No Extra Benefit Found from Surgery for Chronic Knee Pain

Todd Neale
HELSINKI, Finland, Dec. 13 -- For relief of chronic patellofemoral pain syndrome, eight weeks of home exercise was just as effective as arthroscopic surgery plus the exercise, researchers found in a randomized trial here.
In a 56-patient randomized controlled trial, both the arthroscopic surgery-exercise group and the exercise-only group showed similar improvements at nine months, with no significant differences, Jyrki Kettunen, Ph.D., of the ORTON Research Institute in Helsinki, and colleagues, reported online in BMC Medicine.
The improvements were measured by an increased Kujala score on patellofemoral pain and function, assessed on a questionnaire-based 100-point scale.
For the arthroscopy-exercise group, the mean improvement from baseline was 12.9 points (69.0 versus 81.9, 95% CI: 8.2 to 17.6) and for the exercise-only group, the mean improvement was 11.4 (71.1 versus 82.5, 95% CI: 6.9 to 15.8). An increase of about eight to 10 points reflects a clinically significant improvement, according to the researchers.
"There is some evidence that exercise therapy reduces anterior knee pain in patients with [patellofemoral pain syndrome]," the authors wrote. Although many physicians prefer conservative therapies, they continued, "in chronic cases and after the failure of conservative treatment, arthroscopy is often carried out."
Citing a lack of evidence for a benefit from surgery, the investigators selected 56 patients ages 18 to 40 with chronic patellofemoral pain symptoms for at least six months. All participants had been admitted from May 2003 through February 2005. Competitive athletes or those who had previous knee surgery were excluded. If the patients had pain in both knees, the knee with the more severe symptoms was included in the study.
Twenty-eight participants were placed in the arthroscopy-exercise group (one dropped out prior to the exercise) and 28 received only the eight-week exercise program. The home exercise program consisted of lower-body strengthening and stretching.
During arthroscopic surgery, which was done one week following randomization, there was resection of inflamed/scarred medial plicae, abrasion of chondral lesions and shaving of excessive and inflamed synovium, minor corrections of the patellofemoral articulation, and treatment of minor meniscal tears.
A physiotherapist instructed patients on how to do the daily exercises, which began three weeks after randomization in both groups. The first four weeks of the program focused on lower-limb muscle strengthening and stretching. For the last half of the program, participants were given a rubber sling to be placed around the ankle for resistance exercises.
All participants kept a daily exercise diary. The questionnaires measuring Kujala scores were administered before randomization, following the exercise program, and at nine months.
One patient in the arthroscopic surgery group and three in the exercise-only group were lost to follow-up at nine months.
Three in the exercise-only group insisted on having arthroscopic surgery following the exercise program, and their responses were analyzed according to their original group assignment; they did not have greater improvement than any of the other controls.
Compliance with the exercise program was similar in both groups. The mean weekly exercise frequency was 5.0 in the surgery group and 5.2 in the exercise-only group (P=0.52).
A second questionnaire was mailed at 24 months following randomization, yielding a response rate of 89% in the surgery group and 82% in the exercise-only group. The mean improvement in Kujala score was maintained in both groups.
The authors pointed out that in the absence of a control group, this study could not demonstrate the efficacy of exercise. "It should be emphasized that the primary aim was not to investigate the effectiveness of exercise therapy in patients with patellofemoral pain syndrome," they wrote. "In fact, we found no association between frequency of weekly exercise and improvement."
"In conclusion, on the basis of our randomized study, which was planned using available knowledge on the diagnosis and methods of treating patellofemoral pain syndrome," Dr. Kettunen and colleagues wrote, "arthroscopy cannot be recommended for patients with chronic patellofemoral pain syndrome."
The study was supported by a grant from the Social Insurance Institution of Finland.
The authors declared that they had no financial conflicts.
Primary source: BMC MedicineSource reference:Kettunen J, "Knee arthroscopy and exercise versus exercise only for chronic patellofemoral pain syndrome: a randomized controlled trial" BMC Medicine 2007; DOI:10.1186/1741-7015-5-38.