a compensatory response, which could prevent a further reduction in the PG content and hence the development of osteoarthritis in the remaining patellar articular cartilage.

Sports participation, sports injuries and osteoarthritis: implications for prevention

There is increasing concern that too much physical activity may lead to osteoarthritis. The continuous stress that physical activity places on the joints can result in microtrauma and degeneration of the articular cartilage. However, the onset of osteoarthritis appears to depend on the frequency, intensity and duration of physical activity. Research has shown that individuals of all ages can tolerate moderate amounts of exercise without adverse consequences or accelerated development of osteoarthritis. However, excessive participation in high impact sports, particularly over a long period of time and at an elite level, can increase the risk of developing osteoarthritis. Participants may also be at risk if they have abnormal joint anatomy or alignment, joint instability, underlying muscle weakness or imbalance, or if they are overweight and engage in significant amounts of exercise. Individuals who have experienced sports injuries to joints, or macrotrauma, may also be at risk of accelerated development of osteoarthritis. Certain types of surgery for the treatment of severe sports injuries, particularly to the knee, also appear to be associated with an increased risk. If surgery to the knee is required, continuous passive motion is an ideal form of rehabilitative treatment, as it promotes healing of the articular cartilage, ligaments and tendons. Moreover, athletes who have undergone surgery should return slowly to sporting activities to ensure they do not place too much stress on their injured joint(s). Further research into the causes of osteoarthritis is required; in particular, prospective and retrospective cohort studies are needed to confirm the association between exposure to risk factors and the development of osteoarthritis.

Esculetin (dihydroxycoumarin) inhibits the production of matrix metalloproteinases in cartilage explants, and oral administration of its prodrug, CPA-926, suppresses cartilage destruction in rabbit experimental osteoarthritis

OBJECTIVE

To investigate the in vitro effects of 6,7-dihydroxycoumarin (esculetin) on the production of matrix metalloproteinases (MMP) in rabbit articular cartilage, and the in vivo effects of orally administered CPA-926, a prodrug of esculetin, on cartilage destruction in rabbit experimental osteoarthritis (OA).

METHODS

In vitro studies were performed using rabbit articular cartilage explants. Esculetin 10-100 microM was added to cartilage explants in the presence or absence of interleukin 1alpha (IL-1alpha). Effects of esculetin on cartilage metabolism were assessed. Proteoglycan release into medium was determined by dye precipitation with 1,9-dimethylmethylene blue, synthesis of proMMP-1 (interstitial procollagenase) and proMMP-3 (prostromelysin 1) by Western blotting, and collagen degradation activity using FITC labeled collagen. In vivo experimental OA was induced in the knee joints of 15 Japanese adult white rabbits by partial lateral meniscectomy. Ten rabbits were orally administered 200 or 400 mg/kg/day of CPA-926 from the day of surgery for 14 days. The size of the macroscopic erosive area on the femoral condyle and tibial plateau was measured, and cartilage destruction was histologically evaluated. Collagenolytic activities in synovial fluid were measured using FITC labeled collagen as a substrate.

RESULTS

In vitro, esculetin inhibited the IL-1alpha induced release of proteoglycan into the medium in a dose dependent manner. The collagenolytic activities in cartilage explant medium induced by IL-1alpha were also suppressed with the addition of 33-100 microM esculetin (p = 0.0209 at 33 and 100 microM, p = 0.0202 at 66 microM). Western blotting of cartilage explant medium showed a decrease in the levels of proMMP-1 and proMMP-3 in the medium by treatment with esculetin. In vivo: At 14 days after surgery, the femoral condyle and tibial plateau in the control group showed macroscopic erosions of cartilage. Compared with the control group, the rabbits treated with CPA-926 at the dose of 400 mg/kg exhibited reduction of the size of the erosive area on the tibial plateau (p = 0.009). Histological evaluation indicated protection against the development of destructive changes in the tibial plateau cartilage at a dose of 200 mg/kg (p = 0.0442) and 400 mg/kg (p = 0.0446) of CPA-926.

