Genetic risk of knee osteoarthritis: a sibling study

OBJECTIVES

To determine whether there is a genetic contribution to knee osteoarthritis (OA) as defined by structural change on plain radiographs.

DESIGN

Sibling study. Comparison of knee OA prevalence in the community with knee OA prevalence among siblings of index cases with knee OA.

SUBJECTS

490 knee OA index cases listed for total knee replacement and 737 of their siblings aged >40 years, 1729 community subjects aged >40 years.

MAIN OUTCOME MEASURE

Odds ratio for radiographic knee OA in siblings v community participants.

RESULTS

The age, sex, and knee pain adjusted odds ratios in siblings were 2.9 (95% confidence interval 2.3 to 3.7) for tibiofemoral OA and 1.7 (1.4 to 2.2) for patellofemoral OA. This difference remained after adjustment for important environmental risk factors. The heritability estimate for knee OA was 0.62.

CONCLUSIONS

Siblings are at increased risk of knee OA in comparison with the general population. This is likely to be due to genetic factors.

Evidence-based recommendations for the role of exercise in the management of osteoarthritis of the hip or knee--the MOVE consensus

OBJECTIVES

Exercise is an effective and commonly prescribed intervention for lower limb osteoarthritis (OA). Many unanswered questions remain, however, concerning the practical delivery of exercise therapy. We have produced evidence-based recommendations to guide health-care practitioners.

METHODS

A multidisciplinary guideline development group was formed from representatives of professional bodies to which OA is of relevance and other interested parties. Each participant contributed up to 10 propositions describing key clinical points regarding exercise therapy for OA of the hip or knee. Ten final recommendations were agreed by the Delphi technique. The research evidence for each was determined. A literature search was undertaken in the Medline, PubMed, EMBASE, PEDro, CINAHL and Cochrane databases. The methodological quality of each retrieved publication was assessed. Outcome data were abstracted and effect sizes calculated. The evidence for each recommendation was assessed and expert consensus highlighted by the allocation of two categories: (1) strength of evidence and (2) strength of recommendation.

RESULTS

The first round of the Delphi process produced 123 propositions. This was reduced to 10 after four rounds. These related to aerobic and strengthening exercise, group versus home exercise, adherence, contraindications and predictors of response. The literature search identified 910 articles; 57 intervention trials relating to knee OA, 9 to hip OA and 73 to adherence. The evidence to support each proposition is presented.

CONCLUSION

These are the first recommendations for exercise in hip and knee OA to clearly differentiate research evidence and expert opinion. Gaps in the literature are identified and issues requiring further study highlighted.

Relative risk of knee chondrocalcinosis in siblings of index cases with pyrophosphate arthropathy

OBJECTIVES

To examine the genetic contribution to common, apparently sporadic, radiographic knee chondrocalcinosis (CC) and pyrophosphate arthropathy (PA).

METHOD

(1).

DESIGN

radiographic sibling study. Comparison of the prevalences of knee CC and PA in siblings of index cases with PA with those in the community. (2).

SUBJECTS

80 index cases with PA listed for total knee replacement; 122 of their siblings aged >or=40 years; and 1729 participants from community knee pain surveys who had undergone knee radiographs. (3).

MAIN OUTCOME MEASURE

odds ratios of knee CC and PA in siblings versus community participants.

RESULTS

The prevalence of knee CC was 13% (15/116) in the siblings and 6.9% (119/1727) in the community participants. The adjusted odds ratio (aOR) was 1.2, 95% confidence interval (CI) 0.6 to 2.3. The main risk factors for knee CC were age, knee pain, and knee OA. The prevalence of knee PA was 7% (9/122) in the siblings and 3.4% (59/1729) among the community participants (aOR = 1.1, 95% CI 0.4 to 2.7). The main risk factors for PA were age and knee pain. The age, sex, and knee pain standardised prevalence of PA in the Nottingham community aged >or=40 was 2.40%.

CONCLUSION

The risk of knee CC and PA in siblings of index cases with PA is no higher than that in the general population. Although rare familial CC is recognised, this study suggests that no major genetic predisposition to CC occurs in common symptomatic knee OA.

