Lavage/Debridement (Recommendation Against)
Arthroscopy with lavage and/or debridement in patients with a primary diagnosis of knee osteoarthritis is not recommended.


There were four studies that met the inclusion criteria for this recommendation.  There was one high strength (Moseley et al 2002), two moderate strength (Kirkley et. Al 2008, Kalunian et. Al 2000), and one low quality (Saeed 2015).

Kirkely et al 2008 compared arthroscopic surgery which, included lavage and debridement combined with physical therapy and medical treatment versus physical therapy and medical treatment alone. The outcome measures utilized were the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Short Form-36 (SF-36) Physical Component Summary score, McMaster–Toronto Arthritis Patient Preference Disability Questionnaire (MACTAR), and the Arthritis Self-Efficacy Scale (ASES) and standard-gamble utility scores. Six patients assigned to surgery elected not to have the procedure; data from these patients were analyzed, according to the intention to- treat principle, with data from the surgery group. Out of all potential outcomes, only two were statistically significant in favor of surgery. In summary, this randomized controlled trial demonstrated no benefit of arthroscopic lavage and debridement compared to physical therapy and medical treatment for osteoarthritis of the knee.

Kalunian et al. 2000 compared arthroscopic lavage (3000ml) with placebo (250ml). The study was performed at 4 different institutes and included a large number of enrolled patients from one institution with intra-articular crystals in their knee. The arthroscopes used were less than usual caliber in size ranging from 1.7mm to 2.7mm. Outcome measures were WOMAC scores at 12 months. There were not any statistically significant differences in aggregate WOMAC scores between the two treatment groups. The study concludes that irrigation may be helpful in a small subset of patients, especially those with crystals.

Mosley et al 2002 study is an RCT comparing arthroscopic debridement, arthroscopic lavage, versus placebo / sham surgery. The study provides strong evidence that knee arthroscopy with or without debridement is not better and appears to be equivalent to a placebo procedure in improving knee pain and self-reported function. However, the study raised questions regarding its limited sampling (mostly male veterans) as well as the number of potential study participants who declined randomization into a treatment group. They also used a non-validated Knee Specific Pain score. Also, patients with substantial malalignment (varus or valgus deformity) and those with advanced disease, who might have a poorer response to surgical intervention were included in the trial.

Saeed et al 2015 compared HA injections versus arthroscopic debridement in patients with OA in an RCT where only the pain component of the knee society score was utilized. In short term follow up of 6 months, arthroscopy failed to show better pain outcome than injections.

Most of the studies excluded patients with meniscal tear, loose body, or other mechanical derangement, with concomitant diagnosis of osteoarthritis of the knee. The present recommendation does not apply to such patients.

Benefits/Harms of Implementation

Owing to lack of strong evidence in support of clinical benefits from lavage surgery coupled with increased risks from surgery, the workgroup decided to recommend against arthroscopic debridement and/or lavage in patients with a primary diagnosis of osteoarthritis of the knee.

Future Research

Most studies included in this review had compared lavage to variety of nonoperative modalities. However, considering emergence of new modalities and technology it would be worthwhile to do high quality study with arthroscopic lavage done with a standardized size instrument comparing with nonoperative measures which could include PRP injections, nerve ablations, etc. Recent introduction of nanoscopes also warrants further studies of use of such devices in an office setting and comparing it to cost effectiveness of doing procedures in the operating room.