CONCLUSION

These results indicate that esculetin inhibits matrix degradation in rabbit joint cartilage explants through the suppression of MMP synthesis, secretion, or activity. Prophylactic administration of its prodrug, CPA-926, appears to provide some protection against cartilage destruction in a short term rabbit experimental OA model.

Meniscal allograft transplantation

Meniscal allograft transplantation remains an investigational procedure. Loss of native meniscal function has been consistently shown to result in the development and progression of degenerative joint disease. Allograft reconstruction is a technically feasible and reproducible procedure in both animals and humans with demonstrated incorporation of the transplanted graft with host tissue. However, the ultimate success or failure of the meniscal reconstruction cannot be judged solely on demonstration of allograft incorporation. Success must be measured by the prevention or deceleration of the progression of degenerative changes in the knee that has undergone meniscectomy or by the additional stability the reconstruction provides to the knee. To date the long-term viability and function of the meniscal allograft transplant remains unknown.

Recruiting adults with osteoarthritis into an aquatic exercise class: strategies for a statewide intervention

OBJECTIVE

Although research suggests that regular exercise can be helpful in reducing the dysfunction and discomfort of osteoarthritis, promoting exercise among older adults within this population is neither straightforward nor easily accomplished. This article describes the various methods, and their relative success rates, that were employed to recruit older adults throughout the state of Washington into an aquatic exercise program.

METHODS

Strategies included a recruitment letter distributed to Arthritis Foundation (AF) members in Washington state, local media news coverage, physician referrals, and advertisements in local papers and newsletters.

RESULTS

The most successful methods for enrolling participants were through the AF recruitment letters and local television coverage. The AF recruitment letter was the most expensive method of generating responses, while the television coverage was the least expensive.

CONCLUSIONS

Collaborating with a well-reputed community-based organization and capitalizing on available publicity resources are important strategies researchers can use to gain access to a difficult and geographically dispersed population.

Effect of an inhibitor of matrix metalloproteinases on spontaneous osteoarthritis in guinea pigs

Recently discovered chemically modified tetracyclines have been found to be effective inhibitors of matrix metalloproteinase (MMP)-mediated connective tissue destruction in a variety of pathologic processes, including rheumatoid arthritis and osteoarthritis (OA). Since the histologic techniques used in our laboratory have been validated in Hartley guinea pigs, which have a high incidence of OA-like changes in the proximal tibia, we have used two tetracyclines which have potent inhibitory capacity against various MMPs, doxycycline (Dox) and a compound known as chemically modified tetracyclines (CMT-7). These were given by mouth to a group of guinea pigs for 4 to 8 months, and we assessed the effect of the compound on morphologic and biochemical aspects of OA. We found that prophylactic CMT-7 given orally decreases OA changes in the knee joints both in vitro and in vivo in the guinea pig OA model. Cartilage fibrillation and destruction, in addition to subchondral bone sclerosis and cyst formation, were all decreased in the central compartment of the medial condyle, which is most affected by OA compared with controls. Also collagen, hyaluronan and proteoglycancontent in cartilage was higher in the CMT-7 treated group compared with controls. In contrast, OA changes were not decreased in the Dox group. Our results confirm that various tetracyclines have reduced the severity of OA in animal models, indicating the therapeutic potential of this class of compounds in the future.

Exercise protects against articular cartilage degeneration in the hamster

OBJECTIVE

It has been reported that osteoarthritis can occur in hamsters. The present study was undertaken to determine the effects of exercise on the composition of articular cartilage and synovial fluid and on the development of cartilage degeneration in these animals.

METHODS

Young (2.5-month-old) group-housed hamsters were compared with 5.5-month-old hamsters that had undergone 3 months of daily wheel running exercise (6-12 km/day) or 3 months of sedentary, individually housed living. The condition of the femoral condyles was determined by scanning electron microscopy in 12 exercising hamsters, 12 sedentary hamsters, and 6 of the young controls. The content of proteoglycan, hyaluronic acid, hydroxyproline, and proline in synovial fluid and patellar cartilage was measured.