Summary of recommendations for the design of clinical trials and the registration of drugs used in the treatment of asthma

With new drugs being introduced to treat asthma it is timely to review criteria that can be used to assess efficacy in clinical trials. Anti-asthma drugs are classified into symptoms-modifying, symptom preventers and disease modifying agents. Attention is drawn to the types of experimental evidence required in preclinical studies to support further clinical development of a new therapy. Clinical trials demand careful selection of patients to maximise the strength of the efficacy signal according to the type of trial being designed. While provocation tests are useful in suggesting efficacy, negative tests do not necessarily indicate lack of anti-asthma activity. Therapeutic trial designs need to take account of duration of treatment, dose-response relationships and confirmatory trials. Outcome measures include symptoms, lung function, reduction in concomitant medication, exacerbations, quality of life and measures of inflammation. Interpretation of results need to include the clinical relevance of any changes as well as statistical significance. Special consideration needs to be given to the evaluation of drugs for acute severe asthma, asthma in children and older people, co-morbidity such as rhinitis, and inhaler devices. As with all drugs introduced into practice, careful attention needs to be paid to both short- and long-term safety.

Extended haplotypes and linkage disequilibrium in the IL1R1–IL1A–IL1B–IL1RN gene cluster: association with knee osteoarthritis

The interleukin-1 gene cluster is a key regulator in a number of chronic disease processes. We explored the linkage between nine polymorphic loci in the IL1R1 promoter, eight in the IL1A-IL1B-IL1RN gene complex, and their association with osteoarthritis (OA), a common complex disease associated with low-level inflammation. Using 195 healthy controls, we identified eight novel polymorphisms in the IL1R1 exon 1A region. We found limited LD between IL1R1 and the IL1A-IL1B-IL1RN cluster, although LD within these two individual groups was high. To test association with knee OA, we genotyped 141 patients from Bristol (UK) at the 17 loci. IL1R1 promoter haplotypes showed no association with disease. However, within the IL1A-IL1B-IL1RN complex, we identified a common haplotype conferring a four-fold risk of OA (P=0.00043; Pc=0.0043) and one IL1B-IL1RN haplotype conferring a four-fold reduced risk (P=0.0036; Pc=0.029). To replicate these associations, we subsequently examined 163 knee OA patients from London. Here, the effects of the haplotypes were confirmed: the risk IL1A-IL1B-IL1RN haplotype conferred a two-fold risk of OA (P=0.02), and the protective IL1B-IL1RN haplotype conferred a five-fold reduced risk of OA (P=0.0000008). These results may help to explain the genome-wide scan linkage data and functional observations concerning association between IL-1 and OA.

Influence of radiographic phenotype on risk of hip osteoarthritis within families

OBJECTIVE

To determine whether the magnitude of the genetic influence on the development of hip osteoarthritis (OA) varies according to the radiographic phenotype within families.

PARTICIPANTS AND METHODS

331 families in which at least one sibling (index participant) had undergone total hip replacement for OA and whose preoperative x ray findings were available; 505 siblings of these index participants, who have high exposure to genetic risk of hip OA; and 1718 participants who had previously undergone intravenous urography, representative of the average general population exposure to genetic risk. Prevalence of hip OA was determined by individual radiographic features and minimum hip joint space. OA phenotype was partitioned according to pattern of femoral head migration and osteophyte bone response. Age adjusted odds ratios for hip OA in siblings, stratified according to phenotypic pattern in their index sibling, were assessed by unconditional logistic regression.

RESULTS

The superior pattern of femoral head migration was more common in men, and the axial pattern more common in women. A poor bone response (absent osteophytosis) was associated with an indeterminate pattern of migration. The age adjusted odds ratios for definite hip OA were twofold higher in siblings of index participants who had no osteophyte response than in siblings whose index case had any degree of osteophyte (OR 2.05, 95% CI 1.12 to 3.76). The risk of the siblings from these families having undergone hip replacement themselves was threefold higher. Patterns of migration and bone response were not concordant within families, even among same sex siblings.

CONCLUSION

Careful phenotypic characterisation is essential for genetic studies of hip OA. The results of these studies are likely to be influenced by the phenotypic pattern of hip disease, particularly osteophyte bone response.

Does paracetamol (acetaminophen) reduce the pain of osteoarthritis? A meta-analysis of randomised controlled trials

OBJECTIVE

To assess the best available evidence for efficacy of paracetamol (acetaminophen) in the treatment of osteoarthritis (OA).

