Knee vs hip single-joint intra-articular hyaluronic acid injection in patients with both hip and knee osteoarthritis: a pilot study

This paper aims to compare the results of single-joint knee vs hip hyaluronic acid (HA) injections in patients with osteoarthritis (OA) involving both the knee and hip joints. Thirty-eight patients who were diagnosed to have both hip and knee OA were enrolled. Patients were divided into two groups to receive HA injection three times at 1-week intervals either to the hip or knee joints. Pain level during activities and rest was measured by using visual analog scale (VAS). Western Ontario and McMaster University Osteoarthritis Index (WOMAC 5-point Likert 3.0) was also used prior to the injections and 1 month after the 3rd injection. In the knee injection group, the intragroup analysis revealed significant improvements in VAS activity pain, VAS rest pain, and WOMAC pain values following injection when compared with preinjection values, while no significant difference was detected in WOMAC stiffness, WOMAC physical function, and WOMAC total values. In the hip injection group, VAS activity pain, VAS rest pain, WOMAC pain, WOMAC stiffness, WOMAC physical function, and WOMAC total values showed significant improvement after the injection when compared with preinjection values. Although statistically not significant (p > 0.05), the comparison of the differences (preinjection–postinjection) between the groups demonstrated higher values in the hip injection group. We imply that intra-articular single-joint HA injections either to the knee or hip joints in OA patients with involvement of both of these joints are effective with regard to pain and functional status.     

Nonrandom evolution of end-stage osteoarthritis of the lower limbs

OBJECTIVE: Patients with unilateral hip or knee replacements for end-stage osteoarthritis (OA) are at high risk for future progression of OA in other joints of the lower extremities, often requiring additional joint replacements. Although the risks of future surgery in the contralateral cognate joints (i.e., contralateral hip replacement after an initial hip replacement) have been evaluated, the evolution of end-stage hip OA to OA involving the knee joints, and vice versa (i.e., noncognate progression) has not been investigated. Because characterization of OA progression in noncognate joints may shed light on the pathogenesis of multijoint OA, we investigated the pattern of evolution of end-stage lower extremity OA in a large, clinical cohort. METHODS: Total joint replacement (TJR) was selected as a marker of end-stage OA, and a database comprising all lower extremity TJRs performed at a large referral center between 1981 and 2001 was accessed. Of the 5,894 patients identified, 486 patients with idiopathic OA who underwent hip replacement and 414 who underwent initial knee replacement were analyzed to determine the relative likelihood of subsequent TJRs. Patients with the systemic inflammatory arthropathy, rheumatoid arthritis (RA), were evaluated as a control population because RA progression is not considered to be a primarily mechanically mediated process. RESULTS: The contralateral cognate joint was the most common second joint to undergo replacement in both the OA and the RA groups. However, in OA patients for whom the second TJR was in a noncognate joint, that joint was >2-fold more likely to be on the contralateral limb than on the ipsilateral limb (hip to knee P < 0.001; knee to hip P = 0.013). In contrast, among the RA cohort, the evolution was random and no laterality for noncognate TJR was observed at either the hip or the knee (P = 0.782). CONCLUSION: This characterization of end-stage lower extremity OA demonstrates that the disease evolves nonrandomly; after 1 joint is replaced, the contralateral limb is significantly more likely to show progression of OA than is the ipsilateral limb. Thus, OA in 1 weight-bearing joint appears to influence the evolution of OA in other joints. The absence of such laterality in RA suggests that OA progression may be mediated by extrinsic factors such as altered joint loading.     

