Quantitative magnetic resonance imaging evaluation of knee osteoarthritis progression over two years and correlation with clinical symptoms and radiologic changes

OBJECTIVE

To evaluate the change in osteoarthritic (OA) knee cartilage volume over a two-year period with the use of magnetic resonance imaging (MRI) and to correlate the MRI changes with radiologic changes.

METHODS

Thirty-two patients with symptomatic knee OA underwent MRI of the knee at baseline and at 6, 12, 18, and 24 months. Loss of cartilage volumes were computed and contrasted with changes in clinical variables for OA and with standardized semiflexed knee radiographs at baseline at 1 and 2 years.

RESULTS

Progression of cartilage loss at all followup points was statistically significant (P < 0.0001), with a mean +/- SD of 3.8 +/- 5.1% for global cartilage loss and 4.3 +/- 6.5% for medial compartment cartilage loss at 6 months, 3.6 +/- 5.1% and 4.2 +/- 7.5% at 12 months, and 6.1 +/- 7.2% and 7.6 +/- 8.6% at 24 months. Discriminant function analysis identified 2 groups of patients, those who progressed slowly (<2% of global cartilage loss; n = 21) and those who progressed rapidly (>15% of global cartilage loss; n = 11) over the 2 years of study. At baseline, there was a greater proportion of women (P = 0.001), a lower range of motion (P = 0.01), a greater circumference and higher level of pain (P = 0.05) and stiffness in the study knee, and a higher body mass index in the fast progressor group compared with the slow progressor group. No statistical correlation between loss of cartilage volume and radiographic changes was seen.

CONCLUSION

Quantitative MRI can measure the progression of knee OA precisely and can help to identify patients with rapidly progressing disease. These findings indicate that MRI could be helpful in assessing the effects of treatment with structure-modifying agents in OA.

Quantitative magnetic resonance imaging of articular cartilage in knee osteoarthritis

PURPOSE OF REVIEW

Attempts to evaluate knee cartilage damage and progression seem logical in osteoarthritis research. Magnetic resonance imaging allows for precise visualization of joint structures such as cartilage, bone, synovial tissues, ligaments and menisci, and their pathologic changes.

RECENT FINDINGS

Recent advances in magnetic resonance technology have enabled researchers to evaluate cartilage damage and progression over the cross-sectional and longitudinal planes. Although anatomic changes can be seen, for many years the quantification of the cartilage changes has been the real challenge. Quantitative assessment of cartilage morphology using magnetic resonance imaging with fat-suppressed gradient echo sequences and digital postprocessing techniques provides high accuracy and adequate precision for cross-sectional and longitudinal studies in osteoarthritis patients. Recent data on precision, reliability, and sensitivity to change of quantitative parameters of cartilage morphology in osteoarthritis are presented in this review. Longitudinal studies currently available suggest that changes of cartilage volume, potentially as much as 5% per year, occur in osteoarthritis in most knee compartments, exceeding the variability of these measurements.

SUMMARY

Magnetic resonance imaging provides reliable and quantitative data on cartilage status throughout all compartments of the knee, and robust acquisition protocols for multicenter trials are now available. Magnetic resonance imaging technology should hopefully reduce the number of patients needed in clinical trials, improve retention of these patients, and reduce the overall costs and the length of clinical trials of treatment response to disease-modifying osteoarthritis drugs.

Computer-aided method for quantification of cartilage thickness and volume changes using MRI: validation study using a synthetic model

The primary objective of this study was to develop a computer-aided method for the quantification of three-dimensional (3-D) cartilage changes over time in knees with osteoarthritis (OA). We introduced a local coordinate system (LCS) for the femoral and tibial cartilage boundaries that provides a standardized representation of cartilage geometry, thickness, and volume. The LCS can be registered in different data sets from the same patient so that results can be directly compared. Cartilage boundaries are segmented from 3-D magnetic resonance (MR) slices with a semi-automated method and transformed into offset-maps, defined by the LCS. Volumes and thickness are computed from these offset-maps. Further anatomical labeling allows focal volumes to be evaluated in predefined subregions. The accuracy of the automated behavior of the method was assessed, without any human intervention, using realistic, synthetic 3-D MR images of a human knee. The error in thickness evaluation is lower than 0.12 mm for the tibia and femur. Cartilage volumes in anatomical subregions show a coefficient of variation ranging from 0.11% to 0.32%. This method improves noninvasive 3-D analysis of cartilage thickness and volume and is well suited for in vivo follow-up clinical studies of OA knees.