DESIGN

Systematic review and meta-analysis of randomised controlled trials (RCTs).

DATA SOURCES

Medline, Embase, Scientific Citation Index, CINAHL, Cochrane Library, and conference abstracts in the past 2 years from the British Society for Rheumatology, the European League Against Rheumatism, the American College of Rheumatology, and the Osteoarthritis Research Society International.

SUBJECTS

10 RCTs including 1712 patients with either symptomatic OA of the knee (6 trials) or hip/knee (3 trials) or multiple joints (1 trial).

MAIN OUTCOME MEASURES

(a). effect size (ES) for pain, stiffness, and functional scores from baseline to end point; (b). rate ratio (RR) and number needed to treat for clinical response rate and patient preference for treatment.

RESULTS

Paracetamol was effective in relieving pain due to OA (ES = 0.21, 95% confidence interval (CI) 0.02 to 0.41). Non-steroidal anti-inflammatory drugs (NSAIDs) were better than paracetamol for pain relief (ES = 0.20, 95% CI 0.10 to 0.30). Clinical response rate was higher with NSAIDs than with paracetamol (RR = 1.24, 95% CI 1.08 to 1.41), and the number of patients who preferred NSAIDs was more than twice the number of those preferring paracetamol (RR = 2.46, 95% CI 1.51 to 4.12). NSAIDs were associated with more frequent gastrointestinal discomfort than paracetamol (RR = 1.35, 95% CI 1.05 to 1.75).

CONCLUSION

Paracetamol is an effective agent for pain relief due to OA. Although safer, it is less effective than NSAIDs. For safety reasons paracetamol should be the first line treatment, with NSAIDs reserved for those who do not respond.

Phase II study of external irradiation and weekly paclitaxel for nonmetastatic, unresectable pancreatic cancer: RTOG-98-12

Unresectable cancer of the pancreas was treated with the combination of weekly paclitaxel and external beam irradiation in an effort to improve palliation and extend life expectancy. One hundred twenty-two patients were entered in a multicentered protocol. Thirteen patients were either ineligible, cancelled, or had delinquent data, thus providing 109 for analysis. Unresectable cancer was based on imaging studies (computed tomography or magnetic resonance imaging), all had histologic proof of adenocarcinoma, and none had evidence of metastatic disease or peritoneal seeding. Image-guided radiotherapy treatment consisted of 50.4 Gy in 28 fractions over 5.5 weeks with coplanar anterior/posterior and lateral ports. An initial dose of 45 Gy was given to fields covering the primary tumor plus the regional peripancreatic, celiac, and porta hepatis lymph nodes. A cone down field was used for the last three fractions to encompass the gross tumor volume with a 1- to 1.5-cm margin. Paclitaxel was administered weekly with irradiation in a dosage of 50 mg/m2 as a 3-hour infusion. The median age was 63 and 53% were female. The Karnofsky performance status was greater than or equal to 80 in 81%. Eighty percent were classified T3 or 4; 20% had N1 disease. The primary tumor was located in the pancreatic head in 65%. Eighty-five percent received all six cycles of paclitaxel per protocol, whereas 93% received irradiation with acceptable protocol variation. Field placement, total dose, fractionation, and overall treatment time were given per protocol in greater than or equal to 90%. Acute toxicity (worst per patient) occurred in 39% with grade III (35% of these were asymptomatic neutropenia), 5% with grade IV, and one patient died of infection during the fourth cycle of chemotherapy (grade V). The median follow-up time for alive patients is 20.6 months (range 5-30). The median survival is 11.2 months (95% CI 10.1, 12.3) with estimated 1- and 2-year survivals of 43% and 13%, respectively. External irradiation plus concurrent weekly paclitaxel is well tolerated when given with large-field radiotherapy. The median survival is better than historical results achieved with irradiation and fluoropyrimidines. These data provide the basis for a new Radiation Therapy Oncology Group trial using paclitaxel and irradiation combined with a second radiation sensitizer, gemcitabine, now under way.

EULAR Recommendations 2003: an evidence based approach to the management of knee osteoarthritis: Report of a Task Force of the Standing Committee for International Clinical Studies Including Therapeutic Trials (ESCISIT)

OBJECTIVES

To update the EULAR recommendations for management of knee osteoarthritis (OA) by an evidence based medicine and expert opinion approach.