Sports activities 5 years after total knee or hip arthroplasty: the Ulm Osteoarthritis Study

OBJECTIVE: To analyse sports activities of patients with hip or knee osteoarthritis (OA) over lifetime, preoperatively, and 5 years after arthroplasty. METHODS: In a longitudinal four centre study, 809 consecutive patients with advanced OA of the hip (420) or the knee (389) joint under the age of 76 years who required total joint replacement were recruited. A completed questionnaire about sports activities at 5 year follow up was received from 636 (79%) of the 809 patients. RESULTS: Although most patients with hip (97%) and knee (94%) OA had performed sports activities during their life, only 36% (hip patients) and 42% (knee patients) had maintained sports activities at the time of surgery. Five years postoperatively, the proportion of patients performing sports activities increased to 52% among patients with hip OA, but further declined to 34% among those with knee OA. Accordingly, the proportion of patients with hip OA performing sports activities for more than 2 hours a week increased from 8 to 14%, whereas this proportion decreased from 12 to 5% among patients with knee OA. Pain in the replaced joint was reported by 9% of patients with hip and by >16% with knee OA. CONCLUSION: Differences in pain 5 years after joint replacement may explain some of the difference of sports activities between patients with hip and knee OA. Reasons for reduction of sports activities may include the increasing age of the patients, their worries about an "artificial joint", and the advice of their surgeon to be cautious.     

Nonrandom evolution of end‐stage osteoarthritis of the lower limbs

Objective

Patients with unilateral hip or knee replacements for end‐stage osteoarthritis (OA) are at high risk for future progression of OA in other joints of the lower extremities, often requiring additional joint replacements. Although the risks of future surgery in the contralateral cognate joints (i.e., contralateral hip replacement after an initial hip replacement) have been evaluated, the evolution of end‐stage hip OA to OA involving the knee joints, and vice versa (i.e., noncognate progression) has not been investigated. Because characterization of OA progression in noncognate joints may shed light on the pathogenesis of multijoint OA, we investigated the pattern of evolution of end‐stage lower extremity OA in a large, clinical cohort.

Methods

Total joint replacement (TJR) was selected as a marker of end‐stage OA, and a database comprising all lower extremity TJRs performed at a large referral center between 1981 and 2001 was accessed. Of the 5,894 patients identified, 486 patients with idiopathic OA who underwent hip replacement and 414 who underwent initial knee replacement were analyzed to determine the relative likelihood of subsequent TJRs. Patients with the systemic inflammatory arthropathy, rheumatoid arthritis (RA), were evaluated as a control population because RA progression is not considered to be a primarily mechanically mediated process.

Results

The contralateral cognate joint was the most common second joint to undergo replacement in both the OA and the RA groups. However, in OA patients for whom the second TJR was in a noncognate joint, that joint was >2‐fold more likely to be on the contralateral limb than on the ipsilateral limb (hip to knee P < 0.001; knee to hip P = 0.013). In contrast, among the RA cohort, the evolution was random and no laterality for noncognate TJR was observed at either the hip or the knee (P = 0.782).

Conclusion

This characterization of end‐stage lower extremity OA demonstrates that the disease evolves nonrandomly; after 1 joint is replaced, the contralateral limb is significantly more likely to show progression of OA than is the ipsilateral limb. Thus, OA in 1 weight‐bearing joint appears to influence the evolution of OA in other joints. The absence of such laterality in RA suggests that OA progression may be mediated by extrinsic factors such as altered joint loading.

     

An innovative care model coordinated by a physical therapist and nurse practitioner for osteoarthritis of the hip and knee in specialist care: a prospective study

The subject of the study is to investigate whether health-related quality of life (HRQoL), pain and function of patients with hip or knee osteoarthritis (OA) improves after a specialist care intervention coordinated by a physical therapist and a nurse practitioner (NP) and to assess satisfaction with this care at 12 weeks. This observational study included all consecutive patients with hip or knee OA referred to an outpatient orthopaedics clinic. The intervention consisted of a single, standardized visit (assessment and individually tailored management advice, to be executed in primary care) and a telephone follow-up, coordinated by a physical therapist and a NP, in cooperation with an orthopaedic surgeon. Assessments at baseline and 10 weeks thereafter included the short form-36 (SF-36), EuroQol 5D (EQ-5D), hip or knee disability and osteoarthritis outcome score (HOOS or KOOS), the intermittent and constant osteoarthritis pain questionnaire (ICOAP) for hip or knee and a multidimensional satisfaction questionnaire (23 items; 4 point scale). Eighty-seven patients (57 female), mean age 68 years (SD 10.9) were included, with follow-up data available in 63 patients (72 %). Statistically significant improvements were seen regarding the SF-36 physical summary component score, the EQ-5D, the ICOAP scores for hip and knee, the HOOS subscale sports and the KOOS subscales pain, symptoms and activities of daily living. The proportions of patients reporting to be satisfied ranged from 79 to 98 % per item. In patients with hip and knee OA pain, function and HRQoL improved significantly after a single-visit multidisciplinary OA management intervention in specialist care, with high patient satisfaction.     

