Incident knee pain in the Nottingham community: a 12-year retrospective cohort study.

OBJECTIVES: To determine the community incidence of knee pain and associated risk factors over a 12-year period in people over the age of 40 years. METHOD: A cohort study of knee pain was undertaken in 2156 people from four general practices in North Nottinghamshire, UK. Knee pain was defined as 'pain around the knee for most days of at least a month'. Cumulative incidence over 12 years and person-year incidence rate of knee pain were estimated. Survival analysis was undertaken for time to the onset of knee pain. Hazard ratio (HR) and 95% confidence interval (CI) were estimated for relative risk between exposure and non-exposure. Cox regression model was used to adjust for confounding factors. RESULTS: The 12-year cumulative incidence of knee pain was 34.4% (32% for men and 35% for women), corresponding to an average incidence rate of 32 (31 for men and 34 for women)/1000 person-years. Incident knee pain was associated with female gender (HR 1.27, 95% CI 1.08, 1.49), obesity (1.80; 95% CI 1.37, 2.38), varus (1.68, 95% CI 1.15, 2.47) and valgus (1.83, 95% CI 1.05, 3.20) mal-alignment, and knee injury (2.37, 95% CI 2.98, 2.85). CONCLUSIONS: For people over age 40, one in three will develop knee pain within 12 years. On average, the risk of knee pain was 32/1000 person-years. This risk is associated with a variety of constitutional and environmental biomechanical insults to the knee. Some of these could be modified to possibly reduce the incidence of the condition.

Recommendations for standardization and phenotype definitions in genetic studies of osteoarthritis: the TREAT-OA consortium.

OBJECTIVE: To address the need for standardization of osteoarthritis (OA) phenotypes by examining the effect of heterogeneity among symptomatic (SOA) and radiographic osteoarthritis (ROA) phenotypes. METHODS: Descriptions of OA phenotypes of the 28 studies involved in the TREAT-OA consortium were collected. We investigated whether different OA definitions result in different association results by creating various hip OA definitions in one large population based cohort (the Rotterdam Study I (RSI)) and testing those for association with gender, age and body mass index using one-way ANOVA. For ROA, we standardized the hip-, knee- and hand ROA definitions and calculated prevalence's of ROA before and after standardization in nine cohort studies. This procedure could only be performed in cohort studies and standardization of SOA definitions was not feasible at this moment. RESULTS: In this consortium, all studies with SOA phenotypes (knee, hip and hand) used a different definition and/or assessment of OA status. For knee-, hip- and hand ROA five, four and seven different definitions were used, respectively. Different hip ROA definitions do lead to different association results. For example, we showed in the RSI that hip OA defined as "at least definite joint space narrowing (JSN) and one definite osteophyte" was not associated with gender (P =0.22), but defined as "at least one definite osteophyte" was significantly associated with gender (P=3×10(-9)). Therefore, a standardization process was undertaken for ROA definitions. Before standardization a wide range of ROA prevalence's was observed in the nine cohorts studied. After standardization the range in prevalence of knee- and hip ROA was small. CONCLUSION: Phenotype definitions influence the prevalence of OA and association with clinical variables. ROA phenotypes within the TREAT-OA consortium were standardized to reduce heterogeneity and improve power in future genetics studies.

Large-scale meta-analysis of interleukin-1 beta and interleukin-1 receptor antagonist polymorphisms on risk of radiographic hip and knee osteoarthritis and severity of knee osteoarthritis.

OBJECTIVE: To clarify the role of common genetic variation in the Interleukin-1ß (IL1B) and Interleukin-1R antagonist (IL1RN) genes on risk of knee and hip osteoarthritis (OA) and severity of knee OA by means of large-scale meta-analyses. METHODS: We searched PubMed for articles assessing the role of IL1B and IL1RN polymorphisms/haplotypes on the risk of hip and/or knee OA. Novel data were included from eight unpublished studies. Meta-analyses were performed using fixed- and random-effects models with a total of 3595 hip OA and 5013 knee OA cases, and 6559 and 9132 controls respectively. The role of ILRN haplotypes on radiographic severity of knee OA was tested in 1918 cases with Kellgren-Lawrence (K/L) 1 or 2 compared to 199 cases with K/L 3 or 4. RESULTS: The meta-analysis of six published studies retrieved from the literature search and eight unpublished studies showed no evidence of association between common genetic variation in the IL1B or IL1RN genes and risk of hip OA or knee OA (P>0.05 for rs16944, rs1143634, rs419598 and haplotype C-G-C (rs1143634, rs16944 and rs419598) previously implicated in risk of hip OA). The C-T-A haplotype formed by rs419598, rs315952 and rs9005, previously implicated in radiographic severity of knee OA, was associated with reduced severity of knee OA (odds ratio (OR)=0.71 95%CI 0.56-0.91; P=0.006, I(2)=74%), and achieved borderline statistical significance in a random-effects model (OR=0.61 95%CI 0.35-1.06 P=0.08). CONCLUSION: Common genetic variation in the Interleukin-1 region is not associated with prevalence of hip or knee OA but our data suggest that IL1RN might have a role in severity of knee OA.

