Lack of efficacy of acetaminophen in treating symptomatic knee osteoarthritis: a randomized,double-blind,placebo-controlled comparison trial with diclofenac sodium

BACKGROUND: Recommendations state that acetaminophen should be used in preference to nonsteroidal anti-inflammatory drugs in the initial treatment of symptomatic osteoarthritis (OA) of the hip or knee, because of lesser toxicity and the pervasive belief that acetaminophen is not only effective in treating OA pain but is of equal analgesic efficacy as nonsteroidal anti-inflammatory drugs. METHODS: This was a randomized, double-blind, placebo-controlled trial of diclofenac sodium, 75 mg twice daily, vs acetaminophen, 1000 mg 4 times daily, in 82 subjects with symptomatic OA of the medial knee. Osteoarthritis was quantitated radiographically, and subjects met stringent baseline pain criteria. The primary evaluation of efficacy used the Western Ontario and McMaster Universities Osteoarthritis Index, with evaluations at screening, baseline, and 2 and 12 weeks after treatment. Intention-to-treat analysis was used. RESULTS: Twenty-five subjects were randomized to diclofenac, 29 to acetaminophen, and 28 to placebo. The groups were closely matched for age, sex, body mass index, prior use of OA medications, baseline pain, and radiographic features. At 2 and 12 weeks, clinically and statistically significant (P<.001) improvements were seen in the diclofenac-treated group; however, no significant improvements were seen in the acetaminophen-treated group (P =.92 at 2 weeks and.19 at 12 weeks). Stratification of subjects according to baseline pain, prestudy OA medication, and radiographic grade showed no clear pattern of preferential response to diclofenac, and did not reveal a subset of subjects who responded to acetaminophen. CONCLUSIONS: Diclofenac is effective in the symptomatic treatment of OA of the knee, but acetaminophen is not. A review of the literature reveals that there is scanty published evidence for a therapeutic effect of acetaminophen relative to placebo in patients with OA of the knee, because most published studies use active comparators (ie, nonsteroidal anti-inflammatory drugs) only. The advocacy of acetaminophen use in subjects with OA of the knee should be reconsidered pending further placebo-controlled studies.     

Evaluation of glucosamine sulfate compared to ibuprofen for the treatment of temporomandibular joint osteoarthritis: a randomized double blind controlled 3 month clinical trial.

OBJECTIVE: To compare the treatment potential of glucosamine sulfate (GS) and ibuprofen in patients diagnosed with temporomandibular joint (TMJ) osteoarthritis (OA). METHODS: Forty women and 5 men received either GS (500 mg tid) or ibuprofen (400 mg tid) for 90 days in a randomized double blind study. Assessment: TMJ pain with function, pain-free, and voluntary maximum mouth opening, Brief Pain Inventory (BPI) questionnaire and masticatory muscle tenderness were performed after a one week washout and at Day 90. Acetaminophen (500 mg) dispensed for breakthrough pain was counted every 30 days to Day 120. RESULTS: In total, 176 adults were interviewed, 45 (26%) qualified, 39 (87%) completed the study (21 GS, 18 ibuprofen). Four discontinued due to stomach upset (3 ibuprofen, one GS), one due to dizziness (GS), one due to inadequate pain control (ibuprofen). Within-group analysis revealed significant improvement compared to baseline of all variables in both treatment groups but no change in acetaminophen used. Fifteen GS (71%) and 11 ibuprofen (61%) improved, with positive clinical response taken as a 20% decrease in primary outcome (TMJ pain with function). The number of patients with positive clinical response was not statistically different between groups (p = 0.73). Between-group comparison revealed that patients taking GS had a significantly greater decrease in TMJ pain with function, effect of pain, and acetaminophen used between Day 90 and 120 compared with patients taking ibuprofen. CONCLUSION: GS and ibuprofen reduce pain levels in patients with TMJ degenerative joint disease. In the subgroup that met the initial efficacy criteria, GS had a significantly greater influence in reducing pain produced during function and effect of pain with daily activities. GS has a carryover effect.     