A STUDY OF THE ROLE OF PARVOVIRUS B19 IN RHEUMATOID ARTHRITIS

Serum and synovial tissue from 26 patients with rheumatoid arthritis(RA) (according to the diagnostic criteria of the American RheumatismAssociation) and 26 patients with osteoarthritis (OA) were examined.Among the RA group, the female to male ratio was 4.2:1, andthe age range was 44–82 yr with a mean of 64.0 yr; jointsfrom which synovium was sampled were hip (n = 12), knee (n =9), ankle (n = 3) and shoulder (n = 2). The duration of rheumatoiddisease ranged from 6 to 24 yr with a mean of 13.9 yr. Amongthe OA group, the female to male ratio was 2.25:1, and the agerange was 51–88 yr with a mean of 68.2 yr; joints fromwhich synovium was sampled were hip (n = 18) and knee (n = 8).Twenty-one patients from the RA group and 20 patients from theOA group had evidence of previous parvovirus B19 infection (serumanti-B19 IgG), and all patients from both groups were serumanti-B19 IgM negative. Synovial sections from all 52 patientswere stained with mouse monoclonal antibodies, 3H8 (to B19 capsidproteins) and     

A high interleukin 1 receptor antagonist/IL-1beta ratio occurs naturally in knee osteoarthritis

OBJECTIVE: To assess the interleukin 1 receptor antagonist (IL-1Ra)/IL-1beta ratio in synovial fluid (SF) of patients with knee osteoarthritis (OA) or rheumatoid arthritis (RA) to determine a possible relation between cytokine level and disease activity. METHODS: IL-1beta and IL-1Ra concentrations were measured by ELISA in knee SF from patients with OA (n = 42) or RA (n = 11). For OA patients, pain and disability were assessed by a visual analog scale (VAS) and the Lequesne index. RA disease activity was assessed using the Disease Activity Score 28 Joint Count (DAS28). RESULTS: Patients with OA showed lower median levels of IL-1beta and IL-1Ra in SF than patients with RA (p < 0.001) but a higher IL-1Ra/IL-1beta ratio: 1793 (584-6221) versus 773.5 (187.64-1570.5) (p = 0.05). For patients with OA, the IL-1Ra/IL-1beta ratio was not associated with pain or disability. For patients with RA, the IL-1Ra/IL-1beta ratio and IL-1Ra and IL-1beta levels were related to SF white blood cell count. CONCLUSION: High endogenous IL-1Ra/IL-1beta ratio occurs in SF from knee OA and does not correlate with pain or Lequesne index. Our results suggest that intraarticular injection of IL-1Ra might be self-limited in patients with knee OA and a naturally high SF ratio.     

A COMPARISON OF THE CLINICAL FEATURES OF HOSPITAL OUT-PATIENTS WITH RHEUMATOID DISEASE AND OSTEOARTHRITIS IN PAKISTAN AND ENGLAND

