Cochrane for Clinicians

Putting Evidence into Practice

Arthroscopic Surgery for Knee Osteoarthritis

nathan hitzeman, MD, and CRYSTAL MASLEY, MD
Sutter Health Family Medicine Residency Program, Sacramento, California

The Cochrane Abstract on the next page is a summary of a review from the Cochrane Library. It is accompanied by an interpretation that will help clinicians put evidence into practice. Drs. Hitzeman and Masley present a clinical scenario and question based on the Cochrane Abstract, followed by an evidence-based answer and a critique of the review. The practice recommendations in this activity are available at http://www.cochrane.org/reviews/en/ab005118.html.

Clinical Scenario

A 53-year-old man presents for follow-up of knee pain. Examination and plain radiography confirmed osteoarthritis. After little relief with analgesics and a corticosteroid injection, he inquires about arthroscopic surgery.

Clinical Question

Is arthroscopic debridement an effective therapy for improving pain and function in patients with osteoarthritis of the knee?

Evidence-Based Answer

Compared with other modalities of treatment such as sham surgery, joint lavage, and joint washout, arthroscopic debridement does not improve outcomes for patients with osteoarthritis of the knee.1

Practice Pointers

Various factors that contribute to degradation of articular cartilage include age, anatomy, genetics, obesity, and trauma. Arthroscopic surgery has been used for decades for the treatment of osteoarthritis of the knee and is common practice for meniscal or ligamental tears.2 However, its current role in the treatment of osteoarthritis of the knee is controversial.3

The authors of this Cochrane review found three studies that were too dissimilar to undergo meta-analysis calculations. Two of the studies were of poor quality. One 1993 study of 32 patients was inadequately powered, single-blinded, and did not describe concealment. A 1996 study of 76 patients was not blinded at all.

The best study was from 2002. It was a large double-blinded randomized controlled trial (RCT) of moderate quality. Participants were randomized into three groups: arthroscopic debridement, lavage, and sham surgery. Arthroscopic surgery was not shown to be beneficial. This study has been criticized.4 Participants were younger, more likely to be white, and more likely to have severe arthritis than those who chose not to participate; 44 percent of eligible patients declined to participate. The same surgeon performed all of the surgeries. Despite these limitations, this is the highest quality RCT to date of this common surgical procedure.

Sixteen international experts from four medical disciplines met to devise consensus guidelines for osteoarthritis of the knee and hip.3 Ranked by increasing "effect size" (the weighted mean difference or measurement of effectiveness used when comparing outcomes from different studies), the following treatments are beneficial for osteoarthritis pain of the knee: encouraging weight loss, acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDS) with gastroprotection, hyaluronate injections, topical NSAIDs or capsaicin, glucosamine sulfate (not glucosamine hydrochloride)5, acupuncture, aerobic exercise, thermal modalities (ice or heat), and steroid injections. Four patients need to be treated with steroid injections for one of them to have moderate pain relief at two and three weeks (number needed to treat [NNT] = 4), but evidence for relief of pain at four weeks and beyond is lacking. No serious adverse events were reported.6 Knee braces, lateral wedged insoles, transcutaneous electrical nerve stimulation units, and chondroitin supplements have less discernible benefit, but are thought to be safe. The guidelines published in BMJ Clinical Evidence generally agree with the above stated modalities, with the exception that acupuncture, capsaicin, and glucosamine are labeled as having unknown effectiveness.7

Opioid analgesics are not recommended as first-line agents for treatment, although many physicians prescribe them.3,7 On plain radiography, progression of disease does not correlate well with symptoms.8

Regarding surgical treatments, high tibial osteotomy for young and active patients with severe unicompartmental knee osteoarthritis may prolong time until joint replacement. Total knee joint arthroplasty is reasonable and cost-effective for severe, debilitating osteoarthritis. About 10 percent of patients will need a revision at 10 years.3

Address correspondence to Nathan Hitzeman, MD, at hitzemn@sutterhealth.org. Reprints are not available from the author.

Author disclosure: Nothing to disclose.

REFERENCES

1. Laupattarakasem W, Laopaiboon M, Laupattarakasem P, Sumananont C. Arthroscopic debridement for knee osteoarthritis. Cochrane Database Syst Rev. 2008;(1):CD005118.

2. Owings MF, Kozak L J. Ambulatory and inpatient procedures in the United States, 1996. Vital Health Stat 13. 1998;(139):1-119.

3. Zhang W, Moskowitz RW, Nuki G, et al. OARSI recommendations for the management of hip and knee osteoarthritis, Part II: OARSI evidence-based, expert consensus guidelines. Osteoarthritis Cartilage. 2008;16(2):137-162.

4. Bernstein J, Quach T. A perspective on the study of Moseley et al: questioning the value of arthroscopic knee surgery for osteoarthritis. Cleve Clin J Med. 2003;70(5):401,405-406,408-410.

