Cochrane for Clinicians

Putting Evidence into Practice

Intra-articular Corticosteroid for Treating Osteoarthritis of the Knee

Steven E. Roskos, M.D., University of Tennessee, Graduate School of Medicine, Knoxville, Tennessee

The Cochrane Abstract below is a summary of a review from the Cochrane Library. It is accompanied by an interpretation that will help clinicians put evidence into practice. Steven E. Roskos, M.D., presents a clinical scenario and question based on the Cochrane Abstract, followed by an evidence-based answer and a full critique of the review.

This clinical content conforms to AAFP criteria for evidence-based continuing medical education (EB CME). EB CME is clinical content presented with practice recommendations supported by evidence that has been reviewed systematically by an AAFP-approved source. The practice recommendations in this activity are available online at http://www.cochrane.org/cochrane/revabstr/AB005328.htm.

Clinical Scenario

A 60-year-old woman with osteoarthritis of her right knee has pain and swelling despite daily use of nonsteroidal anti-inflammatory drugs (NSAIDs).

Clinical Question

Would this patient benefit from an intra-articular injection of a corticosteroid?

Evidence-Based Answer

An injection of the knee joint with a corticosteroid may improve the patient's symptoms for up to three weeks after the injection (number needed to treat [NNT]= 3 to 4). There is no evidence that this intervention improves function, and there is little evidence of the benefits persisting beyond three weeks. Risk of dangerous adverse effects is minimal. Injection of hyaluronan and hylan products (Hyalgan, Orthovisc, Synvisc) may provide longer-lasting benefit.

Practice Pointers

This review1 shows that intra-articular injection of a corticosteroid is useful in improving pain and the patient's global assessment of symptoms for up to three weeks in patients with osteoarthritis of the knee. The analysis was based on 26 trials with a total of
1,721 patients. However, most studies were small and brief, with fewer than 100 participants and a duration of less than 26 weeks. Only good-quality studies that used standardized rheumatologic outcome measures were included in the review. The authors made an adequate attempt to find all relevant articles and combined data using standard techniques.

There are many effective treatments available for mild symptomatic osteoarthritis, including patient education, physical and occupational therapy, oral and topical analgesics, and NSAIDs.2-4 Nonetheless, many patients still suffer from pain and reduced function despite treatment efforts. Since the 1950s, patients have been given intra-articular corticosteroid injections when other nonsurgical therapies are inadequate. This review did not find strong evidence to support the use of one particular corticosteroid preparation, dose, injection technique, or frequency of injection, but triamcinolone hexacetonide (Aristospan) was superior to betamethasone (Celestone) in the number of patients reporting pain relief at four weeks. The reviewers also found no particular indication (e.g., joint effusion) that would help select patients who are more likely to benefit.

The same authors published a separate review5 of injection with hyaluronan and hylan derivatives for osteoarthritis of the knee, in which they found this treatment to be effective. The Cochrane Collaboration has elsewhere reviewed corticosteroid injections for shoulder pain,6 finding weak evidence for a small and short-lived benefit in rotator cuff disease and adhesive capsulitis. The collaboration also has reviewed local injection of corticosteroid for carpal tunnel syndrome7 and found benefit lasting up to one month. Some evidence-based clinical guidelines2,4 recommend intra-articular corticosteroid injection for treatment of osteoarthritis of the knee when other, more conservative, treatments are not effective. Several authors have described injection techniques in detail.8-10 This Cochrane review covers the best and most recent evidence available and supports the use of intra-articular corticosteroids for osteoarthritis of the knee.

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The Author

Steven E. Roskos, M.D., is assistant professor of family medicine at the University of Tennessee, Graduate School of Medicine, Knoxville. He received his medical degree from Temple University School of Medicine, Philadelphia, and completed a residency in family medicine at Lancaster General Hospital, Lancaster, Pa.

Address correspondence to Steven E. Roskos, M.D., Department of Family Medicine, University of Tennessee, Graduate School of Medicine, 1924 Alcoa Highway, U-67, Knoxville, TN 37920 (e-mail: sroskos@mc.utmck.edu). Reprints are not available from the author.