METHODS

The literature search and guidelines were restricted to treatments for knee OA pertaining to clinical and/or radiological OA of any compartment of the knee. Papers for combined treatment of knee and other types of OA were excluded. Medline and Embase were searched using a combination of subject headings and key words. Searches for those treatments previously investigated were conducted for January 1999 to February 2002 and for those treatments not previously investigated for 1966 to February 2002. The level of evidence found for each treatment was documented. Quality scores were determined for each paper, an effect size comparing the treatment with placebo was calculated, where possible, and a toxicity profile was determined for each treatment modality.

RESULTS

497 new publications were identified by the search. Of these, 103 were intervention trials and included in the overall analysis, and 33 treatment modalities were identified. Previously identified publications which were not exclusively knee OA in the initial analysis were rejected. In total, 545 publications were included. Based on the results of the literature search and expert opinion, 10 recommendations for the treatment of knee OA were devised using a five stage Delphi technique. Based on expert opinion, a further set of 10 items was identified by a five stage Delphi technique as important for future research.

CONCLUSION

The updated recommendations support some of the previous propositions published in 2000 but also include modified statements and new propositions. Although a large number of treatment options for knee OA exist, the evidence based format of the EULAR Recommendations continues to identify key clinical questions that currently are unanswered.

Articular hypermobility is a protective factor for hand osteoarthritis

OBJECTIVE

Very few studies have evaluated the association of articular hypermobility and radiographic osteoarthritis (OA) in humans. We assessed hypermobility and its relationship to radiographic hand OA in a family-based study.

METHODS

A total of 1,043 individuals were enrolled in the multicenter Genetics of Generalized Osteoarthritis study, in which families were required to have 2 siblings with radiographic OA involving >/=3 joints (distributed bilaterally) of the distal interphalangeal (DIP), proximal interphalangeal (PIP), or carpometacarpal (CMC) joint groups, and OA in at least one DIP joint. Radiographic OA was defined as a score of >/=2 on the Kellgren/Lawrence scale in one or more joints within the group. The Beighton criteria for assessment of hypermobility were recorded on a 0-9-point scale. Hypermobility was defined as a Beighton score of >/=4, a threshold generally used to establish a clinical diagnosis of joint laxity. A threshold of >/=2 was also evaluated to assess lesser degrees of hypermobility. The Beighton score for the present was calculated based on clinical examination, and that for the past was based on recall of childhood hypermobility in the first 2 decades of life. The association of hypermobility and radiographic OA of the PIP, CMC, and metacarpophalangeal joints was evaluated in all participants and in men and women separately. Multiple logistic regression was used to examine the relationship of hypermobility with radiographic OA in each joint group, after adjusting for age and sex. The association of hypermobility and DIP OA was not evaluated, because evidence of DIP OA was required for study inclusion.

RESULTS

Using a threshold Beighton score of 4, 3.7% of individuals were classified as hypermobile based on the present examination, and 7.4% were classified as hypermobile based on the past assessment. A significant negative association between present hypermobility and age was observed. In persons with hypermobility, the odds of OA in PIP joints was lower (for present, odds ratio [OR] 0.34, 95% confidence interval [95% CI] 0.16-0.71; for past, OR 0.43, 95% CI 0.24-0.78). Similar results were obtained using a threshold Beighton score of 2. The lower odds of PIP OA with hypermobility were significant after adjusting for sex and age (for present, OR 0.44, 95% CI 0.20-0.94; for past, OR 0.48, 95% CI 0.26-0.87).

CONCLUSION

This study demonstrated a joint-protective effect of hypermobility for radiographic OA of PIP joints. In contrast to previous studies showing an association of hypermobility and CMC OA, in this cohort there was no evidence for increased odds of OA in any joint group of the hand in association with articular hypermobility.

