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Surgery for arthritic knee: roundup


Clinical bottom line

Arthroscopy for arthritic knees is not supported by evidence of effectiveness. What evidence we have from high-quality trials is that it does not work.


When medical therapy has failed to relieve pain of knee osteoarthritis, an additional treatment often used is lavage or debridement using arthroscopy. There are an estimated 650,000 procedures costing $3.5 billion each year in the USA alone.

The evidence on which this has been based was a number of papers of case series, showing that about half of patients so treated did reasonably well in the long term. A number of randomised trials using a variety of techniques and comparators have tested efficacy of the techniques. Most, but not all, claimed efficacy for lavage and/or debridement.

There are problems with these studies. All were small, some were of short duration, and some used surrogate end points like muscle strength. None used a true "placebo" control of sham operation. The accumulation of evidence that these procedures are beneficial is neither large, nor compelling.

So when a new randomised trial, superbly conducted and relatively large pops up and tells us these procedures do not work [Bandolier 102], then we need to put our thinking caps on. We need to balance what we think we know with what someone is telling us we should know. Bandolier 102 promised to examine the trials that have been done, which is what is done here.


To find studies we read several papers and reviews, and performed a search on PubMed (July 2002) for any additional randomised studies examining arthroscopy or surgery on the knee for osteoarthritis. This probably uncovers most studies, but is not exhaustive, and if readers know of additional studies we may have missed, we'd love to know about them.

Reference Design Included patients Outcomes Results

Moseley et al, 2002

Quality score 5/5

Randomised, double-blind, parallel-group comparing placebo surgery (60) with lavage (61) and lavage plus debridement (59). Study duration 24 months. Osteoarthritis of the knee by ACR criteria, 75 years or younger, at least moderate pain with maximum medical therapy. Mean age 52 years, 93% men. Pain in knee at 24 months, plus other assessments At no point did either active treatment differ from placebo

Ravaud et al, 1999

Quality score 4/5

Randomised, double blind comparison of placebo and steroid, with or without lavage (21-28 patients per group). Duration 6 months. ACR criteria of OA knee, at least moderate pain, plus X-ray changes. Mean age 66 years, 34% men. Knee effusion, pain on activity, functional disability, patient assessment Lavage better than placebo at six months for pain and disability.

Moseley et al, 1996

Quality score 1/5

Randomised comparison of arthroscopic debridement (2), arthroscopic lavage (3) and placebo (5) in a pilot study with follow up over six months Moderate or severe symptoms from OA knee. Mean age 46 years, all men. Various pain outcomes All three groups did well

Chang et al, 1993

Quality score 3/5

Randomised, blinded comparison of arthroscopy (18) or lavage (14) over 12 months Persistent knee pain for more than 3 months despite medical and rehabilitation management, age over 20 years, and X-ray evidence of damage. Mean age 63 years, 30% men. Various pain, functioning and economic outcomes No difference between procedures, but arthroscopy cost $3,800 more

Ike et al, 1992

Quality score 2/5

Randomised comparison on knee irrigation (29) with medical management (28) consisting of exercise, education, and analgesics, but not intra articular steroid, with 12 week follow up OA knee by ACR criteria, age over 21 years, knee pain at rest or motion and X-ray changes. Mean age 66 years, 46% men. Various pain outcomes, plus global evaluation

Very effective at 12 weeks:

Irrigation 8/29

Medical 2/28

Otherwise little difference

Gibson et al, 1992

Quality score 1/5

Randomised comparison of arthroscopic lavage (10) or debridement with removal of osteophytes (10) over 12 weeks follow up Moderate unilateral OA knee under 70 years. Mean age 55 years, 70% men. Quadriceps and hamstring muscle powers No clinical improvement after either procedure, some improvement in muscle torque with lavage but not debridement

Livesley et al, 1991

Quality score 0 or 1/5

Allocation between physiotherapy (24) and lavage plus physiotherapy (37) by initial referral. Outcomes assessed over 12 months. Not a randomised trial. All new referrals for OA knee, and those with pain and no obvious mechanical derangement entered the trial. Mean age 61 years, 62% men. Pain at rest, night and on motion, plus other evaluations Statistically significant improvement with lavage, but clinical significance unclear

Dawes et al, 1987

Quality score 1/5

Randomised comparison between saline washout (10) and saline injection (10) with follow up over 12 weeks Clinical and X-ray evidence of OA knee with clinically detectable effusions. Mean age 60 years, 40% men. Various pain and other outcomes Both groups improved, with slightly more improvement with the saline injection rather than lavage.

Most of the studies were randomised, though that from Livesley et al was not a randomised trial. Only two studies showed any real benefit for lavage or debridement. One was the non-randomised study by Livesley et al, though the statistical results were almost impossible to translate into clinical benefit, as the average values for each group were usually the same. The other was the hint of benefit of very effective improvement for irrigation over medical management in the study by Ike et al.


The results of the most recent randomised study [1] should not be a surprise based on the evidence from the literature. There never was any good evidence that lavage or debridement were useful things to do. The studies we had were generally small, and of limited methodological quality. When larger, better, studies were done, they were negative.


  1. JB Moseley et al. A controlled trial of arthroscopic surgery for Osteoarthritis of the knee. New England Journal of Medicine 2002 347: 81-88.
  2. P Ravaud et al. Effects of joint lavage and steroid injections in patients with osteoarthritis of the knee. Arthritis & Rheumatism 1999 42: 475-482.
  3. JB Moseley et al. Arthroscopic treatment of osteoarthritis of the knee: a prospective, randomized, placebo-controlled trial. American Journal of Sports Medicine 1996 24: 28-34.
  4. RW Chang et al. A randomized, controlled trial of arthroscopic surgery versus closed-needle joint lavage for patients with osteoarthritis of the knee. Arthritis & Rheumatism 1993 36: 289-296.
  5. RW Ike et al. Tidal irrigation versus conservative medical management in patients with osteoarthritis of the knee: a prospective randomized study. Journal of Rheumatology 1992 19: 772-729.
  6. JN Gibson et al. Arthroscopic lavage and debridement for osteoarthritis of the knee. Journal of Bone and Joint Surgery 1992 74-B:534-537.
  7. PJ Livesley et al. Arthroscopic lavage of osteoarthritic knees. Journal of Bone and Joint Surgery 1991 73-B:922-926.
  8. PT Dawes et al. Saline washout for knee osteoarthritis: results of a controlled study. Clinical Rheumatology 1987 6: 61-63.