Safety and efficacy of long-term intraarticular steroid injections in osteoarthritis of the knee: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

To evaluate the safety and efficacy of long-term intraarticular (IA) steroid injections for knee pain related to osteoarthritis (OA).

METHODS

In a randomized, double-blind trial, 68 patients with OA of the knee received IA injections of triamcinolone acetonide 40 mg (34 patients) or saline (34 patients) into the study knee every 3 months for up to 2 years. The primary outcome variable was radiologic progression of joint space narrowing of the injected knee after 2 years. Measurements of minimum joint space width were performed by an automated computerized method on standardized fluoroscopically guided radiographs taken with the patient standing and with the knee in a semiflexed position. The clinical efficacy measure of primary interest was the pain subscale from the Western Ontario and McMaster Universities OA Index (WOMAC). Efficacy measures of secondary interest were the total score on the WOMAC, physician's global assessment, patient's global assessment, patient's assessment of pain, range of motion (ROM) of the affected knee, and 50-foot walking time. Clinical symptoms were assessed just before each injection.

RESULTS

At the 1-year and 2-year followup evaluations, no difference was noted between the two treatment groups with respect to loss of joint space over time. The steroid-injected knees showed a trend toward greater symptom improvement, especially at 1 year, for the WOMAC pain subscale, night pain, and ROM values (P = 0.05) compared with the saline-injected knees. Using area under the curve analyses, knee pain and stiffness were significantly improved throughout the 2-year study by repeated injections of triamcinolone acetonide, but not saline (P < 0.05).

CONCLUSION

Our findings support the long-term safety of IA steroid injections for patients with symptomatic knee OA. No deleterious effects of the long-term administration of IA steroids on the anatomical structure of the knee were noted. Moreover, long-term treatment of knee OA with repeated steroid injections appears to be clinically effective for the relief of symptoms of the disease.

A prospective, randomized, pragmatic, health outcomes trial evaluating the incorporation of hylan G-F 20 into the treatment paradigm for patients with knee osteoarthritis (Part 2 of 2): economic results

OBJECTIVE

Viscosupplementation with hylan G-F 20 has recently become registered for treatment of patients with osteoarthritis (OA) of the knee in most parts of the world. The cost effectiveness and cost utility of this new therapeutic modality were determined as part of a Canadian prospective, randomized, 1-year, open-label, multicentered trial.

DESIGN

A total of 255 patients were randomized to 'Appropriate care with hylan G-F 20' (AC+H) or 'Appropriate care without hylan G-F 20' (AC). Costs (1999 Canadian dollars) were collected from the societal viewpoint and included all costs related to OA of the knee and OA in all joints. Patients completed a number of outcomes questionnaires including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Health Utilities Index Mark 3 (HUI3). Data were collected at clinic visits (baseline, 12 months) and by telephone (1, 2, 4, 6, 8, 10, and 12 months).

RESULTS

The AC+H group over the year had higher costs ($2125-$1415=$710, P< 0.05), more patients improved (69%-40%=29%,P =0.0001), greater increases in HUI3 (0.13-0.03=0.10, P< 0.0001) and increased quality-adjusted life years (QALYs) (0.071, P< 0.05). The incremental cost-effectiveness ratio was $2505/patient improved. The incremental cost-utility ratio was $10000/QALY gained. Sensitivity analyses and a second cost perspective gave similar results.

CONCLUSION

The cost-utility ratio is below the suggested Canadian adoption threshold. The results provide strong evidence for adoption of treatment with hylan G-F 20 in the patients and settings studied in the trial.