Low frequency of the "plateau phenomenon" during maximal exercise in elite British athletes

A plateau in oxygen consumption (VO(2)) has long been considered the criterion for maximal effort during an incremental exercise test. But, surprisingly, the termination of a maximum exercise test often occurs in the absence of a VO(2) plateau. To explain this inconsistency, some have proposed that an oxygen limitation in skeletal muscle occurs only in elite athletes. To evaluate this hypothesis, we determined the frequency with which the "plateau phenomenon" developed in a group of elite male and female athletes. Fifty subjects performed a continuous incremental treadmill test to measure maximal oxygen consumption (VO(2max)). Treadmill velocity increased by 0.31 m s(-1) until the respiratory exchange ratio ( R) reached 1.00. Thereafter the treadmill gradient increased by 1% each minute until exhaustion. The VO(2max) was the highest VO(2) sustained for 60 s. Three criteria were used to determine maximal efforts: (1) a plateau in the VO(2), defined as an increase of less than 1.5 ml kg(-1) min(-1); (2) a final R of 1.1 or above; (3) a final heart rate (HR) above 95% of the age-related maximum. Mean VO(2max) exceeded 65 ml kg(-1) min(-1) in both groups. The criteria for R and HR were satisfied by 72% of males and 56% females, and 55% of males and 69% of females, respectively. In contrast a VO(2) plateau was identified in only 39% of males and 25% of females. These findings refute the twin arguments: (1) that the absence of a "plateau phenomenon" results from an inadequate motivational effort in poorly trained athletes and (2) that the "plateau phenomenon" and a consequent skeletal muscle anaerobiosis occur only in athletes with the highest VO(2max) values.

Reliability of a combined 3-min constant load and performance cycling test

Most fitness assessments either use a constant load to exhaustion (exercise capacity test) or an "all-out" effort (performance test). The purpose of this study was to determine the reliability of a high-intensity assessment that combined a constant load element with a performance test. Ten moderately trained male cyclists completed a ramp test to voluntary exhaustion in order to measure maximum minute power output (mean +/- s, 349.3 w +/- 55.0 w). On two other occasions subjects cycled at a constant load at maximum minute power output for 2-min immediately followed by a 1-min performance test. All tests were conducted on the subjects' own bicycles using a Kingcycle trade mark test rig. Power output was measured each second using SRM trade mark Power Cranks. The data were analysed by measuring the reliability of each 30 s of the 3-min test together with the peak power and the peak cadence achieved in the performance element of the test. There was no systematic bias in the data from trial 1 to trial 2 for any of the 6, 30 s blocks of the test, the peak power (mean, 95 % CI, 413.8 w, 357.8 - 469.7 w and 403.8 w, 339.9 - 467.6 w, trial 1 and trial 2, respectively) or peak cadence (95.0 rev x min(-1), 89.5 - 100.5 rev x min(-1) and 95.1 rev x min(-1), 90.0 - 100.1 rev x min(-1), trial 1 and trial 2, respectively). Mean (+/- s) total distance over the 3-min was 2.23 +/- 0.23 km and 2.26 +/- 0.26 km for trial 1 and trial 2 respectively (p > 0.05). The coefficients of variation ranged from 0.9 - 5.4 % and the intraclass correlation coefficients ranged from 0.96 - 0.99. It is concluded that in moderately trained subjects, the 3-min combination test provides reliable data and could therefore be used for short-term, high-intensity cycling intervention studies.

UK community prevalence of knee chondrocalcinosis: evidence that correlation with osteoarthritis is through a shared association with osteophyte

OBJECTIVES

(1) To estimate the prevalence of chondrocalcinosis (CC) in the community and to characterise its compartmental distribution within the knee. (2) To investigate the associations between CC and individual radiographic features of osteoarthritis (OA) at the tibiofemoral joint (TFJ) and patellofemoral joint (PFJ).

METHODS

From three community questionnaire studies investigating the prevalence of knee pain, standing anteroposterior and skyline radiographs were obtained on 1727 subjects (1084 women, 643 men; mean age 63.7; 999 (58%) with knee pain). A single observer recorded the presence and site of CC and graded osteophyte and joint space narrowing (JSN) using a line atlas. "OA" was globally defined as the presence of definite osteophyte and definite JSN. Minimum joint space width (JSW) was measured to 0.1 mm with a metered dial caliper

RESULTS

(1) The crude prevalence of CC was 7.0% (95% confidence interval (CI) 5.8 to 8.2). This showed a strong association with age. The age adjusted odds ratio (aOR) for CC in women v men was 0.79 (95% CI 0.52 to 1.12). The age, sex, and knee pain standardised estimate for those aged >40 in Nottingham, UK was 4.5%. Patellofemoral CC was seen in only nine cases, all with tibiofemoral CC. (2) The age-sex aOR for the association between CC and OA was 2.08 at the PFJ (1.38 to 3.12) and 2.00 (1.11 to 3.60) at the TFJ. There was no association between measured JSW and CC at either the PFJ or TFJ. Both total osteophyte score and total number of sites with osteophyte were positively associated with CC; aOR for the upper quartile was 2.40 (1.48 to 3.90) and 1.94 (1.15 to 3.26), respectively. An association between CC and diuretic use was also demonstrated (aOR=2.07, 1.02 to 4.19).