RESULTS

By scanning electron microscopy, the femoral articular cartilage was smooth and undulating in young controls and older exercising hamsters. In contrast, the femoral condyles were fibrillated in all 12 of the sedentary hamsters. There was no difference in the patellar cartilage collagen content between the 3 groups, but proteoglycan content and synthesis were lower in the patellar cartilage of the sedentary group. Synovial fluid volume was also decreased in the sedentary group compared with the young controls or the older exercising hamsters.

CONCLUSION

A sedentary lifestyle in the hamster leads to a lower proteoglycan content in the cartilage and a lower synovial fluid volume. These changes are associated with cartilage fibrillation, pitting, and fissuring. Daily exercise prevents early cartilage degeneration and maintains normal articular cartilage.

The effects of social support and education on health care costs after three years

OBJECTIVE

To determine whether experimentally developed social support, education about appropriate use of the health care system, and their combination are effective in reducing health care costs for people with osteoarthritis at a 3-year followup assessment.

METHOD

Three hundred sixty-three health maintenance organization members with osteoarthritis were randomly assigned to 1 of 3 intervention groups or to a control group. Two hundred fifty-six participants completed the 3-year assessment. Health status and health care use were assessed upon entering the study, and after 1, 2, and 3 years.

RESULTS

Health care costs in the combined experimental groups were lower than those in the control group by $1,279/participant/year in year 3. There were no significant changes in health status between participants' entry into the study and the year 3 assessment. The 3 interventions had nearly equal effects on health status and health care costs. Implementation costs were least for the social support intervention, but the group that combined education and social support had less attrition and greater persistence.

CONCLUSION

Interventions that target appropriate use of the health care system can be highly cost-effective without adversely affecting health status.

Ro 32-3555, an orally active collagenase selective inhibitor, prevents structural damage in the STR/ORT mouse model of osteoarthritis

OBJECTIVE

To determine the efficacy of a selective inhibitor of collagenases in an animal model of osteoarthritis (OA).

METHODS

Ro 32-3555, an orally active collagenase selective inhibitor, was administered to STR/ORT mice. Microfocal x-ray-generated images of the hind limbs were visually scored for joint space narrowing, osteophyte formation, and calcification of tendons. Histologic sections of the knees were scored for cartilage changes including loss of surface matrix, fibrillation, and eburnation.

RESULTS

Significant inhibition of joint space narrowing and osteophyte formation was achieved in groups of animals treated with 10-50 mg/kg(-1) of Ro 32-3555. These effects were confirmed histologically in the same groups of animals: histologic analysis revealed that Ro 32-3555 protected cartilage from degradative changes.

CONCLUSION

Ro 32-3555, a collagenase selective inhibitor, inhibits both the cartilage and bone changes in this mouse model of OA, and thus shows great potential as a treatment of OA in humans.

A matrix metalloproteinase proenzyme activator produced by articular cartilage

Matrix metalloproteinases (MMPs) are involved in connective tissue turnover under physiological and pathological conditions. MMP activity is regulated by the requirement for zymogen activation. This report describes a proMMP-3 activator produced by articular cartilage. The activator initiates a step-wise processing of proMMP-3 to generate an array of active species. Sequencing of activation intermediates demonstrated cleavage on the NH2-terminal side of certain basic residues in the MMP-3 propeptide. Metal ion chelators inhibited activator-dependent proteolysis, and activity was restored by low levels of ZnCl2. These catalytic properties suggest similarity to members of the insulinase superfamily of metalloendopeptidases with in vitro specificity for single arginine or paired basic processing sites in a variety of prohormones. Dibasic sites also exist in the propeptides of several MMPs including proMMP-3. This is the first report that cartilage produces a potent MMP proenzyme activator, opening the possibility of a novel intrinsic activation pathway for catabolic processes in this avascular tissue.

Effect of intraarticular hyaluronan injection in experimental canine osteoarthritis

OBJECTIVE

To determine if intraarticular injections of hyaluronan (HA) protect against the early stages of joint damage in a canine model of osteoarthritis (OA).