Pharmacologic therapy of osteoarthritis

This article presents a brief review of the most current therapies that are used for the relief of the symptoms related to osteoarthritis. The agents used either systematically or locally are described, providing the rationale for their usage in the treatment of osteoarthritis. Moreover, new therapies that have reached clinical evaluations and that can possibly reduce or stop the progression of the disease--namely the inhibitors of metalloproteases--are presented. Overall, it is obvious that significant progress has been made toward the development of new therapeutic agents to reduce the symptoms as well as the structural changes of the disease.

Strong association of autoantibodies to human nuclear lamin B1 with lupus anticoagulant antibodies in systemic lupus erythematosus

OBJECTIVE

To determine the frequency and clinical significance of high titers of IgG autoantibodies to nuclear lamin B1 in a large number of unselected and well-characterized systemic lupus erythematosus (SLE) patients, disease controls, and normal healthy controls.

METHODS

A cross-sectional study of anti-lamin B1 autoantibodies, as measured by enzyme-linked immunosorbent assay using human recombinant lamin B1 autoantigen, was performed on serum samples obtained at first evaluation of 238 consecutive French Canadian adults: 61 healthy control subjects, 20 patients with osteoarthritis, 22 with ankylosing spondylitis, 11 with autoimmune hepatitis, 30 with rheumatoid arthritis, and 94 with SLE. SLE patients were studied for 57 disease manifestations. A case-control study was performed to analyze the relationship between anti-lamin B1 status and thrombotic manifestations between SLE onset and last followup.

RESULTS

High titers of anti-lamin B1 were strikingly restricted to a subset of 8 SLE patients (8.5%). The mean anti-lamin B1 titer was higher in this subset than in the other SLE patients or any control group (P<0.001). By univariate analysis and stepwise multiple logistic regression, the most striking association of anti-lamin B1 was with lupus anticoagulant (LAC) antibodies (P = 0.00001). Although LAC were significantly associated with thrombosis in our SLE patients, anti-lamin B1 was not. The frequency of thrombosis in SLE patients expressing both LAC and anti-lamin B1 was similar to that in patients without LAC (P = 1.0). However, patients expressing LAC without anti-lamin B1 had a greater frequency of thrombosis (P = 0.018).

CONCLUSION

High titers of IgG anti-lamin B1 autoantibodies are highly specific for a subset of SLE patients whose clinical characteristics include the presence of LAC and other laboratory manifestations of the antiphospholipid syndrome. The presence of LAC without anti-lamin B1 may define a subset of SLE patients at greater risk for thrombosis.

Collagenase-1 and collagenase-3 synthesis in normal and early experimental osteoarthritic canine cartilage: an immunohistochemical study

OBJECTIVE

The coexistence of different collagenases in cartilage suggests the possibility of specific roles for these enzymes in the degradation of the collagen network in osteoarthritis (OA). We investigated the in situ synthesis and distribution of collagenase- and collegenase-3 in normal and early experimental OA cartilage.

METHODS

The OA model was created on 12 mongrel dogs by sectioning the anterior cruciate ligament of the right stifle joint with a stab wound. Dogs were divided into 3 groups of 4 animals each, and sacrificed at 4, 8, and 12 weeks, respectively. A 4th group (n = 4) of unoperated dogs was used as control. Articular cartilage from femoral condyles and tibial plateaus was examined histologically to grade severity of lesions, and immunohistochemical and morphometric analyses were performed to detect the presence of chondrocytes producing collagenase-1 and -3.

RESULTS

In OA dogs, the histologic severity of lesions increased with time, being most severe at 8 and 12 weeks after surgery. In cartilage from OA compared to unoperated dogs, the immunoreactivity was 5-9 times higher (p < 0.0002) for collagenase-1, and 3-6 times higher (p < 0.0002) for collagenase-3, in both femoral condyles and tibial plateaus. Although the cell score increased throughout the cartilage, comparison of the superficial and upper intermediate layers (superficial) with the lower intermediate and deep layers (deep) revealed a significantly higher level for collagenase-1 (p < 0.007) in the superficial layers, contrary to the collagenase-3 data, which indicated a higher level (p < 0.007) in the deep layers. For collagenase- , the cell score increased steadily up to the 12th week, and for collagenase-3, the elevation peaked at 8 weeks. Correlation between the histologic severity and cell score in cartilage specimens from unoperated and OA dogs revealed the highest coefficient for collagenase- at the superficial layers (r = 0.69, p < 0.0001), while for collagenase-3, this was noted at the deep layers (r = 0.65, p < 0.0004).