Insights into the genetic architecture of osteoarthritis from stage 1 of the arcOGEN study.

OBJECTIVES: The genetic aetiology of osteoarthritis has not yet been elucidated. To enable a well-powered genome-wide association study (GWAS) for osteoarthritis, the authors have formed the arcOGEN Consortium, a UK-wide collaborative effort aiming to scan genome-wide over 7500 osteoarthritis cases in a two-stage genome-wide association scan. Here the authors report the findings of the stage 1 interim analysis. METHODS: The authors have performed a genome-wide association scan for knee and hip osteoarthritis in 3177 cases and 4894 population-based controls from the UK. Replication of promising signals was carried out in silico in five further scans (44,449 individuals), and de novo in 14 534 independent samples, all of European descent. RESULTS: None of the association signals the authors identified reach genome-wide levels of statistical significance, therefore stressing the need for corroboration in sample sets of a larger size. Application of analytical approaches to examine the allelic architecture of disease to the stage 1 genome-wide association scan data suggests that osteoarthritis is a highly polygenic disease with multiple risk variants conferring small effects. CONCLUSIONS: Identifying loci conferring susceptibility to osteoarthritis will require large-scale sample sizes and well-defined phenotypes to minimise heterogeneity.

Effect of pain reduction on postural sway, proprioception, and quadriceps strength in subjects with knee osteoarthritis.

OBJECTIVE: To investigate whether alleviation of knee pain influences quadriceps function, proprioceptive acuity, and postural stability in patients with knee osteoarthritis (OA). METHODS: A crossover, within-subject, double blind study design involving 68 subjects with painful knee OA. Each subject received an intra-articular injection into one or both knees (both if symptomatic) of either 5 ml 0.5% bupivacaine or 5 ml 0.9% saline. Two weeks later they received an injection of the alternative agent. Subjects and observer were unaware of the order of injection, which was randomly assigned. Knee pain (100 mm visual analogue scale), static postural sway, knee proprioceptive acuity, maximum voluntary contraction (MVC), and percentage activation of the quadriceps were assessed immediately before and one hour after each injection. RESULTS: Significant pain reduction was achieved one hour post-bupivacaine (mean difference as a percentage change 56.85, 95% CI 31.01 to 73.65; p<0.001) and post-saline (mean difference as a percentage change 41.94, 95% CI 11.57 to 76.66; p< 0.001), with no significant difference between the two. Both MVC and activation increased significantly post-bupivacaine (mean percentage differences 18.83, 95% CI -31.79 to -0.26, and -11.90, 95% CI -39.53 to 2.97, respectively; both p<0.001) and post-saline (mean percentage differences -7.64, 95% CI -21.96 to 4.73, and -10.71, 95% CI -25.19 to 2.60 respectively; both p<0.001). Proprioception worsened after bupivacaine (mean percentage difference -28.15%, 95% CI -83.47 to 19.74; p=0.009), but there was no effect on postural sway; saline injection had no effects. There was no order effect, and comparison of median percentage changes showed no significant differences between injections for change in MVC, activation, proprioception, or sway. CONCLUSION: Reduction in knee pain through either peripheral (local anaesthetic) or central (placebo) mechanisms resulted in increased MVC. This increase, however, did not result in improvements in proprioception or static postural stability, suggesting that other mechanisms play a part in these functions, at least in this acute model.

A magnetostatic-coupling based remote query sensor for environmental monitoring.

A new type of in situ, remotely monitored magnetism-based sensor is presented that is comprised of an array of magnetically soft, magnetostatically-coupled ferromagnetic thin-film elements or particles combined with a chemically responsive material that swells or shrinks in response to the analyte of interest. As the chemically responsive material changes size the distance between the ferromagnetic elements changes, altering the inter-element magnetostatic coupling. This in turn changes the coercive force of the sensor, the amplitude of the voltage spikes detected in nearby pick-up coils upon magnetization reversal and the number of higher-order harmonics generated by the flux reversal. Since the sensor is monitored through changes in magnetic flux, no physical connections such as wires or cables are needed to obtain sensor information, nor is line of sight alignment required as with laser telemetry; the sensors can be detected from within sealed, opaque or thin metallic enclosures.

A remotely interrogatable sensor for chemical monitoring.