Several studies have demonstrated differences between ethnicgroups in the severity and pattern of rheumatoid arthritis (RA)and osteoarthritis (OA). The current investigation comparedRA and OA in Pakistani and British White Caucasian out-patientsin two teaching hospitals. There were 88 RA patients in eachsetting, matched for age, gender and disease duration. The patternof OA was sought by recording the details of 44 consecutivenew referrals to each clinic. Amongst the RA patients, jointdeformity and tenderness were similar, but disability was moresevere, ESR higher, anaemia more pronounced and RA latex moreoften positive amongst the Pakistani patients. X-ray damagewas more pronounced amongst the British patients, especiallyin the feet. The British were also more likely to have rheumatoidnodules and to have undergone disease-modifying treatment orjoint surgery. The paradox of more severe indices of diseaseactivity and disability with less X-ray erosion in hands andfeet might be explained by the impact of treatment on jointinflammation and the beneficial influence of surgery on disabilityin the British. The worse X-ray scores in the White Caucasiansmight indicate a genetic predisposition to radiologically moresevere disease. The age of the British OA patients was significantlyhigher, but this is unlikely to have influenced the strikingdisparity in the frequency of isolated knee OA, which was significantlygreater in the Pakistani patients. Comparison with age- andsex-matched healthy Pakistani subjects suggested that susceptibilityto knee OA was strongly associated with body weight, but notwith knee bending at prayer or with joint laxity. Amongst thePakistanis, Heberden nodes, hip involvement and evidence ofgeneralized OA were significantly less, but these observationsmay have been due to their younger age. The study confirmeddifferences in the clinical presentation of both RA and OA amongstpatients in Pakistan compared with White Caucasians in Britain.Several confounding factors, such as patient recruitment, culture,treatment and age, may have influenced the results, but it remainslikely that genetic factors are important. KEY WORDS: Ethnic differences, Arthritis, Genetic influence     

Age and waiting time as predictors of outcome after total hip replacement for osteoarthritis

OBJECTIVE: To investigate in a prospective study the relationship between age, pre-operative status, waiting time and post-operative outcome in patients assigned for unilateral total hip replacement (THR) due to osteoarthritis (OA). METHOD: One hundred and forty-eight patients (mean age 71 yr) with primary OA of the hip were investigated pre-operatively and 3, 6 and 12 months post-operatively with the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). For 56 of the patients an additional evaluation was made when they were placed on the waiting list. RESULTS: One hundred and twenty-four patients fulfilled the study criteria (age 50 yr or over and unilateral THR for OA during the study period). Before surgery there were no differences in the WOMAC or SF-36 subscales (except mental health) between patients aged over and under 72 yr. Post-operatively, the younger patients reached a better score than the older patients. There were no differences in pre-operative status or post-operative outcome between the patients who had been on the waiting list more than and less than 3 months. Most pain relief after hip replacement was obtained by 3 months, while it took at least 1 yr to reach the full benefit in improved function. Ninety per cent of the patients had improved by at least 10 points on a 100-point scale for pain and function at 12 months. CONCLUSION: The age of the patients assigned for THR did not determine their pre-operative status. However, younger patients gained more function post-operatively than older patients and reached higher absolute mean SF-36 values, except for pain. An average difference in time on the waiting list of 3 months did not result in a difference in post-operative outcome. At least 1 yr is required for the average OA patient to gain the full benefit of the THR.     

Determinants of WOMAC function, pain and stiffness scores: evidence for the role of low back pain, symptom counts, fatigue and depression in osteoarthritis, rheumatoid arthritis and fibromyalgia.

OBJECTIVES: The Western Ontario MacMaster (WOMAC) is a validated instrument designed specifically for the assessment of lower extremity pain and function in osteoarthritis (OA) of the knee or hip. In the clinic, however, we have noted that OA patients frequently have other musculoskeletal and non-musculoskeletal problems that might contribute to the total level of pain and functional abnormality that is measured by the WOMAC. In this report, we investigated back pain and non-articular factors that might explain WOMAC scores in patients with OA, rheumatoid arthritis (RA) and fibromyalgia (FM) in order to understand the specificity of this instrument. METHODS: RA, OA and FM patients participating in long-term outcomes studies completed the WOMAC and were assessed for low back pain, fatigue, depression and rheumatic disease symptoms by mailed questionnaires. RESULTS: Regardless of diagnosis, WOMAC functional and pain scores were very much higher (abnormal) among those complaining of back pain. On average, WOMAC scores for back pain (+) patients exceeded those of back pain (-) patients by approximately 65%,, and 52% of OA patients reported back pain. In regression analyses, study symptom variables explained 42, 44 and 38% of the variance in WOMAC function, pain and stiffness scores, respectively. In the subset of OA patients, radiographic scores added little to the explained variance. The strongest predictor of WOMAC abnormality in bivariate and multivariate analyses was the fatigue score, with correlations of 0.58, 0.60 and 0.53 with WOMAC function, pain and stiffness, respectively. The WOMAC performed well in RA and FM, and correlated strongly with the Health Assessment Questionnaire (HAQ) disability scale and a visual analogue scale (VAS) pain scale. CONCLUSION: The WOMAC captures more than just knee or hip pain and dysfunction, and is clearly influenced by the presence of fatigue, symptom counts, depression and low back pain. WOMAC scores also appear to reflect psychological and constitutional status. These observations suggest the need for care in interpreting WOMAC scores as just a measure of function, pain or stiffness, and indicate the considerable importance of psychological factors in rheumatic disease and rheumatic disease assessments.     