Treatment of knee osteoarthritis: relationship of clinical features of joint inflammation to the response to a nonsteroidal antiinflammatory drug or pure analgesic.

Our randomized double blinded comparison of acetaminophen versus analgesic and antiinflammatory doses of ibuprofen in the treatment of 182 subjects with knee osteoarthritis (OA) systematically evaluated soft tissue tenderness and joint swelling. Improvement in these signs of joint inflammation was associated with lessening of disability (p = 0.02), and reduction in rest pain (p = 0.07), but not with the drug treatment regimen. Thus, joint tenderness and swelling, presumptive evidence of synovitis, may not be a priori indications for use of an antiinflammatory drug, or predict greater responsiveness to treatment with an antiinflammatory drug than to a pure analgesic, in symptomatic treatment of patients with knee OA.     

A randomized trial of the efficacy and tolerability of the COX-2 inhibitor rofecoxib vs ibuprofen in patients with osteoarthritis. Rofecoxib/Ibuprofen Comparator Study Group

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2). It is not known whether a specific inhibitor of COX-2 will provide efficacy in osteoarthritis (OA) comparable with NSAIDs. Therefore, we compared the efficacy and safety of the rofecoxib, which specifically inhibits COX-2, with those of the NSAID ibuprofen in patients with OA. OBJECTIVE: To compare the clinical efficacy and tolerability of rofecoxib (12.5 and 25 mg once daily) with ibuprofen (800 mg 3 times daily). METHODS: A randomized, double-blind trial of 809 adults with OA was conducted. Patients with OA in whom the knee or hip was the primary source of pain were randomized to 1 of 4 treatment groups on demonstration of disease activity: placebo; rofecoxib, 12.5 or 25 mg once daily; or ibuprofen, 800 mg 3 times daily. Clinical efficacy and safety were monitored during a 6-week treatment period. RESULTS: Both doses of rofecoxib demonstrated efficacy clinically comparable with ibuprofen as assessed by 3 primary end points (pain walking on a flat surface [Western Ontario and McMaster Universities Osteoarthritis Index], patient global assessment of response to therapy, and investigator global assessment of disease status) according to predefined comparability criteria. Both rofecoxib doses and the ibuprofen dose provided significantly (P<.001) greater efficacy than placebo on all primary end points. Results from secondary end points were consistent with those of the primary end points. All treatments were well tolerated; the overall incidence rates of clinical adverse experiences were not significantly different (P>.05) among the treatment groups. CONCLUSION: Rofecoxib was well tolerated and provided clinical efficacy comparable with a high dose of the NSAID ibuprofen.     

Effects of ibuprofen on molecular markers of cartilage and synovium turnover in patients with knee osteoarthritis

OBJECTIVE: The aim of this study was to evaluate the effect of ibuprofen on the urinary excretion of C-terminal crosslinking telopeptide of type II collagen (CTX-II) and urinary glucosyl galactosyl pyridinoline (Glc-Gal-PYD), two new molecular markers of cartilage and synovial tissue metabolism, respectively, in patients with knee osteoarthritis (OA). METHODS: We studied 201 patients with knee pain and radiographic evidence of knee OA who were on treatment with non-steroidal anti-inflammatory drugs (NSAIDs) prior to study initiation. After an initial screening visit, patients were withdrawn from their pre-study NSAID and, following a flare of their OA symptoms, were randomised to ibuprofen (2400 mg/day) or placebo. Urinary CTX-II and Glc-Gal-PYD levels were measured at time of randomisation (baseline) and after 4-6 weeks of treatment. RESULTS: After 4 to 6 weeks, urinary CTX-II (+17%, p = 0.023) and Glc-Gal-PYD (+10%, p = 0.020) increased significantly from baseline in the placebo group whereas marginal or no increase was observed in the ibuprofen group (CTX-II +2%, NS and Glc-Gal-PYD +4%, p = 0.045). For urinary CTX-II, the difference in the change from baseline between placebo and ibuprofen treated groups was significant (13%, p = 0.017). At baseline, urinary levels of CTX-II and Glc-Gal-PYD were higher in patients with knee swelling (n = 127) than in those without (n = 74) (p<0.02 for both markers). When patients were stratified according to presence or absence of knee swelling at baseline, the increases over 4-6 weeks of urinary CTX-II and Glc-Gal-PYD in the placebo group were restricted to patients with knee swelling (+22% from baseline, p = 0.001 and +12%, p = 0.011, for urinary CTX-II and Glc-Gal-PYD respectively). In patients with knee swelling who were treated with ibuprofen this increase was not observed and the difference from placebo was significant for urinary CTX-II (p = 0.014). CONCLUSION: In patients with a flare of knee OA, specifically in patients with evidence of joint inflammation documented by knee swelling, there was a significant increase in markers reflecting cartilage and synovium metabolism that could partly be prevented by high doses of ibuprofen. These data suggest that patients with a flare of knee OA are characterised by increased cartilage and synovial tissue degradation, which may be partly prevented by high doses of NSAIDs.     