CONCLUSIONS

In this large UK community study the age, sex, and knee pain adjusted prevalence of CC was 4.5%. There was a strong age association, but no sex predisposition. Patellofemoral CC was uncommon. An association between OA and CC was confirmed, but this appears to operate through an association with osteophyte rather than JSN. The new association between CC and diuretic use might theoretically be explained by diuretic induced hypomagnesaemia.

Prion protein (PrP) gene polymorphisms associated with natural scrapie cases and their flock-mates in Ireland

The PrP genotypes associated with natural scrapie in Ireland were determined and a comparison was made between genotypes found in scrapie-infected sheep and those found in healthy animals from scrapie-infected flocks. Seven PrP genotypes were identified in scrapie-infected animals: VV(136)RR(154)QQ(171),VA(136)RR(154)QQ(171),VA(136)RR(154)QR(171),VA(136)RR(154)QH(171),AA(136)RR(154)QQ(171),AA(136)RR(154)QH(171) and AA(136)RR(154)HH(171). Of 11 scrapie-infected flocks, 15 genotypes were identified in the healthy flock-mates. The genotypes identified in scrapie-affected animals were also all identified in healthy flock-mates. In 9 of the 11 flocks studied, the genotype frequencies among scrapie-infected animals were significantly different from those among healthy flock-mates. The results show that there is a significant risk of developing the clinical signs of scrapie associated with particular PrP genotypes in the Irish sheep population. The association between the V(136)R(154)Q(171) allele and scrapie was evident, as was the association between A(136)R(154)R(171) and resistance to developing the clinical signs of scrapie. The presence of the A(136)H(154)Q(171) allele in the flocks examined resulted in a decreased risk of developing scrapie compared to the presence of the A(136)R(154)Q(171).

Home based exercise programme for knee pain and knee osteoarthritis: randomised controlled trial

OBJECTIVES

To determine whether a home based exercise programme can improve outcomes in patients with knee pain.

DESIGN

Pragmatic, factorial randomised controlled trial of two years' duration.

SETTING

Two general practices in Nottingham.

PARTICIPANTS

786 men and women aged >/=45 years with self reported knee pain.

INTERVENTIONS

Participants were randomised to four groups to receive exercise therapy, monthly telephone contact, exercise therapy plus telephone contact, or no intervention. Patients in the no intervention and combined exercise and telephone groups were randomised to receive or not receive a placebo health food tablet.

MAIN OUTCOME MEASURES

Primary outcome was self reported score for knee pain on the Western Ontario and McMaster universities (WOMAC) osteoarthritis index at two years. Secondary outcomes included knee specific physical function and stiffness (scored on WOMAC index), general physical function (scored on SF-36 questionnaire), psychological outlook (scored on hospital anxiety and depression scale), and isometric muscle strength.

RESULTS

600 (76.3%) participants completed the study. At 24 months, highly significant reductions in knee pain were apparent for the pooled exercise groups compared with the non-exercise groups (mean difference -0.82, 95% confidence interval -1.3 to -0.3). Similar improvements were observed at 6, 12, and 18 months. Regular telephone contact alone did not reduce pain. The reduction in pain was greater the closer patients adhered to the exercise plan.

CONCLUSIONS

A simple home based exercise programme can significantly reduce knee pain. The lack of improvement in patients who received only telephone contact suggests that improvements are not just due to psychosocial effects because of contact with the therapist.

Circadian effects on the acute responses of salivary cortisol and IgA in well trained swimmers

OBJECTIVE

To examine whether time of day significantly affects salivary cortisol and IgA levels before and after submaximal swimming.