A new type of continuously operating, in-situ, remotely monitored sensor is presented. The sensor is comprised of a thin film array of magnetostatically coupled, magnetically soft ferromagnetic thin film structures, adhered to or encased within a thin polymer layer. The polymer is made so that it swells or shrinks in response to the chemical analyte of interest, which in this case is pH. As the polymer swells or shrinks, the magnetostatic coupling between the magnetic elements changes, resulting in changes in the magnetic switching characteristics of the sensor. Placed within a sinusoidal magnetic field the magnetization vector of the coupled sensor elements periodically reverses directions, generating magnetic flux that can be remotely detected as a series of voltage spikes in appropriately placed pickup coils. one preliminary sensor design consists of four triangles, initially spaced approximately 50 micrometers apart, arranged to form a 12 mm x 12 mm square with the triangle tips centered at a common origin. Our preliminary work has focused on monitoring of pH using a lightly crosslinked pH sensitive polymer layer of hydroxyethylmethacrylate and 2-(dimethylamino) ethylmethacrylate. As the polymer swells or shrinks the magnetostatic coupling between the triangles changes, resulting in measurable changes in the amplitude of the detected voltage spirits.

Black-white difference in oral hygiene performance test scores. A preliminary finding.

This paper describes OHPT (Oral Hygiene Performance Test) which was used to measure race differences between African-American and European-American elderly 65 years old and above in performance of daily oral hygiene activities. A total of 80 community-dwelling subjects of which 43 were African-American and 37 European-American participated in the study which involved completion of a battery of functional status measurements including the OHPT. The instrument detected differences in performance as recorded by the length of time to complete each of the 17-items of OHPT. The instrument, the Oral Hygiene Performance Test, is a direct observation measure which objectively quantifies the ability to perform oral hygiene and thus reduces subjective evaluation.

The effects of health education on patients' subsequent dental visits: a practice-based research in health promotions.

We conducted a practice-based research project on health education (discharge counselling) in Gallatin, TN involving 280 patients for more than two and one-half years. Half of the patients were randomly assigned to a "discharge counsellor" after receiving treatment from the dentist. A non-dentist office staff provided the discharge counselling. Patient compliance with treatment modalities and after-treatment dental instruction was the key element of this study. This study confirms that health education (discharge counselling) was effective in reducing the number of patients in this project who would revisit the dentists for (1) emergency treatment, (2) the same complaint as their initial complaint, (3) pain management, and (4) prescription refills. In this study, gender difference was not revealed as a factor, but racial difference might be a factor.

The oral hygiene performance test: development and validation of dental dexterity scale for the elderly.

This paper describes a test which was developed for use in assessing the functional oral hygiene status of an elderly population. The instrument was tested among 80 community-dwelling elderly subjects 65 or more years old. The instrument, the Oral Hygiene Performance Test [OHPT], is a direct-observation measure which objectively quantifies the individual's ability to perform oral hygiene and thus reduces subjective evaluation. The test utilized several items from other already-validated instruments currently in use in geriatric medicine to assess functional abilities in a geriatric population. Additional items were developed by the research team and were included in this 17-item test. The OHPT was validated with common measures of physical function and direct-observation measures. Construct validity was assessed by comparison of the OHPT scores with other commonly used measures of other dimensions. The instrument proved to be reliable and demonstrated construct as well as concurrent validity. It appears that the OHPT can prove useful to clinicians in assessing the oral physical function of elderly patients with regard to their maintenance of oral hygiene. Because the OHPT is a direct-observation instrument, it can even elicit higher functions in elderly patients. While effective among the studied population, the instrument may still need to be validated among more diverse populations, such as various ethnic groups and demented or severely impaired populations.

Basic issues in screening for oral cancer among male subpopulation.

The value of population screening for oral cancer among male adults as a method of oral cancer control is an issue of great controversy. Screening programs have different objectives, varying costs, undocumented benefits, and some may have harmful effects. Consequently, these programs are not unanimously accepted and with the many constraints in evaluating these programs, the future of screening as oral cancer prevention strategy is questionable. Basic issues in the prevalence of oral cancer include factors affecting the patient such as age, sex, exposure to carcinogens, plus the site or the type of the neoplasm. Oral cancer afflicts primarily middle-aged and older adults, particularly heavy users of tobacco and alcohol; long-term exposure to ultraviolet radiation may also be important in the initiation of the disease. Eighty percent of oral cancer patients are over 45 years of age. Exposure to tobacco and/or alcohol seems to be a critical factor in the transformation of normal cells to cancer-producing cells. In the U.S.A., 70-80 percent of oral cancers detected occurred in men. 27,000 new cases of oral cancer are found annually in the United States and at least 9,000 of the cases will result in death. Squamous cell carcinomas represent 90 percent of all oral soft tissue cancers. The most common sites are the floor of the mouth, and soft palate complex. Cancers of the lip and tongue show the greatest association with age while major salivary gland cancers show the least. An inexpensive test should be developed in the near future and subjects should be followed carefully.