Arthroscopic lavage and debridement for osteoarthritis of the knee: an evidence-based analysis.
OBJECTIVE
The purpose of this review was to determine the effectiveness and adverse effects of arthroscopic lavage and debridement, with or without lavage, in the treatment of symptoms of osteoarthritis (OA) of the knee, and to conduct an economic analysis if evidence for effectiveness can be established.  QUESTIONS ASKED: Does arthroscopic lavage improve motor function and pain associated with OA of the knee?Does arthroscopic debridement improve motor function and pain associated with OA of the knee?If evidence for effectiveness can be established, what is the duration of effect?What are the adverse effects of these procedures?What are the economic considerations if evidence for effectiveness can be established?


OBJECTIVE
Osteoarthritis, the most common rheumatologic musculoskeletal disorder, affects about 10% of the Canadian adult population. Although the natural history of OA is not known, it is a degenerative condition that affects the bone cartilage in the joint. It can be diagnosed at earlier ages, particularly within the sports injuries population, though the prevalence of non-injury-related OA increases with increasing age and varies with gender, with women being twice as likely as men to be diagnosed with this condition. Thus, with an aging population, the impact of OA on the health care system is expected to be considerable. Treatments for OA of the knee include conservative or nonpharmacological therapy, like physiotherapy, weight management and exercise; and more generally, intra-articular injections, arthroscopic surgery and knee replacement surgery. Whereas knee replacement surgery is considered an end-of-line intervention, the less invasive surgical procedures of lavage or debridement may be recommended for earlier and more severe disease. Both arthroscopic lavage and debridement are generally indicated in patients with knee joint pain, with or without mechanical problems, that are refractory to medical therapy. The clinical utility of these procedures is unclear, hence, the assessment of their effectiveness in this review.  LAVAGE AND DEBRIDEMENT: Arthroscopic lavage involves the visually guided introduction of saline solution into the knee joint and removal of fluid, with the intent of extracting any excess fluids and loose bodies that may be in the knee joint. Debridement, in comparison, may include the introduction of saline into the joint, in addition to the smoothening of bone surface without any further intervention (less invasive forms of debridement), or the addition of more invasive procedures such as abrasion, partial or full meniscectomy, synovectomy, or osteotomy (referred to as debridement in combination with meniscectomy or other procedures). The focus of this health technology assessment is on the effectiveness of lavage, and debridement (with or without meniscal tear resection).


METHODS
THE MEDICAL ADVISORY SECRETARIAT FOLLOWED ITS STANDARD PROCEDURES AND SEARCHED THESE ELECTRONIC DATABASES: Ovid MEDLINE, EMBASE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and The International Network of Agencies for Health Technology Assessment. THE KEYWORDS SEARCHED WERE: arthroscopy, debridement, lavage, wound irrigation, or curettage; arthritis, rheumatoid, osteoarthritis; osteoarthritis, knee; knee or knee joint. TIME FRAME: Only 2 previous health technology assessments were identified, one of which was an update of the other, and included 3 of 4 randomized controlled trials (RCTs) from the first report. Therefore, the search period for inclusion of studies in this assessment was January 1, 1995 to April 24, 2005. EXCLUDED WERE: case reports, comments, editorials, and letters. Identified were 335 references, including previously published health technology assessments, and 5 articles located through a manual search of references from published articles and health technology assessments. These were examined against the criteria, as described below, which resulted in the inclusion of 1 health technology assessment and its corresponding update, and 4 articles (2 RCTs and 2 level 4 studies) for arthroscopic lavage and 8 papers (2 RCTs and 6 level 4 studies) for arthroscopic debridement.


METHODS
English-language articles from PubMed, EMBASE, Cochrane Systematic Reviews, and health technology assessments from January 1, 1995 onwardStudies on OA of the knee with a focus on the outcomes of motor function and painStudies of arthroscopic procedures onlyStudies in which meniscal tear resection/meniscectomy (partial or full) has been conducted in conjunction with lavage or debridement.


METHODS
Studies that focus on inflammatory OA, joint tuberculosis, septic joints, psoriatic joints (e.g., psoriatic knee joint synovitis), synovitis, chondropathy of the knee and gonarthrosis (which includes varotic gonarthrosis)Studies that focus on rheumatoid arthritisStudies that focus on meniscal tears from an acute injury (e.g., sports injury)Studies that are based on lavage or debridement for microfracture of the kneeStudies in which other surgical procedures (e.g., high tibial osteotomy, synovectomy, have been conducted in addition to lavage/debridement)Studies based on malalignment of the knee (e.g., varus/valgus arthritic conditions).Studies that compare lavage to lavage plus drug therapyStudies on procedures that are not arthroscopic (i.e., visually guided) (e.g., nonarthroscopic lavage)Studies of OA in children.


METHODS
Arthroscopic lavage or debridement, with or without meniscectomy, for the treatment of motor function symptoms and pain associated with OA of the knee.


METHODS
Studies in which there was a comparison group of either diseased or healthy subjects or one in which subjects were their own control were included. Comparisons to other treatments included placebo (or sham) arthroscopy. Sham arthroscopy involved making small incisions and manipulating the knee, without the insertion of instruments.


RESULTS
IN EARLY OA OF THE KNEE WITH PAIN REFRACTORY TO MEDICAL TREATMENT, THERE IS LEVEL 1B EVIDENCE THAT: Arthroscopic lavage gives rise to a statistically significant, but not clinically meaningful effect in improving pain (WOMAC pain and VAS pain) up to 12 months following surgery. The effect on joint function (WOMAC function) and the primary outcome (WOMAC aggregate) was neither statistically nor clinically significant. IN MODERATE OR SEVERE OA OF THE KNEE WITH PAIN REFRACTORY TO MEDICAL TREATMENT, THERE IS: Level 1b evidence that the effect on pain and function of arthroscopic lavage (10 L saline) and debridement (with 10 L saline lavage) is not statistically significant up to 24 months following surgery.Level 2 evidence that arthroscopic debridement (with 3 L saline lavage) is effective in the control of pain in severe OA of the medial femoral condyle for up to 5 years.For debridement in combination with meniscectomy, there is level 4 evidence that the procedure, as appropriate, might be effective in earlier stages, unicompartmental disease, shorter symptom duration, sudden onset of mechanical symptoms, and preoperative full range of motion. However, as these findings are derived from very poor quality evidence, the identification of subsets of patients that may benefit from this procedure requires further testing.In patients with pain due to a meniscal tear, of the medial compartment in particular, repair of the meniscus results in better pain control at 2 years following surgery than if the pain is attributable to other causes. There is insufficient evidence to comment on the effectiveness of lateral meniscus repair on pain control.


CONCLUSIONS
Arthroscopic debridement of the knee has thus far only been found to be effective for medial compartmental OA. All other indications should be reviewed with a view to reducing arthroscopic debridement as an effective therapy. Arthroscopic lavage of the knee is not indicated for any stage of OA. There is very poor quality evidence on the effectiveness of debridement with partial meniscectomy in the case of meniscal tears in OA of the knee.