Efficacy and safety of 5% ibuprofen cream treatment in knee osteoarthritis. Results of a randomized, double-blind, placebo-controlled study

OBJECTIVE: To investigate the efficacy and safety of a cream containing 5% ibuprofen (Dolgit) cream) in primary knee osteoarthritis (OA) in a double-blind, randomized, placebo-controlled, parallel-group study using an adaptive sequential design. METHODS: Patients of both sexes aged 40-75 years, with a visual analog scale (VAS) score for pain on motion of >or= 40 mm, a Lequesne index score of 5-13, and a Kellgren-Lawrence radiographic score grade II-III were enrolled between January 2001 and July 2001. Study medication was applied in a 10-cm strip tid for 7 days on the more painful knee. Each strip of the active treatment contained approximately 200 mg ibuprofen. The primary efficacy variable was the treatment response rate compared between the 2 groups. Response was defined as a reduction of pain on motion, self-assessed on VAS, of >or= 18 mm or >or= 23% compared to baseline. RESULTS: The second interim analysis scheduled post-inclusion of 2 25 patients revealed a response rate of 21 patients (84.0%) in the ibuprofen group and of 10 patients (40.0%) in the placebo group (p = 0.0015). The study was then terminated. All secondary endpoints such as pain at rest, overall pain, Lequesne index, and global assessment of efficacy also showed the superiority of ibuprofen. No adverse event was recorded. CONCLUSION: The efficacy and safety of ibuprofen cream in treatment of primary knee OA were statistically significant and clinically relevant compared to placebo.     

Intra-articular hyaluronan injections in the treatment of osteoarthritis of the knee: a randomised, double blind, placebo controlled multicentre trial. Hyaluronan Multicentre Trial Group.

OBJECTIVE: To assess the effects of intra-articular injections of hyaluronan on symptoms of knee osteoarthritis (OA). METHODS: Two hundred and forty patients with symptomatic, radiological knee OA were randomly assigned to treatment with weekly injections for five weeks with either 25 mg of high molecular weight hyaluronan or vehicle. Results were evaluated at weeks 1, 2, 3, 4, 5, 13, and 20 by visual analogue scales (pain, function, motion, activity), algofunctional index, and global evaluation by patient and investigator. Analysis was by "intention to treat', "per protocol', and area under the curve principles on unstratified patient groups and for patients stratified into four groups of equal size by age and baseline algofunctional index. RESULTS: No serious side effects were reported. At 20 weeks both treatment groups were improved compared with baseline, with no difference between unstratified groups treated with placebo or hyaluronan. Comparison of treatment groups stratified by age and baseline algofunctional index revealed a significant difference in favour of hyaluronan over placebo (pain, activity, algofunctional index, global evaluations by patient and investigator) for patients older than 60 years and with a baseline algofunctional index greater than 10. There was no clinically relevant difference between the two treatments for the other three stratified subgroups of younger age or fewer symptoms. Similar results were obtained by area under the curve, intention to treat, and per protocol analysis. CONCLUSIONS: Patients older than 60 years with knee osteoarthritis and with significant symptoms corresponding to an index of severity of knee disease of 10 or more, comprise the group most likely to benefit from treatment with intra-articular hyaluronan injections.     