Incidence and risk factors of prosthetic joint infection after total hip or knee replacement in patients with rheumatoid arthritis

Objective

Prosthetic joint infection is one of the most dreaded complications after total joint arthroplasty, a common procedure in patients with rheumatoid arthritis (RA). We conducted a study to evaluate potential risk factors of prosthetic joint infection and to clarify if RA is an independent predictor of this complication.

Methods

This study included all patients with RA who underwent total hip or knee replacement at the Mayo Clinic Rochester between January 1996 and June 2004. The association of potential risk factors with prosthetic joint infection was examined using Cox models. A matched cohort of patients with osteoarthritis (OA) was assembled to determine whether RA is an independent risk factor for prosthetic joint infection.

Results

We identified 462 patients with RA who underwent a total of 657 hip or knee replacements. Overall, 23 (3.7%) joint arthroplasties were complicated by an infection during a mean ± SD followup of 4.3 ± 2.4 years. Revision arthroplasty (hazard ratio [HR] 2.99, 95% confidence interval [95% CI] 1.02–8.75) and a previous prosthetic joint infection of the replaced joint (HR 5.49, 95% CI 1.87–16.14) were significant predictors of postoperative prosthetic joint infection. Comparison of RA patients with a matched cohort of OA patients identified an increased risk of prosthetic joint infections (HR 4.08, 95% CI 1.35–12.33) in patients with RA.

Conclusion

Patients with RA who undergo total hip or knee replacement are at increased risk of prosthetic joint infection, which is further increased in the setting of revision arthroplasty and a previous prosthetic joint infection. These findings highlight the importance of perioperative prophylactic measures and vigilance during the postoperative period.     

End-stage coxarthrosis and gonarthrosis. Aetiology, clinical patterns and radiological features of idiopathic osteoarthritis

OBJECTIVES: To determine and compare the aetiological background, clinical patterns and radiological features of idiopathic osteoarthritis (OA) of the hip and the knee warranting arthroplasty. METHODS: A total of 402 Caucasians consecutively undergoing total hip replacement (THR) or total knee replacement (TKR) for idiopathic OA at a major centre was surveyed. RESULTS: Previous joint injury was more common in the TKR group (P < 0.0001). However, both groups manifested a mixed occupational background, body mass indices similar to the general population and a predominance of females (F:M = 1.3-1.4:1). The TKR group had a significantly younger age of symptom onset (56 yr) than the THR group (61 yr) but both groups had a tendency to bilateral arthroplasty (33%), nodal involvement (54-59%), a significant excess of right-sided replacements (1.8:1, THR; 2.2:1, TKR) and similar levels of pre-operative pain and disability. Up to 40% of hips manifested acetabular dysplasia and 10% possible previous slipped upper femoral epiphyses. Eighty-five per cent with end-stage coxarthrosis or gonarthrosis had an identical pattern of radiographic disease contralaterally. CONCLUSIONS: Our data suggest the importance of a constitutional tendency to idiopathic, end-stage OA, a disorder traditionally associated with environmental factors leading to 'wear and tear'.     