REFERENCES

1. Bellamy N, Campbell J, Robinson V, Gee T, Bourne R, Wells G. Intraarticular corticosteroid for treatment of osteoarthritis of the knee. Cochrane Database Syst Rev 2005;(2):CD005328.

2. Recommendations for the medical management of osteoarthritis of the hip and knee: 2000 update. American College of Rheumatology Subcommittee on Osteoarthritis Guidelines. Arthritis Rheum 2000;43:1905-15.

3. Health care guideline: diagnosis and treatment of adult degenerative joint disease (DJD) of the knee. Bloomington, Minn.: Institute for Clinical Systems Improvement, 2004. Accessed online July 13, 2005, at: http://www.icsi.org/knowledge/detail.asp?catID=29&itemID=165.

4. Simon LS, Lipman AG, Jacox AK, Caudill-Slosberg M, Gill LH, Keefe FJ, et al. Pain in osteoarthritis, rheumatoid arthritis, and juvenile chronic arthritis. 2d ed. Glenview, Ill.: American Pain Society, 2002. Summary accessed online July 13, 2005, at: http://www.guideline.gov/summary/summary.aspx?ss=15&doc_id=3691.

5. Bellamy N, Campbell J, Robinson V, Gee T, Bourne R, Wells G. Viscosupplementation for the treatment of osteoarthritis of the knee. Cochrane Database Syst Rev 2005;(2):CD005321.

6. Buchbinder R, Green S, Youd JM. Corticosteroid injections for shoulder pain. Cochrane Database Syst Rev 2003;(1):CD004016.

7. Marshall S, Tardif G, Ashworth N. Local corticosteroid injection for carpal tunnel syndrome. Cochrane Database Syst Rev 2002;(4):CD001554.

8. Cardone DA, Tallia AF. Diagnostic and therapeutic injection of the hip and knee. Am Fam Physician 2003;67:2147-52.

9. Greene WB, ed. Essentials of musculoskeletal care. 2d ed. Rosemont, Ill.: American Academy of Orthopaedic Surgeons, 2001:20-3,371-2.

10. Pfenninger JL. Joint and soft tissue aspiration and injection (arthrocentesis). In: Pfenninger JL, Fowler GC, eds. Pfenninger and Fowler's Procedures for primary care. 2d ed. St. Louis: Mosby, 2003:1479-500.

Cochrane Briefs

clarissa kripke, m.d.

Does a Low Glycemic Index Diet Reduce CHD?

Clinical Question

For patients with risk factors for coronary heart disease (CHD), does a low glycemic index diet reduce heart disease or improve risk factors?

Evidence-Based Answer

There is limited, weak evidence that a low glycemic index diet improves risk factors for CHD, but there are no randomized controlled trials (RCTs) showing a reduction in morbidity or mortality. (SORT rating C)

Practice Pointers

CHD is associated with high fat intake. However, there is uncertainty regarding how rapidly-metabolized dietary carbohydrates may affect the risk for heart attack and stroke. The glycemic index is a measure of the effect of dietary carbohydrate on blood glucose, on a scale from zero to 100; higher numbers correspond to a greater effect.

Kelly and colleagues systematically reviewed RCTs to determine whether a low glycemic index diet decreased mortality or CHD events (patient-oriented outcomes) or had a beneficial effect on risk factors for CHD such as abnormal lipids, glucose metabolism, blood pressure, weight, and clotting factors (surrogate markers that may or may not affect patient outcomes). Fifteen trials lasting four weeks or more were identified. Interventions included dietary advice or a prescribed diet for adult outpatients with at least one major risk factor. None of the studies reported morbidity or mortality. The studies were of poor quality and had too few patients to identify clinically important effects. There was a small reduction in A1C (0.45 percent) and total cholesterol levels (6.6 mg per 100 mL [0.17 mmol per L]). However, these outcomes were not sufficient to recommend low glycemic index diets for patients with risk factors for CHD.

Despite the lack of supporting evidence, several organizations recommend diets rich in complex carbohydrates for patients with risk factors for CHD. The National Cholesterol Education Program (NCEP) recommends that 50 to 60 percent of calories come from foods rich in complex carbohydrates, including grains (especially whole grains), fruits, and vegetables1; this is essentially a low glycemic index diet. The American Dietetic Association supports the dietary recommendations of the NCEP for patients with hyperlipidemia.2 The U.S. Preventive Services Task Force recommends intensive behavioral dietary counseling for adult patients with hyperlipidemia and other known risk factors for cardiovascular disease, but does not specify which diet should be recommended.3

editor's note: See p. 1154 or http://www.aafp.org/afpsort.xml for SORT information.