Knee osteoarthritis compromises early mobility function: The Women's Health and Aging Study II

OBJECTIVE: To examine associations between osteoarthritis (OA) of the knee and early functional limitations in a cohort of high-functioning older women, and evaluate the contributions of muscle strength, body weight, and pain severity to these limitations. Methods. Cross sectional analyses were conducted on baseline data of the Women's Health and Aging Study II (WHAS II), an observational study of disability transitions in a cohort of women aged 70-79 upon entry and who were representative of the one-third highest-functioning community-resident women. Standardized questionnaires and examinations were used to assess knee OA features, medication use, pain severity, knee extensor muscle strength, and body weight. Functional limitation was assessed using validated performance measures and self-report measures of task modification and task difficulty. RESULTS: Sixty-nine women classified as "symptomatic" for knee OA, 48 with "asymptomatic/intermittently symptomatic," knee OA, and 285 with "no knee OA" were included in the final analysis. Despite selection for their high level of self-reported function, performance was slower and task modification was more frequently reported among women with knee OA than women without knee OA. Lower knee extensor strength, higher body weight, and greater pain severity were associated with knee OA, and also with functional limitations. Conclusion. Knee OA appeared to be associated with early functional limitations in this cohort of high-functioning, older, community-resident women. Lower knee extensor strength, higher body weight, and pain severity were closely associated with these limitations. The extent to which modification of these factors attenuates knee OA associated functional decline should be investigated.     

Severity of joint pain and Kellgren-Lawrence grade at baseline are better predictors of joint space narrowing than bone scintigraphy in obese women with knee osteoarthritis

OBJECTIVE: To compare the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of a baseline late-phase bone scan and assessments of the radiographic and symptomatic severity of knee osteoarthritis (OA) at baseline as predictors of loss of articular cartilage thickness, as reflected in joint space narrowing (JSN) in the medial tibiofemoral compartment. METHODS: Subjects (174 obese women, 45-64 yrs of age, with unilateral knee OA) were a subset of a larger cohort who participated in a placebo controlled trial of a disease modifying OA drug. Uptake of technetium medronate (99mTc-MDP) in anteroposterior (AP) and lateral views of a late-phase bone scan was measured at baseline in a region of interest drawn around the medial tibia, and was adjusted for (i.e., expressed as a ratio to) uptake in a reference segment of the tibial shaft, which served as an internal standard. Each subject underwent a fluoroscopically standardized radiographic examination of the knees (semiflexed AP view) and a pain assessment with the WOMAC OA Index at baseline, 16 months, and 30 months. RESULTS: Controlling for baseline joint space width and treatment group, multiple linear regression models showed that the adjusted 99mTc-MDP uptake at baseline was a significant predictor of joint space narrowing (JSN) in the index knee at 16 months (b = 0.180, p = 0.015) and 30 months (b = 0.221, p = 0.049). In the contralateral knee, uptake was only a marginally significant predictor of JSN at 30 months (b = 0.246, p = 0.083). Uptake in the upper and middle tertiles of the distribution predicted subjects who would exhibit JSN >/= 0.50 mm within 16 months with 65% sensitivity (PPV 23%) and 36% specificity (NPV 77%). In contrast, a prediction rule based solely on the presence of Kellgren-Lawrence grade 3 OA severity and greater than median WOMAC Pain score identified progressors with 65% sensitivity (PPV 48%) and 79% specificity (NPV 88%). CONCLUSION: Although the level of adjusted 99mTc-MDP uptake was significantly associated with JSN in knees with established radiographic OA, baseline bone scintigraphy is inferior to the radiographic severity of OA and knee pain (alone or in combination) as a predictor of loss of articular cartilage in subjects with knee OA.     

