Osteoarthritis is a common ailment that causes symptoms in many adults. Arthroscopic debridement of the knee joint is frequently recommended when medical treatment does not relieve symptoms, although the outcomes have not been well studied. Validated, health-related, quality-of-life outcome measures are useful to evaluate treatment success in chronic disorders. Dervin and associates studied the effect of arthroscopic debridement in knee osteoarthritis on health-related quality of life and tried to develop a prediction rule to define which patients would optimally benefit from this procedure.
Patients with osteoarthritis of the knee who remained symptomatic after physical therapy and medical treatment were considered for arthroscopy, with the final decision about surgery determined by discussion between the patient and surgeon. Study participants had arthroscopy and debridement performed under general or local anesthesia, and classification of initial articular cartilage damage was recorded.
Health-related quality-of-life assessments, using the Short Form-36 (SF-36) and a disease-specific scale designed to assess patients with osteoarthritis of the knee or hip (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) were administered preoperatively and at six, 12, and 24 months postoperatively. Before the procedure, surgeons and fellows made preadmission estimates of potential improvement.
Pain was the most common presenting symptom among the 126 study patients who completed the protocol. Obesity was common and correlated with increased disability in all subsets of the WOMAC at baseline. After arthroscopic debridement, 56 patients (44 percent) had important reduction in pain at two years after surgery, and treatment was considered to have failed in the remaining 70 patients. Failure was commonly apparent in the first year after surgery.
The ability of fellows to predict preoperatively which patients would improve was only slightly better than chance, while the predictive ability of attending orthopedists was somewhat better. Three variables found to be independently associated with improvement included the presence of medial joint–line tenderness, a positive Steinman test, and the presence of an unstable meniscal tear at the time of arthroscopy. Better results occurred with procedures that included resection of chondral flaps and unstable meniscal tears rather than simple lavage or abrasion arthroplasty. Negative prognostic factors included limb malalignment, severe osteoarthritis of the medial compartment, and lengthier preoperative symptoms. Obesity did not predict outcome.
The authors conclude that experienced physicians can somewhat accurately predict which patients with knee osteoarthritis will benefit from arthroscopic debridement. Fewer than one half of patients undergoing this procedure have sustained pain reduction. The development of clinical prediction rules to evaluate the effect of surgical debridement treatment in patients with knee osteoarthritis does not seem possible with clinical findings alone and may require further study of the usefulness of other biologic markers, such as synovial fluid.