METHODS

Fourteen male competitive swimmers (mean (SD) age 18 (3.2) years) volunteered to participate in the study. In a fully randomised, cross over design, each subject performed 5 x 400 m front crawl at 85 (1.2)% of their seasonal best time (277 (16) seconds), with one minute rest between each 400 m, at 0600 and 1800 hours on two separate days. Timed, unstimulated saliva samples were collected before and after exercise. Saliva samples were analysed for cortisol and IgA by radioimmunoassay and single radial immunodiffusion respectively.

RESULTS

Significant time of day effects (am and pm respectively) were observed in IgA concentration (0.396 (0.179) v 0.322 (0.105) mg/ml, p<0.05), IgA secretory rate (0.109 (0.081) v 0.144 (0.083) mg/min, p<0.01), and saliva flow rate (0.31 (0.23) v 0.46 (0.22) ml/min, p<0.001) before exercise (all values mean (SD)). Differences in cortisol levels before exercise (1.09 (0.56) v 0.67 (0.94) microg/dl) approached significance (p = 0.059). The exercise protocol did not significantly affect IgA concentration and secretory rate (p>0.05) but, in comparison with values before exercise, caused significant alterations in cortisol (p<0.01) and saliva flow rate (p<0.01). There was no significant interaction effect of time of day by exercise on any salivary variables measured (p>0.05). However, most of the values of the salivary variables before exercise were significantly inversely related to their exercise induced response (p<0.05).

CONCLUSION

These results suggest a significant circadian variation in the variables measured before exercise, without showing a significant effect on their acute responses to exercise.

Long-term outcome after tibial shaft fracture: is malunion important?

BACKGROUND

Fractures of the shaft of the tibia often heal with some angulation. Although there is biomechanical evidence that such angulation alters load transmission through the joints of the lower limb, it is not clear whether it can eventually lead to osteoarthritis.

METHODS

One hundred and sixty-four individuals who had sustained a tibial shaft fracture were assessed in a research clinic thirty to forty-three years after the injury. The subjects were evaluated with regard to self-reported lower limb joint pain, stiffness, and disability (assessed with the Western Ontario and McMaster Universities [WOMAC] osteoarthritis questionnaire); clinical signs of osteoarthritis; and radiographic evidence of osteophytes and joint-space narrowing in the knees, ankles, and subtalar joints.

RESULTS

Twenty-two (15%) of the 151 subjects who reported no other knee injury reported at least moderate knee pain, and eight (6%) of the 145 subjects who reported no other ankle injury reported at least moderate ankle pain. Seventeen (13%) of the 135 subjects who reported no other knee or ankle injury reported at least moderate disability. The ipsilateral side demonstrated a higher prevalence than the contralateral side in terms of pain with passive ankle movement (nineteen versus nine subjects, p = 0.02), pain with passive subtalar movement (fifteen versus four subjects, p = 0.01), and radiographic signs of ankle joint space narrowing (twelve subjects versus one subject, p = 0.0055). Knee osteoarthritis was frequently bilateral. Forty-seven fractures (29%) healed with coronal angulation of > or = 5 degrees. Apart from an association between shortening of > or = 10 mm and self-reported knee pain (p = 0.016), there were no significant univariate associations between these malunions and the development of osteoarthritis. Seventeen (15%) of 114 eligible subjects had overall malalignment of the lower limb, defined as a hip-knee-ankle angle outside the normal range of 6.25 degrees of varus to 4.75 degrees of valgus. This malalignment was due to the fracture malunion in nine subjects and predated the fracture in eight. In limbs with varus or valgus malalignment, there was an excess of subtalar stiffness (p = 0.04) and a nonsignificant trend toward more frequent knee pain. In limbs with varus malalignment, there was a nonsignificant trend toward more frequent radiographic evidence of osteoarthritis in the medial compartment of the knee joint. Most of the subjects in whom osteoarthritis was observed had normal overall alignment of the lower limb.

CONCLUSIONS

The thirty-year outcome after a tibial shaft fracture is usually good, although mild osteoarthritis is common. Fracture malunion is not the cause of the higher prevalence of symptomatic ankle and subtalar osteoarthritis on the side of the fracture. Although varus malalignment of the lower limb occurs occasionally and may cause osteoarthritis in the medial compartment of the knee, other factors are more important in causing osteoarthritis after a tibial shaft fracture.

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.