Efficacy of periosteal stimulation therapy for the treatment of osteoarthritis-associated chronic knee pain: an initial controlled clinical trial

OBJECTIVES: To examine the efficacy of periosteal stimulation therapy (PST, osteopuncture) for the treatment of chronic pain associated with advanced knee osteoarthritis. DESIGN: Randomized, controlled clinical trial. SETTING: Outpatient pain clinic. PARTICIPANTS: Eighty-eight community-dwelling older adults with moderate knee pain or greater for 3 months or longer and Kellgren-Lawrence (K-L) grade 2 through 4 radiographic severity (80% had K-L 4). INTERVENTION: Participants were randomized to receive PST or control PST once a week for 6 weeks. MEASUREMENTS: Pain severity and self-reported function (Western Ontario and McMasters University Osteoarthritis Index (WOMAC)) and physical performance (Short Physical Performance Battery (SPPB)) were assessed at baseline, after the last PST session (post), and 3 months later (follow-up). Pain severity was also assessed monthly using the multidimensional pain inventory short form. RESULTS: Pain was reduced significantly more in the PST group than in the control PST group at post (P=.003; mean WOMAC pain subscale baseline 9.4 vs 6.4) and 1 month later (P<.001), but by 2 months, pain levels had regressed to pre-intervention levels. The group-by-time interaction for the WOMAC function scale was significant at post (P=.04) but not at follow-up (P=.63). No significant group differences were found for the SPPB. Neither analgesic use nor global improvement differed between groups. There were four treatment dropouts. CONCLUSION: PST affords short-term modest pain reduction for older adults with advanced knee OA. Future research should test the effectiveness of booster treatments in sustaining analgesic benefits and of combining PST with therapeutic exercise in ameliorating disability risk.     

Comparison of general internists,family physicians,and rheumatologists managing patients with symptoms of osteoarthritis of the knee

Objective . To evaluate the nature, risks, and benefits of osteoarthritis (OA) management by primary care physicians and rheumatologists. Methods . Subjects were 419 patients followed for symptoms of knee OA by either a specialist in family medicine (FM) or general internal medicine (GIM) or by a rheumatologist (RH). Management practices were characterized by in-home documentation by a visiting nurse of drugs taken to relieve OA pain or to prevent gastrointestinal side effects of nonsteroidal anti-inflammatory drugs (NSAIDs) and by patient report (self-administered survey) of nonpharmacologic treatments. Changes in outcomes (knee pain and physical function) over 6 months were measured with the Western Ontario and McMaster Universities Osteoarthritis Index. Results . Patients of RHs were 2-3 years older (P = 0.035) and tended to exhibit greater radiographic severity of OA (P = 0.064) and poorer physical function (P = 0.076) at baseline than the other 2 groups. In all 3 groups, knee pain and physical function improved slightly over 6 months; however, between-group differences were not significant. Compared to drug management of knee pain by FMs or RHs, that by the GIMs was distinguished by greater utilization of acetaminophen and nonacetylated salicylates (P = 0.008), lower prescribed doses of NSAIDs (P = 0.007), and, therefore, lower risk of iatrogenic gastroenteropathy (P < 0.001). In contrast, patients of RHs were more likely than those of FMs and GIMs to report that they had been instructed in use of isometric quadriceps and range-of-motion exercises (P ≦ 0.001), application of heat (P = 0.051) and cold (P < 0.001) packs, and in the principles of joint protection (P = 0.016). Neither physician specialty nor specific management practices accounted for variations in patient outcomes. Conclusion . This observational study identified specialty-related variability in key aspects of the management of knee OA in the community (i.e., frequency and dosing of NSAIDs, use of nonpharmacologic modalities) that bear strong implications for long-term safety and cost. However, changes in knee pain and function over 6 months were unrelated to variations in management practices.     

Effects of doxycycline on progression of osteoarthritis: results of a randomized, placebo-controlled, double-blind trial