5. Clegg DO, Reda DJ, Harris CL, et al. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. N Engl J Med. 2006;354(8):795-808.

6. 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. 2006;(2):CD005328.

7. Scott D, Kowalczyk A. Osteoarthritis of the knee. BMJ Clin Evid. 2007;12:389-390.

8. Dieppe PA, Cushnaghan J, Shepstone L. The Bristol 'OA500' study: progression of osteoarthritis (OA) over 3 years and the relationship between clinical and radiographic changes at the knee joint. Osteoarthritis Cartilage. 1997;5(2):87-97.

Cochrane Briefs

Cranberry Products for Treatment of Urinary Tract Infection

Clinical Question

Does ingesting cranberry reduce the frequency of symptomatic urinary tract infections or asymptomatic bacteriuria?

Evidence-Based Answer

Over a 12-month period, cranberry products decrease the incidence of symptomatic urinary tract infections (UTIs), especially in women with recurrent UTIs. Optimal dosage and form of administration (juice, tablets, or capsules) is unclear. There are no studies comparing cranberry juice with antibiotic prophylactic therapy. Unacceptable taste and gastrointestinal upset are commonly reported adverse effects.

Practice Pointers

Cranberries are thought to contain a substance that can reduce the incidence of UTIs by changing the surface properties of Escherichia coli. This prevents it from adhering to the wall of the bladder. In this Cochrane review, the authors found 10 studies (N = 1,049; five cross-over and five parallel group) of cranberry products, including juice, concentrate, or tablets. A meta-analysis of four of these 10 studies found that cranberry products significantly reduced the incidence of UTIs at 12 months (relative risk [RR] = 0.66; 95% confidence interval [CI], 0.47 to 0.92) compared with placebo or control.

A meta-analysis of two randomized controlled trials (RCTs) of cranberry products was done for persons with recurrent UTIs (i.e., four or more UTIs in the past year, one or more in the previous three months, or two symptomatic culture-confirmed UTIs in the past calendar year). The study patients were given cranberry concentrate daily in the form of 400 mg capsules, tablets in 1:30 concentrated juice twice per day, or 250 mL of juice three times per day. The meta-analysis showed an RR of 0.61 (95% CI, 0.40 to 0.91) for one symptomatic recurrent UTI. Two studies in older men and women showed no statistically significant difference in symptomatic UTIs in the cranberry group compared with the control group. In those patients requiring indwelling or intermittent catheterization, four studies showed no statistically significant difference in symptomatic UTIs.

One study of older adults using cranberry versus control showed that the persons in the cranberry group were 58 percent (P = .004) less likely to have asymptomatic bacteriuria with pyuria. Five studies of patients needing catheterization showed no statistically significant difference in asymptomatic bacteriuria in those taking cranberry products compared with the control group. Of note, there is no known benefit of treatment of asymptomatic bacteriuria in these populations.

In these studies, drop out rates were generally high (20 to 55 percent). Compliance dropped below 80 percent in many studies of those with recurrent UTIs. Side effects were common and included gastroesophageal reflux, nausea, and frequent bowel movements. Withdrawal rate was high in many studies; some withdrawals were for unknown reasons, whereas other studies cited side effects of gastrointestinal upset, unpleasant taste, cost, caloric load, or high blood sugar.

No national practice guidelines have recommended cranberry juice as a preventive strategy for recurrent UTI. The Society of Obstetricians and Gynaecologists of Canada recommends that women experiencing recurrent UTIs should be instructed that the consumption of pure cranberry-lingonberry juice, rather than cranberry drink, will decrease their risk of urinary infections.1

Cranberry tablets cost $10 to $15 for a 30-day supply; juice costs vary depending on preparation and brand. Based on one recent RCT, a reasonable recommended cranberry tablet dosage is 1 tablet (300 to 400 mg) twice daily; the recommended dosage for unsweetened juice is 8 oz three times daily.2 Caution should be taken in the long-term use of cranberry in patients who are known urinary oxalate stone formers. Cranberry does not have significant drug interactions.2

janelle guirguis-blake, MD

Author disclosure: Nothing to disclose.

Source: Jepson RG, Craig JC. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2008;(1):CD001321.

REFERENCES

1. Society of Obstetricians and Gynaecologists of Canada. SOGC clinical practice guidelines. The detection and management of vaginal atrophy. No. 145, May 2004. Int J Gynaecol Obstet. 2005;88(2):222-228.

2. Lynch DM. Cranberry for prevention of urinary tract infections. Am Fam Physician. 2004;70(11):2175-2177.

This clinical content conforms to AAFP criteria for evidence-based continuing medical education (EB CME). See CME Quiz on page 311.

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

A collection of Cochrane for Clinicians published in AFP is available at http://www.aafp.org/afp/cochrane.

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