This summary of a Cochrane review presents what we know from research about the effect of arthroscopic debridement (AD) for osteoarthritis (OA) of the knee.
The review shows that in people with OA, arthroscopic debridement:
- Probably does not improve pain or ability to function compared to placebo (sham surgery)
- Probably leads to little or no difference in pain or ability to function compared to lavage
- May improve pain compared to washout
- May not lead to any difference in pain or ability to function compared to closed needle joint lavage
We often do not have precise information about side effects and complications. This is particularly true for rare but serious side effects. Possible side effects may include a small risk of infection and of venous thromboembolism.
What is osteoarthritis and what is arthroscopic debridement?
Osteoarthritis (OA) is the most common form of arthritis that can affect the hands, hips, shoulders and knees. In OA, the cartilage that protects the ends of the bones breaks down and causes pain and swelling. OA can occur in different areas of the knee or the whole knee. When the cartilage breaks down, bits of tissue are left around the joint which can add to the inflammation and prevent the joint from working properly.
Arthroscopic debridement (AD) involves using instruments to remove damaged cartilage or bone. Often the doctor will start the procedure by using a tool to spray jets of fluid to wash and suck out all debris around the joint. This is called lavage or washout. Then, the parts of the joint bone that are loose or misshapen are removed.
Best estimate of what happens to people with OA who have arthroscopic debridement compared with washout:
Pain: 66 more people out of 100 reported being pain free after 1 year and 48 more people out of 100 reported being pain free after 2 years. These results are based on low quality evidence.
Best estimate of what happens to people with OA who have arthroscopic debridement compared with placebo:
Pain two weeks after treatment: Pain scores increased by 9 more points on a scale of 0-100.
Physical function two weeks after treatment: The ability to function improved 8 more points on a scale of 0-100 for the placebo group. These results are based on moderate quality evidence.
Physical function 12 months after treatment: The ability to function improved 7 more points on a 0-100 scale for the placebo group, indicating that the AD group experienced significantly more limited function. These results are based on low quality evidence.
The numbers given are our best estimate. When possible, we have also presented a range because there is a 95 percent chance that the true effect of the treatment lies somewhere between that range.
There is 'gold' level evidence that AD has no benefit for undiscriminated OA (mechanical or inflammatory causes).
Knee osteoarthritis (OA) is a progressive disease that initially affects the articular cartilage. Observational studies have shown benefits for arthroscopic debridement (AD) on the osteoarthritic knee, but other recent studies have yielded conflicting results that suggest AD may not be effective.
To identify the effectiveness of AD in knee OA on pain and function.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2006); MEDLINE (1966 to August, 2006); CINAHL (1982 to 2006); EMBASE (1988 to 2006) and Web of Science (1900 to 2006) and screened the bibliographies, reference lists and cited web sites of papers.
We included randomised controlled trials (RCT) or controlled clinical trials (CCT) assessing effectiveness of AD compared to another surgical procedure, including sham or placebo surgery and other non-surgical interventions, in patients with a diagnosis of primary or secondary OA of the knees, who did not have other joint involvement or conditions requiring long term use of non-steroidal anti-inflammatory drugs (NSAIDs). The main outcomes were pain relief and improved function of the knee.
Two review authors independently selected trials for inclusion, assessed trial quality and extracted the data. Results are presented using weighted mean difference (WMD) for continuous data and relative risk (RR) for dichotomous data, and the number needed to treat to benefit (NNTB) or harm (NNTH).
Three RCTs were included with a total of 271 patients. They had different comparison groups and a moderate risk of bias. One study compared AD with lavage and with sham surgery. Compared to lavage the study found no significant difference. Compared to sham surgery placebo, the study found worse outcomes for AD at two weeks (WMD for pain 8.7, 95% CI 1.7 to 15.8, and function 7.7, 95% CI 1.1 to 14.3; NNTH=5) and no significant difference at two years. The second trial, at higher risk of bias, compared AD and arthroscopic washout, and found that AD significantly reduced knee pain compared to washout at five years (RR 5.5, 95% CI 1.7 to 15.5; NNTB=3). The third trial, also at higher risk of bias, compared AD to closed-needle lavage, and found no significant difference.