CONCLUSION

The number of chondrocytes involved in the synthesis of collagenase-1 and collegenase-3 increases dramatically in the early phase of OA. However, the difference in the topographic distribution of these enzymes, as well as the variation in their correlation pattern, may reflect a different function allocated for each collagenase in the OA cartilage degradation process.

Lymphoma and luekemia in rheumatoid arthritis: are they associated with azathioprine, cyclophosphamide, or methotrexate?

Incident cases of lymphoma and leukemia in a cohort of 3824 rheumatoid arthritis (RA) patients from the Arthritis, Rheumatism and Aging Medical Information System (ARAMIS) database were identified, and the use of azathioprine, cyclophosphamide, and methotrexate was compared in a matched case-control study. Controls were matched on age, sex, year of study entry, disease duration, center, and years of follow-up. Twenty-four cases of lymphoma and 10 cases of leukemia were identified: 21% of patients with cancer versus 9% of controls had taken azathioprine [McNemar statistic 1.50 (p = 0.22), odds ratio 5.0 (95% confidence interval 0.6,236.5)]. Equal numbers of cases and controls (6% each) had taken cyclophosphamide and 18% of cases and 12% of controls had taken methotrexate [McNemar statistic 0.13 (p = 0.72), odds ratio 1.7 (0.3, 10.7)]. Results suggest but do not prove that RA patients taking azathioprine and methotrexate may have an increased risk of developing lymphoma. However, even if this increased risk can be confirmed, it accounts for only a small proportion of the greatly increased incidence of these malignancies in RA.

Comparing the bivariate effects of toxicity and efficacy of treatments

Medical studies often involve comparing the toxicity and efficacy of drugs. Separately evaluating toxicity and efficacy, the usual practice, does not correspond to how doctors manage patients and does not use the information provided in their bivariate relationship. This paper presents methods for analysing the bivariate data. One method is based on assessing the benefit for patient values to lie in different regions of the toxicity-efficacy plane. A second method includes patient thresholds for tolerating drugs. We propose dividing the toxicity-efficacy plane into regions where patients are likely to tolerate the drug. Several statistics are defined on these regions for measuring the toxic-therapeutic relationship, and the bootstrap is proposed for estimating their variances. We illustrate with treatment information available on rheumatoid arthritis patients.

The in vivo effects of intraarticular corticosteroid injections on cartilage lesions, stromelysin, interleukin-1, and oncogene protein synthesis in experimental osteoarthritis

BACKGROUND

Osteoarthritis (OA) is characterized by a progressive erosion of the articular cartilage. Studies suggest that cytokines and metalloproteases play an important role in this process. Previously, we found that corticosteroids given prophylactically reduce the severity of cartilage lesions. In this study, we examined and compared the in vivo efficacy of a corticosteroid, triamcinolone hexacetonide (TH), administered either prophylactically or therapeutically, on OA lesions and on cartilage metalloproteases, interleukin-1 beta (IL-1 beta), and oncogene synthesis in experimental OA.

EXPERIMENTAL DESIGN

This study examines the effect of intraarticular injections of TH on the progression of lesions in the experimental dog model of OA. The animals had the anterior cruciate ligament of the right knee sectioned and were killed 12 weeks after surgery. A total of 30 dogs were used in four groups: group 1 (n = 8) had no treatment; group 2 (n = 8; TH-3) received TH at time of surgery and at 4 and 8 weeks later; group 3 (n = 7; TH-2) received TH at 4 and 8 weeks after surgery; and group 4 (n = 7; TH-1) received TH at 8 weeks after surgery. Knee cartilage was submitted to macroscopic and microscopic examinations, as well as immunohistochemical studies for stromelysin, IL-1 beta, and oncoproteins, c-Fos and c-Myc.