Linkage analysis of candidate genes as susceptibility loci for osteoarthritis-suggestive linkage of COL9A1 to female hip osteoarthritis

OBJECTIVE: To examine 11 candidate genes as susceptibility loci for osteoarthritis (OA). METHODS: A total of 481 families have been ascertained in which at least two siblings have had joint replacement surgery of the hip, or knee, or hip and knee for idiopathic OA. Each candidate gene was targeted using one or more intragenic or closely linked microsatellite marker. The linkage data were analysed unstratified and following stratification by sex and by joint replaced (hip or knee). RESULTS: The analyses revealed suggestive linkage of the type IX collagen gene COL9A1 (6q12-q13) to a subset of 132 families that contained affected females who were concordant for hip OA (female-hip) with a P-value of 0.00053 and logarithm of the odds (LOD) score of 2.33 [corrected P-value of 0. 0016, corrected LOD score of 1.85]. CONCLUSIONS:COL9A1 may therefore be a susceptibility locus for female hip OA. In addition, there was weak evidence of linkage to HLA/COL11A2 (6p21.3) in female hip OA with a corrected P-value of 0.016.     

A systematic review and meta‐analysis comparing complications following total joint arthroplasty for rheumatoid arthritis versus for osteoarthritis

Objective

Most of the evidence regarding complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA) is based on studies of patients with osteoarthritis (OA), with little being known about outcomes in patients with rheumatoid arthritis (RA). The objective of the present study was to review the current evidence regarding rates of THA/TKA complications in RA versus OA.

Methods

Data sources used were Medline, EMBase, Cinahl, Web of Science, and reference lists of articles. We included reports published between 1990 and 2011 that described studies of primary total joint arthroplasty of the hip or knee and contained information on outcomes in ≥200 RA and OA joints. Outcomes of interest included revision, hip dislocation, infection, 90‐day mortality, and venous thromboembolic events. Two reviewers independently assessed each study for quality and extracted data. Where appropriate, meta‐analysis was performed; if this was not possible, the level of evidence was assessed qualitatively.

Results

Forty studies were included in this review. The results indicated that patients with RA are at increased risk of dislocation following THA (adjusted odds ratio 2.16 [95% confidence interval 1.52–3.07]). There was fair evidence to support the notion that risk of infection and risk of early revision following TKA are increased in RA versus OA. There was no evidence of any differences in rates of revision at later time points, 90‐day mortality, or rates of venous thromboembolic events following THA or TKA in patients with RA versus OA. RA was explicitly defined in only 3 studies (7.5%), and only 11 studies (27.5%) included adjustment for covariates (e.g., age, sex, and comorbidity).

Conclusion

The findings of this literature review and meta‐analysis indicate that, compared to patients with OA, patients with RA are at higher risk of dislocation following THA and higher risk of infection following TKA.

     

Lumiracoxib is effective in the treatment of osteoarthritis of the knee: a 13 week, randomised, double blind study versus placebo and celecoxib

OBJECTIVES: To compare the efficacy and safety of lumiracoxib with placebo and celecoxib for osteoarthritis OA in a 13 week, multicentre, randomised, double blind study. METHODS: After a 37 day washout period for nonsteroidal antiinflammatory drugs, 1702 patients with knee OA were randomised to lumiracoxib 200 or 400 mg once daily od, celecoxib 200 mg od, or placebo 2221. A visual analogue scale VAS pain intensity > or =40 mm was required. Primary efficacy variables were OA pain intensity VAS mm in the target knee, patients global assessment of disease activity VAS mm, and WOMAC pain subscale and total scores at 13 weeks. OA pain intensity, patients and physicians global assessment of disease activity, and WOMAC total and all subscale scores were analysed by visit as secondary variables. RESULTS: Lumiracoxib showed significant improvements in all primary and secondary variables compared with placebo. Lumiracoxib 200 mg od and celecoxib 200 mg od achieved similar improvements in OA pain intensity and functional status. Lumiracoxib 400 mg od demonstrated better efficacy for OA pain intensity and patients global assessment of disease activity at weeks 2, 4, and 8 and similar efficacy at week 13 compared with celecoxib 200 mg od. The incidence of adverse events AEs, serious AEs, and discontinuations due to AEs was similar in each group. CONCLUSION: Lumiracoxib demonstrated significant improvement in OA pain intensity, patients global assessment of disease activity, and the WOMAC pain subscale and total scores compared with placebo. Lumiracoxib was well tolerated in this study, with overall tolerability similar to that of placebo and celecoxib.     