OBJECTIVE: To confirm preclinical data suggesting that doxycycline can slow the progression of osteoarthritis (OA). The primary outcome measure was joint space narrowing (JSN) in the medial tibiofemoral compartment. METHODS: In this placebo-controlled trial, obese women (n = 431) ages 45-64 years with unilateral radiographic knee OA were randomly assigned to receive 30 months of treatment with 100 mg doxycycline or placebo twice a day. Tibiofemoral JSN was measured manually in fluoroscopically standardized radiographic examinations performed at baseline, 16 months, and 30 months. Severity of joint pain was recorded at 6-month intervals. RESULTS: Seventy-one percent of all randomized subjects completed the trial. Radiographs were obtained from 85% of all randomized subjects at 30 months. Adherence to the dosing regimen was 91.8% among subjects who completed the study per protocol. After 16 months of treatment, the mean +/- SD loss of joint space width in the index knee in the doxycycline group was 40% less than that in the placebo group (0.15 +/- 0.42 mm versus 0.24 +/- 0.54 mm); after 30 months, it was 33% less (0.30 +/- 0.60 mm versus 0.45 +/- 0.70 mm). Doxycycline did not reduce the mean severity of joint pain, although pain scores in both treatment groups were low at baseline and remained low throughout the trial, suggesting the presence of a floor effect. However, the frequency of followup visits at which the subject reported a > or = 20% increase in pain in the index knee, relative to the previous visit, was reduced among those receiving doxycycline. In contrast, doxycycline did not have an effect on either JSN or pain in the contralateral knee. In both treatment groups, subjects who reported a > or = 20% increase in knee pain at the majority of their followup visits had more rapid JSN than those whose pain did not increase. CONCLUSION: Doxycycline slowed the rate of JSN in knees with established OA. Its lack of effect on JSN in the contralateral knee suggests that pathogenetic mechanisms in that joint were different from those in the index knee.     

Paracetamol in osteoarthritis of the knee

BACKGROUND: Paracetamol is a recommended symptomatic treatment of osteoarthritis (OA), but in clinical trials sample sizes have been relatively small and variable daily doses of paracetamol have been used. OBJECTIVES: To determine the therapeutic efficacy of paracetamol in OA of the knee and identify predictive factors of clinical response to treatment. METHODS: A double blind, parallel group, placebo controlled trial of analgesic efficacy and safety of paracetamol versus placebo including 779 patients with OA of the knee. Patients were randomly assigned to receive paracetamol 4 g/day (n = 405) or placebo (n = 374) for 6 weeks. Symptomatic OA of the knee was required at inclusion with global pain intensity of the knee during physical activities for the past 24 hours of >or=30 mm on a 100 mm visual analogue scale. The primary end point was a 30% decrease of global pain intensity of the knee. Intention to treat analyses were performed. RESULTS: The percentage of responders did not differ significantly between groups: 52.6% and 51.9% in paracetamol and placebo groups, respectively (p = 0.840). In a subgroup of patients with chronic mechanical knee pain without signs of inflammation (n = 123), the mean change in pain intensity from baseline was 25.2 mm v 15.2 mm, in the paracetamol (n = 63) and placebo (n = 60) groups, respectively-mean difference 10.0 mm; 95% CI 1.0 to 19.0; p = 0.0294. No serious adverse events were attributable to treatment. CONCLUSION: A statistically significant symptomatic effect of oral paracetamol 4 g/day over placebo was not found, suggesting that paracetamol use in symptomatic OA of the knee should be further explored. The tolerability and safety of paracetamol, at the recommended maximum dose of 4 g/day, was confirmed over 6 weeks.     

Minimal perceptible clinical improvement with the Western Ontario and McMaster Universities osteoarthritis index questionnaire and global assessments in patients with osteoarthritis

OBJECTIVE: To determine the minimal perceptible clinical improvement (MPCI) in patients with osteoarthritis (OA) with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, and patient and investigator global assessment of disease status in randomized clinical trials for treatment of OA. METHODS: Subjects with OA of the knee or hip were randomized to receive either rofecoxib 12.5 or 25 mg once daily, ibuprofen 800 mg 3 times daily, or placebo for 6 weeks. The WOMAC and global assessments were completed at baseline and Weeks 2, 4, and 6. A patient global assessment of response to therapy (0 to 4 scale) was used to "anchor" the WOMAC scores. MPCI was defined as the difference in mean change from baseline in WOMAC (100 mm normalized visual analog scale, VAS) between patients with 0 = "None" global response to therapy and patients with 1 = "Poor" global response to therapy. RESULTS: MPCI was determined to be 9.7, 9.3, and 10.0 mm for the WOMAC pain, physical function and stiffness subscales, respectively, and 11.1 mm for WOMAC question 1: Pain walking on a flat surface. The MPCI for the investigator was 0.4 with investigator assessment of disease status reported on a 0 to 4 Likert scale. Of note, the estimated MPCI for the WOMAC and investigator globals were similar irrespective of treatment, sex, age, or geographic region. CONCLUSION: In this analysis, mean changes of roughly 9 to 12 mm (100 mm normalized VAS) on WOMAC scales were perceptible changes to patients with hip and knee OA. A mean decrease of 0.4 in global disease status (0 to 4 Likert scale) as assessed by the investigator corresponded to the patients' MPCI. Understanding the minimal perceptible differences may permit a better assessment of the clinical relevance of therapeutic interventions in OA.     