RESULTS

Injections with TH significantly reduced the size of osteophytes in dogs from groups TH-3 (p < 0.0001) and TH-2 (p < 0.0002). The histologic severity of cartilage lesions was significantly reduced on condyles in all TH groups and on plateaus of dogs from groups TH-3 and TH-2. Immunohistochemistry revealed that TH significantly reduced the percentage of immunoreactive chondrocytes for stromelysin, and the effect was proportional to the number of injections received. For c-fos and c-myc, the reduction was particularly significant in the TH-3 and TH-2 groups. For IL-1 beta, the reduction was significant only in the TH-3 group.

CONCLUSIONS

This study provides novel data showing the protective effect of corticosteroid injections on OA cartilage lesions not only under prophylactic but also under therapeutic conditions. The effect of TH may be mediated through a direct reduction in the expression and synthesis of proteolytic enzymes, such as stromelysin. Alternatively, the steroid could act by inhibiting the stimulation of protease synthesis by cytokines/oncogenes (IL-1 beta, c-Fos, and c-Myc).

Serum keratan sulfate levels in rheumatoid arthritis: inverse correlation with radiographic staging

OBJECTIVE

To correlate the serum levels of keratan sulfate (KS) in patients with rheumatoid arthritis (RA) with different clinical and radiographic variables.

METHODS

Serum KS levels were measured in 85 patients with RA and 41 age matched controls. Patients with RA were classified according to their disease activity, the presence of rheumatoid factor, the medication prescribed, and to the severity of the joint radiographic changes.

RESULTS

Patients with RA had significantly (p < 0.02) higher levels of serum KS compared to the healthy controls. More significantly, there was an inverse correlation of the serum KS levels with the disease activity (p = 0.02) and the severity of the radiographic changes (p = 0.012).

CONCLUSIONS

Serum KS levels appear to correlate with the severity of articular cartilage damage in RA.

Intraarticular injections with methylprednisolone acetate reduce osteoarthritic lesions in parallel with chondrocyte stromelysin synthesis in experimental osteoarthritis

OBJECTIVE

To examine the effect of intraarticular injections of methylprednisolone acetate (MA) on osteoarthritic lesions and chondrocyte stromelysin synthesis in experimental osteoarthritis (OA).

METHODS

In 15 mongrel dogs, the anterior cruciate ligament of the right knee was sectioned by a stab wound. Eight dogs received intraarticular injections of MA (20 mg) at the time of surgery and 4 weeks later; 7 had no treatment. The dogs were killed 8 weeks after surgery. Five normal dogs were used as controls. Macroscopic evaluation of the lesions, including measurements of osteophytes and areas of surface lesions on the condyles and plateaus, was conducted, along with histologic evaluation of the severity of lesions. Immunohistochemical analysis was carried out using a rabbit polyclonal antibody against stromelysin, followed by evaluation of matrix and chondrocyte staining using morphometric analysis.

RESULTS

Treatment with MA significantly reduced the incidence (P < 0.0004) and size (P < 0.0001) of osteophytes. The histologic grading of cartilage lesions was also significantly reduced both on condyles (P < 0.01) and on plateaus (P < 0.002). Immunohistochemical studies revealed, for OA cartilage, a marked increase (P < 0.002) in the percentage of chondrocytes positive for stromelysin and in the intensity of staining throughout all the layers of the cartilage, as well as specific matrix staining (P < 0.005). Treatment with MA reduced staining at both the chondrocyte (P < 0.002) and the matrix (P < 0.01) levels toward normal.

CONCLUSION

These findings provide additional evidence for the protective effect of corticosteroid injections on OA lesions, and indicate that the effect of this drug may be mediated through the suppression of stromelysin synthesis.

A reevaluation of aspirin therapy in rheumatoid arthritis

BACKGROUND

Aspirin therapy has been largely superseded by prescription nonsteroidal anti-inflammatory drug (NSAID) therapy in rheumatoid arthritis, in part because of premarketing studies suggesting lesser toxic effects for NSAIDs than for aspirin. This study evaluates these toxic effects in a postmarketing population of patients with rheumatoid arthritis.

