Evaluating treatment effectiveness: benchmarks for rehabilitation after partial meniscectomy knee arthroscopy

The purpose of this study was to give a detailed description of recovery benchmarks that occur in patients whose therapy after partial meniscectomy knee arthroscopy consists of a home program of exercise. These benchmarks can be used as a basis for clinicians to compare improvements to individual patients who receive supervised care.

Thirty-nine patients (five females, mean age = 41) who underwent an uncomplicated arthroscopic partial meniscectomy were included. Test sessions occurred at 5 and 50 days after surgery. Outcome measures included: 1) Hughston Clinic knee self-assessment questionnaire; 2) EQ-5D Tariff for assessment of quality of life; 3) number of days taken to return to work after surgery; 4) knee passive range of motion; and 5) knee swelling assessed by evaluation of knee circumference. Stepwise regression analysis was used to evaluate factors that might have influenced the amount of pre- to posttest change in the outcome measures (the benchmarks) during the first 7 wks after surgery. The factors used in this analysis were: 1) age, 2) body mass index, 3) period from injury to surgery, and 4) the baseline value of the variable to be examined (except for return to work, where we used a score estimating the challenge to the knee offered by work).

None of the factors considered (age, body mass index, period from injury to surgery, stressfulness of the work on the knee) affected the number of days taken to return to work. Baseline scores affected change in all the other outcomes, and knee girth change was also affected by body mass index. Regression equations are presented where suitable for the benchmarks presented.

Quick recovery occurs in these patients when only a home exercise program is given. This paper highlights the utility of using historical control group data instead of test-retest analysis of measurement error in evaluating patients whose recovery with a home exercise program is rapid. Of the variables analyzed in this study, quality of life and knee self-assessment changes offer the most useful benchmarks for evaluating treatment effectiveness.