Acetaminophen, like conventional NSAIDs, may reduce synovitis in osteoarthritic knees

OBJECTIVE: To determine the extent to which treatment of patients with symptomatic knee osteoarthritis (OA) with non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen (ACET) reduces total effusion volume and synovial tissue volume, as quantified by magnetic resonance imaging (MRI). METHODS: Sequential pilot studies used subjects whose knee OA was treated with NSAIDs (n=10) or with ACET or=15 of 25 on the Western Ontario and McMaster Universities' pain scale underwent l.5T MRI. Effusion was quantified in axial short tau inversion recovery images; to measure synovial tissue volume, fat-suppressed T1-weighted axial images were obtained 3 min after i.v. injection of gadolinium contrast. After the initial MRI examination, patients resumed their customary pain medications until the severity of knee pain returned to baseline, when pain was again measured and the MRI was repeated. RESULTS: Pain severity after washout was similar in subjects taking ACET and NSAIDs. Reinstitution of ACET resulted in a 50% decrease in the mean of pain scores (P=1.7 x 10(-12)) that was comparable with that seen after the reinstitution of NSAID (49%, P=6.0 x 10(-7)). The mean total effusion volume measured during the flare of knee pain induced by the withdrawal of the two drugs was comparable (ACET 16.9 ml, NSAID 16.2 ml; P=0.884). Significant decreases in mean total effusion volume were observed after reinstitution of both ACET (-4.5 ml, P=0.009) and NSAID (-3.3 ml, P=0.013); the difference between drugs was not significant. Analyses of synovial volume yielded similar results. CONCLUSION: While uncontrolled and derived from small samples, these data suggest that ACET may have a significant anti-inflammatory effect in patients with knee OA, comparable with that achieved with NSAIDs, possibly through an effect on neurogenic inflammation. Joint pain is the clinical feature of OA that most often leads the affected individual to seek medical attention. Because many patients with OA improve symptomatically with the use of NSAIDs, it has been widely assumed that the pain of OA is due to synovial inflammation. However, the origins of OA pain are numerous and may vary from patient to patient and, within the same subject, from visit to visit. Although the articular cartilage is usually the site of the most obvious pathological changes in this disease, it is aneural and, therefore, is not the source of joint pain. However, in addition to the synovium, the subchondral bone, joint capsule, osteophytes, menisci, ligaments, periarticular tendons, entheses and bursae all contain nociceptive nerve endings, stimulation of which by chemical or physical mediators may be a basis for OA pain.     

How does tibial cartilage volume relate to symptoms in subjects with knee osteoarthritis?

BACKGROUND: No consistent relationship between the severity of symptoms of knee osteoarthritis (OA) and radiographic change has been demonstrated. OBJECTIVES: To determine the relationship between symptoms of knee OA and tibial cartilage volume, whether pain predicts loss of cartilage in knee OA, and whether change in cartilage volume over time relates to change in symptoms over the same period. METHOD: 132 subjects with symptomatic, early (mild to moderate) knee OA were studied. At baseline and 2 years later, participants had MRI scans of their knee and completed questionnaires quantifying symptoms of knee OA (knee-specific WOMAC: pain, stiffness, function) and general physical and mental health (SF-36). Tibial cartilage volume was determined from the MRI images. RESULTS: Complete data were available for 117 (89%) subjects. A weak association was found between tibial cartilage volume and symptoms at baseline. The severity of the symptoms of knee OA at baseline did not predict subsequent tibial cartilage loss. However, weak associations were seen between worsening of symptoms of OA and increased cartilage loss: pain (r(s) = 0.28, p = 0.002), stiffness (r(s) = 0.17, p = 0.07), and deterioration in function (r(s) = 0.21, p = 0.02). CONCLUSION: Tibial cartilage volume is weakly associated with symptoms in knee OA. There is a weak association between loss of tibial cartilage and worsening of symptoms. This suggests that although cartilage is not a major determinant of symptoms in knee OA, it does relate to symptoms.     