METHODS

We studied 1521 consecutive courses of aspirin and 4860 courses of NSAIDs in patients with rheumatoid arthritis from eight Arthritis, Rheumatism, and Aging Medical Information System Post-marketing Surveillance Centers. Toxicity index scores were generated from symptoms, laboratory abnormalities, and hospitalizations, weighted for variable severity and severity of side effect.

RESULTS

The toxicity index was only 1.37 (SE = 0.10) for aspirin and 1.87 to 2.90 for selected nonsalicylate NSAIDs. These differences were consistent across centers and remained after statistical adjustment for differing patient characteristics. There was a different toxicity with different aspirin preparations, with a score for plain aspirin of 1.36 (SE = 0.23), for buffered aspirin of 1.10 (0.20), and for enteric-coated aspirin preparations of 0.92 (0.14). Most important, there were strong dose effects, with a score of 0.73 (0.09) for 651 to 2600 mg daily, 1.08 (0.17) for 2601 to 3900 mg, and 1.91 (0.38) for more than 3900 mg. The average aspirin dose taken was only 2665 mg/d, approximately eight "tablets," compared with 3600 to 4800 mg/d used in the 16 pivotal premarketing studies reviewed. Average NSAID doses were, on the other hand, lower in premarketing trials (eg, naproxen 500 mg/d vs 773 mg/d in the Arthritis, Rheumatism, and Aging Medical System clinical practices).

CONCLUSIONS

Aspirin therapy, in doses commonly employed in practice, has an excellent safety profile in rheumatoid arthritis, and it is the least costly NSAID. The safety advantage is explained primarily by a dose effect and secondarily by possible differences between formulations. Newer management strategies for rheumatoid arthritis emphasize NSAID use as symptomatic therapy and use of disease-modifying anti-rheumatic drug therapy for anti-inflammatory objectives. Thus, the original recommendation for "anti-inflammatory" doses of aspirin now is less easily justified. Aspirin therapy merits reconsideration as adjunctive therapy for the management of rheumatoid arthritis.

Seasonal variation in the onset of Wegener's granulomatosis, polyarteritis nodosa and giant cell arteritis

OBJECTIVE

The hypothesis of a seasonal pattern in the onset of symptoms for some vasculitides has been raised in previous small studies.

METHODS

Using the data collected by the American College of Rheumatology (ACR) Subcommittee on Classification of Vasculitis, we specifically tested for a higher proportion of onset of symptoms in winter, lower in summer, and intermediate for the other seasons for polyarteritis nodosa (PAN) and Wegener's granulomatosis. We also tested for a higher proportion of onset of symptoms in the spring-summer months for giant cell arteritis (GCA).

RESULTS AND CONCLUSIONS

The results of our study support the hypothesis of a seasonal trend for the onset of symptoms of Wegener's granulomatosis (p = 0.04) as described previously. No seasonal pattern was found for the other vasculitides studied (PAN and GCA).

Unilateral ptosis as an initial manifestation of D-penicillamine induced myasthenia gravis

We describe 2 patients presenting with isolated unilateral ptosis without other signs of cranial or peripheral nerve involvement or sympathetic denervation. Both patients (one case of progressive systemic sclerosis and one of rheumatoid arthritis) were currently taking D-penicillamine. In these cases, the ptosis was reversed a few minutes after a Tensilon test, hallmark of myasthenia gravis. Antibodies to acetylcholine receptors were present. Myasthenia gravis should be suspected with ptosis without other cranial nerve involvement or miosis, even if the ptosis is unilateral. Thus, unilateral ptosis can be the first manifestation of a toxic side reaction to D-penicillamine.

The health assessment questionnaire 1992: status and review

Over 100 papers describing and utilizing the Stanford Health Assessment Questionnaire (HAQ) have been published since 1980. A brief overview of the HAQ is presented along with a guide to the accumulated literature. The topics covered include: studies using the disability, pain, economic, and drug side effect dimensions of the HAQ; reliability and validity studies; applications to various rheumatic diseases; language adaptations; modifications and derivative scales; studies correlating the HAQ with sociodemographic, health status, laboratory, and physical measures; and randomized controlled trials and observational studies using the HAQ. A few comments regarding future directions for research are also presented.