Arthroscopic knee debridement most effective in mild osteoarthritis

Knees with mild osteoarthritis are likely to gain most benefit from arthroscopic debridement but those with severe arthritis fare poorly, a review of 122 consecutive cases has concluded.Improvements were observed in 52 of 58 knees (90%) with mild arthritis, normal alignment and a joint space width of at least 3 mm. "Conversely, only five of 25 knees (20%) with severe arthritis, limb malalignment and a joint space width less than 2 mm had substantial relief of symptoms," the authors stated. Consequently, the authors recommended that arthroscopic debridement should not be routinely advised for patients with severe knee osteoarthritis, except for specific treatment goals such as alleviating mechanical locking. Of patients who had improvement, 61% achieved improvement within six months of the arthroscopy. Valgus knees did particularly poorly, but most with mild varus alignment had pronounced pain relief."Still unresolved is the role of arthroscopy for patients with moderate osteoarthritis (Kellgren-Lawrence grade 3)," the researchers said. In this group the severity of cartilage lesions measured during surgery was the only strong predictor of clinical outcome, and the likelihood of substantial pain relief could not be predicted from demographic, clinical or radiographic variables before the operation. "Patients need to be counselled that their clinical outcome may depend on the severity of the cartilage lesions identified at surgery and that their expectations of benefit must take this factor into account," they said.Overall, the patients in the study had a significant improvement in average pain scores, and 65% gained significant relief. These pooled findings were consistent with other studies, but did nothing to define those who were likely to benefit and those who were not. The results emphasised the importance of radiographic grading of severity in predicting the outcome. Symptoms and physical signs were too nonspecific, and the presence of arthritis often obscured the diagnosis of internal knee derangements.Reference...