Kelly S, et al. Low glycaemic index diets for coronary heart disease. Cochrane Database Syst Rev 2004;(4):CD004467.

REFERENCES

1. Grundy SM, Cleeman JI, Merz CN, Brewer HB Jr, Clark LT, Hunninghake DB, et al. Implications of recent clinical trials for the National Cholesterol Education Program Adult Treatment Panel III guidelines. Circulation 2004;110:227-39.

2. American Dietetic Association. Hyperlipidemia medical nutrition therapy protocol. Chicago: American Dietetic Association, 2001.

3. U.S. Preventive Services Task Force. Behavioral counseling in primary care to promote a healthy diet: recommendations and rationale. Am J Prev Med 2003;24:93-100.

Lower- vs. Higher-Dose Estrogen for Contraception

Clinical Question

Compared with higher-dose pills, are combination oral contraceptives with 20 mcg of estrogen (ethinyl estradiol) equally effective and well tolerated?

Evidence-Based Answer

Although no difference in effectiveness has been demonstrated in existing trials, too few patients have been studied to detect small but clinically important differences in pregnancy rates. Low-dose estrogen pills have higher rates of discontinuation and bleeding disturbances.

Practice Pointers

Although complications are rare with these pills, combination oral contraceptives have been linked to breast cancer, cerebral vascular complications, thrombosis, and myocardial infarction. Therefore, many physicians and patients prefer to use the lowest-dose pill that will provide adequate cycle control and effectiveness.

Gallo and colleagues reviewed the literature to determine how pills containing 20 mcg of ethinyl estradiol compare with higher-dose pills. They found 69 randomized controlled trials. Most trials followed patients for six to 12 cycles. The trials varied in dose of estrogen and in type and dose of progesterone; therefore, meta-analysis was not possible. No trial found a difference in contraceptive effectiveness; however, because pregnancy in women who take oral contraceptives is uncommon, the studies were insufficiently powered to show such a difference. In many of the lower-dose groups, early discontinuation occurred because of amenorrhea, adverse events, or bleeding irregularities. More specific information about which pills are most effective or which estrogen-progestin combinations have the fewest bleeding problems could not be determined. Furthermore, it could not be determined whether lower-dose estrogen pills have the same advantages as higher-dose pills for prevention of ovarian and endometrial cancer and reduction of acne.

Current data indicate disadvantages, but no clear advantages, to combined contraceptive pills with 20 mcg of estrogen. Therefore, it is reasonable to prescribe pills with more than 20 mcg of ethinyl estradiol for most women. The American College of Obstetricians and Gynecologists (ACOG) finds little or no increased risk of oral contraceptives for women with fibroadenoma, benign breast disease with epithelial hyperplasia with or without atypia, or a family history of breast cancer.1 ACOG recommends progesterone-only pills for lactating women and those with increased risk of thromboembolism. Caution should be used when prescribing combination pills for women older than 35 years who smoke. ACOG recommends pills with less than 35 mcg of estrogen for women younger than 35 years who have hypertension.1

For all women, the best form of birth control is the one that will be used consistently. For women who wish to reduce side effects and have regular periods, pills with 30 to 35 mcg of ethinyl estradiol may be a better choice than those with only 20 mcg.

Gallo MF, et al. 20 mcg versus >20 mcg estrogen combined oral contraceptives for contraception. Cochrane Database Syst Rev 2004;(4):CD003989.

REFERENCE

1. ACOG Practice Bulletin no. 18, July 2000. The use of hormonal contraception in women with coexisting medical conditions. Washington, D.C.: American College of Obstetricians and Gynecologists, 2000.

The series coordinator for AFP is Clarissa Kripke, M.D., Department of Family and Community Medicine, University of California, San Francisco.

Copyright © 2005 by the American Academy of Family Physicians. This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP. Contact afpserv@aafp.org for copyright questions and/or permission requests.

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