Risk of revision for infection in primary total hip and knee arthroplasty in patients with rheumatoid arthritis compared with osteoarthritis: A prospective,population‐based study on 108,786 hip and knee joint arthroplasties from the Norwegian Arthroplasty Register

Objective

To compare differences in the risk of revision for infection and changes in risk over time and in time from primary surgery to revision for infection after total hip replacement (THR) and total knee replacement (TKR) in rheumatoid arthritis (RA) and osteoarthritis (OA) patients.

Methods

In the Norwegian Arthroplasty Register, 6,629 and 102,157 primary total joint replacements in patients with RA and OA, respectively, were identified from 1987 (1994 for knees) until 2008. Survival analyses with revision due to infection as the end point were performed using Kaplan‐Meier methods for constructing survival curves and multiple Cox regression to calculate relative risk (RR) estimates for diagnosis, age, sex, and year of primary surgery. An extended Cox model was used to estimate RR within different followup intervals.

Results

RA patients with TKR had a 1.6 times higher risk of revision for infection than OA patients, whereas there was no difference in the THRs. In the THRs, we found a higher risk of revision for infection from 2001 onward, whereas the development for TKRs was the opposite. These time effects affected the RA and OA groups equally. The risk of revision for infection from 6 years postoperatively on was higher in RA patients.

Conclusion

The overall risk of revision for infection after TKR was higher in RA patients. The risk of late infection leading to revision of the TKR and THR was higher in RA patients than in OA patients. After the year 2000, the RR of revision for infection in RA compared with OA remained unchanged.     

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.     

Knee pain, knee osteoarthritis, and the risk of fracture

OBJECTIVE: Patients with osteoarthritis (OA) have increased bone mineral density; however, the association between knee OA and fracture is controversial. Few data exist on the association between knee pain and fracture. We examined the association of knee OA and knee pain with fracture and falls in elderly men and women. METHODS: The study group comprised 6,641 men and women ages > or =75 years who participated in a 3-year randomized controlled trial of intramuscular vitamin D therapy. Patients completed a questionnaire about knee pain and OA. Fracture and fall data were collected prospectively every 6 months. RESULTS: Knee pain prevalence and a clinician diagnosis of knee OA were 35.2% and 6.8%, respectively. A total of 436 incident nonvertebral fractures were reported, and 3,992 patients sustained a fall. Prevalent knee pain was associated with an increased risk of falls (hazard ratio [HR] 1.26, 95% confidence interval [95% CI] 1.17-1.36) and hip fracture (HR 2.0, 95% CI 1.18-3.37). Increasing severity of knee pain was associated with a greater risk of falls and hip fracture. Clinician diagnosis of knee OA was associated with an increased risk of nonvertebral fractures (HR 1.61, 95% CI 1.09-2.36). The increased risk of fracture was not substantially reduced by adjusting for falls, but was attenuated by adjustment for the use of walking aids. CONCLUSION: Patients with a clinical diagnosis of knee OA and with knee pain have an increased risk of nonvertebral and hip fracture. This is not explained by the increased risk of falls, but is more likely to be due to the severity of falls sustained. Knee pain and OA should be regarded as independent risk factors for fracture.     

Coping, pain, and disability in osteoarthritis: a longitudinal study

OBJECTIVE: To establish the role of coping styles as prospective determinants of pain and disability in patients with osteoarthritis (OA) of the knee or hip. METHODS: Data from 71 patients with OA of the hip and 119 patients with OA of the knee were used. Using regression analysis, relationships were established between the use of active and passive coping styles and the level of pain and disability 36 weeks later. RESULTS: In patients with knee OA, the passive coping style of resting was found to predict a higher level of disability 36 weeks later after controlling for the baseline level of disability. In the same manner in patients with knee OA, the active coping style of transforming pain was found to predict higher levels of pain 36 weeks later. In patients with hip OA, no significant relationship between coping styles and pain and disability was found. CONCLUSION: The role of resting as a prospective determinant of disability, as reported in patients with other chronic disorders, could also be established for knee OA, but not hip OA. Transforming pain was found to be a risk factor for pain in knee OA.