Patient Preference for Placebo, Acetaminophen (paracetamol) or Celecoxib Efficacy Studies (PACES): two randomised, double blind, placebo controlled, crossover clinical trials in patients with knee or hip osteoarthritis

BACKGROUND: Acetaminophen (paracetamol) is recommended as the initial pharmacological treatment for knee or hip osteoarthritis. However, survey and clinical trial data indicate greater efficacy for non-steroidal anti-inflammatory drugs and cyclo-oxygenase-2 specific inhibitors. DESIGN: Two randomised, double blind, placebo controlled, crossover multicentre clinical trials, Patient Preference for Placebo, Acetaminophen or Celecoxib Efficacy Studies (PACES).Patients: Osteoarthritis of knee or hip.Intervention: "Wash out" of treatment; randomisation; 6 weeks of celecoxib 200 mg/day, acetaminophen 1000 mg four times a day, or placebo; second "wash out;" crossover to 6 weeks of second treatment.Measurements: Western Ontario McMaster Osteoarthritis Index (WOMAC), visual analogue pain scale, patient preference between two treatments. RESULTS: Celecoxib was more efficacious than acetaminophen in both periods in both studies; WOMAC and pain scale scores differed at p<0.05 in period II and both periods combined of PACES-a and in periods I and II and both periods combined in PACES-b, but not in period I of PACES-a. Acetaminophen was more efficacious than placebo, generally p<0.05 in PACES-b, and >0.05 in PACES-a. Patient preferences were 53% celecoxib v 24% acetaminophen in PACES-a (p<0.001) and 50% v 32% in PACES-b (p = 0.009); 37% acetaminophen v 28% placebo in PACES-a (p = 0.340) and 48% v 24% in PACES-b (p = 0.007). No clinically or statistically significant differences were seen in adverse events or tolerability among the three treatment groups. CONCLUSIONS: Greater efficacy was seen for celecoxib v acetaminophen v placebo, while adverse events and tolerability were similar. Variation in results and statistical significance in the two different trials are of interest.     

Disease-specific pain and function predict future pain impact in hip and knee osteoarthritis

The objective of this study is to determine if osteoarthritis (OA) pain and function, persistent low back pain (LBP) and psychosocial factors predict future pain impact (PI) in people with hip and knee OA. In a population-based cohort with hip/knee OA, a standardized telephone questionnaire was used to assess baseline sociodemographics, baseline PI, patient-reported OA severity (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) summary score), psychosocial factors (fatigue, pain catastrophizing (PC), anxiety, social network, and depression), and self-reported persistent LBP. Two years post-baseline, PI was assessed using the Pain Impact Questionnaire. The association of key independent variables with PI was evaluated through multivariable linear regression, adjusting for covariates (e.g., age, sex, baseline PI, etc.) In 462 participants, the mean age was 76 years (range 58 to 96), 78 % were female and 35 % reported LBP at baseline. Mean scores for PC (9.4), and anxiety (3.7) were low and social network (20.1) high. In multivariable regression analyses, only the WOMAC summary score (unstandardized ß 0.181 95% CI (0.12, 0.24) p < 0.001) was independently associated with greater PI at follow-up. In a population-based cohort with hip/knee OA, only the baseline WOMAC summary score was an independent predictor of future PI. This suggests that treatment needs to be focused on limiting pain severity and functional limitations in individuals with hip and knee OA. However, scores for the psychosocial factors are indicative of a healthy cohort and therefore results may not be generalizable to those with poorer psychosocial health.