METHODS

OA was induced in adult mongrel dogs by transection of the anterior cruciate ligament of the left knee. One group of dogs (n=7) was treated with 5 weekly injections of HA (MW 1,500,000) into the operated knee beginning 1 day after ligament transection. The control group (n=6) was injected with saline on the same schedule. Twelve weeks after surgery, all dogs were killed, the severity of pathologic changes of OA was graded, and composition of the cartilage and extent of aggregation of proteoglycans (PGs) synthesized in vitro by cartilage slices were determined.

RESULTS

All dogs showed gross morphologic changes typical of OA in the unstable knee. The severity of joint pathology in HA-treated dogs was comparable with that in the saline-injected controls. In OA cartilage from the saline-treated group, the mean uronic acid concentration was 30-60% greater than that in the contralateral knee. In sharp contrast, the uronic acid concentration in OA cartilage from the HA-treated dogs was 10-30% lower than that in cartilage from the contralateral knee (P=0.02 and P=0.03, respectively, for samples from the medial and lateral femoral condyle). The extent of aggregation of PG synthesized in vitro by cartilage from HA-injected animals was similar to that synthesized by cartilage from the saline-injected dogs.

CONCLUSION

In this canine model of OA, the series of intraarticular injections of HA did not alter development of osteophytosis or fibrillation. However, the PG concentration of cartilage in the OA knee was significantly reduced by this treatment, suggesting that HA therapy might adversely affect the biomechanical properties of the cartilage.

The effects of estrogen on osteoarthritis

The prevalence of osteoarthritis is higher in women than men, and in women it increases dramatically in the years after menopause. These observations and others reporting a painful form of hand osteoarthritis after the menopause suggest that loss of estrogen at the time of menopause increases a woman's risk of getting osteoarthritis. This article reviews biologic evidence for hormone sensitivity of cartilage, animal studies testing the effect of estrogen on the joints of ovariectomized animals, and human epidemiologic and clinical studies evaluating endogenous estrogen levels and estrogen replacement therapy and their relation to the occurrence of osteoarthritis. Overall the evidence for a role of estrogen in osteoarthritis is conflicting. Epidemiologic studies of women who take estrogen replacement therapy, however, consistently report that these women have a lower prevalence of osteoarthritis than women not taking estrogen, suggesting a possible therapeutic role for estrogen in osteoarthritis.

[Do 'chondroprotective agents' agents exist in osteoarthritis? Required proof]

The term 'chondroprotective agent' must be dropped in favour of that of structure-modifying drug which allows consideration of the global process of osteoarthritis (OA). A structure-modifying drug is defined as being able to prevent, retard, stabilize or even reverse all or a part of the lesions of bone and cartilage which form the structure of human OA. The demonstration of an eventual structure-modifying effect can only be provided by the proof of a favourable result on the anatomical lesions of OA. The measurement of joint-space narrowing by manual 'radiochondrometry' or performed by computer is presently the 'method of choice', but requires the strict respect of standardized rules during the radiographic procedure. MRI may allow, in the future, a satisfactory assessment of the volume of articular cartilage. Chondroscopy permits a direct evaluation of lesions but is an invasive technique. Molecular markers still lack reliability. Until now, no drug has been able to provide well-established proof of a real effect of structuromodulation.

Education in rheumatology

The increasing burden of arthritis and musculoskeletal conditions in both developed and developing societies is shown by national and community-based surveys. Many complaints are sufficiently severe to cause disability and loss of time from work. Medical care is provided most often by primary health care physicians who are often inadequately trained to handle these conditions. Better medical student education that focuses on common community problems remains crucial. Strong rheumatology units with a commitment to teaching and research are necessary to redress any imbalance as new curricula are developed. Such units also have to take responsibility for primary health care physician and nurse education in how to manage common musculoskeletal problems. Arthritis Foundations and patient support groups have a role in public education and in increasing community knowledge on the causes and prevention of some common conditions so as to assist in improving overall care. New initiatives in professional and public education have given encouraging results, but further changes in community attitudes and perceptions of chronic conditions are necessary and are within the scope of most Arthritis Foundations' key objectives.